Mangiferin and Cancer: Mechanisms of Action

Abstract

Mangiferin, a bioactive compound derived primarily from Anacardiaceae and Gentianaceae families and found in mangoes and honeybush tea, has been extensively studied for its therapeutic properties. Mangiferin has shown promising chemotherapeutic and chemopreventative potential. This review focuses on the effect of mangiferin on: (1) inflammation, with respect to NFκB, PPARү and the immune system; (2) cell cycle, the MAPK pathway G₂/M checkpoint; (3) proliferation and metastasis, and implications on β-catenin, MMPs, EMT, angiogenesis and tumour volume; (4) apoptosis, with a focus on Bax/Bcl ratios, intrinsic/extrinsic apoptotic pathways and telomerase activity; (5) oxidative stress, through Nrf2/ARE signalling, ROS elimination and catalase activity; and (6) efficacy of chemotherapeutic agents, such as oxaliplatin, etoposide and doxorubicin. In addition, the need to enhance the bioavailability and delivery of mangiferin are briefly addressed, as well as the potential for toxicity.

Full text

nutrients
Review
Mangiferin and Cancer: Mechanisms of Action
Fuchsia Gold-Smith 1, Alyssa Fernandez 2and Karen Bishop 1, *
1
Auckland Cancer Society Research Center, Faculty of Medical and Health Sciences, University of Auckland,
Private Bag 92019, Auckland 1142, New Zealand; fgol315@aucklanduni.ac.nz
2Faculty of Medical and Health Sciences, University of Auckland, Private Bag 92019, Auckland 1142,
New Zealand; afer098@aucklanduni.ac.nz
*Correspondence: k.bishop@auckland.ac.nz; Tel.: +64-9-923-4471
Received: 20 April 2016; Accepted: 22 June 2016; Published: 28 June 2016
Abstract:
Mangiferin, a bioactive compound derived primarily from Anacardiaceae and Gentianaceae
families and found in mangoes and honeybush tea, has been extensively studied for its therapeutic
properties. Mangiferin has shown promising chemotherapeutic and chemopreventative potential.
This review focuses on the effect of mangiferin on: (1) inflammation, with respect to NF
κ
B, PPAR
Review
Mangiferin and Cancer: Mechanisms of Action
Fuchsia Gold-Smith 1, Alyssa Fernandez 2 and Karen Bishop 1,*
1 Auckland Cancer Society Research Center, Faculty of Medical and Health Sciences, University of
Auckland, Private Bag 92019, Auckland 1142, New Zealand; fgol315@aucklanduni.ac.nz
2 Faculty of Medical and Health Sciences, University of Auckland, Private Bag 92019, Auckland 1142, New
Zealand; afer098@aucklanduni.ac.nz
* Correspondence: k.bishop@auckland.ac.nz; Tel.: +64-9-923-4471
Received: 20 April 2016; Accepted: 22 June 2016; Published: date
Abstract: Mangiferin, a bioactive compound derived primarily from Anacardiaceae and
Gentianaceae families and found in mangoes and honeybush tea, has been extensively studied for
its therapeutic properties. Mangiferin has shown promising chemotherapeutic and
chemopreventative potential. This review focuses on the effect of mangiferin on: (1) inflammation,
with respect to NFκB, PPARү and the immune system; (2) cell cycle, the MAPK pathway G2/M
checkpoint; (3) proliferation and metastasis, and implications on β-catenin, MMPs, EMT,
angiogenesis and tumour volume; (4) apoptosis, with a focus on Bax/Bcl ratios, intrinsic/extrinsic
apoptotic pathways and telomerase activity; (5) oxidative stress, through Nrf2/ARE signalling, ROS
elimination and catalase activity; and (6) efficacy of chemotherapeutic agents, such as oxaliplatin,
etoposide and doxorubicin. In addition, the need to enhance the bioavailability and delivery of
mangiferin are briefly addressed, as well as the potential for toxicity.
Keywords: mangiferin; cancer; inflammation; NFκB; oxidative stress; cell cycle; combination
therapy; nutraceuticals; bioavailability; hallmarks of cancer
1. Introduction
Cancer has been identified as the leading cause of non-communicable disease mortality globally [1],
and is responsible for significant morbidity and costs to healthcare systems. Cancer incidence and
mortality has been increasing at a greater rate than population growth alone could account for. The
International Agency for Research on Cancer (IARC) reported 14.1 million cases and over 8.2 million
mortalities due to cancer in 2012 compared to 10 million cases and six million mortalities in 2000 [2]
in a baseline population of 7.1 billion and 6.1 billion, respectively [3]. Much of this increase is due to
rising cancer burden in less developed countries (LDCs), with 57% of new cases, and 65% of cancer
related deaths occurring in LDCs [2]. When standardized by age, the total number of cases per 100,000
population is greater in more developed countries (MDCs) than LDCs (overall age standardized rate:
268 and 148 respectively) [4]. One exception to this pattern is infection-attributable cancers, which are
responsible for 26% of the cancer burden in LDCs but only 8% in MDCs [5].
Cancer is less likely to be identified early or treated successfully in LDCs due to reduced access
to screening tools and chemotherapeutic drugs. Previously, cancer has been regarded as a MDC
disease. However, through the adoption of a more Westernised lifestyle, cancer incidence has been
steadily increasing in LDCs. From the data published by Parkin et al., it can be seen that 40%–45% of
cancers can be attributable to lifestyle factors such as diet, smoking status, alcohol consumption and
lack of physical activity [6]. Some compounds naturally present in the diet, such as mangiferin in
mangoes and honeybush tea, are thought to modulate risk of cancer and retard cancer progression.
Mangiferin (1,3,6,7-tetrahydroxyxanthone-C2-β-D glucoside) [7–11] is a polyphenol [8,11–15]
found in many plant species, in particular, those from the Anacardiaceae [7,9,16–20] and
Gentianaceae families [7,9,13,17,18,20]. For an extensive breakdown of plant sources of mangiferin
and mangiferin content, see Matkowski et al. [21].
Nutrients 2016, 8, 396; doi:10.3390/nu8070396 www.mdpi.com/journal/nutrients
and the immune system; (2) cell cycle, the MAPK pathway G
2
/M checkpoint; (3) proliferation
and metastasis, and implications on
β
-catenin, MMPs, EMT, angiogenesis and tumour volume;
(4) apoptosis, with a focus on Bax/Bcl ratios, intrinsic/extrinsic apoptotic pathways and telomerase
activity; (5) oxidative stress, through Nrf2/ARE signalling, ROS elimination and catalase activity; and
(6) efficacy of chemotherapeutic agents, such as oxaliplatin, etoposide and doxorubicin. In addition,
the need to enhance the bioavailability and delivery of mangiferin are briefly addressed, as well as
the potential for toxicity.
Keywords:
mangiferin; cancer; inflammation; NF
κ
B; oxidative stress; cell cycle; combination therapy;
nutraceuticals; bioavailability; hallmarks of cancer
1. Introduction
Cancer has been identified as the leading cause of non-communicable disease mortality
globally [
1
], and is responsible for significant morbidity and costs to healthcare systems. Cancer
incidence and mortality has been increasing at a greater rate than population growth alone could
account for. The International Agency for Research on Cancer (IARC) reported 14.1 million cases
and over 8.2 million mortalities due to cancer in 2012 compared to 10 million cases and six million
mortalities in 2000 [
2
] in a baseline population of 7.1 billion and 6.1 billion, respectively [
3
]. Much of
this increase is due to rising cancer burden in less developed countries (LDCs), with 57% of new cases,
and 65% of cancer related deaths occurring in LDCs [
2
]. When standardized by age, the total number
of cases per 100,000 population is greater in more developed countries (MDCs) than LDCs (overall age
standardized rate: 268 and 148 respectively) [
4
]. One exception to this pattern is infection-attributable
cancers, which are responsible for 26% of the cancer burden in LDCs but only 8% in MDCs [5].
Cancer is less likely to be identified early or treated successfully in LDCs due to reduced access to
screening tools and chemotherapeutic drugs. Previously, cancer has been regarded as a MDC disease.
However, through the adoption of a more Westernised lifestyle, cancer incidence has been steadily
increasing in LDCs. From the data published by Parkin et al., it can be seen that 40%–45% of cancers
can be attributable to lifestyle factors such as diet, smoking status, alcohol consumption and lack of
physical activity [
6
]. Some compounds naturally present in the diet, such as mangiferin in mangoes
and honeybush tea, are thought to modulate risk of cancer and retard cancer progression.
Mangiferin (1,3,6,7-tetrahydroxyxanthone-C2-
β
-Dglucoside) [
7
–
11
] is a polyphenol [
8
,
11
–
15
]
found in many plant species, in particular, those from the Anacardiaceae [
7
,
9
,
16
–
20
] and Gentianaceae
Nutrients 2016,8, 396; doi:10.3390/nu8070396 www.mdpi.com/journal/nutrients

Nutrients 2016,8, 396 2 of 25
families [
7
,
9
,
13
,
17
,
18
,
20
]. For an extensive breakdown of plant sources of mangiferin and mangiferin
content, see Matkowski et al. [21].
Mangiferin is not only present in everyday foods, but utilised in a number of natural medicines.
In traditional medicine, different cultures have cultivated and processed mangiferin rich plants
for the treatment of a range of illnesses including cardiovascular disease, diabetes, infection and
cancer [
22
–
24
]. In India, Ayurvedic practitioners [
22
] have used Salicia chinesis (saptarangi)
[21,25,26]
and Mangifera indica (mango), which are two species that contain high levels of mangiferin.
Salicia chinesis has been used for its hypo-lipidaemic, anti-diabetic, hepatoprotective and antioxidant
properties. Salicia chinesis has now been over-exploited and research is being conducted into how
this plant may be grown in a more sustainable way to meet demands [
27
]. Mangifera indica is used
not only in Ayurvedic medicine but also used in Cuba [
23
], China [
21
,
24
] and throughout East
Asia [
21
] for its anti-inflammatory, anti-viral, anti-diabetic and anti-cancer properties. Mangifera indica,
a member of the Gentianaceae family, contains mangiferin [
10
,
20
,
21
,
28
–
30
] in its bark (18.33 g/kg
dry weight [
31
]), leaves [
15
] (old leaves 36.9 g/kg and young leaves 58.12 g/kg dry weight [
31
]) and
root along with the seed, pulp (0 to 2.65 mg/kg dry weight, depending on the variety [
32
]) and skin
of the fruit [
7
,
8
,
12
,
20
,
33
–
35
] (4.94 g/kg dry weight [
31
]). However, the concentration of mangiferin
in the pulp is unlikely to be sufficient to provide significant health benefits, and can vary greatly
depending on variety and the maturity of the fruit [
32
]. Although somewhat lower than levels found
in bark and leaves, the mangiferin in the skin [
36
] and seed/kernel [
31
], which are usually considered
waste products, may provide a promising sustainable option for mangiferin extraction. To date, these
mango by-products have been used to enhance the nutritional density of pasta, biscuits, muffins and
pancakes [
37
–
40
]. Although the phenolic content of these food items increased 2.8–3.9 fold [
37
,
39
],
the mangiferin content was not reported. However, in the results detailed in the sections hereafter,
the concentrations used or administered varied from 12.5 to 100
µ
g/mL in
in vitro
studies [
12
] and
approximately 100 mg/kg body weight in
in vivo
studies [
7
]. Clearly, the consumption of such
quantities is not achievable by consuming fresh mango pulp, but maybe achievable by adding a leaf,
bark, and/or seed extract as a supplement to food, or consuming as a liquid (if palatable).
In Cuba, aqueous extracts of Mangifera indica bark have become popular [
7
,
12
,
41
,
42
] for treatment
of not only cancer but gastric and dermatological disorders, AIDS and asthma [
43
]. Stem bark extracts
contain polyphenols, terpenoids, steroids, fatty acids and trace elements alongside mangiferin
[21,23]
.
The natural medicine, Vimang
®
[
7
,
12
,
42
], produced from aqueous extracts of Mangifera indica, contains
~20% mangiferin [
23
] and is available in tablets, creams and syrups. Vimang
®
is registered as
an “anti-inflammatory phytomedicine” by the Cuban Regulatory Health Authorities and is primarily
used by those with multiple and different types of cancer. In China, mango leaves [
21
,
24
] and
Dobinea delavayi (Baill.) leaves [
44
], which both contain mangiferin, are often used in traditional
medicines. The greatest dietary source of mangiferin is Honeybush tea, popular in South Africa
and obtained from Cyclopia sp. [
21
]. Honeybush tea leaves have been found to consist of up to 4%
mangiferin by dry weight [21].
Research into mangiferin has resulted in the identification of a similar compound, namely
mangiferin aglycone or norathyriol, which appears to have greater biological activity in some instances.
The compound mangiferin aglycone can be artificially synthesized, bypassing any sustainability
concerns surrounding mangiferin. The structure of mangiferin and mangiferin aglycone are shown in
Figure 1. Mangiferin aglycone has shown greater biological activity in some targets than mangiferin,
possibly due to greater water solubility [
28
], and the former appears to reduce UV-induced skin
cancer [
8
]. Further studies are required to elucidate the degree of similarity in action of mangiferin
and mangiferin aglycone.

Nutrients 2016,8, 396 3 of 25
Nutrients 2016, 8, 396 3 of 25
Figure 1. The molecular structure of: (A) mangiferin [45]; and (B) mangiferin aglycone [46].
Evidence suggests that mangiferin could prove to be a useful, inexpensive compound to not only
maintain and improve health in the worried well, but also to significantly improve the outlook for
those with certain cancers (e.g., breast cancer [41]) and reduce the likelihood of developing cancer.
This is of particular relevance to LDCs, where the more expensive chemotherapeutic drugs may be
inaccessible, while mangiferin containing plants are abundant. In MDCs, the potential enhanced
synergistic effect seen with major chemotherapeutic drugs may allow for lower dosages of drugs,
thus reducing toxicity and providing greater selective toxicity to malignant cells, reducing the extent
of side effects [47]. However, it is acknowledged that the quantity of fruit required in order to achieve
clinically relevant levels of mangiferin may be unreasonably high. For this reason substitution of flour
and sugar with mango processing by product [37,39] may prove an additional and useful method of
increasing mangiferin intake.
The anti-cancer properties of mangiferin have been extensively studied over the past few
decades. This review article seeks to consolidate the most recent research on the anti-neoplastic
properties of mangiferin, with a focus on molecular pathways and uses of mangiferin, in conjunction
with known chemotherapeutic agents, to aid further research on this topic.
2. Molecular Mechanisms of the Anti-Cancer Action of Mangiferin
Mangiferin acts through a myriad of mechanisms to exert anti-inflammatory [11,14,20–
24,28,29,42,48], immunomodulatory [8,9,14,19,20,23,24,28,29,49], cell cycle arrest, anti-proliferative,
anti-apoptotic [48], anti-oxidative [8,11,14,15,19,20,22–24,28–30,36,42,48–51], anti-genotoxic [30] and
anti-viral [11,15,20,48] effects which cumulatively result in anti-tumour activity [9,11,15,19–
21,23,24,29,41,50]. Mangiferin has demonstrated broad-spectrum efficacy against an array of different
cancers in in vitro and in vivo studies [8,11,12,14,21]. To date, evidence suggests that the side effects
of mangiferin vary from mild to non-existent [52]; however, there may be some variation according
to source of mangiferin.
2.1. Inflammation
The chronic activation of inflammatory processes is widely regarded as an enabling
characteristic towards the acquisition of cancer [53]. Approximately 20% of cancers are attributable
to chronic inflammation [54], which may be induced by bacterial or viral infections, autoimmune
disease, or constant exposure to irritants. Chronic inflammation can drive tumour growth by
Figure 1. The molecular structure of: (A) mangiferin [45]; and (B) mangiferin aglycone [46].
Evidence suggests that mangiferin could prove to be a useful, inexpensive compound to not only
maintain and improve health in the worried well, but also to significantly improve the outlook for
those with certain cancers (e.g., breast cancer [
41
]) and reduce the likelihood of developing cancer.
This is of particular relevance to LDCs, where the more expensive chemotherapeutic drugs may be
inaccessible, while mangiferin containing plants are abundant. In MDCs, the potential enhanced
synergistic effect seen with major chemotherapeutic drugs may allow for lower dosages of drugs, thus
reducing toxicity and providing greater selective toxicity to malignant cells, reducing the extent of
side effects [
47
]. However, it is acknowledged that the quantity of fruit required in order to achieve
clinically relevant levels of mangiferin may be unreasonably high. For this reason substitution of flour
and sugar with mango processing by product [
37
,
39
] may prove an additional and useful method of
increasing mangiferin intake.
The anti-cancer properties of mangiferin have been extensively studied over the past few decades.
This review article seeks to consolidate the most recent research on the anti-neoplastic properties of
mangiferin, with a focus on molecular pathways and uses of mangiferin, in conjunction with known
chemotherapeutic agents, to aid further research on this topic.
2. Molecular Mechanisms of the Anti-Cancer Action of Mangiferin
Mangiferin acts through a myriad of mechanisms to exert anti-inflammatory [
11
,
14
,
20
–
24
,
28
,
29
,
42
,
48
],
immunomodulatory [
8
,
9
,
14
,
19
,
20
,
23
,
24
,
28
,
29
,
49
], cell cycle arrest, anti-proliferative, anti-apoptotic [
48
],
anti-oxidative [
8
,
11
,
14
,
15
,
19
,
20
,
22
–
24
,
28
–
30
,
36
,
42
,
48
–
51
], anti-genotoxic [
30
] and anti-viral [
11
,
15
,
20
,
48
]
effects which cumulatively result in anti-tumour activity [
9
,
11
,
15
,
19
–
21
,
23
,
24
,
29
,
41
,
50
]. Mangiferin
has demonstrated broad-spectrum efficacy against an array of different cancers in
in vitro
and
in vivo
studies [
8
,
11
,
12
,
14
,
21
]. To date, evidence suggests that the side effects of mangiferin vary from mild to
non-existent [52]; however, there may be some variation according to source of mangiferin.
2.1. Inflammation
The chronic activation of inflammatory processes is widely regarded as an enabling characteristic
towards the acquisition of cancer [
53
]. Approximately 20% of cancers are attributable to chronic
inflammation [
54
], which may be induced by bacterial or viral infections, autoimmune disease,
or constant exposure to irritants. Chronic inflammation can drive tumour growth by providing
a favourable environment, rich in inflammatory mediators, to enhance cell growth and survival [
53
,
55
].

Nutrients 2016,8, 396 4 of 25
In addition, inflammation involves the production of reactive oxygen species (ROS), which can cause
DNA damage, enhancing carcinogenic capabilities [
56
]. Mangiferin is thought to dampen down
the inflammatory response primarily by interference with Nuclear Factor
κ
-light-chain-enhancer of
activated B cells (NFκB) [34].
By reducing inflammation, mangiferin not only provides unfavourable conditions for cancer, but
can provide anti-diabetic effects [
11
,
15
,
19
,
21
,
23
,
24
,
28
,
29
,
50
] and reduce risk of cardiovascular disease.
Mangiferin also reduces serum glucose levels and lipid levels [
8
,
14
,
30
], further decreasing development
and severity of diabetes and cardiovascular disease. Thus, while many medications used to treat these
widespread non-communicable diseases may create adverse conditions in the body that may lead to
other diseases, mangiferin provides broad spectrum benefits across a range of diseases such as cancers,
cardiovascular disease and diabetes [26,33,35,39].
2.1.1. Nuclear Factor κ-Light-Chain-Enhancer of Activated B Cells Activity
The transcription factor NF
κ
B regulates many important processes in inflammation, including
the expression of pro-inflammatory cytokines, migration molecules, growth factors and other genes
involved in proliferation and survival [
34
]. NF
κ
B is up-regulated during inflammation. Under
inflammatory conditions, ligands bind and activate Toll-like receptors (TLRs) and Interleukin-1
Receptors (IL-1R), triggering the Myeloid Differentiation Primary Response Gene 88 (Myd88) to
recruit Interleukin-1 Receptor Activated Kinase 1 (IRAK1) to this receptor-signalling complex for
phosphorylation [
57
,
58
]. Association of IRAK1 with Myd88 allows phosphorylation by IRAK4
and subsequent autophosphorylation. In its phosphorylated form, IRAK1 interacts with Tumour
necrosis factor Receptor-Associated Factor 6 (TRAF6) to form a complex, which signals sequentially
through Transforming growth factor beta-activated kinase 1/Transforming growth factorbeta-activated
kinase 1-binding protein 1 and 2 (TAK1/TAB1/TAB2), NF
κ
B Essential Modulator/Inhibitor of NF
κ
B
Kinase subunit-
β
/Inhibitor of NF
κ
B Kinase subunit-
α
(NEMO/IKK-
β
/IKK-
α
) and Inhibitor of
κ
B
(I
κ
B)/p50/p65 complexes to ultimately activate NF
κ
B [
57
]. Recent findings suggest mangiferin inhibits
NF
κ
B activation at various steps in the pathway (Figure 2A,B) [
11
,
47
]. NF
κ
B can be activated via the
classical or alternative pathways. The classical pathway is regulated by the I
κ
B kinase complex and
p50, while the alternative pathway is regulated by IKKαand p52 [59].
Nutrients 2016, 8, 396 4 of 25
providing a favourable environment, rich in inflammatory mediators, to enhance cell growth and
survival [53,55]. In addition, inflammation involves the production of reactive oxygen species (ROS),
which can cause DNA damage, enhancing carcinogenic capabilities [56]. Mangiferin is thought to
dampen down the inflammatory response primarily by interference with Nuclear Factor κ-light-
chain-enhancer of activated B cells (NFκB) [34].
By reducing inflammation, mangiferin not only provides unfavourable conditions for cancer,
but can provide anti-diabetic effects [11,15,19,21,23,24,28,29,50] and reduce risk of cardiovascular
disease. Mangiferin also reduces serum glucose levels and lipid levels [8,14,30], further decreasing
development and severity of diabetes and cardiovascular disease. Thus, while many medications
used to treat these widespread non-communicable diseases may create adverse conditions in the
body that may lead to other diseases, mangiferin provides broad spectrum benefits across a range of
diseases such as cancers, cardiovascular disease and diabetes [26,33,35,39].
2.1.1. Nuclear Factor -Light-Chain-Enhancer of Activated B Cells Activity
The transcription factor NFκB regulates many important processes in inflammation, including
the expression of pro-inflammatory cytokines, migration molecules, growth factors and other genes
involved in proliferation and survival [34]. NFB is up-regulated during inflammation. Under
inflammatory conditions, ligands bind and activate Toll-like receptors (TLRs) and Interleukin-1
Receptors (IL-1R), triggering the Myeloid Differentiation Primary Response Gene 88 (Myd88) to
recruit Interleukin-1 Receptor Activated Kinase 1 (IRAK1) to this receptor-signalling complex for
phosphorylation [57,58]. Association of IRAK1 with Myd88 allows phosphorylation by IRAK4 and
subsequent autophosphorylation. In its phosphorylated form, IRAK1 interacts with Tumour necrosis
factor Receptor-Associated Factor 6 (TRAF6) to form a complex, which signals sequentially through
Transforming growth factor beta-activated kinase 1/Transforming growth factor beta-activated
kinase 1-binding protein 1 and 2 (TAK1/TAB1/TAB2), NFκB Essential Modulator/Inhibitor of NFB
Kinase subunit-β/Inhibitor of NFB Kinase subunit-α (NEMO/IKK-β/IKK-α) and Inhibitor of κB
(IκB)/p50/p65 complexes to ultimately activate NFκB [57]. Recent findings suggest mangiferin
inhibits NFκB activation at various steps in the pathway (Figure 2A,B) [11,47]. NFκB can be activated
via the classical or alternative pathways. The classical pathway is regulated by the IκB kinase complex
and p50, while the alternative pathway is regulated by IKKα and p52 [59].
A
Figure 2. Cont.

Nutrients 2016,8, 396 5 of 25
Nutrients 2016, 8, 396 5 of 25
Figure 2. Inhibition of NFκB via the (A) classical and (B) alternative pathways by mangiferin and
Vimang (adapted from [11,45,55]) (abbreviations: Mng, mangiferin; V, Vimang®).
Initial Stimulus for NFκB Activation
When studied, it was found that mangiferin blocks Tumour Necrosis Factor (TNF) [8],
lipopolysaccharide (LPS), peptidoglycan (PDG) [60], phorbol-12-myristate-13-acetate (PMA) [11] or
hydrogen peroxide (H2O2) mediated NFκB activation by inhibiting ROS production [61]. This effect
has been demonstrated in U-937 (lymphoma), HeLa (cervical cancer), MCF-7 (breast cancer) and IRB3
AN27 (human foetal neuronal) cell lines [11]. Jeong et al. [60] demonstrated that the inhibitory effect
of mangiferin on NFB expression when induced by LPS and PDG in peritoneal macrophages was
elicited in part by inhibition of IRAK1 phosphorylation and consequently activation. In parallel,
mangiferin impedes NFκB activation via inflammatory genes [11,48]. Inhibition of IRAK1 by
mangiferin may reduce development of resistance to chemotherapeutic drugs. In particular, triple
negative breast cancers have been associated with overexpression of IRAK1, and it is reported that
inhibition of IRAK1, through the p38-MCL1 pathway, may reverse paclitaxel resistance [62].
Mangiferin, as a component of combination therapy, will be addressed in Section 4.
Subsequent studies have implicated mangiferin in suppressing the TNF signal transduction
pathway [11,48], where under normal conditions, canonic interactions of TNF Receptor (TNFR) with
Tumour Necrosis Factor Receptor type-1-Associated Death Domain protein (TRADD), TNFR-
Associated Factor 2 (TRAF2) and NCK Interacting Kinase (NIK) along with subsequent
phosphorylation and degradation of IκBα initiates NFκB activation (Figure 2A) [11]. To identify the
site of action, U-937 cells were transfected with TNFR1, TRADD, TRAF2, NIK, IKK and p65 plasmids.
Secreted Embryonic Alkaline Phosphatase (SEAP) was used as a reporter gene for NFκB and
expression levels were monitored in treated and un-treated cells. Mangiferin inhibited TNFR1,
TRADD, TRAF2, NIK and IKK induced SEAP expression but did not have a significant effect on p65
induced SEAP expression. Consequently, mangiferin must act downstream from IKK [11].
Signal Transduction to Activate NFκB
In a study carried out by García-Rivera et al. on estrogen negative MDA-MB231 breast cancer
cells, the efficacy of Vimang® (aqueous extract from Mangifera indica) was investigated and compared
to treatment with either mangiferin only or gallic acid only (another bioactive present in Vimang®)
[41]. At baseline, MDA-MB231 cells, which have a mutated p53 gene, demonstrate high NFκB activity
[41]. When cells were pre-treated for 4 h with 200 µg/mL Vimang® or 100 µg/mL of mangiferin, there
was no change in IKKα expression, but reduced phosphorylation of IKKα and IKKβ was observed
[41]. These proteins must be phosphorylated in order to transduce the signal and activate NFκB, thus
mangiferin attenuated signal transduction. These authors also report that time taken for IκB
B
Figure 2.
Inhibition of NF
κ
B via the (
A
) classical and (
B
) alternative pathways by mangiferin and
Vimang (adapted from [11,45,55]) (abbreviations: Mng, mangiferin; V, Vimang®).
Initial Stimulus for NFκB Activation
When studied, it was found that mangiferin blocks Tumour Necrosis Factor (TNF) [
8
],
lipopolysaccharide (LPS), peptidoglycan (PDG) [
60
], phorbol-12-myristate-13-acetate (PMA) [
11
]
or hydrogen peroxide (H
2
O
2
) mediated NF
κ
B activation by inhibiting ROS production [
61
]. This effect
has been demonstrated in U-937 (lymphoma), HeLa (cervical cancer), MCF-7 (breast cancer) and IRB3
AN27 (human foetal neuronal) cell lines [
11
]. Jeong et al. [
60
] demonstrated that the inhibitory effect of
mangiferin on NF
κ
B expression when induced by LPS and PDG in peritoneal macrophages was elicited
in part by inhibition of IRAK1 phosphorylation and consequently activation. In parallel, mangiferin
impedes NF
κ
B activation via inflammatory genes [
11
,
48
]. Inhibition of IRAK1 by mangiferin may
reduce development of resistance to chemotherapeutic drugs. In particular, triple negative breast
cancers have been associated with overexpression of IRAK1, and it is reported that inhibition of IRAK1,
through the p38-MCL1 pathway, may reverse paclitaxel resistance [
62
]. Mangiferin, as a component of
combination therapy, will be addressed in Section 4.
Subsequent studies have implicated mangiferin in suppressing the TNF signal transduction
pathway [
11
,
48
], where under normal conditions, canonic interactions of TNF Receptor (TNFR)
with Tumour Necrosis Factor Receptor type-1-Associated Death Domain protein (TRADD),
TNFR-Associated Factor 2 (TRAF2) and NCK Interacting Kinase (NIK) along with subsequent
phosphorylation and degradation of I
κ
B
α
initiates NF
κ
B activation (Figure 2A) [
11
]. To identify
the site of action, U-937 cells were transfected with TNFR1, TRADD, TRAF2, NIK, IKK and p65
plasmids. Secreted Embryonic Alkaline Phosphatase (SEAP) was used as a reporter gene for NF
κ
B
and expression levels were monitored in treated and un-treated cells. Mangiferin inhibited TNFR1,
TRADD, TRAF2, NIK and IKK induced SEAP expression but did not have a significant effect on p65
induced SEAP expression. Consequently, mangiferin must act downstream from IKK [11].
Signal Transduction to Activate NFκB
In a study carried out by García-Rivera et al. on estrogen negative MDA-MB231 breast cancer
cells, the efficacy of Vimang
®
(aqueous extract from Mangifera indica) was investigated and compared
to treatment with either mangiferin only or gallic acid only (another bioactive present in Vimang
®
) [
41
].
At baseline, MDA-MB231 cells, which have a mutated p53 gene, demonstrate high NF
κ
B activity [
41
].
When cells were pre-treated for 4 h with 200
µ
g/mL Vimang
®
or 100
µ
g/mL of mangiferin, there was no

Nutrients 2016,8, 396 6 of 25
change in IKK
α
expression, but reduced phosphorylation of IKK
α
and IKK
β
was observed [
41
]. These
proteins must be phosphorylated in order to transduce the signal and activate NF
κ
B, thus mangiferin
attenuated signal transduction. These authors also report that time taken for I
κ
B phosphorylation
and consequently degradation in response to TNF stimulation was doubled and time taken for I
κ
B
resynthesis was significantly reduced [
41
]. The action of mangiferin on I
κ
B degradation has also been
reported in a number of other studies [11,41,47,48,63]. Once IκBαis degraded, its inhibitory effect on
the NF
κ
B activation pathway is diminished [
63
] and thus NF
κ
B can freely bind to DNA, allowing
transcription and translation of the respective genes and proteins that it regulates [
64
]. Additionally,
mangiferin and Vimang
®
were found to reduce phosphorylation and translocation of p65 into the
nucleus and impeded NF
κ
B/DNA binding in response to TNF [
41
]. Other studies have also reported
that mangiferin affects I
κ
B
α
and p65 in this way [
8
,
11
,
48
]. García-Rivera et al. revealed that Vimang
®
,
but not mangiferin alone was found to prevent parallel NF
κ
B transactivation [
41
], emphasising the
beneficial effects provided by other bioactive constituents of this aqueous extract.
It is clear that mangiferin is likely to attenuate NF
κ
B expression in a multifaceted way, [
34
,
47
]
with additional mechanisms yet to be elucidated.
Consequential Effects of NFκB Downregulation
NF
κ
B is implicit in regulating expression of Cyclooxygenase-2 (COX-2), Intercellular Adhesion
Molecule-1 (ICAM-1), B Cell Lymphoma-2 (bcl-2), Interleukin-6 (IL-6), Interleukin-8 (IL-8), C-X-C
Chemokine Receptor type-4 (CXCR4), X linked Inhibitor of Apoptosis Protein (XIAP) and Vascular
Endothelial Growth Factor (VEGF), which are all involved in inflammation, metastasis, cell survival
and angiogenesis [
11
,
29
,
42
,
48
] (more on COX-2 below). As a downregulator of NF
κ
B, mangiferin
consequentially reduces expression of the genes listed above [41] and increases apoptosis [8].
IL-6 and IL-8 are both inflammatory cytokines that enhance cell proliferation. In MDA-MB231 cells,
proliferation is conditional on autocrine synthesis of inflammatory cytokines and growth factors [
41
].
Vimang
®
and mangiferin have each been found to down-regulate IL-6 and IL-8 production when
stimulated by TNF [41], thus reducing the inflammatory response.
2.1.2. Peroxisome Proliferator-Activated Receptor
Review
Mangiferin and Cancer: Mechanisms of Action
Fuchsia Gold-Smith 1, Alyssa Fernandez 2 and Karen Bishop 1,*
1 Auckland Cancer Society Research Center, Faculty of Medical and Health Sciences, University of
Auckland, Private Bag 92019, Auckland 1142, New Zealand; fgol315@aucklanduni.ac.nz
2 Faculty of Medical and Health Sciences, University of Auckland, Private Bag 92019, Auckland 1142, New
Zealand; afer098@aucklanduni.ac.nz
* Correspondence: k.bishop@auckland.ac.nz; Tel.: +64-9-923-4471
Received: 20 April 2016; Accepted: 22 June 2016; Published: date
Abstract: Mangiferin, a bioactive compound derived primarily from Anacardiaceae and
Gentianaceae families and found in mangoes and honeybush tea, has been extensively studied for
its therapeutic properties. Mangiferin has shown promising chemotherapeutic and
chemopreventative potential. This review focuses on the effect of mangiferin on: (1) inflammation,
with respect to NFκB, PPARү and the immune system; (2) cell cycle, the MAPK pathway G2/M
checkpoint; (3) proliferation and metastasis, and implications on β-catenin, MMPs, EMT,
angiogenesis and tumour volume; (4) apoptosis, with a focus on Bax/Bcl ratios, intrinsic/extrinsic
apoptotic pathways and telomerase activity; (5) oxidative stress, through Nrf2/ARE signalling, ROS
elimination and catalase activity; and (6) efficacy of chemotherapeutic agents, such as oxaliplatin,
etoposide and doxorubicin. In addition, the need to enhance the bioavailability and delivery of
mangiferin are briefly addressed, as well as the potential for toxicity.
Keywords: mangiferin; cancer; inflammation; NFκB; oxidative stress; cell cycle; combination
therapy; nutraceuticals; bioavailability; hallmarks of cancer
1. Introduction
Cancer has been identified as the leading cause of non-communicable disease mortality globally [1],
and is responsible for significant morbidity and costs to healthcare systems. Cancer incidence and
mortality has been increasing at a greater rate than population growth alone could account for. The
International Agency for Research on Cancer (IARC) reported 14.1 million cases and over 8.2 million
mortalities due to cancer in 2012 compared to 10 million cases and six million mortalities in 2000 [2]
in a baseline population of 7.1 billion and 6.1 billion, respectively [3]. Much of this increase is due to
rising cancer burden in less developed countries (LDCs), with 57% of new cases, and 65% of cancer
related deaths occurring in LDCs [2]. When standardized by age, the total number of cases per 100,000
population is greater in more developed countries (MDCs) than LDCs (overall age standardized rate:
268 and 148 respectively) [4]. One exception to this pattern is infection-attributable cancers, which are
responsible for 26% of the cancer burden in LDCs but only 8% in MDCs [5].
Cancer is less likely to be identified early or treated successfully in LDCs due to reduced access
to screening tools and chemotherapeutic drugs. Previously, cancer has been regarded as a MDC
disease. However, through the adoption of a more Westernised lifestyle, cancer incidence has been
steadily increasing in LDCs. From the data published by Parkin et al., it can be seen that 40%–45% of
cancers can be attributable to lifestyle factors such as diet, smoking status, alcohol consumption and
lack of physical activity [6]. Some compounds naturally present in the diet, such as mangiferin in
mangoes and honeybush tea, are thought to modulate risk of cancer and retard cancer progression.
Mangiferin (1,3,6,7-tetrahydroxyxanthone-C2-β-D glucoside) [7–11] is a polyphenol [8,11–15]
found in many plant species, in particular, those from the Anacardiaceae [7,9,16–20] and
Gentianaceae families [7,9,13,17,18,20]. For an extensive breakdown of plant sources of mangiferin
and mangiferin content, see Matkowski et al. [21].
Nutrients 2016, 8, 396; doi:10.3390/nu8070396 www.mdpi.com/journal/nutrients
(PPAR
Review
Mangiferin and Cancer: Mechanisms of Action
Fuchsia Gold-Smith 1, Alyssa Fernandez 2 and Karen Bishop 1,*
1 Auckland Cancer Society Research Center, Faculty of Medical and Health Sciences, University of
Auckland, Private Bag 92019, Auckland 1142, New Zealand; fgol315@aucklanduni.ac.nz
2 Faculty of Medical and Health Sciences, University of Auckland, Private Bag 92019, Auckland 1142, New
Zealand; afer098@aucklanduni.ac.nz
* Correspondence: k.bishop@auckland.ac.nz; Tel.: +64-9-923-4471
Received: 20 April 2016; Accepted: 22 June 2016; Published: date
Abstract: Mangiferin, a bioactive compound derived primarily from Anacardiaceae and
Gentianaceae families and found in mangoes and honeybush tea, has been extensively studied for
its therapeutic properties. Mangiferin has shown promising chemotherapeutic and
chemopreventative potential. This review focuses on the effect of mangiferin on: (1) inflammation,
with respect to NFκB, PPARү and the immune system; (2) cell cycle, the MAPK pathway G2/M
checkpoint; (3) proliferation and metastasis, and implications on β-catenin, MMPs, EMT,
angiogenesis and tumour volume; (4) apoptosis, with a focus on Bax/Bcl ratios, intrinsic/extrinsic
apoptotic pathways and telomerase activity; (5) oxidative stress, through Nrf2/ARE signalling, ROS
elimination and catalase activity; and (6) efficacy of chemotherapeutic agents, such as oxaliplatin,
etoposide and doxorubicin. In addition, the need to enhance the bioavailability and delivery of
mangiferin are briefly addressed, as well as the potential for toxicity.
Keywords: mangiferin; cancer; inflammation; NFκB; oxidative stress; cell cycle; combination
therapy; nutraceuticals; bioavailability; hallmarks of cancer
1. Introduction
Cancer has been identified as the leading cause of non-communicable disease mortality globally [1],
and is responsible for significant morbidity and costs to healthcare systems. Cancer incidence and
mortality has been increasing at a greater rate than population growth alone could account for. The
International Agency for Research on Cancer (IARC) reported 14.1 million cases and over 8.2 million
mortalities due to cancer in 2012 compared to 10 million cases and six million mortalities in 2000 [2]
in a baseline population of 7.1 billion and 6.1 billion, respectively [3]. Much of this increase is due to
rising cancer burden in less developed countries (LDCs), with 57% of new cases, and 65% of cancer
related deaths occurring in LDCs [2]. When standardized by age, the total number of cases per 100,000
population is greater in more developed countries (MDCs) than LDCs (overall age standardized rate:
268 and 148 respectively) [4]. One exception to this pattern is infection-attributable cancers, which are
responsible for 26% of the cancer burden in LDCs but only 8% in MDCs [5].
Cancer is less likely to be identified early or treated successfully in LDCs due to reduced access
to screening tools and chemotherapeutic drugs. Previously, cancer has been regarded as a MDC
disease. However, through the adoption of a more Westernised lifestyle, cancer incidence has been
steadily increasing in LDCs. From the data published by Parkin et al., it can be seen that 40%–45% of
cancers can be attributable to lifestyle factors such as diet, smoking status, alcohol consumption and
lack of physical activity [6]. Some compounds naturally present in the diet, such as mangiferin in
mangoes and honeybush tea, are thought to modulate risk of cancer and retard cancer progression.
Mangiferin (1,3,6,7-tetrahydroxyxanthone-C2-β-D glucoside) [7–11] is a polyphenol [8,11–15]
found in many plant species, in particular, those from the Anacardiaceae [7,9,16–20] and
Gentianaceae families [7,9,13,17,18,20]. For an extensive breakdown of plant sources of mangiferin
and mangiferin content, see Matkowski et al. [21].
Nutrients 2016, 8, 396; doi:10.3390/nu8070396 www.mdpi.com/journal/nutrients
)
PPAR
Review
Mangiferin and Cancer: Mechanisms of Action
Fuchsia Gold-Smith 1, Alyssa Fernandez 2 and Karen Bishop 1,*
1 Auckland Cancer Society Research Center, Faculty of Medical and Health Sciences, University of
Auckland, Private Bag 92019, Auckland 1142, New Zealand; fgol315@aucklanduni.ac.nz
2 Faculty of Medical and Health Sciences, University of Auckland, Private Bag 92019, Auckland 1142, New
Zealand; afer098@aucklanduni.ac.nz
* Correspondence: k.bishop@auckland.ac.nz; Tel.: +64-9-923-4471
Received: 20 April 2016; Accepted: 22 June 2016; Published: date
Abstract: Mangiferin, a bioactive compound derived primarily from Anacardiaceae and
Gentianaceae families and found in mangoes and honeybush tea, has been extensively studied for
its therapeutic properties. Mangiferin has shown promising chemotherapeutic and
chemopreventative potential. This review focuses on the effect of mangiferin on: (1) inflammation,
with respect to NFκB, PPARү and the immune system; (2) cell cycle, the MAPK pathway G2/M
checkpoint; (3) proliferation and metastasis, and implications on β-catenin, MMPs, EMT,
angiogenesis and tumour volume; (4) apoptosis, with a focus on Bax/Bcl ratios, intrinsic/extrinsic
apoptotic pathways and telomerase activity; (5) oxidative stress, through Nrf2/ARE signalling, ROS
elimination and catalase activity; and (6) efficacy of chemotherapeutic agents, such as oxaliplatin,
etoposide and doxorubicin. In addition, the need to enhance the bioavailability and delivery of
mangiferin are briefly addressed, as well as the potential for toxicity.
Keywords: mangiferin; cancer; inflammation; NFκB; oxidative stress; cell cycle; combination
therapy; nutraceuticals; bioavailability; hallmarks of cancer
1. Introduction
Cancer has been identified as the leading cause of non-communicable disease mortality globally [1],
and is responsible for significant morbidity and costs to healthcare systems. Cancer incidence and
mortality has been increasing at a greater rate than population growth alone could account for. The
International Agency for Research on Cancer (IARC) reported 14.1 million cases and over 8.2 million
mortalities due to cancer in 2012 compared to 10 million cases and six million mortalities in 2000 [2]
in a baseline population of 7.1 billion and 6.1 billion, respectively [3]. Much of this increase is due to
rising cancer burden in less developed countries (LDCs), with 57% of new cases, and 65% of cancer
related deaths occurring in LDCs [2]. When standardized by age, the total number of cases per 100,000
population is greater in more developed countries (MDCs) than LDCs (overall age standardized rate:
268 and 148 respectively) [4]. One exception to this pattern is infection-attributable cancers, which are
responsible for 26% of the cancer burden in LDCs but only 8% in MDCs [5].
Cancer is less likely to be identified early or treated successfully in LDCs due to reduced access
to screening tools and chemotherapeutic drugs. Previously, cancer has been regarded as a MDC
disease. However, through the adoption of a more Westernised lifestyle, cancer incidence has been
steadily increasing in LDCs. From the data published by Parkin et al., it can be seen that 40%–45% of
cancers can be attributable to lifestyle factors such as diet, smoking status, alcohol consumption and
lack of physical activity [6]. Some compounds naturally present in the diet, such as mangiferin in
mangoes and honeybush tea, are thought to modulate risk of cancer and retard cancer progression.
Mangiferin (1,3,6,7-tetrahydroxyxanthone-C2-β-D glucoside) [7–11] is a polyphenol [8,11–15]
found in many plant species, in particular, those from the Anacardiaceae [7,9,16–20] and
Gentianaceae families [7,9,13,17,18,20]. For an extensive breakdown of plant sources of mangiferin
and mangiferin content, see Matkowski et al. [21].
Nutrients 2016, 8, 396; doi:10.3390/nu8070396 www.mdpi.com/journal/nutrients
is a nuclear receptor that also functions as a transcription factor, regulating expression of
genes involved in cell differentiation and tumourigenesis [
65
]. Under normal circumstances, when
the corresponding ligand binds to PPAR
Review
Mangiferin and Cancer: Mechanisms of Action
Fuchsia Gold-Smith 1, Alyssa Fernandez 2 and Karen Bishop 1,*
1 Auckland Cancer Society Research Center, Faculty of Medical and Health Sciences, University of
Auckland, Private Bag 92019, Auckland 1142, New Zealand; fgol315@aucklanduni.ac.nz
2 Faculty of Medical and Health Sciences, University of Auckland, Private Bag 92019, Auckland 1142, New
Zealand; afer098@aucklanduni.ac.nz
* Correspondence: k.bishop@auckland.ac.nz; Tel.: +64-9-923-4471
Received: 20 April 2016; Accepted: 22 June 2016; Published: date
Abstract: Mangiferin, a bioactive compound derived primarily from Anacardiaceae and
Gentianaceae families and found in mangoes and honeybush tea, has been extensively studied for
its therapeutic properties. Mangiferin has shown promising chemotherapeutic and
chemopreventative potential. This review focuses on the effect of mangiferin on: (1) inflammation,
with respect to NFκB, PPARү and the immune system; (2) cell cycle, the MAPK pathway G2/M
checkpoint; (3) proliferation and metastasis, and implications on β-catenin, MMPs, EMT,
angiogenesis and tumour volume; (4) apoptosis, with a focus on Bax/Bcl ratios, intrinsic/extrinsic
apoptotic pathways and telomerase activity; (5) oxidative stress, through Nrf2/ARE signalling, ROS
elimination and catalase activity; and (6) efficacy of chemotherapeutic agents, such as oxaliplatin,
etoposide and doxorubicin. In addition, the need to enhance the bioavailability and delivery of
mangiferin are briefly addressed, as well as the potential for toxicity.
Keywords: mangiferin; cancer; inflammation; NFκB; oxidative stress; cell cycle; combination
therapy; nutraceuticals; bioavailability; hallmarks of cancer
1. Introduction
Cancer has been identified as the leading cause of non-communicable disease mortality globally [1],
and is responsible for significant morbidity and costs to healthcare systems. Cancer incidence and
mortality has been increasing at a greater rate than population growth alone could account for. The
International Agency for Research on Cancer (IARC) reported 14.1 million cases and over 8.2 million
mortalities due to cancer in 2012 compared to 10 million cases and six million mortalities in 2000 [2]
in a baseline population of 7.1 billion and 6.1 billion, respectively [3]. Much of this increase is due to
rising cancer burden in less developed countries (LDCs), with 57% of new cases, and 65% of cancer
related deaths occurring in LDCs [2]. When standardized by age, the total number of cases per 100,000
population is greater in more developed countries (MDCs) than LDCs (overall age standardized rate:
268 and 148 respectively) [4]. One exception to this pattern is infection-attributable cancers, which are
responsible for 26% of the cancer burden in LDCs but only 8% in MDCs [5].
Cancer is less likely to be identified early or treated successfully in LDCs due to reduced access
to screening tools and chemotherapeutic drugs. Previously, cancer has been regarded as a MDC
disease. However, through the adoption of a more Westernised lifestyle, cancer incidence has been
steadily increasing in LDCs. From the data published by Parkin et al., it can be seen that 40%–45% of
cancers can be attributable to lifestyle factors such as diet, smoking status, alcohol consumption and
lack of physical activity [6]. Some compounds naturally present in the diet, such as mangiferin in
mangoes and honeybush tea, are thought to modulate risk of cancer and retard cancer progression.
Mangiferin (1,3,6,7-tetrahydroxyxanthone-C2-β-D glucoside) [7–11] is a polyphenol [8,11–15]
found in many plant species, in particular, those from the Anacardiaceae [7,9,16–20] and
Gentianaceae families [7,9,13,17,18,20]. For an extensive breakdown of plant sources of mangiferin
and mangiferin content, see Matkowski et al. [21].
Nutrients 2016, 8, 396; doi:10.3390/nu8070396 www.mdpi.com/journal/nutrients
, transcriptional activation of COX-2 is suppressed through
a number of mechanisms [
66
]. COX-2 is one of the key drivers of chronic inflammation through the
production of prostaglandins leading to further activation of inflammatory processes [
67
], and thus
COX-2 overexpression favours cancer progression [
29
]. PPAR
Review
Mangiferin and Cancer: Mechanisms of Action
Fuchsia Gold-Smith 1, Alyssa Fernandez 2 and Karen Bishop 1,*
1 Auckland Cancer Society Research Center, Faculty of Medical and Health Sciences, University of
Auckland, Private Bag 92019, Auckland 1142, New Zealand; fgol315@aucklanduni.ac.nz
2 Faculty of Medical and Health Sciences, University of Auckland, Private Bag 92019, Auckland 1142, New
Zealand; afer098@aucklanduni.ac.nz
* Correspondence: k.bishop@auckland.ac.nz; Tel.: +64-9-923-4471
Received: 20 April 2016; Accepted: 22 June 2016; Published: date
Abstract: Mangiferin, a bioactive compound derived primarily from Anacardiaceae and
Gentianaceae families and found in mangoes and honeybush tea, has been extensively studied for
its therapeutic properties. Mangiferin has shown promising chemotherapeutic and
chemopreventative potential. This review focuses on the effect of mangiferin on: (1) inflammation,
with respect to NFκB, PPARү and the immune system; (2) cell cycle, the MAPK pathway G2/M
checkpoint; (3) proliferation and metastasis, and implications on β-catenin, MMPs, EMT,
angiogenesis and tumour volume; (4) apoptosis, with a focus on Bax/Bcl ratios, intrinsic/extrinsic
apoptotic pathways and telomerase activity; (5) oxidative stress, through Nrf2/ARE signalling, ROS
elimination and catalase activity; and (6) efficacy of chemotherapeutic agents, such as oxaliplatin,
etoposide and doxorubicin. In addition, the need to enhance the bioavailability and delivery of
mangiferin are briefly addressed, as well as the potential for toxicity.
Keywords: mangiferin; cancer; inflammation; NFκB; oxidative stress; cell cycle; combination
therapy; nutraceuticals; bioavailability; hallmarks of cancer
1. Introduction
Cancer has been identified as the leading cause of non-communicable disease mortality globally [1],
and is responsible for significant morbidity and costs to healthcare systems. Cancer incidence and
mortality has been increasing at a greater rate than population growth alone could account for. The
International Agency for Research on Cancer (IARC) reported 14.1 million cases and over 8.2 million
mortalities due to cancer in 2012 compared to 10 million cases and six million mortalities in 2000 [2]
in a baseline population of 7.1 billion and 6.1 billion, respectively [3]. Much of this increase is due to
rising cancer burden in less developed countries (LDCs), with 57% of new cases, and 65% of cancer
related deaths occurring in LDCs [2]. When standardized by age, the total number of cases per 100,000
population is greater in more developed countries (MDCs) than LDCs (overall age standardized rate:
268 and 148 respectively) [4]. One exception to this pattern is infection-attributable cancers, which are
responsible for 26% of the cancer burden in LDCs but only 8% in MDCs [5].
Cancer is less likely to be identified early or treated successfully in LDCs due to reduced access
to screening tools and chemotherapeutic drugs. Previously, cancer has been regarded as a MDC
disease. However, through the adoption of a more Westernised lifestyle, cancer incidence has been
steadily increasing in LDCs. From the data published by Parkin et al., it can be seen that 40%–45% of
cancers can be attributable to lifestyle factors such as diet, smoking status, alcohol consumption and
lack of physical activity [6]. Some compounds naturally present in the diet, such as mangiferin in
mangoes and honeybush tea, are thought to modulate risk of cancer and retard cancer progression.
Mangiferin (1,3,6,7-tetrahydroxyxanthone-C2-β-D glucoside) [7–11] is a polyphenol [8,11–15]
found in many plant species, in particular, those from the Anacardiaceae [7,9,16–20] and
Gentianaceae families [7,9,13,17,18,20]. For an extensive breakdown of plant sources of mangiferin
and mangiferin content, see Matkowski et al. [21].
Nutrients 2016, 8, 396; doi:10.3390/nu8070396 www.mdpi.com/journal/nutrients
also has a pleiotropic effect on blood
glucose levels. PPAR
Review
Mangiferin and Cancer: Mechanisms of Action
Fuchsia Gold-Smith 1, Alyssa Fernandez 2 and Karen Bishop 1,*
1 Auckland Cancer Society Research Center, Faculty of Medical and Health Sciences, University of
Auckland, Private Bag 92019, Auckland 1142, New Zealand; fgol315@aucklanduni.ac.nz
2 Faculty of Medical and Health Sciences, University of Auckland, Private Bag 92019, Auckland 1142, New
Zealand; afer098@aucklanduni.ac.nz
* Correspondence: k.bishop@auckland.ac.nz; Tel.: +64-9-923-4471
Received: 20 April 2016; Accepted: 22 June 2016; Published: date
Abstract: Mangiferin, a bioactive compound derived primarily from Anacardiaceae and
Gentianaceae families and found in mangoes and honeybush tea, has been extensively studied for
its therapeutic properties. Mangiferin has shown promising chemotherapeutic and
chemopreventative potential. This review focuses on the effect of mangiferin on: (1) inflammation,
with respect to NFκB, PPARү and the immune system; (2) cell cycle, the MAPK pathway G2/M
checkpoint; (3) proliferation and metastasis, and implications on β-catenin, MMPs, EMT,
angiogenesis and tumour volume; (4) apoptosis, with a focus on Bax/Bcl ratios, intrinsic/extrinsic
apoptotic pathways and telomerase activity; (5) oxidative stress, through Nrf2/ARE signalling, ROS
elimination and catalase activity; and (6) efficacy of chemotherapeutic agents, such as oxaliplatin,
etoposide and doxorubicin. In addition, the need to enhance the bioavailability and delivery of
mangiferin are briefly addressed, as well as the potential for toxicity.
Keywords: mangiferin; cancer; inflammation; NFκB; oxidative stress; cell cycle; combination
therapy; nutraceuticals; bioavailability; hallmarks of cancer
1. Introduction
Cancer has been identified as the leading cause of non-communicable disease mortality globally [1],
and is responsible for significant morbidity and costs to healthcare systems. Cancer incidence and
mortality has been increasing at a greater rate than population growth alone could account for. The
International Agency for Research on Cancer (IARC) reported 14.1 million cases and over 8.2 million
mortalities due to cancer in 2012 compared to 10 million cases and six million mortalities in 2000 [2]
in a baseline population of 7.1 billion and 6.1 billion, respectively [3]. Much of this increase is due to
rising cancer burden in less developed countries (LDCs), with 57% of new cases, and 65% of cancer
related deaths occurring in LDCs [2]. When standardized by age, the total number of cases per 100,000
population is greater in more developed countries (MDCs) than LDCs (overall age standardized rate:
268 and 148 respectively) [4]. One exception to this pattern is infection-attributable cancers, which are
responsible for 26% of the cancer burden in LDCs but only 8% in MDCs [5].
Cancer is less likely to be identified early or treated successfully in LDCs due to reduced access
to screening tools and chemotherapeutic drugs. Previously, cancer has been regarded as a MDC
disease. However, through the adoption of a more Westernised lifestyle, cancer incidence has been
steadily increasing in LDCs. From the data published by Parkin et al., it can be seen that 40%–45% of
cancers can be attributable to lifestyle factors such as diet, smoking status, alcohol consumption and
lack of physical activity [6]. Some compounds naturally present in the diet, such as mangiferin in
mangoes and honeybush tea, are thought to modulate risk of cancer and retard cancer progression.
Mangiferin (1,3,6,7-tetrahydroxyxanthone-C2-β-D glucoside) [7–11] is a polyphenol [8,11–15]
found in many plant species, in particular, those from the Anacardiaceae [7,9,16–20] and
Gentianaceae families [7,9,13,17,18,20]. For an extensive breakdown of plant sources of mangiferin
and mangiferin content, see Matkowski et al. [21].
Nutrients 2016, 8, 396; doi:10.3390/nu8070396 www.mdpi.com/journal/nutrients
agonists such as thiazolidinediones are widely used in management of diabetes
and have a hypoglycaemic effect [
65
]. Hyperglycaemia is regarded as an emerging risk factor for
cancer development [
65
]. Mangiferin, like thiazolidinedione may also act to reduce hyperglycaemia,
benefiting diabetics and decreasing cancer risk.
Mangiferin increases mRNA expression of the PPAR
Review
Mangiferin and Cancer: Mechanisms of Action
Fuchsia Gold-Smith 1, Alyssa Fernandez 2 and Karen Bishop 1,*
1 Auckland Cancer Society Research Center, Faculty of Medical and Health Sciences, University of
Auckland, Private Bag 92019, Auckland 1142, New Zealand; fgol315@aucklanduni.ac.nz
2 Faculty of Medical and Health Sciences, University of Auckland, Private Bag 92019, Auckland 1142, New
Zealand; afer098@aucklanduni.ac.nz
* Correspondence: k.bishop@auckland.ac.nz; Tel.: +64-9-923-4471
Received: 20 April 2016; Accepted: 22 June 2016; Published: date
Abstract: Mangiferin, a bioactive compound derived primarily from Anacardiaceae and
Gentianaceae families and found in mangoes and honeybush tea, has been extensively studied for
its therapeutic properties. Mangiferin has shown promising chemotherapeutic and
chemopreventative potential. This review focuses on the effect of mangiferin on: (1) inflammation,
with respect to NFκB, PPARү and the immune system; (2) cell cycle, the MAPK pathway G2/M
checkpoint; (3) proliferation and metastasis, and implications on β-catenin, MMPs, EMT,
angiogenesis and tumour volume; (4) apoptosis, with a focus on Bax/Bcl ratios, intrinsic/extrinsic
apoptotic pathways and telomerase activity; (5) oxidative stress, through Nrf2/ARE signalling, ROS
elimination and catalase activity; and (6) efficacy of chemotherapeutic agents, such as oxaliplatin,
etoposide and doxorubicin. In addition, the need to enhance the bioavailability and delivery of
mangiferin are briefly addressed, as well as the potential for toxicity.
Keywords: mangiferin; cancer; inflammation; NFκB; oxidative stress; cell cycle; combination
therapy; nutraceuticals; bioavailability; hallmarks of cancer
1. Introduction
Cancer has been identified as the leading cause of non-communicable disease mortality globally [1],
and is responsible for significant morbidity and costs to healthcare systems. Cancer incidence and
mortality has been increasing at a greater rate than population growth alone could account for. The
International Agency for Research on Cancer (IARC) reported 14.1 million cases and over 8.2 million
mortalities due to cancer in 2012 compared to 10 million cases and six million mortalities in 2000 [2]
in a baseline population of 7.1 billion and 6.1 billion, respectively [3]. Much of this increase is due to
rising cancer burden in less developed countries (LDCs), with 57% of new cases, and 65% of cancer
related deaths occurring in LDCs [2]. When standardized by age, the total number of cases per 100,000
population is greater in more developed countries (MDCs) than LDCs (overall age standardized rate:
268 and 148 respectively) [4]. One exception to this pattern is infection-attributable cancers, which are
responsible for 26% of the cancer burden in LDCs but only 8% in MDCs [5].
Cancer is less likely to be identified early or treated successfully in LDCs due to reduced access
to screening tools and chemotherapeutic drugs. Previously, cancer has been regarded as a MDC
disease. However, through the adoption of a more Westernised lifestyle, cancer incidence has been
steadily increasing in LDCs. From the data published by Parkin et al., it can be seen that 40%–45% of
cancers can be attributable to lifestyle factors such as diet, smoking status, alcohol consumption and
lack of physical activity [6]. Some compounds naturally present in the diet, such as mangiferin in
mangoes and honeybush tea, are thought to modulate risk of cancer and retard cancer progression.
Mangiferin (1,3,6,7-tetrahydroxyxanthone-C2-β-D glucoside) [7–11] is a polyphenol [8,11–15]
found in many plant species, in particular, those from the Anacardiaceae [7,9,16–20] and
Gentianaceae families [7,9,13,17,18,20]. For an extensive breakdown of plant sources of mangiferin
and mangiferin content, see Matkowski et al. [21].
Nutrients 2016, 8, 396; doi:10.3390/nu8070396 www.mdpi.com/journal/nutrients
gene [
68
] and thus decreases transcriptional
activation of COX-2. This reduces inflammation and creates a less favourable environment for
acquisition and proliferation of malignant cells. Mangiferin also impedes expression of COX-2 [
41
]
via upregulation of TGF-
β
and downregulation of NF
κ
B. Mangiferin may play a beneficial role in
modulating PPAR
Review
Mangiferin and Cancer: Mechanisms of Action
Fuchsia Gold-Smith 1, Alyssa Fernandez 2 and Karen Bishop 1,*
1 Auckland Cancer Society Research Center, Faculty of Medical and Health Sciences, University of
Auckland, Private Bag 92019, Auckland 1142, New Zealand; fgol315@aucklanduni.ac.nz
2 Faculty of Medical and Health Sciences, University of Auckland, Private Bag 92019, Auckland 1142, New
Zealand; afer098@aucklanduni.ac.nz
* Correspondence: k.bishop@auckland.ac.nz; Tel.: +64-9-923-4471
Received: 20 April 2016; Accepted: 22 June 2016; Published: date
Abstract: Mangiferin, a bioactive compound derived primarily from Anacardiaceae and
Gentianaceae families and found in mangoes and honeybush tea, has been extensively studied for
its therapeutic properties. Mangiferin has shown promising chemotherapeutic and
chemopreventative potential. This review focuses on the effect of mangiferin on: (1) inflammation,
with respect to NFκB, PPARү and the immune system; (2) cell cycle, the MAPK pathway G2/M
checkpoint; (3) proliferation and metastasis, and implications on β-catenin, MMPs, EMT,
angiogenesis and tumour volume; (4) apoptosis, with a focus on Bax/Bcl ratios, intrinsic/extrinsic
apoptotic pathways and telomerase activity; (5) oxidative stress, through Nrf2/ARE signalling, ROS
elimination and catalase activity; and (6) efficacy of chemotherapeutic agents, such as oxaliplatin,
etoposide and doxorubicin. In addition, the need to enhance the bioavailability and delivery of
mangiferin are briefly addressed, as well as the potential for toxicity.
Keywords: mangiferin; cancer; inflammation; NFκB; oxidative stress; cell cycle; combination
therapy; nutraceuticals; bioavailability; hallmarks of cancer
1. Introduction
Cancer has been identified as the leading cause of non-communicable disease mortality globally [1],
and is responsible for significant morbidity and costs to healthcare systems. Cancer incidence and
mortality has been increasing at a greater rate than population growth alone could account for. The
International Agency for Research on Cancer (IARC) reported 14.1 million cases and over 8.2 million
mortalities due to cancer in 2012 compared to 10 million cases and six million mortalities in 2000 [2]
in a baseline population of 7.1 billion and 6.1 billion, respectively [3]. Much of this increase is due to
rising cancer burden in less developed countries (LDCs), with 57% of new cases, and 65% of cancer
related deaths occurring in LDCs [2]. When standardized by age, the total number of cases per 100,000
population is greater in more developed countries (MDCs) than LDCs (overall age standardized rate:
268 and 148 respectively) [4]. One exception to this pattern is infection-attributable cancers, which are
responsible for 26% of the cancer burden in LDCs but only 8% in MDCs [5].
Cancer is less likely to be identified early or treated successfully in LDCs due to reduced access
to screening tools and chemotherapeutic drugs. Previously, cancer has been regarded as a MDC
disease. However, through the adoption of a more Westernised lifestyle, cancer incidence has been
steadily increasing in LDCs. From the data published by Parkin et al., it can be seen that 40%–45% of
cancers can be attributable to lifestyle factors such as diet, smoking status, alcohol consumption and
lack of physical activity [6]. Some compounds naturally present in the diet, such as mangiferin in
mangoes and honeybush tea, are thought to modulate risk of cancer and retard cancer progression.
Mangiferin (1,3,6,7-tetrahydroxyxanthone-C2-β-D glucoside) [7–11] is a polyphenol [8,11–15]
found in many plant species, in particular, those from the Anacardiaceae [7,9,16–20] and
Gentianaceae families [7,9,13,17,18,20]. For an extensive breakdown of plant sources of mangiferin
and mangiferin content, see Matkowski et al. [21].
Nutrients 2016, 8, 396; doi:10.3390/nu8070396 www.mdpi.com/journal/nutrients
and COX-2 regulation as evidenced by
in vitro
studies in MDA-MB231 breast
cancer cells [43].
2.1.3. Immune Response
Cancer cells can sometimes escape detection and avoid the immune system, which would
otherwise destroy abnormal cells. Cancer cells not only express immune checkpoint proteins that
dampen the immune response, but they may also release cytokines and growth factors that promote

Nutrients 2016,8, 396 7 of 25
tumour cell proliferation and minimize apoptosis. By enhancing a patient’s immune response a better
outcome can be achieved. In
in vivo
studies, mangiferin has been found to enhance the number and
activity of immune cells [9,10].
Rajendran et al. found that in mice treated with benzo(a)pyrene (B(a)P) to induce lung
cancer, dosing with mangiferin influenced the types of immune cells present and concentrations
of various immunoglobulins [
9
]. Mangiferin treatment resulted in higher numbers of lymphocytes and
neutrophils [
9
]. Mangiferin treatment of B(a)P mice increased levels of IgG and IgM immunoglobulins
and decreased levels of IgA immunoglobulins, relative to animals only receiving B(a)P treatment [
9
].
In addition, mangiferin inhibited phagocytic capacity and nitric oxide production of macrophages
when stimulated with LPS and IFN
Review
Mangiferin and Cancer: Mechanisms of Action
Fuchsia Gold-Smith 1, Alyssa Fernandez 2 and Karen Bishop 1,*
1 Auckland Cancer Society Research Center, Faculty of Medical and Health Sciences, University of
Auckland, Private Bag 92019, Auckland 1142, New Zealand; fgol315@aucklanduni.ac.nz
2 Faculty of Medical and Health Sciences, University of Auckland, Private Bag 92019, Auckland 1142, New
Zealand; afer098@aucklanduni.ac.nz
* Correspondence: k.bishop@auckland.ac.nz; Tel.: +64-9-923-4471
Received: 20 April 2016; Accepted: 22 June 2016; Published: date
Abstract: Mangiferin, a bioactive compound derived primarily from Anacardiaceae and
Gentianaceae families and found in mangoes and honeybush tea, has been extensively studied for
its therapeutic properties. Mangiferin has shown promising chemotherapeutic and
chemopreventative potential. This review focuses on the effect of mangiferin on: (1) inflammation,
with respect to NFκB, PPARү and the immune system; (2) cell cycle, the MAPK pathway G2/M
checkpoint; (3) proliferation and metastasis, and implications on β-catenin, MMPs, EMT,
angiogenesis and tumour volume; (4) apoptosis, with a focus on Bax/Bcl ratios, intrinsic/extrinsic
apoptotic pathways and telomerase activity; (5) oxidative stress, through Nrf2/ARE signalling, ROS
elimination and catalase activity; and (6) efficacy of chemotherapeutic agents, such as oxaliplatin,
etoposide and doxorubicin. In addition, the need to enhance the bioavailability and delivery of
mangiferin are briefly addressed, as well as the potential for toxicity.
Keywords: mangiferin; cancer; inflammation; NFκB; oxidative stress; cell cycle; combination
therapy; nutraceuticals; bioavailability; hallmarks of cancer
1. Introduction
Cancer has been identified as the leading cause of non-communicable disease mortality globally [1],
and is responsible for significant morbidity and costs to healthcare systems. Cancer incidence and
mortality has been increasing at a greater rate than population growth alone could account for. The
International Agency for Research on Cancer (IARC) reported 14.1 million cases and over 8.2 million
mortalities due to cancer in 2012 compared to 10 million cases and six million mortalities in 2000 [2]
in a baseline population of 7.1 billion and 6.1 billion, respectively [3]. Much of this increase is due to
rising cancer burden in less developed countries (LDCs), with 57% of new cases, and 65% of cancer
related deaths occurring in LDCs [2]. When standardized by age, the total number of cases per 100,000
population is greater in more developed countries (MDCs) than LDCs (overall age standardized rate:
268 and 148 respectively) [4]. One exception to this pattern is infection-attributable cancers, which are
responsible for 26% of the cancer burden in LDCs but only 8% in MDCs [5].
Cancer is less likely to be identified early or treated successfully in LDCs due to reduced access
to screening tools and chemotherapeutic drugs. Previously, cancer has been regarded as a MDC
disease. However, through the adoption of a more Westernised lifestyle, cancer incidence has been
steadily increasing in LDCs. From the data published by Parkin et al., it can be seen that 40%–45% of
cancers can be attributable to lifestyle factors such as diet, smoking status, alcohol consumption and
lack of physical activity [6]. Some compounds naturally present in the diet, such as mangiferin in
mangoes and honeybush tea, are thought to modulate risk of cancer and retard cancer progression.
Mangiferin (1,3,6,7-tetrahydroxyxanthone-C2-β-D glucoside) [7–11] is a polyphenol [8,11–15]
found in many plant species, in particular, those from the Anacardiaceae [7,9,16–20] and
Gentianaceae families [7,9,13,17,18,20]. For an extensive breakdown of plant sources of mangiferin
and mangiferin content, see Matkowski et al. [21].
Nutrients 2016, 8, 396; doi:10.3390/nu8070396 www.mdpi.com/journal/nutrients
[
9
]. Thus, with respect to the inflammatory response, less
collateral damage is likely to occur. In a later study, it was found that in tumour bearing Swiss mice,
mangiferin promoted cytotoxic behaviour of lymphocytes and macrophages against malignant cells,
and thus the incidence of fibrosarcoma was reduced [7].
2.2. Cell Cycle
Maintenance of a normal cell cycle is essential for homeostasis. It allows cells to be replaced at the
same rate as they are lost. Often in cancer, the length of the cell cycle is reduced, allowing aberrant
proliferation of malignant cells.
Findings suggest that mangiferin influences the Mitogen Activated Protein Kinase (MAPK)
pathway and progression from the G
2
/M checkpoint, thus maintaining a more normal cell cycle length,
or cell cycle arrest at the appropriate checkpoint [8,13,52].
2.2.1. Mitogen Activated Protein Kinase Pathway
The MAPK pathway is frequently implicated in tumourigenesis as it plays a role in processes
such as cell proliferation, growth, differentiation, apoptosis and migration [
69
]. Mangiferin attenuates
MAPK signalling [
34
] by inhibiting MAPKs p38, Extracellular signal-Regulated Kinase (ERK) and
c Jun N-terminal Kinase phosphorylation [
60
]. Li et al. found that mangiferin aglycone, a metabolite of
mangiferin, formed through deglycosylation
in vivo
, also inhibited ERK1/2 when phosphorylation was
induced by UVB [
70
]. In this study, mangiferin aglycone was found to significantly reduce UV-induced
skin cancers in mice, primarily through this interaction with ERK [
70
]. While further study is required,
this suggests a beneficial effect against skin cancer.
2.2.2. G2/M Checkpoint
Under normal conditions, cells with mutations are not able to undergo mitosis, as there are
a number of checkpoints in the cycle that prevent mutated DNA from replicating [
71
]. Cancer cells
must acquire characteristics that allow them to bypass these checkpoints in order to survive and
proliferate [71].
The G
2
/M checkpoint occurs during the transition from G
2
to mitotic entry. The G
2
phase
involves rapid growth of a cell as it prepares for mitosis. Cell progression from the G
2
/M checkpoint
only occurs in the absence of DNA damage signals [
72
]. DNA damage can be sensed by Ataxia
telangiectasia mutated protein (ATM) and Ataxia Telangiectasia and Rad3-related protein (ATR) which
signal via Checkpoint kinase 1 (Chk1) and Checkpoint Kinase 2 (Chk2) to cause degradation of
M-phase inducer phosphatase 1 (cdc25a), which results in inhibition of the Cyclin-Dependent Kinase 1
(CDK1)-cyclinB1 complex and thus cell cycle arrest [
71
,
72
] (see Figure 3). The cdc2-cyclinB1 complex
is often overexpressed in malignant cells, enhancing entry into mitosis in eukaryotic cells. Malignant
cells may acquire characteristics, which enable them to escape cell cycle arrest regardless of mutations.
Chemotherapeutic agents such as etoposide target malignant cells at the G
2
/M checkpoint, thus
when cell cycle progression is inhibited, the efficacy of etoposide at inducing apoptosis is increased.
Mangiferin is thought to induce G
2
/M phase arrest [
8
], reducing proliferation of malignant cells and
increasing efficacy of chemotherapeutic agents that target this phase.

Nutrients 2016,8, 396 8 of 25
Nutrients 2016, 8, 396 8 of 25
Figure 3. Mangiferin affects the molecular events leading to cell cycle G2/M phase arrest (Figure
adapted from [71]).
Mangiferin has been shown to arrest cell cycle progression in a time dependent manner at the
G2/M phase through suppression of the cdc2-cyclin B1 signalling pathway in MCF-7 cells [8]. This
was observed through analysis of cell cycle distribution through flow cytometry, where a greater
number of cells were found in the G2/M phase after incubation with mangiferin [13,52]. These
findings are in keeping with results from the Peng et al. study in HL-60 cells [8]. Peng et al. [52] also
found that in HL-60 leukaemia cells, gene expression of Chk1, cdc25 and Wee1 was elevated when
exposed to low concentrations of mangiferin, but at higher concentrations, Chk1 and cdc25 gene
expression was reduced at the mRNA level. Mangiferin has been shown to significantly inhibit
phosphorylation of ATR, Chk1 and other proteins with anti-proliferative properties such as Wee1,
Akt and Erk1/2, while increasing phosphorylation of cdc2 and cyclinB1 [52]. Lv et al. used a Western
blot assay to identify a reduction in cdc2 (cdk1) and cyclinB1 [8] protein levels in response to
treatment with mangiferin. Findings suggest that inhibition of the ATR-Chk1 stress response DNA
damage pathway by mangiferin is responsible for cell cycle arrest.
While G2/M phase arrest has been identified in response to mangiferin treatment in a number of
cancer cell lines (MCF-7, HL-60, BEL-7404 and CNE2) [16,18,35,52,73], further study is required to
determine dosages of mangiferin required to elicit an effect. In addition to G2/M phase arrest, Lv et
al. also suggest that mangiferin may induce G0/G1 cell cycle arrest in MCF7 cells [8].
2.3. Proliferation/Metastasis
Under normal circumstances, the rate of cell replication and cell death is matched to maintain
homeostasis. In cancer cells, the mediators of these processes may be deregulated, allowing cells to
proliferate continuously, exceeding rates of cell death. Cancer cells may develop a more motile
phenotype, due to deregulation of cell adhesion pathways. Loss of adhesion allows cells to escape
their site of origin and spread to other sites, causing secondary malignancies.
Mangiferin is thought to reduce cell proliferation [16] through modulation of β-catenin and
consequently metalloproteinase-7 (MMP-7), MMP-9, and EMT (epithelial to mesenchymal transition)
[14]. Through NFκB, mangiferin may influence VEGF-A transcription to modulate angiogenesis.
Additionally, in in vivo experiments, mangiferin has shown efficacy at reducing tumour volume in
mice [14].
Figure 3.
Mangiferin affects the molecular events leading to cell cycle G
2
/M phase arrest (Figure
adapted from [71]).
Mangiferin has been shown to arrest cell cycle progression in a time dependent manner at the
G
2
/M phase through suppression of the cdc2-cyclin B1 signalling pathway in MCF-7 cells [
8
]. This was
observed through analysis of cell cycle distribution through flow cytometry, where a greater number
of cells were found in the G
2
/M phase after incubation with mangiferin [
13
,
52
]. These findings are
in keeping with results from the Peng et al. study in HL-60 cells [
8
]. Peng et al. [
52
] also found that
in HL-60 leukaemia cells, gene expression of Chk1, cdc25 and Wee1 was elevated when exposed to
low concentrations of mangiferin, but at higher concentrations, Chk1 and cdc25 gene expression was
reduced at the mRNA level. Mangiferin has been shown to significantly inhibit phosphorylation of
ATR, Chk1 and other proteins with anti-proliferative properties such as Wee1, Akt and Erk1/2, while
increasing phosphorylation of cdc2 and cyclinB1 [
52
]. Lv et al. used a Western blot assay to identify
a reduction in cdc2 (cdk1) and cyclinB1 [
8
] protein levels in response to treatment with mangiferin.
Findings suggest that inhibition of the ATR-Chk1 stress response DNA damage pathway by mangiferin
is responsible for cell cycle arrest.
While G
2
/M phase arrest has been identified in response to mangiferin treatment in a number
of cancer cell lines (MCF-7, HL-60, BEL-7404 and CNE2) [
16
,
18
,
35
,
52
,
73
], further study is required to
determine dosages of mangiferin required to elicit an effect. In addition to G
2
/M phase arrest, Lv et al.
also suggest that mangiferin may induce G0/G1cell cycle arrest in MCF7 cells [8].
2.3. Proliferation/Metastasis
Under normal circumstances, the rate of cell replication and cell death is matched to maintain
homeostasis. In cancer cells, the mediators of these processes may be deregulated, allowing cells
to proliferate continuously, exceeding rates of cell death. Cancer cells may develop a more motile
phenotype, due to deregulation of cell adhesion pathways. Loss of adhesion allows cells to escape
their site of origin and spread to other sites, causing secondary malignancies.
Mangiferin is thought to reduce cell proliferation [
16
] through modulation of
β
-catenin
and consequently metalloproteinase-7 (MMP-7), MMP-9, and EMT (epithelial to mesenchymal
transition) [
14
]. Through NF
κ
B, mangiferin may influence VEGF-A transcription to modulate
angiogenesis. Additionally, in
in vivo
experiments, mangiferin has shown efficacy at reducing tumour
volume in mice [14].

Nutrients 2016,8, 396 9 of 25
In a variety of breast cancer cell lines, mangiferin has been implicated in reduced cell proliferation
(MDA-MB-231, BT-549, MCF-7 and T47D) [
8
,
14
] and reduced metastasis (MDA-MB-231 and BT-549)
in a dose-dependent manner [
14
]. In HL-60 cells, Li et al. reinforced that mangiferin reduced
proliferation [
14
]. In contrast, Wilkinson et al. found that mangiferin did not suppress proliferation
in MCF-7 cells, while mangiferin aglycone did [
74
]. This may be a result of differential activation of
estrogen receptors [
74
]. Kim et al. also reported no significant effect on proliferation when HeLa cells
were treated with 25–200
µ
M of mangiferin [
36
] and Garcia-Rivera et al. found no significant inhibition
of proliferation in MDA-MB231 cells when treated with mangiferin, but proliferation was inhibited by
Vimang®[41]. Thus, further evidence is required to ascertain an effect.
2.3.1. Glycogen Synthase Kinase-3β/β-Catenin
In cancer, aberrant activation of
β
-catenin is often observed [
14
]. High levels of expression of
β
-catenin are associated with proliferation and metastasis. Glycogen synthase kinase -3
β
(GSK-3
β
) is
capable of phosphorylating and degrading
β
-catenin [
14
]. GSK-3
β
may be inhibited by a number of
signals. Mangiferin is hypothesised to suppress the β-catenin pathway [14].
Using a Western blot assay to analyse protein expression in breast cancer cell lines, mangiferin was
found to down-regulate
β
-catenin and decrease levels of inactive GSK-3
β
, indicating suppression of
the
β
-catenin pathway, which in turn down-regulates MMP-7, MMP-9 and snail expression [
14
]. Snail
can be used as an epithelial/mesenchymal phenotye indicator [
14
], thus lower levels of snail, which
are seen on exposure to mangiferin, favour a more epithelial, less mobile phenotype, while higher
expression of snail would indicate a more motile phenotype, allowing malignant cells to metastasise.
2.3.2. Matrix Metalloproteinases
Activation of matrix MMPs is a crucial step towards metastasis as these enzymes facilitate cell
escape from the initial site of the malignancy, through degradation of the extracellular matrix. As above,
mangiferin has been linked to downregulation of NF
κ
B, which in turn influences downstream
expression of MMPs [64,75].
In breast cancer, the matrix metalloproteinases MMP-2, -7 and -9 are often up-regulated [
14
].
Li et al. have demonstrated through a Western blot assay that of these three enzymes, MMP-2
was not significantly affected while MMP-7 and MMP-9 were down-regulated by mangiferin [
14
].
MMP-7 and -9 strongly promote cancer progression by allowing malignant cells to metastasise [
76
].
In LNCaP prostate cancer cells, activation of NF
κ
B by TNF-
α
increases levels of MMP-9 mRNA and
protein present in the cell [
75
]. Mangiferin is capable of attenuating this effect, ultimately reducing
metastasis [
75
]. In addition to this pathway of MMP-9 activation, Xiao et al. (2015) discovered
that mangiferin stimulates miR-15b expression, which in turn down-regulates MMP-9 expression
in U87 glioma cells [
16
], thus reducing the capability of malignant cells to escape the extracellular
matrix and metastasise. In the study by Jung et al., mangiferin prevented PMA induced MMP-9
expression without influencing other MMP expression in human astroglioma cell lines: U87MG,
U373MG and CRT-MG [
19
]. MMP-1, -2, -3 and -14 expressions were not influenced by mangiferin [
19
].
Mangiferin is thought to act by suppressing NF
κ
B and AP-1 binding to the promoter region of
MMP-9 and prevents phosphorylation of Akt and MAP kinases (see above section) induced by
PMA [
19
]. Jung et al. also suggest that mangiferin acts on MMP-9 suppressors, Tissue Inhibitor of
Metalloproteinase -1 and -2 (TIMP-1 and -2). TIMP-1 and TIMP-2 mRNA levels were enhanced by the
presence of mangiferin, implying another favourable quality of mangiferin [
19
]. Jung et al. suggest
that mangiferin, through these mechanisms, may reduce glioma invasiveness [
19
]. Overall, published
studies indicate that mangiferin may play an important role in reducing expression of MMP-9, limiting
cancer invasiveness [16,19].

Nutrients 2016,8, 396 10 of 25
2.3.3. Epithelial to Mesenchymal Transition
EMT involves the loss of adherence and gain of a motile phenotype and resistance to apoptosis,
which may allow motile cancer cells to migrate from their site of origin and survive, causing secondary
metastases [
53
].
β
-catenin signalling may also play a role in EMT [
14
]. Mangiferin appears to enhance
epithelial characteristics in breast cancer cell lines and thus help protect against metastasis [14].
Li et al. [
14
] investigated the effect of mangiferin on EMT through analysis of two
mesenchymal-like breast cancer cell lines (MDA-MB-231 and BT-549). Mesenchymal characteristics
were reduced upon treatment with mangiferin, whereby cells obtained a more epithelial-like
morphology. Associated with these physical observations, increased expression of the epithelial
phenotype marker, E-cadherin, and decreased expression of mesenchymal phenotype markers,
vimentin, snail and slug were seen [
14
]. In MDA-MB-231 xenograft mice treated with mangiferin,
Western blot analysis revealed the same shift in expression in epithelial and mesenchymal markers
with lower expression of active
β
-catenin, MMP-7, MMP-9 and vimentin (mesenchymal markers)
and higher expression of E-cadherin (an epithelial marker) [
14
], reinforcing the
in vitro
results. While
these results are promising in breast cancer cells, investigation in a more diverse range of cell lines is
required to determine if these findings may be applicable to a broader range of breast cancer cell lines
as well as other cancer cell lines.
2.3.4. Angiogenesis
Sustained angiogenesis is widely regarded as an enabling characteristic of cancer, as tumours
are unable to survive beyond a certain size without their own blood supply [
53
]. Angiogenic
tumours are able to grow and proliferate using nutrients and oxygen from their own blood supply.
The VEGF-A protein is known to stimulate angiogenesis [
53
]. Both mangiferin and Vimang
®
extracts
have demonstrated inhibitory effects on TNF-induced transcription of VEGF-A in MDA-MB231
cells [
41
]. However, this experiment was carried out over a short time period. Further investigation
over longer time periods and evidence from
in vivo
/ex vivo studies are required to further determine
the effect of mangiferin on angiogenesis.
2.3.5. Tumour Volume
During
in vivo
experiments in mice, mangiferin has been found to reduce tumour volume.
In C57BL/6J mice inoculated with MCF-7 cells on the neck, a reduction of 89.4% in tumour volume
relative to control was seen when mice were medicated with 100 mg/kg of mangiferin. This value
was closely comparable to the results obtained from cisplatin treatment (91.5%), an established
chemotherapeutic drug [
8
]. In a similar experiment, the lifespan of these mice was extended at
dosages from 10 mg/kg mangiferin and above and 60% of mice survived until the end of the assay
period [
8
], while in the no treatment group, there were no mice surviving after day 40 following
MCF-7 inoculation. A high dosage of mangiferin (100 mg/kg) extended lifespan to the same degree as
cisplatin, with no significant difference (p< 0.05) being observed between these treatments [
8
]. Dose
dependency was observed [8].
These results show that mangiferin can act as a potent chemotherapeutic agent in mice and thus
further investigation into mangiferin-based products could benefit treatment of cancer in humans.
2.4. Apoptosis
In order to survive and proliferate, cancer cells must be able to evade apoptosis, despite
carrying malignant characteristics [
53
]. Under normal circumstances, either the intrinsic pathway
via the mitochondria, or the extrinsic pathway involving death receptors, can induce apoptosis.
The intrinsic pathway generally involves increased permeability of the mitochondrial membrane and
the release of cytochrome C to activate initiator procaspase-9, while the extrinsic pathway involves
Fas Associated Death Domain (FADD) and procaspase-8 [
36
] (Figure 4). Apoptosis is the preferred

Nutrients 2016,8, 396 11 of 25
pathway of cell death, as necrotic cell death may induce inflammatory changes due to the release of
immune-stimulatory molecules. In order to eradicate cancer, many chemotherapeutic agents seek
to induce apoptosis in malignant cells. From the peer reviewed literature, it can be concluded that
mangiferin has promising apoptosis inducing properties in a number of cell lines and is involved in
regulating apoptosis via multiple targets [8,14,36].
Nutrients 2016, 8, 396 11 of 25
induce apoptosis in malignant cells. From the peer reviewed literature, it can be concluded that
mangiferin has promising apoptosis inducing properties in a number of cell lines and is involved in
regulating apoptosis via multiple targets [8,14,36].
Figure 4. Effect of Mangiferin on proteins implicated in apoptosis.
In 2013, two studies were published that demonstrated a dose dependent increase in apoptosis
in response to increasing mangiferin concentration in MDAMB-231, BT-549, MCF7 and T47D breast
cancer cell lines [8,14]. Kim et al. reported similar findings in HeLa cells in response to treatment with
ethanolic extracts of mango skin or flesh [36]. There are a number of suggested mechanisms by which
an increase in apoptosis in these cancer cells may be potentiated. As discussed earlier, mangiferin
down-regulates the transcription factor NFκB. It is hypothesized that this dampening of NFκB
activity is likely to be responsible for increased apoptosis in HL-60 acute myeloid leukaemia (AML)
cells, MCF7 cells and HeLa cells [8,13,35,77].
2.4.1. Mangiferin and Hesperidin in Cyclopia Sp. Extracts
Bartoszewski et al. showed in HeLa cells that treatment with Cyclopia sp. tea extracts, which are
high in mangiferin and hesperidin, caused up-regulation of TRADD and TNFR superfamily member
25 (TRAMP), which are involved in signalling of the extrinsic apoptotic pathway [77]. However,
when compared to mangiferin only and hesperidin only, it would appear that hesperidin is a more
potent activator of apoptosis in HeLa cells than mangiferin [77]. Regardless, mangiferin did enhance
the activity of hesperidin, even when added in low concentrations. Mangiferin itself caused down-
regulation of Baculoviral IAP Repeat Containing 7 (BIRC7), which sensitizes cells to death by the
extrinsic apoptotic pathway [77].
2.4.2. Bax/Bcl-2
The Bcl-2 protein acts to block programmed cell death while the Bcl-2 associated X protein (Bax)
protein favours apoptosis. When the ratio of Bax:Bcl-2 is increased, a cell’s sensitivity to apoptosis is
increased [78], and consequently malignant cells are less likely to survive. Current literature suggests
that the effect of mangiferin on the Bax:Bcl-2 ratio is dependent on cell type, dosage and perhaps the
form of mangiferin used [35,79].
Pan et al. found that when CNE2 nasopharyngeal carcinoma cells were treated with mangiferin,
the mRNA and protein expression levels of Bcl-2 were consistently down-regulated while Bax was
up-regulated [35]. As a consequence, these cells were primed for apoptosis. Bcl-2 was also down-
Figure 4. Effect of Mangiferin on proteins implicated in apoptosis.
In 2013, two studies were published that demonstrated a dose dependent increase in apoptosis
in response to increasing mangiferin concentration in MDAMB-231, BT-549, MCF7 and T47D breast
cancer cell lines [
8
,
14
]. Kim et al. reported similar findings in HeLa cells in response to treatment with
ethanolic extracts of mango skin or flesh [
36
]. There are a number of suggested mechanisms by which
an increase in apoptosis in these cancer cells may be potentiated. As discussed earlier, mangiferin
down-regulates the transcription factor NF
κ
B. It is hypothesized that this dampening of NF
κ
B activity
is likely to be responsible for increased apoptosis in HL-60 acute myeloid leukaemia (AML) cells,
MCF7 cells and HeLa cells [8,13,35,77].
2.4.1. Mangiferin and Hesperidin in Cyclopia Sp. Extracts
Bartoszewski et al. showed in HeLa cells that treatment with Cyclopia sp. tea extracts, which
are high in mangiferin and hesperidin, caused up-regulation of TRADD and TNFR superfamily
member 25 (TRAMP), which are involved in signalling of the extrinsic apoptotic pathway [
77
].
However, when compared to mangiferin only and hesperidin only, it would appear that hesperidin is
a more potent activator of apoptosis in HeLa cells than mangiferin [
77
]. Regardless, mangiferin did
enhance the activity of hesperidin, even when added in low concentrations. Mangiferin itself caused
down-regulation of Baculoviral IAP Repeat Containing 7 (BIRC7), which sensitizes cells to death by
the extrinsic apoptotic pathway [77].
2.4.2. Bax/Bcl-2
The Bcl-2 protein acts to block programmed cell death while the Bcl-2 associated X protein (Bax)
protein favours apoptosis. When the ratio of Bax:Bcl-2 is increased, a cell’s sensitivity to apoptosis is
increased [
78
], and consequently malignant cells are less likely to survive. Current literature suggests
that the effect of mangiferin on the Bax:Bcl-2 ratio is dependent on cell type, dosage and perhaps the
form of mangiferin used [35,79].
Pan et al. found that when CNE2 nasopharyngeal carcinoma cells were treated with mangiferin,
the mRNA and protein expression levels of Bcl-2 were consistently down-regulated while Bax

Nutrients 2016,8, 396 12 of 25
was up-regulated [
35
]. As a consequence, these cells were primed for apoptosis. Bcl-2 was also
down-regulated upon treatment with an ethanolic extract of mango skins, which contained mangiferin,
mangiferin gallate and isomangiferin gallate [
36
]. This ultimately resulted in activation of caspase-3, -6,
-8 and -9 alongside poly (ADP-ribose) polymerase (PARP) protein [
36
], favouring cell death. However,
Klavitha et al. [
22
] have found that the reverse applies in the context of excitotoxicity in neurons,
whereby mangiferin blocks upregulation of Bax, thus attenuating cell death, making it a promising
compound for further research with regard to Parkinson’s disease [
22
]. Furthermore, Bartoszewski
et al. demonstrated that on analysis of green fermented Cyclopia sp. extracts (in which the primary
compounds were mangiferin and hesperidin), there were no significant changes in Bax/Bcl2 mRNA
levels or protein levels [
77
], although Bartoszewski et al. acknowledge that the most likely cause of
this disparate finding was low dosage.
In addition to the Bax/Bcl2 ratio, Zhang et al. and Pan et al. reported that apoptosis could be
triggered by mangiferin in HL-60 cells due to changes in levels of similar proteins [
13
,
35
]. HL-60 cells
responded to mangiferin by decreasing levels of Bcl-extra large (Bcl-xL) and XIAP [
13
,
35
], resulting in
increased apoptosis.
Further experimentation in a wider range of cell lines is required to elucidate what dosage of
mangiferin is likely to provide an effect.
2.4.3. Intrinsic/Extrinsic Apoptotic Pathway
To identify whether mangiferin was acting on the intrinsic or extrinsic apoptotic pathway, Kim
et al. performed a Western blot experiment to assess expression levels of proteins involved in either
the intrinsic pathway, extrinsic pathway or both pathways [
36
]. Results indicated that there was
slightly lower expression levels of BH3 interacting domain (Bid), pro-caspase-3 and pro-caspase-8,
but increased expression of cleaved, active forms of PARP, caspase-7 and caspase-9 [
36
], when HeLa
cells were treated with an ethanolic extract of mango peel. Consequently, it is likely that the ethanolic
extracts of mango pulp and skin influenced both apoptotic pathways, which is crucial for effective
apoptosis. Lv et al. further strengthened the evidence for the role of mangiferin in the intrinsic
apoptotic pathway by considering cytochrome C [
8
]. They found that when MCF-7 cells were treated
with mangiferin, cytochrome C concentration in the mitochondria was reduced, while a corresponding
increase in cytochrome C concentration was observed in the cytosol. This indicates that cytochrome
C was released from the mitochondria in response to mangiferin treatment and thus apoptosis may
be induced via the mitochondrial pathway [
8
]. In addition to these findings, increased expression
of caspase-3, -8 and -9, and decreased expression of procaspase-3, -8 and -9 expression was noted,
suggesting activation of both intrinsic and extrinsic apoptotic pathways [
8
]. Based on results from
their study, du Plessis-Stoman et al. have suggested that mangiferin may favour apoptotic cell death
over necrotic cell death, which has potential to reduce inflammation [48].
2.4.4. Telomerase
Aside from the study of various pathways of apoptosis, in the literature it is reported that
mangiferin can inhibit telomerase activity in K562 human leukaemia cells with dose- and time-
dependent behaviour [
8
,
35
,
80
], promoting apoptosis. It has been suggested that this may be due to
increased fas gene expression and protein levels of fas [
8
]. Enhanced telomerase activity is found in
a variety of cancers and is permissive and required for sustained growth of late cancers. Almost all
cancers exhibit some form of telomerase reactivation [
81
]. By reducing telomerase activity, mangiferin
can be used to reduce the progression of existing cancers and create an environment in which malignant
cells are unlikely to survive.
Mangiferin has demonstrated pro-apoptotic activity in a number of cancer cell lines including
K562 leukaemia, MCF-7 breast cancer and CNE2 nasopharyngeal cells [8,35].

Nutrients 2016,8, 396 13 of 25
2.5. Oxidative Stress
Oxidative stress occurs when the burden of ROS is not balanced by antioxidants and detoxification
systems. The presence of these excess reactive species can result in cellular damage, particularly to
DNA, lipids and proteins. Over time, oxidative stress increases the risk of developing cancer and may
exacerbate inflammation. Mangiferin is thought to play a role in: (1) modulating the Nrf2/antioxidant
response element (ARE) detoxification pathway (Figure 5); (2) directly detoxifying reactive species;
and (3) activating detoxification enzymes such as catalase.
Nutrients 2016, 8, 396 13 of 25
2.5. Oxidative Stress
Oxidative stress occurs when the burden of ROS is not balanced by antioxidants and
detoxification systems. The presence of these excess reactive species can result in cellular damage,
particularly to DNA, lipids and proteins. Over time, oxidative stress increases the risk of developing
cancer and may exacerbate inflammation. Mangiferin is thought to play a role in: (1) modulating the
Nrf2/antioxidant response element (ARE) detoxification pathway (Figure 5); (2) directly detoxifying
reactive species; and (3) activating detoxification enzymes such as catalase.
Figure 5. Effect of Mangiferin on the Nrf2/ARE Detoxification Pathway.
2.5.1. Nrf2/ARE Detoxification Pathway
Under normal conditions, Nrf2 gene transcription is inhibited by Kelch-like ECH-associated
protein-1 (KEAP-1). However, oxidative stress, dietary components and synthetic chemicals can
induce Nrf2 transcription [18]. Consequently, Nrf2 protein can accumulate in the nucleus where it
forms heterodimers with musculoaponeurotic fibrosarcoma (maf) protein. This heterodimer signals
through the ARE to initiate transcription of a number of phase II detoxification enzymes [17], such as
NAD(P)H: quinine reductases (NQO1), glutathione S-transferase (GSH) and heme oxygenase (HO-1)
[18]. HO-1, when activated, can translocate into the nucleus to further activate transcription factors
relevant to the stimulus [82]. Ultimately, this pathway provides activation of detoxification enzymes
when oxidative stresses are presented. Mangiferin manipulates this pathway in such a way that the
survival of healthy cells but not malignant cells is enhanced. Mangiferin modulated this Nrf2/ARE
signaling pathway at multiple steps [13,17,18].
While mangiferin does not directly influence Nrf2 transcription rates, Zhao et al. have
demonstrated that the half-life of Nrf2 is increased due to impaired ubiquitination and thus
degradation of the protein [18], which results in higher levels of the protein being present within the
cell. Zhang et al. also reported similar findings in human umbilical cord mononuclear blood cells,
where mangiferin increased the quantity of Nrf2 accumulating in the nucleus in a time dependent
manner [17]. Protein quantity was assessed by microscopy and verified by Western blotting [17].
Additionally, mangiferin increased the binding of Nrf2 to ARE which in turn was shown to increase
downstream production of NQO1 (a prominent antioxidant enzyme) when assessed in a Western
blot assay [13,17].
Nrf-ARE signaling can provide protection against agents that are chemotherapeutic to normal
cells [13] (more on synergistic effects of mangiferin and chemotheraputics later). Similarly,
overexpression of Nrf2 in cancer cells can promote resistance to therapy, through up-regulation of
Figure 5. Effect of Mangiferin on the Nrf2/ARE Detoxification Pathway.
2.5.1. Nrf2/ARE Detoxification Pathway
Under normal conditions, Nrf2 gene transcription is inhibited by Kelch-like ECH-associated
protein-1 (KEAP-1). However, oxidative stress, dietary components and synthetic chemicals can
induce Nrf2 transcription [
18
]. Consequently, Nrf2 protein can accumulate in the nucleus where it
forms heterodimers with musculoaponeurotic fibrosarcoma (maf) protein. This heterodimer signals
through the ARE to initiate transcription of a number of phase II detoxification enzymes [
17
], such
as NAD(P)H: quinine reductases (NQO1), glutathione S-transferase (GSH) and heme oxygenase
(HO-1) [
18
]. HO-1, when activated, can translocate into the nucleus to further activate transcription
factors relevant to the stimulus [
82
]. Ultimately, this pathway provides activation of detoxification
enzymes when oxidative stresses are presented. Mangiferin manipulates this pathway in such a way
that the survival of healthy cells but not malignant cells is enhanced. Mangiferin modulated this
Nrf2/ARE signaling pathway at multiple steps [13,17,18].
While mangiferin does not directly influence Nrf2 transcription rates, Zhao et al. have
demonstrated that the half-life of Nrf2 is increased due to impaired ubiquitination and thus degradation
of the protein [
18
], which results in higher levels of the protein being present within the cell. Zhang et
al. also reported similar findings in human umbilical cord mononuclear blood cells, where mangiferin
increased the quantity of Nrf2 accumulating in the nucleus in a time dependent manner [
17
]. Protein
quantity was assessed by microscopy and verified by Western blotting [
17
]. Additionally, mangiferin
increased the binding of Nrf2 to ARE which in turn was shown to increase downstream production of
NQO1 (a prominent antioxidant enzyme) when assessed in a Western blot assay [13,17].
Nrf-ARE signaling can provide protection against agents that are chemotherapeutic to normal
cells [
13
] (more on synergistic effects of mangiferin and chemotheraputics later). Similarly,
overexpression of Nrf2 in cancer cells can promote resistance to therapy, through up-regulation
of antiapoptotic bcl-xL. Mangiferin seems able to differentiate between malignant cells and healthy
cells, promoting Nrf2 activation in healthy cells (human umbilical cord mononuclear blood cells) but

Nutrients 2016,8, 396 14 of 25
not cancerous cells (HL-60). Thus, survival is aided in healthy cells by enhanced efficiency of the
Nrf2/ARE detoxification pathway while the development of resistance to chemotherapeutics is not
permitted in malignant cells [
13
]. To date, mangiferin is the only known Nrf2 activator that does not
confer protection to malignant cells against chemotherapeutic agents [
13
], making it a promising agent
for cancer therapy.
Downstream effects in the Nrf2/ARE detoxification pathway have been further studied upon
treatment with Vimang
®
. Treatment of MDA-MB231 breast cancer cells with 200–400
µ
L/mL of
Vimang
®
was found to significantly increase HO-1 transcription. However, when treated with
mangiferin alone, there was no significant increase in HO-1 transcription [
41
]. From this result, one
may deduce that the Nrf2/ARE detoxification pathway may not have been activated by mangiferin, as
was reported earlier in the HL-60 cancer cell line. It is possible that an alternative bioactive, found
in Vimang
®
may be responsible for the up-regulation of HO-1 transcription in the MDA-MB231
breast cancer cells. Overall, results would suggest that mangiferin may provide some benefit through
activation of the Nrf-ARE detoxification pathway.
2.5.2. Elimination of Reactive Species
Reactive species must be eliminated promptly to avoid damage to important biological molecules.
This may be done directly by antioxidant species, or by inducing and up-regulating detoxification
pathways. Mangiferin is an established antioxidant that is able to neutralize a range of reactive species
and influence expression and activity of key detoxification enzymes. By performing these actions,
oxidative stress and inflammation are reduced.
Mangiferin is able to directly protect against hydroxyl [
28
], 2,2-diphenyl-1-picrylhydrazyl (DPPH),
superoxide, hydrogen peroxide [
51
], and peroxynitrite free radicals, lipid peroxides [
9
,
21
], hypochlorus
acid [
28
] and heavy metal induced reactive oxygen species [
15
]. Findings from numerous studies can
be used to reinforce the notion that mangiferin has greater or comparative antioxidative capacity to
other known antioxidants, such as quercetin, baicalein, catechins, phenylpropanoic acids [
21
], vitamin
C, vitamin E and
β
-carotene [
28
]. Alongside its antioxidative potential, mangiferin influences ROS
production through modulating Fenton-type reactions. Fenton-type reactions usually involve the
production of a hydroxyl radical and the oxidation of Fe
2+
to Fe
3+
. In the presence of mangiferin,
Fenton-type reactions are inhibited by chelating Fe
2+
ions, reducing production of subsequent
ROS [
15
,
29
,
51
]. Additionally, Duang et al. have suggested that mangiferin protects against lipid
peroxidation [
29
]. This protection may in part be responsible for reduced DNA damage and
amelioration of cytotoxic action seen in response to ionising radiation in healthy cells [9,83].
Both
in vitro
and
in vivo
evidence suggests that mangiferin up-regulates expression of various
detoxifying enzymes, resulting in enhanced clearance of ROS. In N2A neuroblastoma cells,
Kavintha et al. implicated mangiferin in reducing oxidative stress by providing protection against
1-methyl-4-phenylpyridine (MPP
+
) induced cytotoxicity, due to its capability to restore glutathione
action and reduce expression of superoxide (SOD) and catalase [
22
]. In addition to these findings,
Matkowski et al. also reported that mangiferin influenced SOD, catalase and glutathione peroxidase
in such a way that it halts ROS centred apoptotic pathways through dampening endogenous ROS
production [
21
]. Sarker et al. demonstrated the relationship between mangiferin and glutathione
levels by showing that mangiferin increased levels of GSH more than 2
ˆ
the amount observed
on treatment with other anti-oxidants [
11
]. It has been suggested that mangiferin increases GSH
levels by up-regulation of
Review
Mangiferin and Cancer: Mechanisms of Action
Fuchsia Gold-Smith 1, Alyssa Fernandez 2 and Karen Bishop 1,*
1 Auckland Cancer Society Research Center, Faculty of Medical and Health Sciences, University of
Auckland, Private Bag 92019, Auckland 1142, New Zealand; fgol315@aucklanduni.ac.nz
2 Faculty of Medical and Health Sciences, University of Auckland, Private Bag 92019, Auckland 1142, New
Zealand; afer098@aucklanduni.ac.nz
* Correspondence: k.bishop@auckland.ac.nz; Tel.: +64-9-923-4471
Received: 20 April 2016; Accepted: 22 June 2016; Published: date
Abstract: Mangiferin, a bioactive compound derived primarily from Anacardiaceae and
Gentianaceae families and found in mangoes and honeybush tea, has been extensively studied for
its therapeutic properties. Mangiferin has shown promising chemotherapeutic and
chemopreventative potential. This review focuses on the effect of mangiferin on: (1) inflammation,
with respect to NFκB, PPARү and the immune system; (2) cell cycle, the MAPK pathway G2/M
checkpoint; (3) proliferation and metastasis, and implications on β-catenin, MMPs, EMT,
angiogenesis and tumour volume; (4) apoptosis, with a focus on Bax/Bcl ratios, intrinsic/extrinsic
apoptotic pathways and telomerase activity; (5) oxidative stress, through Nrf2/ARE signalling, ROS
elimination and catalase activity; and (6) efficacy of chemotherapeutic agents, such as oxaliplatin,
etoposide and doxorubicin. In addition, the need to enhance the bioavailability and delivery of
mangiferin are briefly addressed, as well as the potential for toxicity.
Keywords: mangiferin; cancer; inflammation; NFκB; oxidative stress; cell cycle; combination
therapy; nutraceuticals; bioavailability; hallmarks of cancer
1. Introduction
Cancer has been identified as the leading cause of non-communicable disease mortality globally [1],
and is responsible for significant morbidity and costs to healthcare systems. Cancer incidence and
mortality has been increasing at a greater rate than population growth alone could account for. The
International Agency for Research on Cancer (IARC) reported 14.1 million cases and over 8.2 million
mortalities due to cancer in 2012 compared to 10 million cases and six million mortalities in 2000 [2]
in a baseline population of 7.1 billion and 6.1 billion, respectively [3]. Much of this increase is due to
rising cancer burden in less developed countries (LDCs), with 57% of new cases, and 65% of cancer
related deaths occurring in LDCs [2]. When standardized by age, the total number of cases per 100,000
population is greater in more developed countries (MDCs) than LDCs (overall age standardized rate:
268 and 148 respectively) [4]. One exception to this pattern is infection-attributable cancers, which are
responsible for 26% of the cancer burden in LDCs but only 8% in MDCs [5].
Cancer is less likely to be identified early or treated successfully in LDCs due to reduced access
to screening tools and chemotherapeutic drugs. Previously, cancer has been regarded as a MDC
disease. However, through the adoption of a more Westernised lifestyle, cancer incidence has been
steadily increasing in LDCs. From the data published by Parkin et al., it can be seen that 40%–45% of
cancers can be attributable to lifestyle factors such as diet, smoking status, alcohol consumption and
lack of physical activity [6]. Some compounds naturally present in the diet, such as mangiferin in
mangoes and honeybush tea, are thought to modulate risk of cancer and retard cancer progression.
Mangiferin (1,3,6,7-tetrahydroxyxanthone-C2-β-D glucoside) [7–11] is a polyphenol [8,11–15]
found in many plant species, in particular, those from the Anacardiaceae [7,9,16–20] and
Gentianaceae families [7,9,13,17,18,20]. For an extensive breakdown of plant sources of mangiferin
and mangiferin content, see Matkowski et al. [21].
Nutrients 2016, 8, 396; doi:10.3390/nu8070396 www.mdpi.com/journal/nutrients
-Glutamylcysteine Synthetase (
Review
Mangiferin and Cancer: Mechanisms of Action
Fuchsia Gold-Smith 1, Alyssa Fernandez 2 and Karen Bishop 1,*
1 Auckland Cancer Society Research Center, Faculty of Medical and Health Sciences, University of
Auckland, Private Bag 92019, Auckland 1142, New Zealand; fgol315@aucklanduni.ac.nz
2 Faculty of Medical and Health Sciences, University of Auckland, Private Bag 92019, Auckland 1142, New
Zealand; afer098@aucklanduni.ac.nz
* Correspondence: k.bishop@auckland.ac.nz; Tel.: +64-9-923-4471
Received: 20 April 2016; Accepted: 22 June 2016; Published: date
Abstract: Mangiferin, a bioactive compound derived primarily from Anacardiaceae and
Gentianaceae families and found in mangoes and honeybush tea, has been extensively studied for
its therapeutic properties. Mangiferin has shown promising chemotherapeutic and
chemopreventative potential. This review focuses on the effect of mangiferin on: (1) inflammation,
with respect to NFκB, PPARү and the immune system; (2) cell cycle, the MAPK pathway G2/M
checkpoint; (3) proliferation and metastasis, and implications on β-catenin, MMPs, EMT,
angiogenesis and tumour volume; (4) apoptosis, with a focus on Bax/Bcl ratios, intrinsic/extrinsic
apoptotic pathways and telomerase activity; (5) oxidative stress, through Nrf2/ARE signalling, ROS
elimination and catalase activity; and (6) efficacy of chemotherapeutic agents, such as oxaliplatin,
etoposide and doxorubicin. In addition, the need to enhance the bioavailability and delivery of
mangiferin are briefly addressed, as well as the potential for toxicity.
Keywords: mangiferin; cancer; inflammation; NFκB; oxidative stress; cell cycle; combination
therapy; nutraceuticals; bioavailability; hallmarks of cancer
1. Introduction
Cancer has been identified as the leading cause of non-communicable disease mortality globally [1],
and is responsible for significant morbidity and costs to healthcare systems. Cancer incidence and
mortality has been increasing at a greater rate than population growth alone could account for. The
International Agency for Research on Cancer (IARC) reported 14.1 million cases and over 8.2 million
mortalities due to cancer in 2012 compared to 10 million cases and six million mortalities in 2000 [2]
in a baseline population of 7.1 billion and 6.1 billion, respectively [3]. Much of this increase is due to
rising cancer burden in less developed countries (LDCs), with 57% of new cases, and 65% of cancer
related deaths occurring in LDCs [2]. When standardized by age, the total number of cases per 100,000
population is greater in more developed countries (MDCs) than LDCs (overall age standardized rate:
268 and 148 respectively) [4]. One exception to this pattern is infection-attributable cancers, which are
responsible for 26% of the cancer burden in LDCs but only 8% in MDCs [5].
Cancer is less likely to be identified early or treated successfully in LDCs due to reduced access
to screening tools and chemotherapeutic drugs. Previously, cancer has been regarded as a MDC
disease. However, through the adoption of a more Westernised lifestyle, cancer incidence has been
steadily increasing in LDCs. From the data published by Parkin et al., it can be seen that 40%–45% of
cancers can be attributable to lifestyle factors such as diet, smoking status, alcohol consumption and
lack of physical activity [6]. Some compounds naturally present in the diet, such as mangiferin in
mangoes and honeybush tea, are thought to modulate risk of cancer and retard cancer progression.
Mangiferin (1,3,6,7-tetrahydroxyxanthone-C2-β-D glucoside) [7–11] is a polyphenol [8,11–15]
found in many plant species, in particular, those from the Anacardiaceae [7,9,16–20] and
Gentianaceae families [7,9,13,17,18,20]. For an extensive breakdown of plant sources of mangiferin
and mangiferin content, see Matkowski et al. [21].
Nutrients 2016, 8, 396; doi:10.3390/nu8070396 www.mdpi.com/journal/nutrients
-GCS), the enzyme controlling the rate
limiting step of GSH synthesis [
11
].
In vivo
studies demonstrate a similar pattern of increased
detoxification enzyme activity. In experiments using B(a)P-treated mice, B(a)P attenuated SOD
and catalase (see below for more on catalase) activity in lymphocytes, polymorphonuclear cells
and macrophages [
9
]. However, mangiferin co-administration provided a protective effect against
these events.
Rajendran et al.
also found that mangiferin reduced the production of H
2
O
2
in B(a)P
treated animals [
9
]. In animals with lung cancer, enhanced activity of glutathione transferase [
48
],

Nutrients 2016,8, 396 15 of 25
quinine reductase and uridine 5’-diphosphate-glucuronosyl transferase activity has been demonstrated
upon treatment with mangiferin [
8
]. These events each contribute to a reduction in oxidative stress
through increased capacity to deal with assault from reactive species.
Sarker et al.
further suggest
that the ability of mangiferin to reduce oxidative stress may also be linked to NF
κ
B down-regulating
capabilities, which reduces TNF-induced reactive oxygen intermediate generation [11].
2.5.3. Catalase
Catalase is a detoxification enzyme present in most organisms exposed to oxygen that converts
H
2
O
2
into water and oxygen. H
2
O
2
can cause oxidative damage if not rapidly converted into less
toxic species. Mangiferin may directly increase the efficiency of the catalase enzyme by interacting
directly with the enzyme, thus reducing oxidative damage that can be done prior to detoxification of
H
2
O
2
[
61
]. Increased activity of catalase may modulate downstream signalling pathways that favour
an environment that does not promote cancer development and survival. However, not all published
findings are consistent with the notion that mangiferin increases catalase activity [11,61].
In silico docking studies using AutoDock and PyMol predict that mangiferin has the capacity
to bind to the active site of catalase, but not other oxidase enzymes [
61
]. The binding of mangiferin
to catalase enhanced the activity of catalase by 44% during the
in vitro
studies conducted by
Sahoo et al.
[
61
]. An earlier study by Sarkar et al. reported disparate findings, where mangiferin
caused a 0%–23% increase in activity when compared to untreated cells, and did not influence the
quantity of enzyme present [
11
]. In both experiments, U-937 cells were treated alongside other cell
lines with 10 µg/mL of mangiferin for 3 h [11].
To further elucidate the effect of mangiferin on catalase activity, Sahoo et al. conducted
fluorescent spectrophotometry experiments on catalase in the unbound state (peak at 330 nm, excitation
wavelength 280 nm) and subsequently, increasing concentrations of mangiferin were added [
61
]. As the
concentration of mangiferin was increased, the peak at 330 nm decreased in magnitude, suggesting
interaction with mangiferin. When the binding constant was calculated (3.1
ˆ
10
´7
M
´1
), this indicated
a strong binding affinity between catalase and mangiferin [
61
]. Mangiferin also proved capable of
overriding aminotriazole (ATZ) inhibition of catalase in lipid peroxidation assays [
61
]. Sahoo et al.
further demonstrated that direct quenching of H
2
O
2
by mangiferin was not significant, implying that
the entire 44% difference found may be attributable to enhanced activity of the catalase enzyme [61].
It has been suggested that increased catalase activity may dampen excessive activation of
MAPK/AKT, which is commonly found in malignant cells [
61
] (See above for MAKP/AKT).
Sarker et al
. suggested that high expression of catalase would reduce NF
κ
B levels [
11
]. However,
evidence does not support any change in catalase expression, only in the efficiency of this
enzyme [
11
,
61
]. Increased catalase activity could reduce oxidative stress and inflammation, thus
favouring a chemopreventative environment.
2.6. DNA Damage
DNA damage facilitates mutations in the genetic material of a cell. Mutation is required to
initiate the development of cancer and also expedites the acquisition of characteristics required for
a malignant cell to survive. Thus, a higher susceptibility to DNA damage results in a higher incidence
of mutation and the development of cancer [
84
]. The role of mangiferin with regard to DNA damage
is controversial.
Studies have reported that mangiferin is capable of protecting not only DNA [
42
] but also
deoxyribose, phospholipids, polyunsaturated fatty acids and proteins [
21
]. However,
Rodeiro et al.
[
12
]
found that when aqueous extracts from Mangifera indica bark were applied to lymphocytes and
lymphoblastic cells, DNA damage was induced. When this effect was further investigated with
the compound mangiferin alone, there was a reduction in DNA damage, thus there is likely to be
an alternative compound in the extract that is inducing DNA damage [
12
]. In addition,
Rodeiro et al.
found that when DNA damage was induced by
γ
-radiation, the aqueous extract was protective against
DNA damage [12].

Nutrients 2016,8, 396 16 of 25
Radiation Damage
Ionising radiation has been shown to induce DNA damage. In patients undergoing radiotherapy,
many healthy cells acquire collateral damage. Mangiferin and mangiferin aglycone have demonstrated
protective effects against radiation damage during in vitro studies [28].
Lei et al. demonstrated that pre-treatment of human intestinal epithelial cells with mangiferin
aglycone reduced the percentage of cells with double strand breakages in their DNA by 47% when
treated with ionizing radiation [
28
]. This was more effective than the 40% reduction seen following
mangiferin pre-treatment. Currently, there are few radioprotective agents, and these agents tend to be
associated with high levels of toxicity [
28
]. Mangiferin may provide some protection to cancer patients
undergoing chemotherapy as well as improve efficiency of anti-cancer treatments.
3. Synergistic Effects
The use of many chemotherapeutic agents induces a range of side effects, which can cause
serious illness. Mangiferin shows potential to reduce or negate these side effects by selectively
targeting malignant cells for cell death and enhancing survival of healthy cells. Mangiferin may
potentiate cell death by existing drugs through modulation of NF
κ
B activity [
11
] and causing cell cycle
arrest in malignant cells at the G
2
/M checkpoint, leaving cells susceptible to apoptosis induced by
chemotherapeutic agents such as etoposide [
13
]. Through NF
κ
B inhibition, mangiferin is likely to
reduce resistance to chemotherapeutic agents in cancer cells [
13
,
48
]. Studies using pro-apoptotic agents
such as oxaliplatin, etoposide, doxorubicin and paclitaxel have documented additional beneficial
effects when co-administered with mangiferin (Table 1).
Table 1.
Summary of proposed beneficial effects of co-administration of mangiferin alongside
chemotherapeutic agents.
Chemotherapeutic Agent Cell Line Reference Evidence
Oxaliplatin HeLa, HT29, HL60 [48]Reduction in oxaliplatin IC50 values; counteracts
resistance to oxaliplatin.
Etoposide HL60, U937 [11,13]
Reduces oxidative stress. Protects normal cells without
reducing sensitivity of HL60 to etoposide [13]. Activity
of the drug is enhanced by mangiferin [11].
Doxorubicin MCF7, U937 [13,33]
At high concentrations mangiferin can inhibit
P-glycoprotein expression and chemosensitise for
doxorubicin therapy [33]. Activity of the drug is
enhanced by mangiferin [11].
Paclitaxel Triple negative
breast cancer [60,62]IRAK1 overexpression confers a growth advantage [62].
Mangiferin may inhibit IRAK1 activation [60,62].
Cisplatin U937 [11]
Inhibits ROS production [8]. Activity of the drug is
enhanced by mangiferin; Impedes NFκB activation;
Enhanced cell death in the presence of TNF [11].
Vincristine U937 [11]
Inhibits ROS production [8]. Activity of the drug is
enhanced by mangiferin; Impedes NFκB activation;
Enhanced cell death in the presence of TNF [11].
Adriamycin U937 [11]
Inhibits ROS production [8]. Activity of the drug is
enhanced by mangiferin; Impedes NFκB activation;
Enhanced cell death in the presence of TNF [11].
AraC U937 [11]
Inhibits ROS production [8]. Activity of the drug is
enhanced by mangiferin; Impedes NFκB activation;
Enhanced cell death in the presence of TNF [11].
3.1. Pro-Apoptotic Agents
While mangiferin (at a concentration of 10
µ
g/mL) does not trigger apoptotic cell death itself [
11
],
it may enhance action of chemotherapeutic pro-apoptotic agents. Sarker et al. [
11
] demonstrated that
this was due to down-regulation of NF
κ
B by transfecting U-937 cells with an I
κ
B
α
-double negative

Nutrients 2016,8, 396 17 of 25
construct, blocking NF
κ
B activation and also transfecting with a p65 construct and observing cell
death after 36 h by MTT assay, using the Live/Dead cell assay. In I
κ
B
α
-double negative transfected
cells, cell death increased by 12% and increased cell death with TNF from 42% to 53%. Cell death in
the presence of mangiferin was increased a further 4%. In p65 overexpressing cells, cell death was not
observed in response to treatment with TNF or TNF and mangiferin. By considering SEAP as a reporter
gene, I
κ
B
α
-double negative cells were shown to down-regulate NF
κ
B and p65 overexpressing cells
up-regulated NF
κ
B. Thus, it was found that down-regulation of NF
κ
B primes cells for cytotoxic
agents [11].
Sarkar et al. reported that the activity of the pro-apoptotic agents cisplatin, vincristine,
doxorubicin, etoposide, Adriamycin and AraC was enhanced significantly by co-administration
of mangiferin in U-937 cells [
11
]. Unlike other antioxidants, mangiferin was not found to be toxic to
the cells, as it only enhanced cell death when exposed to TNF [11].
Oxidative damage induced by chemotherapeutic drugs correlates with the development of
secondary malignancies such as acute myeloid leukaemia (AML). Mangiferin reduces oxidative stress
induced by these agents and thus reduces likelihood of developing secondary malignancies [13].
By enhancing apoptotic activity against malignant cells upon treatment with chemotherapeutic
agents, lower dosages may be required when co-administered with mangiferin, which may reduce the
side effects associated with toxicity.
3.1.1. Oxaliplatin
Oxaliplatin is a platinum-based anti-neoplastic agent used for the treatment of colon or rectal
cancer once metastasised. It is often given in conjunction with other chemotherapeutic agents.
Common side effects, occurring in >30% of patients, include nausea, vomiting, fatigue, loss of
appetite, mouth sores, low blood count, diarrhoea and peripheral neuropathy [
85
]. Apoptotic
efficacy of oxaliplatin is enhanced by the addition of mangiferin, as mangiferin inhibits NF
κ
B (see
above) [
13
,
14
,
48
,
77
] and is thought to increase the sensitivity of malignant cells to apoptotic cell
death [48].
Du Plessis-Stoman et al. demonstrated the positive effect of mangiferin on oxaliplatin action in
HeLa cells and HT29 cells through use of IC
50
assays [
48
]. When stained with tryptan blue, cells treated
with oxaliplatin and mangiferin displayed fewer non-viable cells than those treated with oxaliplatin
only, indicating that there was less necrosis, suggesting the apoptotic pathway for cell death was
preferred [
48
]. Co-administration of mangiferin with oxaliplatin increased caspase 3 activation in HeLa
and HT29 cell lines relative to cells that only received oxaliplatin, further implicating the apoptotic
pathway of cell death was favoured, thus reducing inflammation [48].
Du Plessis-Stoman et al. have suggested that mangiferin only exhibits NF
κ
B inhibition when used
with platinum containing complexes, as they found that treatment of normal cells with mangiferin
alone resulted in increased NF
κ
B activity [
48
]. When treated with mangiferin and oxaliplatin, the
level of NF
κ
B inhibition was similar to cells treated with oxaliplatin alone. However, in the presence
of mangiferin, the oxaliplatin IC
50
was 3.4 times lower in the cells receiving both treatments [
48
].
In addition, when assessing changes in cell cycle, mangiferin caused a delay in S-phase only when
used in conjunction with oxaliplatin [
48
]. On treatment with oxaliplatin or mangiferin alone, a G
2
/M
phase cell cycle arrest was noted.
Both oxaliplatin and mangiferin are implicated in the mitochondrial pathway of apoptosis
through reduction of mitochondrial membrane potential. However, cells treated with mangiferin and
oxaliplatin did not show a significantly different mitochondrial membrane potential to those treated
with oxaliplatin alone [48].
Evidence indicates that mangiferin increases the efficacy of oxaliplatin at inducing cell death in
malignant cells.

Nutrients 2016,8, 396 18 of 25
3.1.2. Etoposide
As discussed above (Section 2.5.1 on Nrf2), mangiferin protects against etoposide induced
oxidative damage in human umbilical cord blood mononuclear cells by promoting Nrf2 signalling
to activate a number of antioxidant enzymes [
13
]. Side effects such as myelo-suppression are also
reduced. As discussed earlier, literature indicated that mangiferin causes G
2
/M phase cell cycle arrest.
Etoposide targets cells in this phase [
86
]. In addition, oxidative damage in response to etoposide may
result in p53 activation. However, when the effect of mangiferin on etoposide efficacy was studied,
HL-60 cells were used, which lack wild type p53, thus further experimentation is required to elucidate
this effect [13].
3.1.3. Doxorubicin
Louisa et al. (2014) reported that mangiferin increased the efficacy of doxorubicin in MCF-7 [
33
].
Cells were initially incubated with a low concentration of doxorubicin for 10 days. The apoptotic rate
was measured and found to be reduced, indicating the development of drug resistance. Thereafter, cells
were treated with mangiferin and at high concentrations mangiferin significantly reduced cell viability
through reduced expression of P-glycoprotein, which acts as a multidrug transporter. The efficacy of
mangiferin increased in a concentration dependent manner [
33
]. In this study it was found that mRNA
levels associated with multidrug resistance associated protein-1 and breast cancer resistance protein
were unaffected by mangiferin, unlike P-glycoprotein [33].
4. Bioavailability and Delivery of Mangiferin
Extraction, quantification, solubility and bioavailability of polyphenols, including mangiferin, are
of relevance to clinical success. Bioavailability is dependent on bioaccessibility (quantity of compound
released from the food matrix), solubility in gastrointestinal fluids, cellular uptake, compound
metabolism and efficiency of the circulatory system [
87
,
88
]. Like many other polyphenols, the optimal
health benefits of mangiferin are not fully realised due to poor water solubility and oral bioavailability
(1.2% in rats) [89].
Using HPLC-MS, Hou et al. evaluated the pharmacokinetics (PK) of mangiferin following oral
administration (0.1 g. 0.3 g and 0.9 g) in healthy male volunteers [
90
]. The point of maximum plasma
concentration (38.64 ng/mL
´1
) was at approximately 1 h, and was surprisingly low considering the
dose of 0.9 g. This outcome supports other published findings such as those reported by [
89
,
91
]
in rats. Maximal plasma concentrations, both quantity and time, were enhanced when mangiferin
was orally administered to rats as a polyherbal formulation, rather than as mangiferin alone [
92
].
Similarly, Ma et al., in a rat model, found that permeability and plasma concentrations were improved
following administration of a phospholipid complex containing mangiferin, relative to administration
of mangiferin alone [
93
]. However, in addition to whole body PK, intratumoral PK, influenced by
packing density of solid tumour cells and components of the extracellular matrix, is also important [
94
],
and these challenges could be addressed by co-formulation and innovative delivery modes.
Bioavailability can be influenced by the properties of the food matrix (composition and structure)
and hence the oral bioavailability of bioactive compounds, in this case, mangiferin could be improved
if the major limiting factors were characterised [
88
] and modes of delivery designed accordingly.
McClements et al. developed a new system for the classification of factors limiting oral bioavailability
of nutraceuticals such that the design of food matrices can be optimised for each nutraceutical.
The classification system is largely based on bioaccessibility (liberation, solubilisation and interactions),
absorption (mucus layer, bilayer permeability and tight-, active- and efflux- transporters), and
transformation (chemical degradation and metabolism) [
88
]. Such a system assists with determining
an optimal food matrix design that will maximise oral bioavailability e.g., the encapsulation of
a compound with low bilayer permeability or the addition of components that may protect a compound,
that is sensitive to metabolism, against enzymes in the gut [
88
]. Many of these characteristics need to
be assessed for mangiferin in order to improve oral bioavailability.

Nutrients 2016,8, 396 19 of 25
Encapsulation of compounds has improved PK properties in general, and is particularly suitable
for compounds such as mangiferin, that are poorly water soluble [
50
]. Spray-drying formulations
can impact on retention of mangiferin in the particle as demonstrated by the comparison of a pectin
formulation versus a chitosan polysaccharide, with pectin being found to have a better retention of
mangiferin in the particles than a chitosan formulation [
50
]. Numerous types of nanovehicles have
been developed, and many polysaccharide-based nanovehicles have been used for the delivery of
anti-cancer drugs, some of which may interact with membrane receptors. (See Caro and Pozo for
an overview on the application of polysaccharides as nanovehicles in cancer therapy [
95
]). Specialised
polysaccharide-based nanovehicles may be suitable for the delivery of mangiferin. It is clear that
further work is required with respect to improving bioavailability and delivery methods of mangiferin
from fruit or supplement to tumour site. The design of a “smart vehicle” for the delivery of mangiferin
to the tumour cells, rather than healthy cells, and for avoidance or minimisation of a delivery gradient
within the solid tumour, the “smart vehicle” will likely need to be unique to mangiferin and possibly
to the cancer type.
5. Toxicity
In addition to bioavailability and delivery of bioactive compound to enhance health, it is critical
to consider toxicity of the compound. Being a natural compound, mangiferin exhibits minimal
toxicity [
34
] and is generally regarded as non-toxic [
28
]. Stem-bark extract from Mangifera indica
has only shown toxicity in animals when injected intra-peritoneally and after acute exposure [
12
].
Mangiferin’s reported toxic dose in mice is 400 mg/kg [
28
,
50
]. In experiments involving blood
peripheral lymphocytes and hepatocytes of rats, mangiferin did not induce cytotoxicity, genotoxicity
or mutagenicity [
12
]. However, in a more recent study by Prado et al. [
96
], oral administration
of mangiferin in rodents demonstrated low acute and sub-chronic toxicity. Nonetheless, it is still
anticipated that there is a wide safety margin for this compound when taken orally [
96
]. Due to the
polyphenolic structure of mangiferin, it is likely to undergo biotransformation in the liver, and for
this reason it is suggested that further investigation into the safety of mangiferin metabolites may be
required [23].
6. Conclusions
Evidence strongly supports the link between mangiferin treatment and modulation of
many molecular pathways to prevent the development and progression of cancer. Mangiferin
is primarily implicated in down-regulating inflammation, causing cell cycle arrest, reducing
proliferation/metastasis, promoting apoptosis in malignant cells and protecting against oxidative
stress and DNA damage. Perhaps the most promising anti-proliferative effect observed on treatment
with mangiferin was that seen during
in vivo
experiments where mangiferin reduced tumour volume
to a similar extent as treatment with cisplatin. Literature consistently shows that mangiferin enhances
the efficacy of pro-apoptotic chemotherapeutic agents, with the most evidence supporting synergistic
effects with oxaliplatin, etoposide and doxorubicin. This is of particular interest when we consider
that mangiferin exhibits low toxicity and has a wide oral safety margin, unlike other compounds with
similar activity. However, the bioavailability and delivery of mangiferin requires further research
and development.
Ultimately, there is strong evidence, in a number of pathways, for a protective effect of mangiferin.
However, in some cases, there may be variation in effect due to dosage, origin of extract or cell line used.
Furthermore, low water solubility as well as low oral bioavailability are two factors that limit clinical
use at present, and further research efforts targeting appropriate delivery systems are required in order
to improve clinical efficacy. In addition, investigations into
in vivo
effects are required to determine
the significance of these results to human health. Clinical trials in humans could substantially improve
our understanding of the macroscopic effects of mangiferin. Additionally, further investigation into
mangiferin aglycone, may uncover a more sustainable way of achieving greater efficiency than that
observed with mangiferin alone.

Nutrients 2016,8, 396 20 of 25
Acknowledgments:
Funding to Fuchsia Gold-Smith from the School of Medicine Foundation. Funding to Karen
Bishop from the Auckland Cancer Society Research Center, Auckland, New Zealand.
Author Contributions:
All authors conceived of the idea, proofread and edited the manuscript.
Fuchsia Gold-Smith and Alyssa Fernandez summarised the literature and Fuchsia Gold-Smith wrote the
manuscript. Alyssa Fernandez drew the schematic diagrams and Fuchsia Gold-Smith drew the chemical structures.
Karen Bishop guided the development of the manuscript and performed the final manuscript edits.
Conflicts of Interest: The authors declare no conflict of interest.
Abbreviations
The following abbreviations are used in this manuscript:
AML acute myeloid leukaemia
ARE antioxidant response element
ATM Ataxia telangiectasia mutated protein
ATR Ataxia Telangiectasia and Rad3-related protein
ATZ aminotriazole
Bax Bcl-2 associated X protein
bcl-2 B Cell Lymphoma-2
bcl-xL B Cell Lymphoma-extra large
B(a)P benzo(a)pyrene
Bid BH3 interacting domain
BIRC7 Baculoviral IAP Repeat Containing 7
Chk1 Checkpoint kinase 1
CHk2 Checkpoint Kinase 2
CDK1 Cyclin-Dependent Kinase 1
COX Cyclooxygenase-2
CXCR4 C-X-C Chemokine Receptor type-4
DPPH 2,2-diphenyl-1-picrylhydrazyl
EMT Epithelial to Mesenchymal Transition
ERK Extracellular signal-Regulated Kinase
FADD Fas Associated Death Domain
GSH glutathione S-transferase
HO-1 heme oxygenase
H2O2hydrogen peroxide
IARC International Agency for Research on Cancer
ICAM-1 Intercellular Adhesion Molecule-1
IκB Inhibitor of κB
IKK-αInhibitor of NFκB Kinase subunit-α
IKK-βInhibitor of NFκB Kinase subunit-β
IL-1R Interleukin-1 Receptors
IL-6 Interleukin-6
IL-8 Interleukin-8
IRAK1 Interleukin-1 Receptor Activated Kinase 1
IRAK4 Interleukin-1 Receptor Activated Kinase 4
KEAP-1 Kelch-like ECH-associated protein-1
LDC Less Developed Countries
LPS lipopolysaccharide
maf musculoaponeurotic fibrosarcoma
MAPK Mitogen Activated Protein Kinase
MDCs More developed countries
MMP matrix metalloproteinase
MPP+1-methyl-4-phenylpyridine
MTT 3-(4,5-dimethyl-2-thiozolyl)-2,5-diphenyl-2H-tetrazolium bromide
Myd88 Myeloid Differentiation Primary Response Gene 88
NEMO NFκB Essential Modulator
NFκB Nuclear Factor κ-light-chain-enhancer of activated B cells
NIK NCK Interacting Kinase
NQO1 NAD(P)H: quinine reductases
Nrf2 Nuclear factor erythroid 2-Related Factor 2
PDG peptidoglycan
PK pharmacokinetics
PMA phorbol-12-myristate-13-acetate
PPAR
Review
Mangiferin and Cancer: Mechanisms of Action
Fuchsia Gold-Smith 1, Alyssa Fernandez 2 and Karen Bishop 1,*
1 Auckland Cancer Society Research Center, Faculty of Medical and Health Sciences, University of
Auckland, Private Bag 92019, Auckland 1142, New Zealand; fgol315@aucklanduni.ac.nz
2 Faculty of Medical and Health Sciences, University of Auckland, Private Bag 92019, Auckland 1142, New
Zealand; afer098@aucklanduni.ac.nz
* Correspondence: k.bishop@auckland.ac.nz; Tel.: +64-9-923-4471
Received: 20 April 2016; Accepted: 22 June 2016; Published: date
Abstract: Mangiferin, a bioactive compound derived primarily from Anacardiaceae and
Gentianaceae families and found in mangoes and honeybush tea, has been extensively studied for
its therapeutic properties. Mangiferin has shown promising chemotherapeutic and
chemopreventative potential. This review focuses on the effect of mangiferin on: (1) inflammation,
with respect to NFκB, PPARү and the immune system; (2) cell cycle, the MAPK pathway G2/M
checkpoint; (3) proliferation and metastasis, and implications on β-catenin, MMPs, EMT,
angiogenesis and tumour volume; (4) apoptosis, with a focus on Bax/Bcl ratios, intrinsic/extrinsic
apoptotic pathways and telomerase activity; (5) oxidative stress, through Nrf2/ARE signalling, ROS
elimination and catalase activity; and (6) efficacy of chemotherapeutic agents, such as oxaliplatin,
etoposide and doxorubicin. In addition, the need to enhance the bioavailability and delivery of
mangiferin are briefly addressed, as well as the potential for toxicity.
Keywords: mangiferin; cancer; inflammation; NFκB; oxidative stress; cell cycle; combination
therapy; nutraceuticals; bioavailability; hallmarks of cancer
1. Introduction
Cancer has been identified as the leading cause of non-communicable disease mortality globally [1],
and is responsible for significant morbidity and costs to healthcare systems. Cancer incidence and
mortality has been increasing at a greater rate than population growth alone could account for. The
International Agency for Research on Cancer (IARC) reported 14.1 million cases and over 8.2 million
mortalities due to cancer in 2012 compared to 10 million cases and six million mortalities in 2000 [2]
in a baseline population of 7.1 billion and 6.1 billion, respectively [3]. Much of this increase is due to
rising cancer burden in less developed countries (LDCs), with 57% of new cases, and 65% of cancer
related deaths occurring in LDCs [2]. When standardized by age, the total number of cases per 100,000
population is greater in more developed countries (MDCs) than LDCs (overall age standardized rate:
268 and 148 respectively) [4]. One exception to this pattern is infection-attributable cancers, which are
responsible for 26% of the cancer burden in LDCs but only 8% in MDCs [5].
Cancer is less likely to be identified early or treated successfully in LDCs due to reduced access
to screening tools and chemotherapeutic drugs. Previously, cancer has been regarded as a MDC
disease. However, through the adoption of a more Westernised lifestyle, cancer incidence has been
steadily increasing in LDCs. From the data published by Parkin et al., it can be seen that 40%–45% of
cancers can be attributable to lifestyle factors such as diet, smoking status, alcohol consumption and
lack of physical activity [6]. Some compounds naturally present in the diet, such as mangiferin in
mangoes and honeybush tea, are thought to modulate risk of cancer and retard cancer progression.
Mangiferin (1,3,6,7-tetrahydroxyxanthone-C2-β-D glucoside) [7–11] is a polyphenol [8,11–15]
found in many plant species, in particular, those from the Anacardiaceae [7,9,16–20] and
Gentianaceae families [7,9,13,17,18,20]. For an extensive breakdown of plant sources of mangiferin
and mangiferin content, see Matkowski et al. [21].
Nutrients 2016, 8, 396; doi:10.3390/nu8070396 www.mdpi.com/journal/nutrients
Peroxisome Proliferator-Activated Receptor
Review
Mangiferin and Cancer: Mechanisms of Action
Fuchsia Gold-Smith 1, Alyssa Fernandez 2 and Karen Bishop 1,*
1 Auckland Cancer Society Research Center, Faculty of Medical and Health Sciences, University of
Auckland, Private Bag 92019, Auckland 1142, New Zealand; fgol315@aucklanduni.ac.nz
2 Faculty of Medical and Health Sciences, University of Auckland, Private Bag 92019, Auckland 1142, New
Zealand; afer098@aucklanduni.ac.nz
* Correspondence: k.bishop@auckland.ac.nz; Tel.: +64-9-923-4471
Received: 20 April 2016; Accepted: 22 June 2016; Published: date
Abstract: Mangiferin, a bioactive compound derived primarily from Anacardiaceae and
Gentianaceae families and found in mangoes and honeybush tea, has been extensively studied for
its therapeutic properties. Mangiferin has shown promising chemotherapeutic and
chemopreventative potential. This review focuses on the effect of mangiferin on: (1) inflammation,
with respect to NFκB, PPARү and the immune system; (2) cell cycle, the MAPK pathway G2/M
checkpoint; (3) proliferation and metastasis, and implications on β-catenin, MMPs, EMT,
angiogenesis and tumour volume; (4) apoptosis, with a focus on Bax/Bcl ratios, intrinsic/extrinsic
apoptotic pathways and telomerase activity; (5) oxidative stress, through Nrf2/ARE signalling, ROS
elimination and catalase activity; and (6) efficacy of chemotherapeutic agents, such as oxaliplatin,
etoposide and doxorubicin. In addition, the need to enhance the bioavailability and delivery of
mangiferin are briefly addressed, as well as the potential for toxicity.
Keywords: mangiferin; cancer; inflammation; NFκB; oxidative stress; cell cycle; combination
therapy; nutraceuticals; bioavailability; hallmarks of cancer
1. Introduction
Cancer has been identified as the leading cause of non-communicable disease mortality globally [1],
and is responsible for significant morbidity and costs to healthcare systems. Cancer incidence and
mortality has been increasing at a greater rate than population growth alone could account for. The
International Agency for Research on Cancer (IARC) reported 14.1 million cases and over 8.2 million
mortalities due to cancer in 2012 compared to 10 million cases and six million mortalities in 2000 [2]
in a baseline population of 7.1 billion and 6.1 billion, respectively [3]. Much of this increase is due to
rising cancer burden in less developed countries (LDCs), with 57% of new cases, and 65% of cancer
related deaths occurring in LDCs [2]. When standardized by age, the total number of cases per 100,000
population is greater in more developed countries (MDCs) than LDCs (overall age standardized rate:
268 and 148 respectively) [4]. One exception to this pattern is infection-attributable cancers, which are
responsible for 26% of the cancer burden in LDCs but only 8% in MDCs [5].
Cancer is less likely to be identified early or treated successfully in LDCs due to reduced access
to screening tools and chemotherapeutic drugs. Previously, cancer has been regarded as a MDC
disease. However, through the adoption of a more Westernised lifestyle, cancer incidence has been
steadily increasing in LDCs. From the data published by Parkin et al., it can be seen that 40%–45% of
cancers can be attributable to lifestyle factors such as diet, smoking status, alcohol consumption and
lack of physical activity [6]. Some compounds naturally present in the diet, such as mangiferin in
mangoes and honeybush tea, are thought to modulate risk of cancer and retard cancer progression.
Mangiferin (1,3,6,7-tetrahydroxyxanthone-C2-β-D glucoside) [7–11] is a polyphenol [8,11–15]
found in many plant species, in particular, those from the Anacardiaceae [7,9,16–20] and
Gentianaceae families [7,9,13,17,18,20]. For an extensive breakdown of plant sources of mangiferin
and mangiferin content, see Matkowski et al. [21].
Nutrients 2016, 8, 396; doi:10.3390/nu8070396 www.mdpi.com/journal/nutrients
ROS Reactive oxygen species
SEAP Secreted Embryonic Alkaline Phosphatase

Nutrients 2016,8, 396 21 of 25
SOD superoxide
TAB1 Transforming growth factor beta-activated kinase 1-binding protein 1
TAB2 Transforming growth factor beta-activated kinase 1-binding protein 2
TAK1 Transforming growth factor beta-activated kinase 1
TLRs Toll-like receptors
TNF Tumour Necrosis Factor
TNFR Tumour Necrosis Factor Receptor
TRADD TNFR with Tumour Necrosis Factor Receptor type-1-Associated Death Domain protein
TRAF2 Tumour Necrosis Factor Receptor-Associated Factor 2
TRAF6 Tumour necrosis factor Receptor-Associated Factor 6
VEGF Vascular Endothelial Growth Factor
XIAP X linked Inhibitor of Apoptosis Protein
References
1.
WHO. In Health in 2015 from Millenium Development Goals to Sustainable Development Goals 2015.
Available online: http://www.who.int/gho/publications/mdgs-sdgs/MDGs-SDGs2015_chapter6.pdf
(accessed on 20 April 2016).
2.
Torre, L.; Bray, F.; Siegel, R.; Ferlay, J.; Lortet-Tieulent, J.; Jemal, A. Global cancer statistics 2012. Cancer J. Clin.
2015,65, 87–108. [CrossRef] [PubMed]
3.
United Nations Department of Economic and Social Affairs. World Population Prospects: The 2012 Revision,
Highlights and Advance Tables; United Nations: New York, NY, USA, 2013.
4.
World Cancer Research Fund International. Comparing More and Less Developed Countries. Available
online: http://www.wcrf.org/int/cancer-facts-figures/comparing-more-less-developed-countries
(accessed on 12 November 2015).
5. Boon, V.; Carr, J.; Klebe, S. The role of viruses in carcinogenesis. AMSJ 2013,4, 11–15.
6.
Parkin, D.M.; Boyd, L.; Walker, L.C. The fraction of cancer attributable to lifestyle and environmental factors
in the UK in 2010. Br. J. Cancer. 2011,105, S77–S81. [CrossRef] [PubMed]
7.
Rajendran, P.; Rengarajan, T.; Nishigaki, I.; Ekambaram, G.; Sakthisekaran, D. Potent chemopreventive
effect of mangiferin on lung carcinogenesis in experimental Swiss albino mice. J. Cancer Res. Ther.
2014
,10,
1033–1039. [PubMed]
8.
Lv, J.; Wang, Z.; Zhang, L.; Wang, H.L.; Liu, Y.; Li, C.; Deng, J.; Yi, W.; Bao, J.K. Mangiferin induces apoptosis
and cell cycle arrest in MCF-7 cells both in vitro andin vivo. J. Anim. Vet. Adv. 2013,12, 352–359.
9.
Rajendran, P.; Jayakumar, T.; Nishigaki, I.; Ekambaram, G.; Nishigaki, Y.; Vetriselvi, J.; Sakthisekaran, D.
Immunomodulatory effect of mangiferin in experimental animals with Benzo(a)pyrene-induced lung
carcinogenesis. Int. J. Biomed. Sci. 2013,9, 68–74. [PubMed]
10.
Hu, X.Y.; Deng, J.G.; Wang, L.; Yuan, Y.F. Synthesis and anti-tumor activity evaluation of gallic
acid-mangiferin hybrid molecule. Med. Chem. 2013,9, 1058–1062. [CrossRef] [PubMed]
11.
Sarkar, A.; Sreenivasan, Y.; Ramesh, G.T.; Manna, S.K.
β
-D-glucoside suppresses tumor necrosis
factor-induced activation of nuclear transcription factor
κ
B but potentiates apoptosis. J. Biol. Chem.
2004
,279,
33768–33781. [CrossRef] [PubMed]
12.
Rodeiro, I.; Delgado, R.; Garrido, G. Effects of a Mangifera indica L. stem bark extract and mangiferin on
radiation-induced DNA damage in human lymphocytes and lymphoblastoid cells. Cell Prolif.
2014
,47, 48–55.
[CrossRef] [PubMed]
13.
Zhang, B.-P.; Zhao, J.; Li, S.-S.; Yang, L.-J.; Zeng, L.-L.; Chen, Y.; Fang, J. Mangiferin activates Nrf2-antioxidant
response element signaling without reducing the sensitivity to etoposide of human myeloid leukemia cells
in vitro. APS 2014,35, 257–266. [PubMed]
14.
Li, H.; Huang, J.; Yang, B.; Xiang, T.; Yin, X.; Peng, W.; Cheng, W.; Wan, J.; Luo, F.; Li, H. Mangiferin exerts
antitumor activity in breast cancer cells by regulating matrix metalloproteinases, epithelial to mesenchymal
transition, and
β
-catenin signaling pathway. Toxicol. Appl. Pharmacol.
2013
,272, 180–190. [CrossRef]
[PubMed]
15.
Das, S.; Nageshwar Rao, B.; Satish Rao, B.S. Mangiferin attenuates methylmercury induced cytotoxicity
against IMR-32, human neuroblastoma cells by the inhibition of oxidative stress and free radical scavenging
potential. Chem. Biol. Interact. 2011,193, 129–140. [CrossRef] [PubMed]
16.
Xiao, J.; Liu, L.; Zhong, Z.; Xiao, C.; Zhang, J. Mangiferin regulates proliferation and apoptosis in glioma
cells by induction of microRNA-15b and inhibition of MMP-9 expression. Oncol. Rep.
2015
,33, 2815–2820.
[CrossRef] [PubMed]

Nutrients 2016,8, 396 22 of 25
17.
Zhang, B.; Zhao, J.; Li, S.; Zeng, L.; Chen, Y.; Fang, J. Mangiferin activates the Nrf2-ARE pathway and reduces
etoposide-induced DNA damage in human umbilical cord mononuclear blood cells. Pharm. Biol.
2015
,53,
503–511. [CrossRef] [PubMed]
18.
Zhao, J.; Zhang, B.; Li, S.; Zeng, L.; Chen, Y.; Fang, J. Mangiferin increases Nrf2 protein stability by inhibiting
its ubiquitination and degradation in human HL60 myeloid leukemia cells. Int. J. Mol. Med.
2014
,33,
1348–1354. [CrossRef] [PubMed]
19.
Jung, J.S.; Jung, K.; Kim, D.H.; Kim, H.S. Selective inhibition of MMP-9 gene expression by mangiferin
in PMA-stimulated human astroglioma cells: Involvement of PI3K/Akt and MAPK signaling pathways.
Pharmacol. Res. 2012,66, 95–103. [CrossRef] [PubMed]
20.
Das, J.; Ghosh, J.; Roy, A.; Sil, P.C. Mangiferin exerts hepatoprotective activity against D-galactosamine
induced acute toxicity and oxidative/nitrosative stress via Nrf2-NF
κ
B pathways. Toxicol. Appl. Pharmacol.
2012,260, 35–47. [CrossRef] [PubMed]
21.
Matkowski, A.; Ku´s, P.; Góralska, E.; Wo´zniak, D. Mangiferin—A bioactive xanthonoid, not only from mango
and not just antioxidant. Mini Rev. Med. Chem. 2013,13, 439–455. [CrossRef] [PubMed]
22.
Kavitha, M.; Nataraj, J.; Essa, M.M.; Memon, M.A.; Manivasagam, T. Mangiferin attenuates MPTP induced
dopaminergic neurodegeneration and improves motor impairment, redox balance and Bcl-2/Bax expression
in experimental Parkinson’s disease mice. Chem. Biol. Interact. 2013,206, 239–247. [CrossRef] [PubMed]
23.
Tolosa, L.; Rodeiro, I.; Donato, M.T.; Herrera, J.A.; Delgado, R.; Castell, J.V.; Gómez-Lechón, M.J.
Multiparametric evaluation of the cytoprotective effect of the Mangifera indica L. stem bark extract and
mangiferin in HepG2 cells. J. Pharm. Pharmacol. 2013,65, 1073–1082. [CrossRef] [PubMed]
24.
Zou, T.; Wu, H.; Li, H.; Jia, Q.; Song, G. Comparison of microwave-assisted and conventional extraction of
mangiferin from mango (Mangifera indica L.) leaves. J. Sep. Sci. 2013,36, 3457–3462. [PubMed]
25.
Chellan, N.; Joubert, E.; Strijdom, H.; Roux, C.; Louw, J.; Muller, C.J.F. Aqueous extract of unfermented
honeybush (Cyclopia maculata) attenuates STZ-induced diabetes and
β
-cell cytotoxicity. Planta Med.
2014
,80,
622–629. [CrossRef] [PubMed]
26.
Chavan, J.J.; Ghadage, D.M.; Kshirsagar, P.R.; Kudale, S.S. Optimization of extraction techniques and
RP-HPLC analysis of antidiabetic and anticancer drug mangiferin from roots of saptarangi (Salacia chinensis
L.). J. Liq. Chromatogr. Relat. Technol. 2015,38, 963–969. [CrossRef]
27.
Chavan, J.J.; Ghadage, D.M.; Bhoite, A.S.; Umdale, S.D. Micropropagation, molecular profiling and
RP-HPLC determination of mangiferin across various regeneration stages of Saptarangi (Salacia chinensis
L.). Ind. Crops Prod. 2015,76, 1123–1132. [CrossRef]
28.
Lei, J.; Zhou, C.; Hu, H.; Hu, L.; Zhao, M.; Yang, Y.; Chuai, Y.; Ni, J.; Cai, J. Mangiferin aglycone attenuates
radiation-induced damage on human intestinal epithelial cells. J. Cell. Biochem.
2012
,113, 2633–2642.
[CrossRef] [PubMed]
29.
Duang, X.Y.; Wang, Q.; Zhou, X.D.; Huang, D.M. Mangiferin: A possible strategy for periodontal disease to
therapy. Med. Hypotheses 2011,76, 486–488. [CrossRef] [PubMed]
30.
Kaivalya, M.; Rao, B.N.; Satish Rao, B.S. Mangiferin: A xanthone attenuates mercury chloride induced
cytotoxicity and genotoxicity in HepG2 cells. J. Biochem. Mol. Toxicol.
2011
,25, 108–116. [CrossRef] [PubMed]
31.
Barreto, J.C.; Trevisan, M.T.; Hull, W.E.; Erben, G.; de Brito, E.S.; Pfundstein, B.; Wurtele, G.; Spiegelhalder, B.;
Owen, R.W. Characterization and quantitation of polyphenolic compounds in bark, kernel, leaves, and peel
of mango (Mangifera indica L.). J. Agric. Food Chem. 2008,56, 5599–5610. [CrossRef] [PubMed]
32.
Hewavitharana, A.K.; Tan, Z.W.; Shimada, R.; Shaw, P.N.; Flanagan, B.M. Between fruit variability of the
bioactive compounds,
β
-carotene and mangiferin, in mango (Mangifera indica). Nutr. Diet.
2013
,70, 158–163.
[CrossRef]
33.
Louisa, M.; Soediro, T.M.; Suyatna, F.D.
In vitro
modulation of P-glycoprotein, MRP-1 and BCRP expression
by mangiferin in doxorubicin-treated MCF-7 cells. Asian Pac. J. Cancer Prev.
2014
,15, 1639–1642. [CrossRef]
[PubMed]
34.
Dou, W.; Zhang, J.; Ren, G.; Ding, L.; Sun, A.; Deng, C.; Wu, X.; Wei, X.; Mani, S.; Wang, Z. Mangiferin
attenuates the symptoms of dextran sulfate sodium-induced colitis in mice via NF-
κ
B and MAPK signaling
inactivation. Int. Immunopharmacol. 2014,23, 170–178. [CrossRef] [PubMed]
35.
Pan, L.L.; Wang, A.Y.; Huang, Y.Q.; Luo, Y.; Ling, M. Mangiferin induces apoptosis by regulating Bcl-2 and
bax expression in the CNE2 nasopharyngeal carcinoma cell line. Asian Pac. J. Cancer Prev.
2014
,15, 7065–7068.
[CrossRef] [PubMed]

Nutrients 2016,8, 396 23 of 25
36.
Kim, H.; Kim, H.; Mosaddik, A.; Gyawali, R.; Ahn, K.S.; Cho, S.K. Induction of apoptosis by ethanolic extract
of mango peel and comparative analysis of the chemical constitutes of mango peel and flesh. Food Chem.
2012,133, 416–422. [CrossRef] [PubMed]
37.
Ramírez-Maganda, J.; Blancas-Benítez, F.J.; Zamora-Gasga, V.M.; García-Magaña, M.d.L.; Bello-Pérez, L.A.;
Tovar, J.; Sáyago-Ayerdi, S.G. Nutritional properties and phenolic content of a bakery product substituted
with a mango (Mangifera indica)‘Ataulfo’processing by-product. Food Res. Int.
2015
,73, 117–123. [CrossRef]
38.
Yatnatti, S.; Vijayalakshmi, D.; Chandru, R. Processing and Nutritive Value of Mango Seed Kernel Flour.
Curr. Res. Nutr. Food Sci. J. 2014,2, 170–175. [CrossRef]
39.
Ajila, C.M.; Aalami, M.; Leelavathi, K.; Prasada Rao, U.J.S. Mango peel powder: A potential source of
antioxidant and dietary fiber in macaroni preparations. Innov. Food Sci. Emerg. Technol.
2010
,11, 219–224.
[CrossRef]
40.
Bandyopadhyay, K.; Chakraborty, C.; Bhattacharyya, S. Fortification of Mango Peel and Kernel Powder in
Cookies Formulation. J. Acad. Ind. Res. 2014,2, 661.
41.
García-Rivera, D.; Delgado, R.; Bougarne, N.; Haegeman, G.; Vanden Berghe, W. Gallic acid indanone and
mangiferin xanthone are strong determinants of immunosuppressive anti-tumour effects of Mangifera indica
L. bark in MDA-MB231 breast cancer cells. Cancer Lett. 2011,305, 21–31. [CrossRef] [PubMed]
42.
Zhang, B.; Fang, J.; Chen, Y. Antioxidant effect of mangiferin and its potential to be a cancer chemoprevention
agent. Lett. Drug Des. Discov. 2013,10, 239–244. [CrossRef]
43.
Telang, M.; Dhulap, S.; Mandhare, A.; Hirwani, R. Therapeutic and cosmetic applications of mangiferin:
A patent review. Expert Opin. Ther. Pat. 2013,23, 1561–1580. [CrossRef] [PubMed]
44.
Cheng, Z.Q.; Yang, D.; Ma, Q.Y.; Yi, X.H.; Zhou, J.; Zhao, Y.X. A new benzophenone from Dobinea delavayi.
Chem. Nat. Compd. 2013,49, 46–48. [CrossRef]
45.
Xu, G.A. Drug Composition for Treating 2 Type Diabetes and its Chronicity Neopathy. Google Patents EP
2070540 A1, 17 June 2009.
46.
Zhang, W.; Li, P.; Gong, Y.; Gao, X. Mangiferin Aglycone Crystal form i and Preparation Method Thereof.
Google Patents EP 2716637 A1, 9 April 2014.
47.
Ahmad, A.; Padhye, S.; Sarkar, F.H. Role of novel nutraceuticals garcinol, plumbagin and mangiferin in the
prevention and therapy of human malignancies: Mechanisms of anticancer activity. In Nutraceuticals and
Cancer; Springer: New York, NY, USA, 2012; Volume 1, pp. 179–199.
48.
Du Plessis-Stoman, D.; du Preez, J.G.H.; Van de Venter, M. Combination treatment with oxaliplatin and
Mangiferin Causes Increased Apoptosis and downregulation of NF
κ
B in cancer cell lines. AJOL
2011
,8,
177–184.
49.
Hudecová, A.; Kusznierewicz, B.; Rundén-Pran, E.; Magdolenová, Z.; Hašplová, K.; Rinna, A.; Fjellsbo, L.M.;
Kruszewski, M.; Lankoff, A.; Sandberg, W.J.; et al. Silver nanoparticles induce premutagenic DNA oxidation
that can be prevented by phytochemicals from Gentiana asclepiadea. Mutagenesis
2012
,27, 759–769.
[CrossRef] [PubMed]
50.
De Souza, J.R.R.; Feitosa, J.P.A.; Ricardo, N.M.P.S.; Trevisan, M.T.S.; de Paula, H.C.B.; Ulrich, C.M.; Owen, R.W.
Spray-drying encapsulation of mangiferin using natural polymers. Food Hydrocoll.
2013
,33, 10–18. [CrossRef]
51.
Kawpoomhae, K.; Sukma, M.; Ngawhirunpat, T.; Opanasopit, P.; Sripattanaporn, A. Antioxidant and
neuroprotective effects of standardized extracts of Mangifera indica leaf. Thai J. Pharm. Sci. 2010,34, 32–43.
52.
Peng, Z.G.; Yao, Y.B.; Yang, J.; Tang, Y.L.; Huang, X. Mangiferin induces cell cycle arrest at G2/M phase
through ATR-Chk1 pathway in HL-60 leukemia cells. Genet. Mol. Res.
2015
,14, 4989–5002. [CrossRef]
[PubMed]
53. Hanahan, D.; Weinberg, R.A. Hallmarks of cancer: The next generation. Cell 2011,144, 646–674. [CrossRef]
[PubMed]
54.
Pikarsky, E.; Porat, R.M.; Stein, I.; Abramovitch, R.; Amit, S.; Kasem, S.; Gutkovich-Pyest, E.; Urieli-Shoval, S.;
Galun, E.; Ben-Neriah, Y. NF-
κ
B functions as a tumour promoter in inflammation-associated cancer. Nature
2004,431, 461–466. [CrossRef] [PubMed]
55.
Vendramini-Costa, D.B.; Carvalho, J.E. Molecular link mechanisms between inflammation and cancer.
Curr. Pharm. Des. 2012,18, 3831–3852. [CrossRef] [PubMed]
56. Yao, J.; Hu, R.; Gou, Q.L. Inflammation and cancer. Pharm. Biotechnol. 2011,18, 372–376.
57.
Bhoj, V.G.; Chen, Z.J. Ubiquitylation in innate and adaptive immunity. Nature
2009
,458, 430–437. [CrossRef]
[PubMed]

Nutrients 2016,8, 396 24 of 25
58.
Rhyasen, G.W.; Starczynowski, D.T. IRAK signalling in cancer. Br. J. Cancer
2015
,112, 232–237. [CrossRef]
[PubMed]
59.
Tully, J.E.; Nolin, J.D.; Guala, A.S.; Hoffman, S.M.; Roberson, E.C.; Lahue, K.G.; van der Velden, J.; Anathy, V.;
Blackwell, T.S.; Janssen-Heininger, Y.M.W. Cooperation between classical and alternative NF-
κ
B pathways
regulates proinflammatory Responses in Epithelial Cells. Am. J. Respir. Cell Mol. Biol.
2012
,47, 497–508.
[CrossRef] [PubMed]
60.
Jeong, J.J.; Jang, S.E.; Hyam, S.R.; Han, M.J.; Kim, D.H. Mangiferin ameliorates colitis by inhibiting IRAK1
phosphorylation in NF-kappaB and MAPK pathways. Eur. J. Pharmacol.
2014
,740, 652–661. [CrossRef]
[PubMed]
61.
Sahoo, B.K.; Zaidi, A.H.; Gupta, P.; Mokhamatam, R.B.; Raviprakash, N.; Mahali, S.K.; Manna, S.K. A natural
xanthone increases catalase activity but decreases NF-kappa B and lipid peroxidation in U-937 and HepG2
cell lines. Eur. J. Pharmacol. 2015,764, 520–528. [CrossRef] [PubMed]
62.
Wee, Z.N.; Yatim, S.M.J.M.; Kohlbauer, V.K.; Feng, M.; Goh, J.Y.; Bao, Y.; Lee, P.L.; Zhang, S.; Wang, P.P.; Lim, E.
IRAK1 is a therapeutic target that drives breast cancer metastasis and resistance to paclitaxel. Nat. Commun.
2015,6, 8746. [CrossRef] [PubMed]
63.
DiDonato, J.A.; Mercurio, F.; Karin, M. NF-kappaB and the link between inflammation and cancer.
Immunol. Rev. 2012,246, 379–400. [CrossRef] [PubMed]
64.
Hoesel, B.; Schmid, J.A. The complexity of NF-kappaB signaling in inflammation and cancer. Mol. Cancer
2013,12, 86. [CrossRef] [PubMed]
65.
Belfiore, A.; Genua, M.; Malaguarnera, R. PPAR-agonists and their effects on IGF-I receptor signaling:
Implications for cancer. PPAR Res. 2009,2009, 18. [CrossRef] [PubMed]
66.
Vandoros, G.P.; Konstantinopoulos, P.A.; Sotiropoulou-Bonikou, G.; Kominea, A.; Papachristou, G.I.;
Karamouzis, M.V.; Gkermpesi, M.; Varakis, I.; Papavassiliou, A.G. PPAR-gamma is expressed and NF-kB
pathway is activated and correlates positively with COX-2 expression in stromal myofibroblasts surrounding
colon adenocarcinomas. J. Cancer Res. Clin. Oncol. 2006,132, 76–84. [CrossRef] [PubMed]
67. Hugo, H.J.; Saunders, C.; Ramsay, R.G.; Thompson, E.W. New Insights on COX-2 in Chronic Inflammation
Driving Breast Cancer Growth and Metastasis. J. Mammary Gland Biol.
2015
,20, 109–119. [CrossRef]
[PubMed]
68.
Mahmoud-Awny, M.; Attia, A.S.; Abd-Ellah, M.F.; El-Abhar, H.S. Mangiferin mitigates gastric ulcer in
ischemia/reperfused rats: Involvement of PPAR-
γ
, NF-
κ
B and Nrf2/HO-1 signaling pathways. PLoS ONE
2015,10, e0132497. [CrossRef] [PubMed]
69.
Santarpia, L.; Lippman, S.M.; El-Naggar, A.K. Targeting the MAPK-RAS-RAF signaling pathway in cancer
therapy. Expert Opin. Ther. Targets 2012,16, 103–119. [CrossRef] [PubMed]
70.
Li, J.; Malakhova, M.; Mottamal, M.; Reddy, K.; Kurinov, I.; Carper, A.; Langfald, A.; Oi, N.; Kim, M.O.;
Zhu, F.; et al. Norathyriol suppresses skin cancers induced by solar ultraviolet radiation by targeting ERK
kinases. Cancer Res. 2012,72, 260–270. [CrossRef] [PubMed]
71.
Shimada, M.; Nakanishi, M. DNA damage checkpoints and cancer. J. Mol. Histol.
2006
,37, 253–260.
[CrossRef] [PubMed]
72.
Mitra, J.; Enders, G.H. Cyclin A/Cdk2 complexes regulate activation of Cdk1 and Cdc25 phosphatases in
human cells. Oncogene 2004,23, 3361–3367. [CrossRef] [PubMed]
73.
Huang, H.; Nong, C.; Guo, L.; Meng, G.; Zha, X.L. The proliferation inhibition effect and apoptosis induction
of Mangiferin on BEL-7404 human hepatocellular carcinoma cell. Chin. J. Dig. 2002,6, 341–343.
74.
Wilkinson, A.S.; Taing, M.W.; Pierson, J.T.; Lin, C.N.; Dietzgen, R.G.; Shaw, P.N.; Gidley, M.J.; Monteith, G.R.;
Roberts-Thomson, S.J. Estrogen modulation properties of mangiferin and quercetin and the mangiferin
metabolite norathyriol. Food Funct. 2015,6, 1847–1854. [CrossRef] [PubMed]
75.
Dilshara, M.G.; Kang, C.H.; Choi, Y.H.; Kim, G.Y. Mangiferin inhibits tumor necrosis factor-
α
-induced matrix
metalloproteinase-9 expression and cellular invasion by suppressing nuclear factor-
κ
B activity. BMB Rep.
2015,48, 559–564. [CrossRef] [PubMed]
76.
Roy, R.; Yang, J.; Moses, M.A. Matrix metalloproteinases as novel biomarker s and potential therapeutic
targets in human cancer. J. Clin. Oncol. 2009,27, 5287–5297. [CrossRef] [PubMed]
77.
Bartoszewski, R.; Hering, A.; Marsza, M.; Hajduk, J.S.; Bartoszewska, S.; Kapoor, N.; Kochan, K.; Ochocka, R.
Mangiferin has an additive effect on the apoptotic properties of hesperidin in Cyclopia sp. tea extracts.
PLoS ONE 2014,9, e92128. [CrossRef] [PubMed]

Nutrients 2016,8, 396 25 of 25
78.
Salakou, S.; Kardamakis, D.; Tsamandas, A.C.; Zolota, V.; Apostolakis, E.; Tzelepi, V.; Papathanasopoulos, P.;
Bonikos, D.S.; Papapetropoulos, T.; Petsas, T. Increased Bax/Bcl-2 ratio up-regulates caspase-3 and increases
apoptosis in the thymus of patients with myasthenia gravis. In Vivo 2007,21, 123–132. [PubMed]
79.
Kavitha, M.; Manivasagam, T.; Essa, M.M.; Tamilselvam, K.; Selvakumar, G.P.; Karthikeyan, S.;
Thenmozhi, J.A.; Subash, S. Mangiferin antagonizes rotenone: Induced apoptosis through attenuating
mitochondrial dysfunction and oxidative stress in SK-N-SH neuroblastoma cells. Neurochem. Res.
2014
,39,
668–676. [CrossRef] [PubMed]
80.
Cheng, P.; Peng, Z.; Yang, J.; Song, S. The effect of mangiferin on telomerase activity and apoptosis in
Leukemic K562 cells. Zhong Yao Cai 2007,30, 306–309. [PubMed]
81.
Shay, J.W.; Wright, W.E. Role of telomeres and telomerase in cancer. Semin. Cancer Biol.
2012
,21, 349–353.
[CrossRef] [PubMed]
82.
Foresti, R. Anti-Inflammatory and Antioxidant Activities of Nrf2/HO-1 Activators: In Vitro Studies in Microglia and
Retinal Cells; Univesity of Catania: Paris, France, 2014.
83.
Menkovic, N.; Juranic, Z.; Stanojkovic, T.; Raonic-Stevanovic, T.; Šavikin, K.; Zduni´c, G.; Borojevic, N.
Radioprotective activity of Gentiana lutea extract and mangiferin. Phytother. Res.
2010
,24, 1693–1696.
[CrossRef] [PubMed]
84.
Valko, M.; Izakovic, M.; Mazur, M.; Rhodes, C.J.; Telser, J. Role of oxygen radicals in DNA damage and
cancer incidence. Mol. Cell. Biochem. 2004,266, 37–56. [CrossRef] [PubMed]
85.
Chemocare.com. Oxaliplatin. Available online: http://www.chemocare.com/chemotherapy/drug-info/
oxaliplatin.aspx (accessed on 2 September 2016).
86.
Schonn, I.; Hennesen, J.; Dartsch, D.C. Cellular responses to etoposide: Cell death despite cell cycle arrest
and repair of DNA damage. Apoptosis 2010,15, 162–172. [CrossRef] [PubMed]
87.
Carbonell-Capella, J.M.; Buniowska, M.; Barba, F.J.; Esteve, M.J.; Frígola, A. Analytical methods for
determining bioavailability and bioaccessibility of bioactive compounds from fruits and vegetables: A review.
Compr. Rev. Food Sci. Food Saf. 2014,13, 155–171. [CrossRef]
88.
McClements, D.J.; Li, F.; Xiao, H. The Nutraceutical Bioavailability Classification Scheme: Classifying
Nutraceuticals According to Factors Limiting their Oral Bioavailability. Ann. Rev. Food Sci. Technol.
2015
,6,
299–327. [CrossRef] [PubMed]
89.
Han, D.; Chen, C.; Zhang, C.; Zhang, Y.; Tang, X. Determination of mangiferin in rat plasma by liquid-liquid
extraction with UPLC-MS/MS. J. Pharm. Biomed. Anal. 2010,51, 260–263. [CrossRef] [PubMed]
90.
Hou, S.; Wang, F.; Li, Y.; Li, Y.; Wang, M.; Sun, D.; Sun, C. Pharmacokinetic study of mangiferin in human
plasma after oral administration. Food Chem. 2012,132, 289–294. [CrossRef] [PubMed]
91.
Liu, Y.; Xu, F.; Zeng, X.; Yang, L.; Deng, Y.; Wu, Z.; Feng, Y.; Li, X. Application of a liquid
chromatography/tandem mass spectrometry method to pharmacokinetic study of mangiferin in rats.
J. Chromatogr. B 2010,878, 3345–3350. [CrossRef] [PubMed]
92.
Kammalla, A.K.; Ramasamy, M.K.; Inampudi, J.; Dubey, G.P.; Agrawal, A.; Kaliappan, I. Comparative
Pharmacokinetic Study of Mangiferin After Oral Administration of Pure Mangiferin and US Patented
Polyherbal Formulation to Rats. AAPS PharmSciTech 2015,16, 250–258. [CrossRef] [PubMed]
93.
Ma, H.; Chen, H.; Sun, L.; Tong, L.; Zhang, T. Improving permeability and oral absorption of mangiferin by
phospholipid complexation. Fitoterapia 2014,93, 54–61. [CrossRef] [PubMed]
94.
Al-Abd, A.M.; Aljehani, Z.K.; Gazzaz, R.W.; Fakhri, S.H.; Jabbad, A.H.; Alahdal, A.M.; Torchilin, V.P.
Pharmacokinetic strategies to improve drug penetration and entrapment within solid tumors.
J. Control Release 2015,219, 269–277. [CrossRef] [PubMed]
95.
Caro, C.; Pozo, D. Polysaccharide Colloids as Smart Vehicles in Cancer Therapy. Curr. Pharm Des.
2015
,21,
4822–4836. [CrossRef] [PubMed]
96.
Prado, Y.; Merino, N.; Acosta, J.; Herrera, J.A.; Luque, Y.; Hernández, I.; Prado, E.; Garrido, G.; Delgado, R.;
Rodeiro, I. Acute and 28-day subchronic toxicity studies of mangiferin, a glucosyl xanthone isolated from
Mangifera indica L. stem bark. J. Pharm. Pharm. Res. 2015,3, 13–23.
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2016 by the authors; licensee MDPI, Basel, Switzerland. This article is an open access
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