No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
Glycyrrhetinic acid-induced permeability transition in rat liver mitochondria
Abstract
Glycyrrhetinic acid, a hydrolysis product of one of the main constituents of licorice, the triterpene glycoside of glycyrrhizic acid, when added to rat liver mitochondria at micromolar concentrations induces swelling, loss of membrane potential, pyridine nucleotide oxidation, and release of cytochrome c and apoptosis inducing factor. These changes are Ca(2+) dependent and are prevented by cyclosporin A, bongkrekic acid, and N-ethylmaleimide. All these observations indicate that glycyrrhetinic acid is a potent inducer of mitochondrial permeability transition and can trigger the pro-apoptotic pathway.
... Recently, the unusual ability of GA to enhance the activity of other drugs was discovered (Tolstikova and Bryzgalov 2009;Yang et al. 2010;Zu et al. 2013;Stakhneva et al. 2013;Yang et al. 2015;Konkina et al. 2015;Wang et al. 2016;Meteleva et al. 2018). Several mechanisms for the biological activity of GA are proposed, among them the ability of GA to interact with cell membranes and to change membrane properties (Salvi et al. 2003;Fiore et al. 2004;Harada 2005;Sapra et al. 2008;Selyutina et al. 2015Selyutina et al. , 2016aSelyutina et al. , 2016bSelyutina et al. , 2017. However, the reasons of this broad spectrum of the biological activity for GA are still under discussion. ...
... However, the detailed molecular mechanism for enhancement of drug bioavailability by these DDS, as well as the mechanism of their own biological activity is still under debate. In particular, the ability of GA and AG to interact with cell membranes and to change membrane properties was found (Salvi et al. 2003;Fiore et al. 2004;Harada 2005;Selyutina et al. 2015Selyutina et al. , 2016aSelyutina et al. , 2016bSelyutina et al. , 2017. Considering the Fig. 9 Partial density profiles of undissociated (red) and dissociated GA (blue) near a DOPC bilayer calculated along the bilayer thickness (z-axis). ...
The effect of the natural saponin glycyrrhizic acid (GA) and polysaccharide arabinogalactan (AG) on the transmembrane potential of rat thymocytes was investigated using the potential-sensitive fluorescent probe 4-(p-dimethylaminostyryl)-1-methylpyridinium (DSM). Incubation of cells with GA in micellar form resulted in a decrease of the amplitude of observed fluorescence kinetics that points out to a decrease of the transmembrane potential. The proposed mechanism is an increase of membrane ion permeability (passive ion transport) of the plasma cell membrane due to GA incorporation. The incorporation of GA molecules into the cell membrane is extremely sensitive to the degree of GA dissociation. The neutral form of glycyrrhizic acid enters the lipid bilayer in contrast to the deprotonated anionic form. The incubation of rat thymocytes with anionic form of GA, namely with its disodium salt, has no effect on the fluorescence kinetics. The possible reasons of this phenomenon are discussed in the light of the nuclear magnetic resonance (NMR) and molecular dynamics (MD) data. The treatment of thymocytes with AG affects only the initial rate of the probe incorporation. The proposed mechanism is that AG covers the surface of the cell membrane and forms a barrier for the probe. Additionally, our experiments demonstrated that both polysaccharide AG and GA in the neutral form (but not Na2GA) effectively capture the cationic probe in an aqueous solution and then deliver it to the cell membrane.
Graphic Abstract
... Apart from them current research has shown α-dihydro3, 5, 4-trihydroxy-4, 5-diiodopentenylstilbene which is a derivative of dehydrostilbene have the free radical scavenging activity [29,30]. Due the metabolism of glycyrrhizin within the gut, it has the potential to act as hydrocortisone and other corticosteroid hormones [31]. ...
... Glycyrrhetic acid can trigger proapoptotic pathway by inducing mitochondrial permeability transition. This feature can be used to induce the apoptosis of tumor cells [31,32]. The G. glabra extract can arrest G2/M cycle in tumor cells and it induces the Bcl2 phosphorylation. ...
Nature is one of the major sources of medicines since the beginning of human civilization. Different counties around the globe have been used different plant materials to overcome varieties of ailments from a simple cough to hepatitis to more complexes like SARS and most recently COVID 19. This review is an effort to emphasize the phytochemical and chemical constituents of G. glabra and their mechanisms against disease forming microorganisms. This traditional plant which is well known in Sri Lanka as "Welmi" belongs to family Leguminosae/ Fabaceae. Chemical constituents of G. glabra like isoliquiritine, isoflavones, glycyrrhetic acid, saponin, and their derivatives have been examined for their pharmacological activities. Most critical chemical compounds which isolated from the root/stem extract of the G. glabra are Glycyrrhizin and Glycyrrhetic acid. Glycyrrhizin is a prominent triterpenoid contain in Glycyrrhiza glabra which is responsible for the sweet taste of its roots. Glycyrrhizin acts as an anti-viral compound in two ways. It is able to inhibit the replication process of some RNA viruses such as SARS like corona type virus. Another process is acting as an immunostimulator. It has been used to treat patients suffering from chronic hepatitis C virus and HIV-1 patients owing to its capability of stimulating endogenous viral defense mechanisms.
... Several natural compounds have been demonstrated to be involved in the above processes, due to their activity as either anti-or pro-oxidant agents. For example, glycyrrhetinic acid, a triterpene derivative of the main component of licorice root, and the isoflavone genistein, occurring in soybean, can induce oxidative stress in isolated mitochondria as the result of their interactions with the respiratory chain [4][5][6][7][8]. ...
... *Address correspondence to this author at the Department of Biomedical Sciences, University of Padova,Viale G. Colombo, 3, 35131 Padova, Italy; Tel: +39 0498276134; Fax: +39 0498276133; E-mail: antonio.toninello@unipd.it It is noteworthy that the eudesmans, of which CDE is one, ex- hibit therapeutic properties in the treatment of diabetes, cancer and inflammation as glycyrrhetinic acid and isoflavones [5][6][7][8]. These properties are to a greater extent probably linked to the anti-or pro- oxidant action of these compounds, comparable to others such as the alkaloid caffeine and its derivatives [9], the natural yellow pig- ment curcumin [10], flavonoids [11] and polyphenols [12]. ...
Chemical study of Verbesina virgata collected in several localities afforded two eudesmane triols as 4-cinnamates. Their structures were determined by chemical and spectroscopic means. The structure and stereochemistry of one of the triols was confirmed by X-ray crystallography.
... Several natural compounds have been demonstrated to be involved in the above processes, due to their activity as either anti-or pro-oxidant agents. For example, glycyrrhetinic acid, a triterpene derivative of the main component of licorice root, and the isoflavone genistein, occurring in soybean, can induce oxidative stress in isolated mitochondria as the result of their interactions with the respiratory chain [4][5][6][7][8]. ...
... *Address correspondence to this author at the Department of Biomedical Sciences, University of Padova,Viale G. Colombo, 3, 35131 Padova, Italy; Tel: +39 0498276134; Fax: +39 0498276133; E-mail: antonio.toninello@unipd.it It is noteworthy that the eudesmans, of which CDE is one, exhibit therapeutic properties in the treatment of diabetes, cancer and inflammation as glycyrrhetinic acid and isoflavones [5][6][7][8]. These properties are to a greater extent probably linked to the anti-or prooxidant action of these compounds, comparable to others such as the alkaloid caffeine and its derivatives [9], the natural yellow pigment curcumin [10], flavonoids [11] and polyphenols [12]. ...
4β-cinnamoyloxy,1β,3α-dihydroxyeudesm-7,8-ene (CDE) extracted from Verbesina persicifolia induces bioenergetic collapse in rat liver mitochondria (RLM), monitored as a fall in the respiratory control index and ADP/O values. This fall in energy is accompanied by a protonophore effect and membrane potential (ΔΨ) collapse, demonstrating that CDE behaves as a typical uncoupling agent. However, when examining the effect of CDE in detail, we found that it acts as a "mild" uncoupler because it drops ΔΨ and increases respiratory state 4. The proposed mechanism is based on the interaction of CDE with membrane protein cytochrome C oxidase, which is implicated in proton permeability, and with the respiratory chain for the generation of reactive oxygen species which mediate and regulate the activity of the above membrane protein. Considering the energy collapse, "mild" uncoupling, and the fact that CDE is largely used in folk medicines, this extract may be viewed as a potentially effective anti-obesity drug and a natural lead compound for developing new natural uncouplers against obesity.
... For instance, glycyrrhizin was reported to increase the permeability and decrease elasticity modulus of cell membranes [14]. Similarly, glycyrrhizin was shown to induce mitochondrial permeability transition and trigger apoptosis [15]. On the other hand, glycyrrhizin has been reported to maintain normal retinal permeability and retinal capillary coverage through antiinflammatory mechanisms [16]. ...
Purpose: To investigate the mechanism of action involved in the treatment of severe burn injury with glycyrrhizinate (DG). Methods: Exosomes were purified from sera of patients with burn injury using an ultra-high-speed centrifuge, and verified by western blot. Cell proliferation and permeability were assessed using cell counting kit (CCK)-8, transepithelial-transendothelial electrical resistance (TEER), and Fluorescein Isothiocyanate (FITC) dextran assays, while immunoblotting was used for assay of the levels of p38, occluding, and zonula occludens 1 (ZO-1). Results: Serum-derived exosomes (serum-exo) significantly suppressed cell proliferation while causing hyperpermeability in HUVECs (p < 0.001). Furthermore, DG alleviated the hyperpermeability and inhibition of cell proliferation caused by serum-exo (p < 0.001). In addition, the upregulation of p-P38 induced by serum-exo decreased upon DG treatment. Interestingly, the effect of DG was blocked by anisomycin, a specific p38 activator, indicating that p38 signaling pathway may contribute to the function of DG. Conclusion: Glycyrrhizinate attenuates serum-exo-induced cell proliferation and permeability alteration via p38 signaling pathway, thereby making it a potential agent for the management of severe burn injury.
... [48] Glycyrrhetic acid promotes pro apoptotic pathway by enhancing mitochondrial permeability transition which stimulates tumor cell apopotosis. [49] Glycyrrhiza Glabra flavanoids have antioxidant effects. Glabridin an isoflavin isolated from glycyrrhiza glabra root shows antioxidant effect and also inhibits LDL oxidation induced by copper ions or mediated by Macrophages. ...
In the present era, Infectious diseases are leading causes of illness and death. The world is currently witnessing adramatic disruption of everyday life owing to rapid progression of COVID-19 disease. Hence, huge emphasis isbeing given on immunomodulatory effect of drugs which could enhance the immune system and eventually combatthe disease or infection by modulating the immune response. A significant part of Ayurvedic therapeutics aims atprevention of diseases. This is the concept of vyadhikshamatva or immunity. Immunity can be defined as thebody‟s ability to identify and resist large numbers of infectious and potentially harmful microorganisms. Animmunomodulator is a substance, biological or synthetic, which can stimulate (immunostimulants), suppress(immunosuppressors) or modulate any of the components of immune system. Many synthetic immunomodulatorsare in use but they have potential side effects like nausea, mood alterations, arthralgia, etc. Hence there is a needfor safe and potent herbal formulation. In ancient ayurvedic texts concept „Rasayana‟ (drugs reputed to enhancebody resistance) and various indigenous plants and formulations with immunomodulatory effect has beenmentioned. One such Rasayana formulation is „Punarnavadi Ghrita‟. It is a polyherbal formulation consisting ofPunarnava, Yashtimadhu, Godughda and Goghrita. This formulation is said to increase „ojas‟ in the body.According to Ayurveda, ojas is an essence present in every dhatu (tissue)and is considered as sara of all the sevendhatus starting from Rasa to Shukra and is responsible for the strength, vitality and immunity of the body. Variousresearches have been done in recent times which has further validated the immunostimulatory activity of the fourconstituents of the ghrita.
... The latter pathway is activated through changes in mitochondrial outer membrane permeabilization, membrane potential (∆Ψm) collapse, assembly of the permeability pore complex, activation of pro-apoptotic Bcl-2 proteins, release of mitochondrial pro-apoptotic factor cytochrome c (Cyt c) into cytoplasm and activation of caspases (caspase-9, caspase-7, and caspase-3) [32]. As demonstrated by Salvi et al. [33] and Fiore et al. [34], GA induces oxidative stress in liver mitochondria. In fact, GA interaction with the mitochondrial respiratory chain triggers the generation of hydrogen peroxide, which is responsible for the oxidation of critical thiols and pyridine nucleotides, with a consequent opening of the mitochondrial permeability transition pores. ...
Liver cancer is one of the most common causes of cancer mortality worldwide. Chemotherapy and radiotherapy are the conventional therapies generally employed in patients with liver tumors. The major issue associated with the administration of chemotherapeutics is their high toxicity and lack of selectivity, leading to systemic toxicity that can be detrimental to the patient’s quality of life. An important approach to the development of original liver-targeted therapeutic products takes advantage of the employment of biologically active ligands able to bind specific receptors on the cytoplasmatic membranes of liver cells. In this perspective, glycyrrhetinic acid (GA), a pentacyclic triterpenoid present in roots and rhizomes of licorice, has been used as a ligand for targeting the liver due to the expression of GA receptors on the sinusoidal surface of mammalian hepatocytes, so it may be employed to modify drug delivery systems (DDSs) and obtain better liver or hepatocyte drug uptake and efficacy. In the current review, we focus on the most recent and interesting research advances in the development of GA-based hybrid compounds and DDSs developed for potential employment as efficacious therapeutic options for the treatment of hepatic cancer.
... Moreover, it has been reported that GA interacts with the mitochondrial respiratory chain, resulting in the generation of hydrogen peroxide. The hydrogen peroxide oxidizes the thiol groups and endogenous pyridine nucleotides, leading to the opening of mitochondria permeability transition pores [123,124]. GA was functionalized onto graphene oxide (GO) and used as a nanocarrier to deliver DOX into the mitochondria of cancer cells and overcome some barriers to mitochondria delivery such as low permeability of the mitochondrial membrane (200 nm in diameter and approximately −37.6 mV in surface zeta potential). Moreover, GA is reported to exhibit antitumor activity as well [125]. ...
Mitochondria are critical subcellular organelles that produce most of the adenosine triphosphate (ATP) as the energy source for most eukaryotic cells. Moreover, recent findings show that mitochondria are not only the “powerhouse” inside cells, but also excellent targets for inducing cell death via apoptosis that is mitochondria-centered. For several decades, cancer nanotherapeutics have been designed to specifically target mitochondria with several targeting moieties, and cause mitochondrial dysfunction via photodynamic, photothermal, or/and chemo therapies. These strategies have been shown to augment the killing of cancer cells in a tumor while reducing damage to its surrounding healthy tissues. Furthermore, mitochondria-targeting nanotechnologies have been demonstrated to be highly efficacious compared to non-mitochondria-targeting platforms both in vitro and in vivo for cancer therapies. Moreover, mitochondria-targeting nanotechnologies have been intelligently designed and tailored to the hypoxic and slightly acidic tumor microenvironment for improved cancer therapies. Collectively, mitochondria-targeting may be a promising strategy for the engineering of nanoparticles for drug delivery to combat cancer.
... Taking into account the data indicating the decrease in the heart pressure under the use of GA [22], one can expect the synergistic effect of using the GA-NF complex. Several mechanisms for the biological activity of GA are proposed, and one of them is connected with the ability of GA to interact with cell membranes and to change membrane properties [23][24][25][26][27][28][29][30][31]. However, the explanation of the broad spectrum of the biological activity for GA is still under discussion. ...
Glycyrrhizic acid, or glycyrrhizin (GA), a major active component of licorice root, has been widely used in traditional Chinese and Japanese medicine since ancient times. However, only in the last decades has a novel and unusual property of the GA been discovered to form water-soluble, supramolecular complexes with a variety of lipophilic drugs. These complexes show significant advantages over other known delivery systems, in particular, due to strong pH sensitivity, the properties of GA self-associates. In the present study, a supramolecular complex formation of the hypotensive and antiarrhythmic drug nifedipine with GA has been studied at different pH values, corresponding to the different degrees of GA dissociation, including a fully dissociated state of GA. Both NMR experiments and molecular dynamics simulations demonstrate the existence of the nifedipine complex with GA at all dissociation states of GA. However, optical absorption experiments show the decrease of complex stability and solubility at pH > 6 when the GA molecule is fully deprotonated. It means the higher release rate of the drug in a neutral and basic environment compared with acid media. These results could form the basis of follow-up studies of GA self-associates as pH-controlled drug delivery systems.
... Zhang et al. used glycyrrhetinic acid-attached graphene oxide with Dox as a model drug for dual targeting to mitochondria and the cell membrane due to its ability to interact with the mitochondrial respiratory chain and high binding affinity to protein kinase C (PKC) α, which is overexpressed in certain cancer types [135][136][137]. Carbon quantum dots (CQDs) have been used as fluorescent probes for bioimaging/biolabeling and biosensing due to their stable and robust fluorescence and low toxicity [138]. ...
Mitochondria are essential cellular organelles, controlling multiple signalling pathways critical for cell survival and cell death. Increasing evidence suggests that mitochondrial metabolism and functions are indispensable in tumorigenesis and cancer progression, rendering mitochondria and mitochondrial functions as plausible targets for anti-cancer therapeutics. In this review, we summarised the major strategies of selective targeting of mitochondria and their functions to combat cancer, including targeting mitochondrial metabolism, the electron transport chain and tricarboxylic acid cycle, mitochondrial redox signalling pathways, and ROS homeostasis. We highlight that delivering anti-cancer drugs into mitochondria exhibits enormous potential for future cancer therapeutic strategies, with a great advantage of potentially overcoming drug resistance. Mitocans, exemplified by mitochondrially targeted vitamin E succinate and tamoxifen (MitoTam), selectively target cancer cell mitochondria and efficiently kill multiple types of cancer cells by disrupting mitochondrial function, with MitoTam currently undergoing a clinical trial.
... Several reports documented the anticancer efficacy of aqueous G. glabra extract and its related components in vitro [60]. For instance, glycyrrhetic acid was shown to promote the proapoptotic pathway by enhancing mitochondrial permeability transition, which, in particular, stimulates tumor cells apoptosis [61][62][63]. Methanolic licorice extract and its isolated compound, licocoumarone, were documented to stimulate the phosphorylation of BCl 2 and halt the G2/M cycle in cancer cell lines and to induce human monoblastic leukemia U937 cells apoptosis. Furthermore, hydromethanolic root extract demonstrated antimutagenic activity by suppressing the formation of micronucleus and chromosomal abnormalities in the bone marrow cells of albino mice [64,65]. ...
Traditional herbal remedies have been attracting attention as prospective alternative resources of therapy for diverse diseases across many nations. In recent decades, medicinal plants have been gaining wider acceptance due to the perception that these plants, as natural products, have fewer side effects and improved efficacy compared to their synthetic counterparts. Glycyrrhiza glabra L. (Licorice) is a small perennial herb that has been traditionally used to treat many diseases, such as respiratory disorders, hyperdipsia, epilepsy, fever, sexual debility, paralysis, stomach ulcers, rheumatism, skin diseases, hemorrhagic diseases, and jaundice. Moreover, chemical analysis of the G. glabra extracts revealed the presence of several organic acids, liquirtin, rhamnoliquirilin, liquiritigenin, prenyllicoflavone A, glucoliquiritin apioside, 1-metho-xyphaseolin, shinpterocarpin, shinflavanone, licopyranocoumarin, glisoflavone, licoarylcoumarin, glycyrrhizin, isoangustone A, semilicoisoflavone B, licoriphenone, and 1-methoxyficifolinol, kanzonol R and several volatile components. Pharmacological activities of G. glabra have been evaluated against various microorganisms and parasites, including pathogenic bacteria, viruses, and Plasmodium falciparum, and completely eradicated P. yoelii parasites. Additionally, it shows antioxidant, antifungal, anticarcinogenic, anti-inflammatory, and cytotoxic activities. The current review examined the phytochemical composition, pharmacological activities, pharmacokinetics, and toxic activities of G. glabra extracts as well as its phytoconstituents.
... Several reports documented the anticancer efficacy of aqueous G. glabra extract and its related components in vitro [60]. For instance, glycyrrhetic acid was shown to promote the proapoptotic pathway by enhancing mitochondrial permeability transition, which, in particular, stimulates tumor cells apoptosis [61][62][63]. Methanolic licorice extract and its isolated compound, licocoumarone, were documented to stimulate the phosphorylation of BCl2 and halt the G2/M cycle in cancer cell lines and to induce human monoblastic leukemia U937 cells apoptosis. Furthermore, hydromethanolic root extract demonstrated antimutagenic activity by suppressing the formation of micronucleus and chromosomal abnormalities in the bone marrow cells of albino mice [64,65]. ...
Abstract: Traditional herbal remedies have been attracting attention as a prospective alternative resource of therapy for diverse diseases across many nations. In recent decades, medicinal plants have been gaining wider acceptance due to the perception that these plants being natural products have lesser side effects and improved efficacy than their synthetic counterparts. Glycyrrhiza glabra L. (Licorice) is a small perennial herb that has been traditionally used to treat many diseases such as respiratory disorders, hyperdypsia, epilepsy, fever, sexual debility, paralysis, stomach ulcers, rheumatism, skin diseases, hemorrhagic diseases, and jaundice. Moreover, high-performance liquid chromatography (HPLC) analysis of the methanolic G. glabra extract detected the presence of several organic acids, liquirtin, rhamnoliquirilin, liquiritigenin, prenyllicoflavone A, glucoliquiritin apioside, 1-metho-xyphaseolin, shinpterocarpin, shinflavanone, licopyranocoumarin, glisoflavone, licoarylcoumarin, glycyrrhizin, isoangustone A, semilicoisoflavone B, licoriphenone, and 1-methoxyficifolinol, kanzonol R, several volatile components and essential oil. Pharmacologically, G. glabra has been examined against various microorganisms and parasites, including pathogenic bacteria, viruses, and Plasmodium falciparum and completely eradicate P. yoelii parasites. Additionally, it shows antioxidant, antifungal, anticarcinogenic, anti-inflammatory, and cytotoxic activities. The current review examines the phytochemical composition, pharmacological activities, pharmacokinetics, and toxic activities of G. glabra extracts as well as its phytoconstituents.
... 16 Additionally, another study reported that GA has an anticancer effect through the activation of pro-apoptotic pathways by inducing mitochondrial permeability transition. 17 CS, a natural polymer which is obtained from chitin through a simple deacetylation process, has been reported to have beneficial anticancer activity. Depolymerized CS products have shown the ability to inhibit angiogenesis and to induce apoptosis through DNA fragmentation. ...
Introduction
Hepatocellular carcinoma represents a major health problem with the related death numbers still increasing. Active targeting is considered an attractive choice for the development of selective therapeutics with limited side effects and improved efficiency. In this study, we report the design, development and evaluation of a novel dual-ligand functionalized core-shell chitosan-based nanocarrier for the selective delivery of doxorubicin (DOX) for treatment of hepatocellular carcinoma (HCC).
Methods
Following factorial design experiments, DOX was initially complexed with negatively charged carboxymethyl chitosan-g-poly(acrylate) and then the complex was coated with a positively charged dual-ligand (lactobionic acid and glycyrrhetinic acid)-conjugated chitosan. The developed active targeting system was then tested in vitro on Hep-G2 cells using flow cytometry and fluorescence imaging.
Results
The obtained results proved the ability of the dual-ligand system to enhance the intracellular uptake of the drug by 4-fold and 8-fold after 4 hrs and 24 hrs of incubation, respectively. The efficiency of the dual-ligand functionalized nanoparticles was also tested in vivo on Wistar rats with induced liver tumors. Testing of serum biomarkers (albumin, creatinine, urea, alpha fetoprotein, ALT, AST and ALP) in addition to histopathological microscopic examination of liver, kidney and heart tissues confirmed the enhanced safety of the developed targeted nanocarrier system compared to the conventional DOX.
Discussion
The developed targeted system showed improved intracellular drug delivery and uptake as well as enhanced safety profile. The nanoparticles were formed based on electrostatic interactions providing the flexibility that allows their use as a model for delivery of other drugs and other targets.
... It has been found that the addition of 10 μM glycyrrhetic (also known as glycyrrhitinic) acid (a metabolite of glycyrrhizic acid formed by its oral use, Fig. 3) to rat liver mitochondria leads to their loss of membrane potential, swelling of mitochondria, and the release of cytochrome C. This result indicates that glycyrrhetic acid is capable of initiating the opening of mitochondrial pores, and thus triggering a proapoptotic pathway (Salvi et al., 2003). ...
Glycyrrhizic acid is the main active component of Licorice root which has been known in traditional Chinese and Japanese medicine since ancient times. In these cultures glycyrrhizic acid (GA) is one of the most frequently used drugs. However, only in 21-st century a novel unusual property of the GA to enhance the activity of other drugs has been discovered. The review describes briefly the experimental evidences of wide spectrum of own biological activities of glycyrrhizic acid as well as discusses the possible mechanisms of the ability of GA to enhance the activity of other drugs. We have shown that due to its amphiphilic nature GA is able to form self-associates in aqueous and non-aqueous media, as well as water soluble complexes with a wide range of lipophilic drugs. The main purpose of our review is to focus reader's attention on physicochemical studies of the molecular mechanisms of GA activity as a drug delivery system (DDS). In our opinion, the most intriguing feature of glycyrrhizic acid which might be the key factor in its therapeutic activity is the ability of GA to incorporate into the lipid bilayer and to increase the membrane fluidity and permeability. The ability of biomolecules and their aggregates to change the properties of cell membranes is of great significance, from both fundamental and practical points of view.
... It has a wide range of pharmacological, antibacterial, and antioxidant features (Sharma et al. 2013). In this regard, several studies have identified the hepatoprotective (Chan et al. 2003;Jeong et al. 2002;Kimura et al. 2001), antiulcer (He et al. 2001), antiallergy (Park et al. 2004), and anticancer (Fiore et al. 2008;Salvi et al. 2003;Yoon et al. 2005) properties of this compound. Its antiviral activity against various DNA and RNA viruses (Fiore et al. 2008) has been shown in the case of HIV (De Clercq 2000) and severe acute respiratory syndrome (Cinatl et al. 2003). ...
Licorice is a well-known medicinal plant, containing various secondary metabolites of triterpenoid and phenolic families. The aim of this study is to evaluate the effect of salinity stress on the expression of key genes involved in the biosynthetic pathway of triterpenoids such as glycyrrhizin, betulinic acid, soyasaponins, and phytosterols in licorice root, as well as providing a phonemic platform to characterize antioxidant properties, glycyrrhizin, and total phenolic content. This study also includes measuring the gene expression level and glycyrrhizin content in leaves and roots of control plants. The studied genes included squalene synthase (SQS1 and SQS2), β-amyrin synthase (bAS), lupeol synthase (LUS), cycloartenol synthase (CAS), β-amyrin 11-oxidase (CYP88D6), and β-amyrin 24-hydroxylase (CYP93E6). Our results revealed that all of the mentioned genes were upregulated following the stress condition with different transcription rates. The highest increase (12-fold) was observed for the expression of the LUS gene, which is related to the betulinic acid pathway. Also, the highest content of glycyrrhizin was observed at 72 h post-treatment, which was consistent with the upregulated transcription levels of the glycyrrhizin pathway genes especially SQS1 and CYP88D6 at the same time. Correlation and stepwise regression analysis proved the key role of SQS1 gene in the biosynthetic pathway of glycyrrhizin. Antioxidant activity and phenolic content also were increased following stress condition. A comparison between the expression levels of SQS1 and other genes involved in the production of glycyrrhizin, phytosterols, and soyasaponins revealed a similar transcription trend, which shows the gene expression in the roots was significantly higher than the leaves. In contrast, SQS2 and LUS genes displayed a higher expression in leaf tissues. The genes related to betulinic acid biosynthetic pathway exhibited an expression rate different from other triterpenoid pathway genes, which could be observed in the leaves and roots of control plants and the roots of salt-treated plants. Furthermore, results showed that these two SQS genes have different expression rates due to different plant tissues (roots and leaves) and stress conditions. Importantly, in contrast to previous reports, we detected the glycyrrhizin in leaf tissues. This result may indicate the presence of a different genetic background in native Iranian licorice germplasm.
... Some specific characteristics of nanoparticles are included in Table 2. Zhang et al. (2018) described glycyrrhetinic acid (GA)attached GO with Dox as a model drug for mitochondria-targeted cancer treatment ( Figure 7A). The authors chose GA for dual targeting to mitochondria and the cell membrane due to its ability to interact with the mitochondrial respiratory chain and binding affinity to protein kinase C (PKC) α, which is overexpressed on some cancer cells (Salvi et al., 2003;Fiore et al., 2004;Stankovich et al., 2006;Wu et al., 2008). In addition, GO is known to have a large specific surface area, high stability, functionality, and an optimal size for drug delivery (Yang et al., 2013;Battogtokh and Ko, 2016). ...
The mitochondrion is an important intracellular organelle for drug targeting due to its key roles and functions in cellular proliferation and death. In the last few decades, several studies have revealed mitochondrial functions, attracting the focus of many researchers to work in this field over nuclear targeting. Mitochondrial targeting was initiated in 1995 with a triphenylphosphonium-thiobutyl conjugate as an antioxidant agent. The major driving force for mitochondrial targeting in cancer cells is the higher mitochondrial membrane potential compared with that of the cytosol, which allows some molecules to selectively target mitochondria. In this review, we discuss mitochondria-targeting ligand-conjugated anticancer agents and their in vitro and in vivo behaviors. In addition, we describe a mitochondria-targeting nanocarrier system for anticancer drug delivery. As previously reported, several agents have been known to have mitochondrial targeting potential; however, they are not sufficient for direct application for cancer therapy. Thus, many studies have focused on direct conjugation of targeting ligands to therapeutic agents to improve their efficacy. There are many variables for optimal mitochondria-targeted agent development, such as choosing a correct targeting ligand and linker. However, using the nanocarrier system could solve some issues related to solubility and selectivity. Thus, this review focuses on mitochondria-targeting drug conjugates and mitochondria-targeted nanocarrier systems for anticancer agent delivery.
... Glycyrrhizin is the most important triterpene saponin in roots and stolons of Glycyrrhiza (licorice) plant and is a conjugate of two molecules of glucuronic acid and glycyrrhetinic acid aglycone [2]. Glycyrrhizin demonstrates a wide range of pharmacological, antibacterial, hepato-protective [3,4], antiulcer, anti-allergy [5], and anticancer [6][7][8] activities as well as antiviral function against various DNA and RNA viruses [5] including HIV [9] and severe acute respiratory syndrome-associated coronavirus [10]. Biosynthesis of triterpenoids in licorice starts with conversion of two molecules, namely farnesyl diphosphate (FDP) and squalene synthase enzyme (SQS) to squalene [11]. ...
Glycyrrhiza glabra is one of the most important and well-known medicinal plants which produces various triterpene saponins such as glycyrrhizin. Beta-amyrin 11-oxidase (CYP88D6) plays a key role in engineering pathway of glycyrrhizin production and converts an intermediated beta-amyrin compound to glycyrrhizin. In this study, pBI121GUS-9:CYP88D6 construct was transferred to G. glabra using Agrobacterium rhizogene ATCC 15834. The quantitation of transgene was measured in putative transgenic hairy roots using qRT-PCR. The amount of glycyrrhizin production was measured by HPLC in transgenic hairy root lines. Gene expression analysis demonstrated that CYP88D6 was over-expressed only in one of transgenic hairy root lines and was reduced in two others. Beta-amyrin 24-hydroxylase (CYP93E6) was significantly expressed in one of the control hairy root lines. The amount of glycyrrhizin metabolite in over-expressed line was more than or similar to that of control hairy root lines. According to the obtained results, it would be recommended that multi-genes of glycyrrhizin biosynthetic pathway be transferred simultaneously to the hairy root in order to increase glycyrrhizin content.
... Glabridin has shown positive effects in fields such as malignant invasive progression in late-stage neoplastic disease, human promyelocytic leukaemia cells, human hepatoma cells etc. [6][7][8][9]. Glabridin may also trigger the proapoptotic pathway by inducing mitochondrial permeability transition and this property may be useful for inducing apoptosis of yeast cells [10,11]. Like mammalian cells, yeast cells (Saccharomyces cerevisiae and Candida albicans) undergoing apoptosis display characteristic markers such as DNA cleavage, apoptosistypical chromatin condensation, externalisation of phosphatidylserine, and cytochrome c release from mitochondria [12,13]. ...
Objectives:
The growing trend in emergence of antifungal-resistant Candida strains has recently inspired the researchers to design new antifungal agents with novel mechanisms of action. Glabridin is an originally natural substrate with multiple biological activities. Here, the antifungal effect and the possible mechanism of action of Glabridin were investigated.
Methods:
The minimum inhibitory concentrations (MIC) for Glabridin against fluconazole-resistant and fluconazole-susceptible strains of Candida were investigated using the Clinical and Laboratory Standards Institute document M27-A3 and M27-S4 as guidelines. To investigate the possible mechanism of action, the expression of two critical genes involved in yeast apoptosis process, MCA1 and NUC1, was assayed by real-time PCR.
Results:
Both fluconazole susceptible and resistant strains showed the same MICs (MIC50: 8μg/ml). Therefore a distinct azole-independent mechanism might be responsible for the inhibitory activity of Glabridin. Overexpression of MCA1 and NUC1 genes was observed in Candida cells treated with Glabridin suggesting the involvement of apoptosis signaling in Candida albicans stains exposed with Glabridin.
Conclusion:
This study suggests that Glabridin might be considered as safe agent to fight against Candida albicans strains.
... tumor cells and inhibits angiogenesis in in vivo assay, peritoneal and choreoallantonic membrane assay.[69]Glycyrrhetic acid could also trigger the pro-apoptotic pathway by inducing mitochondrial permeability transition and this property may be useful for inducing apoptosis of tumor cells.[70]Shourie et al. ...
... On the other hand, there are many reports about the anticancer effects of several derivatives of its components both in in vivo and in vitro studies. Glycyrrhetic acid could trigger the proapoptotic pathway by inducing mitochondrial permeability transition, and this property may be useful for inducing apoptosis of tumor cells [31,32]. The licorice extract induced the Bcl2 phosphorylation and G2/M cycle arrest in tumor cell lines, and 70 % methanol soluble fraction of licorice acetone extract was found to induce apoptosis in human monoblastic leukemia U937 cells. ...
Nature is an attractive source of new therapeutic candidate compounds as a tremendous chemical diversity is found in millions of species of plants, animals, marine organisms, and microorganisms as potential medicinal agents. This chapter of research is an effort to highlight the phytochemical/chemical constituents of an ancient medicinal plant G. glabra and their pharmacological importance. G. glabra is an old age medicinal plant that belongs to Leguminosae/Fabaceae/Papilionaceae family and commonly known as mulaithi in north India. The chemical composition of G. glabra is glycyrrhizin, glycyrrhetic acid, isoliquiritin, isoflavones, etc., and their derivatives have been reported for several pharmacological activities like, expectorant, antidemulcent, antiulcer, anticancer, anti-inflammatory, antidiabetic, etc. These phytochemicals hold strong promise for designing new herbal drugs, and derivatives of these compounds are being generated to evaluate their pharmacological purposes for future drug use. Natural products have been a prime source for the treatment of many forms of ailments, many of which are consumed daily with the diet. They provide significant protection against various diseases and disorders.
... It has a wide range of pharmacological, anti-bacterial and anti-oxidant activities (Varsha et al., 2013), hepato-protective (Chan et al., 2003;Jeong et al., 2002;Kimura et al., 2001), antiulcer (He et al., 2001), antiallergy (Park et al., 2004). anticancer (Fiore et al., 2004;Salvi et al., 2003;Yoon et al., 2005), antiviral activity against various DNA and RNA viruses (Fiore et al., 2008), including HIV (De Clercq, 2000 and severe acute respiratory syndrome-associated coronavirus (Cinatl et al., 2003). Biosynthesis of triterpenoids in licorice starts with conversion of two molecules farnesyl diphosphate (FDP) by the squalene synthase enzyme (SQS) to squalene (Lu et al., 2008). ...
Licorice is the roots and stolons of Glycyrrhiza uralensis which have several chemical compounds. Triterpene saponins such as glycyrrhizin and glycyrrhetinic acid and flavonoids like liquiritin, isoliquiritigenin and glabron are main compounds detected in liquorice root. The plant's major constituent is a glycyrrhizin. The β-amyrin 11-oxidase catalyzes the sequential two-step oxidation of β-amyrin in C-11 to produce 11-oxo-β-amyrin, a possible biosynthetic intermediate between β-amyrin and glycyrrhizin. In this study, the total RNA was extracted from licorice roots and cDNA synthesis, then PCR products were cloned into pTZ57R/T vector. Sequencing confirmed piece length of 1482 bp that encodes a protein of 493 amino acid residues. The results of alignment showed 99% similarity to β-amyrin sequence of Glycyrrhiza uralensis. Subcellular studies using Softberry and Psort software showed that the activity of this protein is in endoplasmic reticulum. Moreover the protein has a signal peptide and is targeted to the secretory pathway. The results of phylogenetic tree determined most similar amino acid sequence to the CYP88D subfamily of cytochrome P450. These findings can be used for nucleotide or protein manipulation and transformation.
... 1) (Krausse et al., 2004) in vivo, which is responsible for most of its pharmacological properties . It has been used in clinic as a remedy for the treatment of chronic hepatitis (Van Rossum et al., 1998), tumor (Nishino et al., 1984; Lee et al., 2008 ), and human immunodeficiency virus (HIV) infection (Hattori et al., 1989; Salvi et al., 2003). GL suppresses reproduction of some DNA and RNA viruses, including the HIV, inactivating herpes simplex virus particles irreversibly (Pompei et al., 1979; Harada et al., 1999). ...
... On the other hand, there are many studies about the anti-cancer effects of several derivatives of its components both in in vivo and in vitro studies. Glycyrrhetic acid could also trigger the pro-apoptotic pathway by inducing mitochondrial permeability transition and this property may be useful for inducing apoptosis of tumor cells [58,59]. Recently licochalcone E, a new retrochalcone from the roots of G. inflate, exhibited the most potent cytotoxic effect compared with the known antitumor agents, lichochalcone A and isoliquiritigenin [60]. ...
Objective: A review article on Glycyrrhiza glabra, A plant which have lots of medicinal properties. So it may be known as plant for the future. The present article is an effort to highlight the role of a few major constituents of this plant, which have multifaceted pharmacological actions and could be used as a template for designing new herbal medicines. Plants have been one of the important sources of medicines since the beginning of human cultivation. There is a growing demand for plant based medicines, health products, pharmaceuticals, food supplements etc. Conclusion :Glycyrrhiza glabra Linn is an old age plant used in traditional medicine across the globe for its ethanopharmacological value to cure varieties of ailments from simple cough to hepatitis to more complexes like SARS and CANCER. Glycyrrhiza glabra Linn used as a mild laxative, anti-arthritic, anti-inflammatory, antibiotic , anti-viral, anti-ulcer, anti-tissive, anti-oxidant, estrogenic, anti-diuretic, hypolipidmic agent. It is reported to contain important phytoconstituents such as glycyrrhizin, glycyrrhizinic acid, glabrin A&B, triterpene sterols, saponin, and isoflavons.
... GA is an inhibitor of some cancer cells and enzyme, such as choriocarcinoma (Gomez-Sanchez et al., 1996), melanoma (Abe et al., 1987), mastocytoma (Imanishi et al., 1989) and 11βhydroxysteroid dehydrogenase (Marandici and Monder, 1993;Monder et al., 1989). GA is a potent inducer of mitochondrial permeability transition and can trigger the pro-apoptotic pathway (Salvi et al., 2003). It can enhance the activity of hydrocortisone (Edwards and Teelucksingh, 1990) and retard the development of autoimmune disease (Horigome et al., 2001). ...
Interaction of glycyrrhetinic acid, furosemide and hydrochlorothiazide with BSA 223 SHORT COMMUNICATION ABSTRACT: Licorice is the most widely used crude drug in traditional Chinese medicine. Glycyrrhetinic acid (GA) is the metabolite of glycyrrhizic acid, which is the main bioactive ingredient of licorice. In this work, capillary electrophoresis–frontal analysis (CE–FA) was applied to study the binding of bovine serum albumin with GA and two diuretics: furosemide (FU) and hydrochlorothiazide (HZ). The binding parameters of GA were determined by Scatchard analysis, which showed that there are two kinds of binding sites in bovine serum albumin for GA. However, the results showed that the CE–FA method was not suitable for the interaction study of FU and HZ. Therefore, utracentrifugation–CE was used to probe the binding characteristic of these two drugs and the results showed only one kind of binding site for them under the studied conditions. Displacement interactions between these drugs were also investigated by utracentrifugation–CE method and the results showed that GA hardly displaces HZ while it can slightly displace FU and FU can slightly displace HZ. For comparison, the binding of these drugs was also studied by the fluorescence quenching method and the data were processed by the Stern–Volmer quenching equation. Results showed that the binding constants were basically consistent for two methods for all drugs studied. The number of binding sites on one protein molecule was well consistent for FU and HZ while it was quite different for GA.
... Nejnovějším mechanizmem objasňujícím antikarcinogenní působení je skutečnost, že GA indukuje mitochodriální bobtnání (swelling), což společně se změnou potenciálu a uvolněním proapoptogenních proteinů vede ke smrti transformovaných buněk (93). ...
... The in vitro anti-cancer activity of 18b-glycyrrhetinic acid (GA) is well documented. [1][2][3] In addition, various GA derivatives display higher in vitro anti-cancer activity than GA itself, [4] and their mechanisms of action include proapoptotic, [5] antiproliferative [6] and anti-angiogenic [7] activity, among others. Several GA derivatives also target mitochondrial membrane permeability [8] and downregulate H-Ras activity [9] and beta-actin protein expression [10] in cancer cells. ...
The plasma pharmacokinetic profile in CD-1 mice of a novel 18β-glycyrrhetinic acid (GA) derivative, which displays in vitro anti-cancer activity, was assessed.
This study involved an original one-step synthesis of N-(2-{3-[3,5-bis(trifluoromethyl)phenyl]ureido}ethyl)-glycyrrhetinamide, (2) a compound that displays marked anti-proteasome and anti-kinase activity. The bioselectivity profile of 2 on human normal NHDF fibroblasts vs human U373 glioblastoma cells was assessed. Maximal tolerated dose (MTD) profiling of 2 was carried out in CD1 mice, and its serum pharmacokinetics were profiled using an acute intravenous administration of 40 mg/kg body weight.
Compound 2 displayed IC(50) in vitro growth inhibitory concentrations of 29 and 8 μm on NHDF fibroblasts and U373 glioblastoma cells, respectively, thus a bioselectivity index of ∼4. The intravenous pharmacokinetic parameters revealed that 2 was rapidly distributed (t(1/2dist) of ∼3 min) but slowly eliminated (t(1/2elim) = ∼77 min).
This study describes an original and reliable nanoemulsion of a GA derivative with both anti-proteasome and anti-kinase properties and that should be further tested in vivo using various human xenograft or murine syngeneic tumour models with both single and chronic intravenous administration.
... 1) (Krausse et al., 2004) in vivo, which is responsible for most of its pharmacological properties . It has been used in clinic as a remedy for the treatment of chronic hepatitis (Van Rossum et al., 1998), tumor (Nishino et al., 1984; Lee et al., 2008 ), and human immunodeficiency virus (HIV) infection (Hattori et al., 1989; Salvi et al., 2003). GL suppresses reproduction of some DNA and RNA viruses, including the HIV, inactivating herpes simplex virus particles irreversibly (Pompei et al., 1979; Harada et al., 1999). ...
Glycyrrhizin is a well known pharmacologically bioactive natural glycoside. Glycyrrhizin (GL) has been widely used as a therapeutic agent for chronic active liver diseases. Glycyrrhetinic acid is an aglycone and an active metabolite of glycyrrhizin. This study is the first attempt to locate the binding sites of glycyrrhizin and glycyrrhetinic acid to RNA. The effect of the ligand complexation on RNA aggregation was investigated in aqueous solution at physiological conditions, using constant RNA concentration (6.25 mM) and various ligand/polynucleotide (phosphate) ratios of 1/280, 1/240, 1/120, 1/80, 1/40, 1/20, 1/10, 1/5, 1/2 and 1/1. Fourier transform infrared (FTIR) and UV-Visible spectroscopic methods as well as molecular modeling were used to determine the ligand binding modes, the binding constants, and the stability of ligands-RNA complexes in aqueous solution. Spectroscopic evidence showed that glycyrrhizin and glycyrrhetinic acid bind RNA via G-C and A-U base pairs as well as the backbone phosphate group with overall binding constants of K(GL-RNA)=3.03×10(3)M(-1), K(GA-RNA)=2.71×10(3)M(-1). The affinity of ligands-RNA binding is in the order of glycyrrhizin>glycyrrhetinic acid. RNA remains in the A-family structure, while biopolymer aggregation occurred at high triterpenoid concentrations.
Nature is a tremendous source of many bioactive compounds and provides us with many herbal plants with therapeutic properties. Therefore, the demand of herbal plants and its constituents is always in the rise. Glycyrrhiza glabra is considered to be one of the most useful plants across the world for its ethnopharmacological values. It consists of various pharmacological activities including anti-cancer activity. Extracts and bioactive components of Glycyrrhiza glabra are reported for their anti-cancer activity by inducing apoptosis, mitochondrial permeability transition, suppressing micronucleus formation, inhibiting angiogenesis, etc. in various human cancer cell lines, viz. HeLa, MCF-7, MDA-MB-231, Caco-2, and PC3. Proteins targeted by Glycyrrhiza glabra for anti-cancer activity include MKK4, MKK7, JNK1, mTOR, GSK-β, Akt, NF-κB, MAP kinases, and Cdk2 which result in decreased carcinogenesis. This chapter examines about the chemistry and mechanism of various extracts and bioactive constituents of Glycyrrhiza glabra against different cancers.Keywords
Glycyrrhiza glabra
CancerExtractBioactive componentsMechanism
Nephrotoxicity is the dose-limiting factor of cisplatin treatment. Magnesium isoglycyrrhizinate (MgIG) has been reported to ameliorate renal ischemia–reperfusion injury. This study aimed to investigate the protective effect and possible mechanisms of MgIG against cisplatin-induced nephrotoxicity from the perspective of cellular pharmacokinetics. We found that cisplatin predominantly accumulated in mitochondria of renal tubular epithelial cells, and the amount of binding with mitochondrial DNA (mtDNA) was more than twice that with nuclear DNA (nDNA). MgIG significantly lowered the accumulation of cisplatin in mitochondria and, in particular, the degree of target-binding to mtDNA. MgIG notably ameliorated cisplatin-induced changes in mitochondrial membrane potential, morphology, function, and cell viability, while the magnesium donor drugs failed to work. In a mouse model, MgIG significantly alleviated cisplatin-caused renal dysfunction, pathological changes of renal tubules, mitochondrial ultrastructure variations, and disturbed energy metabolism. Both in vitro and in vivo data showed that MgIG recovered the reduction of NAD+-related substances and NAD+-dependent deacetylase sirtuin-3 (SIRT3) level caused by cisplatin. Furthermore, SIRT3 knockdown weakened the protective effect of MgIG on mitochondria, while SIRT3 agonist protected HK-2 cells from cisplatin and specifically reduced platinum-binding activity with mtDNA. In conclusion, MgIG reduces the target-binding amount of platinum to mtDNA and exerts a protective effect on cisplatin-induced renal injury through SIRT3, which may provide a new strategy for the treatment of cisplatin-induced nephrotoxicity.
Triterpenoids are potential antibiotic substances present in plants Kingdome. Some of them have very sweet taste ranging between 30 and 400 times sweeter than sucrose. Four such natural important non saccharide super sweet (NSSS) principles are mentioned below.
Programmed cell death protein 1 (PD-1)/Programmed Cell Death Ligand 1 (PD-L1) blockade immunotherapy has emerged as a promising strategy to treat both solid and hematological malignancies. Despite the considerable therapeutic effects obtained in pre-clinical and clinical studies, PD-1/PD-L1 blockade therapy is still limited by the low benefit rates and a large number of patients still do not respond to this treatment. In this study, we developed a highly efficient and cancer-specific immunogenic cell death nanoinducer for effective tumor immunotherapy. A leukocyte membrane coated poly (lactic-co-glycolic acid) encapsulating glycyrrhetinic acid (GCMNPs) was developed to enhance targeting, tumor-homing capacity, and reduce toxicity in vivo. GCMNPs could induce ferroptosis in acute myeloid leukemia and colorectal cancercells by downregulating glutathione-dependent peroxidases 4, leading to increased lipid peroxidation levels. Moreover, GCMNPs and ferumoxytol could synergistically enhance Fe-dependent cytotoxicity through the Fenton reaction. Finally, in vivo studies showed that GCMNPs synergized with ferumoxytol and anti-PD-L1 synergistically improve T-cell immune response against leukemia and colorectal tumor. This study anticipated that the combination of glycyrrhetinic acid-based nanomaterials and ferrotherapy would provide further insights into anti-cancer immune response to PD-1/PD-L1 blockade for both solid and hematological malignancies.
Statement of Significance
Despite the considerable therapeutic effects obtained in pre-clinical and clinical studies, PD-1/PD-L1 blockade therapy is still limited by the low benefit rates and a large number of patients still do not respond to this treatment. We designed a glycyrrhetinic acid-based nanoplatform as a new ICD inducer (GCMNPs), with high cancer cell specificity and reduced toxicity to AML and CRC. GCMNPs cooperates with ferumoxytol to promote a Fenton reaction and induce ferroptosis. Moreover, the combination of GCMNPs and ferumoxytol enhanced the blockage of PD-1/PD-L1 to activate T cells, subsequently generating a systemic immune response in CRC and AML mouse models. This pre-clinical findings provide the proof-of-concept of combination of glycyrrhizic acid-based nanomaterials and ferrotherapy as an “ICD nano-inducer” and immunotherapeutic agent for treating cancer.
Liver diseases related complications represent a significant source of morbidity and mortality worldwide, creating a substantial economic burden. Oxidative stress, excessive inflammation, and dysregulated energy metabolism significantly contributed to liver diseases. Therefore, discovery of novel therapeutic drugs for the treatment of liver diseases are urgently required. Licorice is one of the most commonly used herbal drugs in Traditional Chinese Medicine for the treatment of liver diseases and drug-induced liver injury (DILI). Various bioactive components have been isolated and identified from the licorice, including glycyrrhizin, glycyrrhetinic acid, liquiritigenin, Isoliquiritigenin, licochalcone A, and glycycoumarin. Emerging evidence suggested that these natural products relieved liver diseases and prevented DILI through multi-targeting therapeutic mechanisms, including anti-steatosis, anti-oxidative stress, anti-inflammation, immunoregulation, anti-fibrosis, anti-cancer, and drug-drug interactions. In the current review, we summarized the recent progress in the research of hepatoprotective and toxic effects of different licorice-derived bioactive ingredients and also highlighted the potency of these compounds as promising therapeutic options for the treatment of liver diseases and DILI. We also outlined the networks of underlying molecular signaling pathways. Further pharmacology and toxicology research will contribute to the development of natural products in licorice and their derivatives as medicines with alluring prospect in the clinical application.
Licorice (or “liquorice”) is one of most widely used in foods, herbal medicine, and extensively researched medicinal plants of the world. In traditional medicine licorice roots have been used against treating many ailments including lung diseases, arthritis, kidney diseases, eczema, heart diseases, gastric ulcer, low blood pressure, allergies, liver toxicity, and certain microbial infections. Licorice extract contains sugars, starch, bitters, resins, essential oils, tannins, inorganic salts, and low levels of nitrogenous constituents such as proteins, individual amino acids, and nucleic acids. A large number of biological active compounds have been isolated from Glycyrrhiza species, where triterpene saponins and flavonoids are the main constitutes which show broad biological activity. This review examines recent studies on the phytochemical and pharmacological data and describes some side effects and toxicity of licorice and its bioactive components.
The beneficial effects of liquorice in treating chills, colds, and coughs have been fully discussed in Ayurveda, as well as in the texts of ancient Egyptians, Greeks, and Romans. The plant has been prescribed for dropsy during the period of famous Hippocrates. The reason being that it was quite helpful as thirst-quenching drugs (Biondi et al. in J Nat Prod 68:1099–1102, 2005; Mamedov and Egamberdieva in Herbals and human health-phytochemistry. Springer Nature Publishers, 41 pp, 2017). No doubt, the clinical use of liquorice in modern medicine started around 1930; Pedanios Dioscorides of Anazarba (Adana), first century AD-Father of Pharmacists, mentions that it is highly effective in the treatment of stomach and intestinal ulcers. In Ayurveda, people in ancient Hindu culture have used it for improving sexual vigor.
Mitochondria-mediated apoptosis (MMA) is a preferential option for cancer therapy due to the presence of cell-suicide factors in mitochondria, however, low permeability of mitochondria is a bottleneck for targeting drug delivery. In this paper, glycyrrhetinic acid (GA), a natural product from Glycyrrhiza glabra, is found to be a novel mitochondria targeting ligand, which can improve mitochondrial permeability and enhance the drug uptake of mitochondria. GA-functionalized graphene oxide (GO) is prepared and used as an effective carrier for targeted delivery of doxorubicin into mitochondria. The detailed in vitro and in vivo mechanism study shows that GA-functionalized GO causes a decrease in mitochondrial membrane potential and activates the MMA pathway. The GA-functionalized drug delivery system demonstrates highly improved apoptosis induction ability and anticancer efficacy compared to the non-GA-functionalized nanocarrier delivery system. The GA-functionalized nanocarrier also shows low toxicity, suggesting that it can be a useful tool for drug delivery.
Ethnopharmacological relevance:
Fuzi, the processed lateral root of Aconitum carmichaelii Debeaux, is a traditional Chinese medicine used for its analgesic, antipyretic, anti-rheumatoid arthritis and anti-inflammation effects; however, it is also well known for its toxicity. Gancao, the root of Glycyrrhiza uralensis Fisch., is often used concurrently with Fuzi to alleviate its toxicity. However, the mechanism of detoxication is still not well clear.
Aim of the study:
In this study, the effect of Gancao on the metabolic changes induced by Fuzi was investigated by NMR-based metabonomic approaches.
Materials and methods:
Fifty male Wistar rats were randomly divided into five groups (group A: control, group B: Fuzi decoction alone, group C: Gancao decoction alone, group D: Fuzi decoction and Gancao decoction simultaneously, group E: Fuzi decoction 5h after Gancao decoction) and urine samples were collected for NMR-based metabolic profiling analysis. Statistical analyses such as unsupervised PCA, t-test, hierarchical cluster, and pathway analysis were used to detect the effects of Gancao on the metabolic changes induced by Fuzi.
Results:
The behavioral and biochemical characteristics showed that Fuzi exhibited toxic effects on treated rats (group B) and statistical analyses showed that their metabolic profiles were in contrast to those in groups A and C. However, when Fuzi was administered with Gancao, the metabolic profiles became similar to controls, whereby Gancao reduced the levels of trimethylamine N-oxide, betaine, dimethylglycine, valine, acetoacetate, citrate, fumarate, 2-ketoglutarate and hippurate, and regulated the concentrations of taurine and 3-hydroxybutyrate, resulting in a decrease in toxicity. Furthermore, important pathways that are known to be involved in the effect of Gancao on Fuzi, including phenylalanine, tyrosine and tryptophan biosynthesis, the synthesis and degradation of ketone bodies, and the TCA cycle, were altered in co-treated rats.
Conclusions:
Gancao treatment mitigated the metabolic changes altered by Fuzi administration in rats, demonstrating that dosing with Gancao could reduce the toxicity of Fuzi at the metabolic level. Fuzi and Gancao administered simultaneously resulted in improved toxicity reduction than when Gancao was administrated 5h prior to Fuzi. In summary, co-administration of Gancao with Fuzi reduces toxicity at the metabolic level.
Licorice (Gan-Cao) is a perennial herb of Fabaceae family cultivated mainly in Shanxi, Gansu and Xinjiang regions of China. “Gan” of licorice in Chinese means umami taste of licorice, therefore, licorice is an important constituent in many traditional Chinese medicine (TCM) to reduce the bitter taste of other herbal medicine. The height of licorice plant for medicinal use is 30–100 cm. The medicinal part of licorice is the cylinder root and underground stem with a diameter of approximately 3–4 cm.
Mitochondria are known to be the main players in important mitochondrial bioenergetic functions such as ATP synthesis, thermoregulatory energy dissipation, Ca2+ transport, generation of reactive oxygen species and mediation of intrinsic apoptosis. Naturally occurring polyamines, due to their high pka are almost completely protonated at physiological pH and behave as polycations in their interactions with mitochondrial membranes. Thanks to these interactions, polyamines are transported electrophoretically into the mitochondrial matrix, where they exhibit a number of effects of significant importance for the above-mentioned mitochondrial functions, particularly inner membrane permeability transition (MPT). This event is closely correlated with the intrinsic occurrence of apoptosis, so that the effect of polyamine interactions with mitochondria has important implications in the pathophysiological consequences of inducing apoptosis, i.e., protection against cancer and neurodegenerative diseases. This review also provides some answers to the old debated problems regarding the possible interactions of polyamines with mitochondrial DNA, overcoming of the Born charging energy by spermine, the ΔΨ threshold value for polyamine transport, and protection of MPT by spermine in in vivo conditions. In conclusion, the old question: "What do polyamines do?" is partially solved.
A serious flaw of many chemotherapeutics employed now for the (post-surgery) treatment of malignant tumors is their high cytotoxicity against vital organs. In addition, tumor cells that survive chemotherapy often show pronounced drug resistance against a wide range of therapeutics. Recently, glycyrrhetinic acid derivatives derived from a cheap and easy-to-obtain natural product have attracted pharmacological interest. Many derivatives of glycyrrhetinic acid showed good to excellent cytotoxicity and inhibited the proliferation of a wide range of human tumor cells. They act predominantly by apoptosis, thus making them an interesting and even fascinating starting point for the development of selective, effective and safe antitumor active drugs.
Pentacyclic triterpenoids comprise a largest class of natural products, bearing several biological activities, among them anticancer activity. This chapter strolls through the antitumor properties of betulin, betulinic acid, oleanolic acid, glycyrrhetinic acid, ursolic acid, and their derivatives. Within each section is presented the most relevant properties that contribute to the antitumor activity of the referred natural triterpenoids and their semisynthetic derivatives. These compounds are potential candidates for the development of more efficient anticancer or cancer preventive drugs, and the semisynthetic derivatives produced so far can shed some light on the path to follow to obtain such compounds.
Glycyrrhiza glabra (licorice) has been known to possess various pharmacological properties including anti-inflammatory, antioxidants, antiviral, and hepatoprotective activities. Magnesium isoglycyrrhizinate (MgIG), a magnesium salt of 18-α glycyrrhizic acid stereoisomer, is clinically used for the treatment of inflammatory liver diseases. However, the mechanism by which MgIG exerts its anti-inflammatory effects remains unknown. In the present study, we investigated the inhibitory potential of MgIG in phospholipase A2 (PLA2)/arachidonic acid (AA) pathway and release of the pathway-generated inflammatory lipid mediators in RAW264.7 macrophages. Results revealed that MgIG suppressed LPS-induced activation of PLA2 and production of AA metabolites such as prostaglandin E2 (PGE2), prostacyclin (PGI2), thromboxane 2 (TXB2), and leukotrienes (LTB4) in macrophages. Furthermore, LPS-induced AA-metabolizing enzymes including COX-2, COX-1, 5-LOX, TXB synthase, and PGI2 synthase were significantly inhibited by MgIG. Taken together, our data suggest that modulation of cyclooxygenase (COXs) and 5-lipoxygenase (LOX) pathways in AA metabolism could be a novel mechanism for the anti-inflammatory effects of MgIG.
Ethnopharmacological relevance:
Aconitum carmichaelii Debx. (Fuzi), a commonly use traditional Chinese medicine (TCM), has often been used in combination with Rhizoma Glycyrrhizae (Gancao) to reduce its toxicity due to diester diterpenoid alkaloids aconitine, mesaconitine, and hypaconitine. However, the mechanism of detoxication is still unclear. Glycyrrhetinic acid (GA) is the metabolite of glycyrrhizinic acid (GL), the major component of Gancao. In present study, the effect of GA on the changes of metabolic profiles induced by mesaconitine was investigated using NMR-based metabolomic approaches.
Materials and methods:
Fifteen male Wistar rats were divided into a control group, a group administered mesaconitine alone, and a group administered mesaconitine with one pretreatment with GA. Their urine samples were used for NMR spectroscopic metabolic profiling. Statistical analyses such as orthogonal projections to latent structures-discriminant analysis (OPLS-DA), t-test, hierarchical cluster, and pathway analysis were used to detect the effects of pretreatment with GA on mesaconitine-induced toxicity.
Results:
The OPLS-DA score plots showed the metabolic profiles of GA-pretreated rats apparently approach to those of normal rats compared to mesaconitine-induced rats. From the t-test and boxplot results, the concentrations of leucine/isoleucine, lactate, acetate, succinate, trimethylamine (TMA), dimethylglycine (DMG), 2-oxo-glutarate, creatinine/creatine, glycine, hippurate, tyrosine and benzoate were significantly changed in metabolic profiles of mesaconitine-induced rats. The disturbed metabolic pathways include amino acid biosynthesis and metabolism.
Conclusions:
GA-pretreatment can mitigate the metabolic changes caused by mesaconitine-treatment on rats, indicating that prophylaxis with GA could reduce the toxicity of mesaconitine at the metabolic level.
Close inspection of human ovarian cancer cells A2780 in the course of an antitumor screening using maslinic acid analogs revealed for one of the compounds, 4-oxa-4-phenyl-butyl 2,3-dihydroxy-olean-12-en-28-oate (1), an unusual behavior. During the incubation of the cells with 1, at the perimeter of the cells or close by crystals were formed consisting of cholesterol and excess 1. Compound 1 was incorporated into the cell's membrane followed by an extrusion of cholesterol from the lipid rafts. As a consequence of the alterations of the cell membrane, a volume decrease was initiated that triggered apoptosis; this extends previous models on apoptosis initiating mechanisms.
Glycyrrhic acid (GA) and liquiritin are the two classes of bioactive components in licorice with known pharmacological effects. In our study, different methods were compared to separate GA an-d liquiritin. Solid-phase extraction (SPE) method was verified to separate GA and liquiritin effectively. The method is fast, easy, reliable, and inexpensive; especially in the quality control. Moreover, we built a new method to determine glycyrrhizic acid and liquiritin simultaneously using reversed phase high performance liquid chromatography (RP-HPLC) In the HPLC analyze, gradient elution and two wavelength were used . The regression line for GA was y =15340.6x+12.81, the regression for liquiritin line was y =9269.1x+20.63, The recovery rates were 101.3% and 99.4%; RSD were 1.01% and 0.92%.
Abstract New oleanane alcohols and their acetates were prepared using classical reductive reagents (LiAlH4, NaBH4, and B2H6-DMS). In this research, we also studied the influence of these reagents on the stereoselectivity of reduction. All compounds
prepared were fully characterized by 1H and 13C NMR spectra, IR spectra, MS, and elemental analysis. These products were tested for cytotoxic activity against T-lymphoblastic
leukemia (CEM), human erythromyeloblastoid leukemia (K562), and human melanoma (SK-MEL1) cell lines. One of the compounds
prepared exhibits significant cytotoxic activity against the mesenchymal type of cancer cell lines.
Graphical abstract
The interaction of 18β-glycyrrhetinic acid (GA): The metabolite of glycyrrhizic acid which is the main active component of a commonly used traditional Chinese medicine (TCM) Glycyrrhiza Uralensis Fisch with bovine serum albumin (BSA) has been investigated. Fluorescence emission spectra of serum albumin in the presence of GA, recorded at the excitation wavelength 280 nm, clearly show that GA act as quencher and have different quenching mechanism at a pH below or above the isoelectric point (pI). The binding sites number n and apparent binding constant K were measured. The thermodynamic parameters ΔH°, ΔG°, ΔS° at different temperatures were calculated. The effects of some common metal ions on binding are considered. Synchronous fluorescence and UV–vis spectra were used to study protein conformation. Energy transfer between GA and HSA was calculated by Förster's theory and the binding site was suggested to be site II. The binding of monoammonium glycyrrhizinate (GL) to BSA is also compared.
One of the most characteristic phenotypes of rapidly growing cancer cells is their propensity to catabolize glucose at high
rates. Type II hexokinase, which is expressed at high levels in such cells and bound to the outer mitochondrial membrane,
has been implicated as a major player in this aberrant metabolism. Here we report the isolation and sequence of a 4.3-kilobase
pair proximal promoter region of the Type II hexokinase gene from a rapidly growing, highly glycolytic hepatoma cell line
(AS-30D). Analysis of the sequence enabled the identification of putative promoter elements, including a TATA box, a CAAT
element, several Sp-1 sites, and response elements for glucose, insulin, cAMP, Ap-1, and a number of other factors. Transfection
experiments with AS-30D cells showed that promoter activity was enhanced 3.4-, 3.3-, 2.4-, 2.1-, and 1.3-fold, respectively,
by glucose, phorbol 12-myristate 13-acetate (a phorbol ester), insulin, cAMP, and glucagon. In transfected hepatocytes, these
same agents produced little or no effect. The results emphasize normal versus tumor cell differences in the regulation of Type II hexokinase and indicate that transcription of the Type II tumor gene
may occur independent of metabolic state, thus, providing the cancer cell with a selective advantage over its cell of origin.
After accumulation of a Ca2+ load, the addition of uncoupler to respiring rat liver mitochondria is followed by opening of the permeability transition pore (MTP), a voltage-dependent channel sensitive to cyclosporin A. The channel's voltage threshold is profoundly affected under conditions of oxidative stress, with a shift to more negative values that may cause MTP opening at physiological membrane potentials. In this paper we further clarify the mechanisms by which oxidative agents affect the apparent voltage dependence of the MTP. We show that two sites can be experimentally distinguished. (i) A first site is in apparent oxidation-reduction equilibrium with the pyridine nucleotide (PN) pool (NADH/NAD + NADPH/NADP); PN oxidation is matched by increased MTP open probability under conditions where the glutathione pool is kept in the fully reduced state; this site can be blocked by N-ethylmaleimide but not by monobromobimane, a thiol-selective reagent. (ii) A second site coincides with the oxidation-reduction-sensitive dithiol we have recently identified (Petronilli, V., Costantini, P., Scorrano, L., Colonna, R., Passamonti, S., and Bernardi, P. (1994) J. Biol. Chem. 269, 16638-16642); dithiol cross-linking at this site by arsenite or phenylarsine oxide is matched by increased MTP open probability under conditions where the PN pool is kept in the fully reduced state; at variance from the first, this site can be blocked by both N-ethylmaleimide and monobromobimane and is probably in equilibrium with the glutathione pool. Based on these findings, we reassess the mechanisms by which many oxidative agents affect the MTP and resolve conflicting reports on the relative role of PN and glutathione oxidation in the permeability transition within the framework of MTP (dys)regulation at two separate sites.
Scientific revolution [1] implies a transformation of the world view in which a dominant paradigm is substituted by a new one, one which furnishes an ameliorated comprehension of facts, as well as an advantage for the design of informative experiments. Apoptosis research has recently experienced a change from a paradigm in which the nucleus determined the apoptotic process to a paradigm in which mitochondria constitute the center of death control. Several pieces of evidence imply mitochondria in the process of apoptosis. Kinetic data indicate that mitochondria undergo major changes in membrane integrity before classical signs of apoptosis become manifest. These changes concern both the inner and the outer mitochondrial membranes, leading to a disruption of the inner transmembrane potential (DeltaPsim) and the release of intermembrane proteins through the outer membrane. Cell-free systems of apoptosis demonstrate that mitochondrial products are rate limiting for the activation of caspases and endonucleases in cell extracts. Functional studies indicate that drug-enforced opening or closing of the mitochondrial megachannel (also called permeability transition pore) can induce or prevent apoptosis. The anti-apoptotic oncoprotein Bcl-2 acts on mitochondria to stabilize membrane integrity and to prevent opening of the megachannel. These observations are compatible with a three-step model of apoptosis: a premitochondrial phase during which signal transduction cascades or damage pathways are activated; a mitochondrial phase, during which mitochondrial membrane function is lost; and a post-mitochondrial phase, during which proteins released from mitochondria cause the activation of catabolic proteases and nucleases. The implication of mitochondria in apoptosis has important consequences for the understanding of the normal physiology of apoptosis, its deregulation in cancer and degenerative diseases, and the development of novel cytotoxic and cytoprotective drugs.
Mineralocorticoid receptor (MR) selectivity for aldosterone is thought to be exerted by enzymes which inactivate competing glucocorticoids before they bind the receptor. Two different 11β-hydroxysteroid dehydrogenases (11β-HSD) have been described. 11β-HSD-1 is NADP+-dependent and has a Km in the micromolar range and bidirectional activity. 11β-HSD-2 is NAD+-dependent, has a Km in the nanomolar range, exhibits only oxidase activity, and colocalizes with the MR in the kidney, so is likely to serve as the gatekeeper for the MR. We have further characterized 11β-HSD activity in JEG-3 cells, a cell line derived from a human choriocarcinoma which was reported to have only the high affinity, NAD+-dependent 11β-HSD-2. We found that the Km for the conversion of corticosterone to 11-dehydrocorticosterone in intact cells and homogenates was about 16 nM. NAD+-dependent corticosterone conversion was equal in the nuclear and mitochondrial fractions and less, but significant, in the microsomal fraction. A high affinity, Km = 40 nM, NADP+-dependent enzyme was also found in homogenates. The subcellular distribution of this high affinity activity was greatest in the mitochondria, less in the nuclei, and even less, but still significant, in microsomes. Because of its cofactor dependency, high affinity, and different subcellular distribution, we suggest that this enzyme is neither the 11β-HSD-1 nor the 11β-HSD-2 and have named it 11β-HSD-3. Conversion of 11-dehydrocorticosterone to corticosterone did not occur in intact cells or in homogenates incubated with NADH or NADPH. Enzyme activity in intact cells was inhibited by glycyrrhetinic acid, carbenoxolone, progesterone, 5β-dihydroprogesterone, and 5α-dihydroprogesterone, but not bile acids.
Tumour cell mitochondria often have a high Ca2+ threshold for induction of the mitochondrial permeability transition (MPT). The mechanisms of inhibited MPT are briefly reviewed. MPT stimulates the release of cytochrome c and apoptosis-inducing factor (AIF) from mitochondria. This is central in the signal pathways leading to apoptosis. Inhibited apoptosis may lead to excessive cell proliferation while induced apoptosis is the aim of cancer therapies. Also cell death by necrosis may result from impaired mitochondrial function due to MPT and the resulting decrease in cellular ATP levels. Many prooxidants trigger cell death by inducing MPT. Tumour cells may have greater resistance to prooxidants and free radicals formed also in radiation therapy. One mechanism for the inhibition of MPT could be increased expression of the Bcl-2 protein in tumour cells. We found this to be the case in Zajdela hepatoma mitochondria. Another mechanism could be the increased contents of Mg2+ in tumour mitochondria, since Mg2+ is an inhibitor of MPT. This was found to be the case in Ehrlich ascites tumour cell mitochondria. Other contributing factors could be inhibition of phospholipase A2 by the Mg2+, changes in the amounts and properties of the adenine nucleotide translocator and/or mitochondrial ATP synthase.
The membrane potential of mitochondria was estimated from the accumulation of tetraphenyl phosphonium (TPP+), which was determined with the TPP+-selective electrode developed in the present study. The preparation and some operational parameters of the electrode were described. The kinetics for uptake by mitochondria of TPP+ and DDA+ (dibenzyldimethyl ammonium) were analyzed, and it was found that TPP+ permeated the mitochondrial membrane about 15 times faster than DDA+. The final amounts of accumulation of TPP+ and DDA+ by mitochondria were approximately equal. For the state-4 mitochondria, the membrane potential was about 180 mV (interior negative). Simultaneous measurements of TPP+-uptake and oxygen consumption showed that the transition between states 3 and 4 was detectable by use of the TPP+-electrode. After the TPP+-electrode showed that state-4 was reached, the extra-mitochondrial phosphorylation potential was measured. The difference in pH across the membrane was measured from the distribution of permeant anion, acetate, so as to calculate the proton electrochemical potential. The ratio of extra-mitochondrial phosphorylation potential to proton electro-chemical potential, n was close to 3. This value of n was also found to be 3 when ATP was hydrolyzed under the condition that the respiratory chain was arrested. The implication that n = 3 was discussed.
A sensitive method is described for the simultaneous determination of glycyrrhizin and glycyrrhetic acid in human plasma. Quantitation is by high-performance liquid chromatography using ion-pair chromatography on a reversed-phase column. Variable-wavelength ultraviolet detection is employed. For the extraction of both compounds from plasma, a new solid-phase ion-pair extraction procedure using octadecylsilane columns was developed. Because of the strong forces involved in the protein binding of glycyrrhizin, quantitative extraction of this compound from plasma was possible only after an alkaline pH shift. A considerable improvement in selectivity and sensitivity was obtained by automated column switching involving on-line preseparation of the solid-phase extract on a short precolumn and chromatographic analysis of a heart-cut from the precolumn eluate. The limit of detection of both glycyrrhizin and glycyrrhetic acid was 0.1 mg/l in 0.5 ml of plasma. From a preliminary study in human volunteers, it was concluded that glycyrrhetic acid rather than glycyrrhizin is preferred in a study in human volunteers to assess the zero effect level of glycyrrhizin.
Glycyrrhizin and its analogues were screened for antihepatotoxic activity by in vitro assay methods using carbon tetrachloride (CCl4)-and galactosarnine-induced cytotoxicity in primary cultured rat hepatocytes. Structure-activity relationship in these substances is discussed. The mechanism of inhibitory activity of glycyrrhizin and glycyrrhetinic acid in CCl4-produced liver damage was investigated by determining the effects of these substances on the initial steps in the sequence of events leading to liver lesion, revealing that anti-oxidative action plays an important part in the antihepatotoxic activity.
1 Liver-protective drugs, Part 14. Also Part 65 in the Tohoku University series on the validity of Oriental medicines.
The effect of the flavonoids flavone, flavanone and quercetin on parietal cell acid production, H+/K(+)-ATPase activity, gastric mucosal prostaglandin E2 biosynthesis and Helicobacter pylori growth was studied. All flavonoids inhibited acid production in isolated parietal cells in response to histamine and dibutyryl-cAMP stimulation (IC50 values between 26 and 139 mumol/l) and inhibited H+/K(+)-ATPase activity. Inhibition of H+/K(+)-ATPase activity was dependent on the ATP concentration. Fluorescence measurements showed that flavanone reacts with ATP. These findings indicate that the inhibitory action of flavonoids on H+/K(+)-ATPase activity is related to their ability to complex ATP. Flavone and flavanone (10 and 100 mumol/l) stimulated prostaglandin E2 production in isolated gastric mucosal cells. Furthermore, the compounds inhibited Helicobacter pylori growth in a concentration-dependent manner. From these finding it appears that flavonoids are a group of compounds which could have a therapeutic potential for treatment of gastrointestinal diseases associated with Helicobacter pylori infection.
18 beta-Glycyrrhetinic acid (GRA) represents a major metabolite of glycyrrhizic acid (glycyrrhizin), an important constituent of licorice and licorice root, and is a potent inhibitor of 11 beta-hydroxysteroid dehydrogenase (11 beta OHSD). Different oral doses of GRA (500, 1000, or 1500 mg) were administered to healthy volunteers in order to study its kinetics and dynamics. In agreement with the lipophilic nature of GRA, with a biphasic decay of the plasma concentration-time curve at doses greater than 500 mg. The mean (+/-SEM) half-life of the second elimination phase was 11.5 +/- 1.2 h after 1000 mg GRA and 38.7 +/- 10.5 h after 1500 mg GRA (P < 0.05). The peak plasma concentration and the area under the plasma concentration-time curve (AUC) increased with increasing GRA doses. Urinary elimination of GRA and GRA glucuronides over 24 h was less than 1% of the dose administered. The dynamics of GRA were assessed by measuring the activity of the 11 beta OHSD in vivo, as reflected by the cortisol and cortisone concentrations in plasma. With increasing doses of GRA, the cortisone concentration declined, and the cortisol/cortisone ratio increased. Both peak plasma concentration and AUCs of GRA correlated with changes in the AUC values of cortisone. Based on the single dose kinetics, the kinetic/dynamic analysis of the data revealed that after multiple doses of 1.5. g GRA/day, the 11 beta OHSD might be constantly inhibited, whereas at daily doses of 500 mg or less, such an inhibition might occur only transiently.
11 beta-Hydroxysteroid dehydrogenase (11 beta HSD) is responsible for the interconversion of cortisol to cortisone [corticosterone (B) to 11-dehydrocorticosterone in rodents] and confers ligand specificity to the mineralocorticoid receptor. Inhibition of 11 beta HSD by licorice derivatives [glycyrrhizic and glycyrrhetinic (GE) acids] results in cortisol/B and not aldosterone acting as a potent mineralocorticoid. 11 beta HSD is ubiquitously expressed and, by converting active glucocorticoid to inactive metabolites, may be an important prereceptor regulator of ligand access to the glucocorticoid receptor (GR). To investigate this further, we have studied the effect of 11 beta HSD inhibition by licorice derivatives on PRL gene expression (a known glucocorticoid target gene) in rat pituitary GH3 cells. Glycyrrhizic acid administration to rats in vivo (75 mg/kg.day for 5 days) resulted in inhibition of 11 beta HSD activity, as previously reported, but also a significant reduction in steady state 11 beta HSD mRNA levels in both predominantly mineralocorticoid (kidney and distal colon) and glucocorticoid (liver and pituitary) target tissues. In vitro, 11 beta HSD mRNA and activity were present in rat pituitary GH3 cells (81% conversion of B to 11-dehydrocorticosterone/4 x 10(6) cells after 24-h incubation) and inhibited by GE in a dose-dependent fashion. While B or GE alone (10(-8)-10(-5) M) had little or no effect on PRL mRNA levels or immunoassayable PRL, combinations of GE plus B resulted in marked inhibition of PRL mRNA levels and secretion, to such an extent that a concentration of 10(-6) M B with 10(-6) M GE was more potent than equimolar concentration of the synthetic GR agonist RU 28362. This inhibitory effect on PRL mRNA levels was blocked by a 10-fold excess of the GR antagonist RU 38486, but not by a 10-fold excess of the mineralocorticoid receptor antagonist RU 26752, confirming that this potentiation of glucocorticoid hormone action was operating through the GR and not the mineralocorticoid receptor. In addition to its established role as a competitive inhibitor of 11 beta HSD, licorice results in pretranslational inhibition of 11 beta HSD both in vitro and in vivo. 11 beta HSD is clearly an important mechanism in regulating tissue levels of active glucocorticoid and, hence, ligand supply to the GR.
We investigated the mitochondrial toxicity of the lipophilic cation, MKT-077, and the role of mitochondria in selective malignant cell killing by this compound by examining the effect of MKT-077 on mitochondrial structure and function in treated cells and in isolated organelles. Results of this study demonstrate changes in mitochondrial ultrastructure that are induced by MKT-077 treatment in carcinoma cells but not in similarly treated normal epithelial cells. In addition, MKT-077 was found to inhibit respiratory activity in isolated intact mitochondria and electron transport activity in freeze-thawed mitochondrial membrane fragments in a dose-dependent manner. The concentration of MKT-077 necessary to obtain half-maximal inhibition of ADP-stimulated respiration was approximately 4-fold greater in mitochondria isolated from cells of the normal epithelial cell line, CV-1 (15 micrograms MKT-077/mg protein), as compared to the human colon carcinoma cell line, CX-1 (4 micrograms MKT-077/mg protein). Further, the data show a selective loss of mitochondrial DNA in CX-1 and CRL1420 cells (carcinoma) but not CV-1 cells (normal epithelial) treated with 3 microgram/ml MKT-077 for up to 3 days. Under the same conditions, nuclear DNA was unaffected in all three cell lines. The sensitivity of the cell lines tested to mitochondrial damage by MKT-077 correlates well with their sensitivity to cytotoxicity by MKT-077. These results demonstrate selective mitochondrial damage by MKT-077 at the cellular, biochemical, and molecular levels and suggest that selective effects on mitochondrial structure and function may provide a basis for the selective malignant cell killing exhibited by this compound.
MKT-077 (formerly known as FJ-776) is a newly synthesized, highly water-soluble ( > 200 mg/ml) rhodacyanine dye that exhibits significant antitumor activity in a variety of model systems. In culture, MKT-077 inhibits the growth of five human cancer cell lines (colon carcinoma CX-1, breast carcinoma MCF-7, pancreatic carcinoma (CRL 1420, bladder transitional cell carcinoma EJ, and melanoma LOX) but not monkey kidney CV-1, an indicator cell line for normal epithelial cells. In nude mice, MKT-077 inhibits the growth of s.c. implanted human renal carcinoma A498 and human prostate carcinoma DU145 and prolongs the survival of mice bearing i.p. implanted human melanoma LOX (tumor:control = 344%). Subcellular localization indicates that MKT-077 is taken up and retained by mitochondria, and flow cytometric analysis suggests that CX-1 cells take up MKT-077 to a much greater extent than CV-1 cells. Quantitation of MKT-077 uptake by ethanol extraction shows that CX-1 cells accumulate 65-fold more MKT-077 than do CV-1 cells. MKT-077 is the first delocalized lipophilic cation with a favorable pharmacological and toxicological profile in preclinical studies. MKT-077 is now being investigated in Phase I clinical trials.
Polyphenolic flavonoids are powerful antioxidants. In the present study we investigated the antioxidative activity against low-density-lipoprotein (LDL) oxidation of a not yet studied subclass of polyphenols, the isoflavans, which are present in licorice alcoholic extract. The study was performed in humans as well as in atherosclerotic apolipoprotein E-deficient mice (E zero), because their LDL is highly susceptible to oxidation. LDL oxidation was induced by incubating it with copper ions as well as with the aqueous or lipid-soluble free radical generators 2,2'-azobis'2-amidino propane hydrochloride (AAPH) and 2,2'-azobis 2,4-dimethylvaleronitrile (AMVN), respectively. The extent of LDL oxidation was determined by measuring the formation of conjugated dienes, thiobarbituric acid reactive-substances (TBARS), and lipid peroxides. By all methods in human studies, licorice ethanolic extract as well as a pure material, which was identified by gas chromatography-mass spectroscopy as the isoflavan glabridin, were shown to inhibit LDL oxidation by a mechanism involving scavenging of free radicals. In an ex vivo study, LDL isolated from the plasma of 10 normolipidemic subjects who were orally supplemented for 2 wk with 100 mg licorice/d was more resistant to oxidation than was LDL isolated before licorice supplementation. Dietary supplementation of each E zero mouse with licorice (200 micrograms/d) or pure glabridin (20 micrograms/d) for 6 wk resulted in a substantial reduction in the susceptibility of their LDL to oxidation along with a reduction in the atherosclerotic lesion area. These results could be related to the absorption and binding of glabridin to the LDL particle and subsequent protection of the LDL from oxidation by multiple modes as shown in humans and in E zero mice.
Scientific revolution [1] implies a transformation of the world view in which a dominant paradigm is substituted by a new one, one which furnishes an ameliorated comprehension of facts, as well as an advantage for the design of informative experiments. Apoptosis research has recently experienced a change from a paradigm in which the nucleus determined the apoptotic process to a paradigm in which mitochondria constitute the center of death control. Several pieces of evidence imply mitochondria in the process of apoptosis. Kinetic data indicate that mitochondria undergo major changes in membrane integrity before classical signs of apoptosis become manifest. These changes concern both the inner and the outer mitochondrial membranes, leading to a disruption of the inner transmembrane potential (DeltaPsim) and the release of intermembrane proteins through the outer membrane. Cell-free systems of apoptosis demonstrate that mitochondrial products are rate limiting for the activation of caspases and endonucleases in cell extracts. Functional studies indicate that drug-enforced opening or closing of the mitochondrial megachannel (also called permeability transition pore) can induce or prevent apoptosis. The anti-apoptotic oncoprotein Bcl-2 acts on mitochondria to stabilize membrane integrity and to prevent opening of the megachannel. These observations are compatible with a three-step model of apoptosis: a premitochondrial phase during which signal transduction cascades or damage pathways are activated; a mitochondrial phase, during which mitochondrial membrane function is lost; and a post-mitochondrial phase, during which proteins released from mitochondria cause the activation of catabolic proteases and nucleases. The implication of mitochondria in apoptosis has important consequences for the understanding of the normal physiology of apoptosis, its deregulation in cancer and degenerative diseases, and the development of novel cytotoxic and cytoprotective drugs.
Glycyrrhizin (GL) was hydrolyzed to glycyrrhetic acid (GA), glycyrrhetic acid mono-beta-D-glucuronide (GAMG) or both by glucuronidases in various organs of rat. GL beta-D-glucuronidase I, hydrolyzing GL to GA; GAMG beta-D-glucuronidase, hydrolyzing GAMG to GA; and 3alpha-hydroxyglycyrrhetinate (3alpha-hydroxyGA) dehydrogenase, oxidizing 3alpha-hydroxyGA to 3-oxo-GA were found in the organs of this animal. GL beta-D-glucuronidase II was distributed in the lysosomal fraction of all organs except brain; 3alpha-hydroxyGA dehydrogenase was distributed in the microsomal fraction of the liver; but other enzymes were distributed in the nuclear, lysosomal, microsomal and soluble fractions of a variety of organs. GL beta-D-glucuronidase I, GL beta-D-glucuronidase II and GAMG beta-D-glucuronidase activities in a mixture of lysosomes and microsomes of rat liver exhibited different patterns on hydroxyapatite column chromatography. These results showed the metabolic pathways of GL to be of two types: a beta-D-glucuronidase hydrolyzing GL to GA, and the other consisting of two different beta-D-glucuronidases hydrolyzing GL to GAMG and GAMG to GA.
It has been proposed that glycyrrhetinic acid (GA) enhances endogenous glucocorticoid (GC) action by suppressing the metabolism of the steroid. We show here that marked involution of the thymus occurred within 24 h of a single intraperitoneal administration of GA in mice. Thymocytes from mice treated with GA exhibited DNA cleavage and mitochondrial transmembrane potential disruption, as demonstrated with agarose gel electrophoresis and flow cytometric analysis. Immunocytochemical staining revealed that CD4(+)CD8(+) double positive cells markedly decreased after GA treatment. In contrast to GA in vivo, GA in vitro did not induce apoptosis of cultured thymocytes. These findings suggest that the apoptosis-inducing effect of GA on thymocytes is due to its indirect action. Because GA has been known to inhibit 11beta-hydroxysteroid dehydrogenase (11beta-HSD), we measured the enzyme activity in major organs and endogenous corticosterone concentration after GA treatment. The results showed a significant decrease of 11beta-HSD activity (P < 0.0001) and an increase in serum corticosterone concentration (P < 0.005). We concluded that the inhibition of hepatic 11beta-HSD activity by GA has a serious effect on GC metabolism, which results in a significant elevation of systemic GC levels. Apoptosis of thymocytes occurred as a consequence of the elevation in the level of endogenous corticosterone.
To the Editor: Extracts of licorice root are widely used in many countries as flavoring agents, breath fresheners, or candy. The active component of licorice is glycyrrhizic acid, which is hydrolyzed in vivo to glycyrrhetinic acid. The well-known mineralocorticoid-like effect of licorice results from the inhibition of 11β-hydroxysteroid dehydrogenase, the enzyme that catalyzes the conversion of cortisol to cortisone, thereby minimizing the binding of cortisol to mineralocorticoid receptors.1 Licorice may also directly activate mineralocorticoid receptors.2 In vitro, licorice can block 17β-hydroxysteroid dehydrogenase, which catalyzes the conversion of androstenedione to testosterone.3 We evaluated the effect of licorice on gonadal function in . . .
Licorice, the root of Glycyrrhiza spp. (Fabaceae), has been used since ancient Egyptian, Greek, and Roman times in the West and since the Former Han era (the 2nd-3rd century B.C.) in ancient China in the East. In traditional Chinese medicine, licorice is one of the most frequently used drugs. In Japan, the oldest specimen of licorice introduced from China in the middle of the 8th century still exists in Shosoin, the Imperial Storehouse, in Nara. Extracts of licorice were recommended as a remedy for gastric ulcer by Revers of the Netherlands in 1946, which was soon withdrawn owing to its side effects. Carbenoxolon sodium, glycyrrhetinic acid (GA) hemisuccinate Na, was prepared from licorice to treat peptic ulcer in the UK. In Japan for the past 60 years, a glycyrrhizin (GL) preparation under the name of Stronger Neo-Minophagen C (SNMC) has been used clinically as an antiallergic and antihepatitis agent. GL and GA sometimes induce edema, hypertension, and hypokalemia in patients treated with higher doses and long-term administration. The mechanism of this side effect, pseudoaldosteronism, has been explained as due to the 11-hydroxy-steroid dehydrogenase inhibitory activity of GL and GA. The excess of endogenous cortisol produced combines with the renal mineral corticoid receptor, which promotes an aldosterone-like action. GL and GA reduce alanine transaminase (ALT) and aspartate transaminase (AST) values in the serum. This hepatoprotective effect has recently been explained as the inhibitory effects of GL and GA on immune-mediated cytotoxicity against hepatocytes and on nuclear factor (NF)-kappa B, which activates genes encoding inflammatory cytokines in the liver. To exclude the side effects and enhance the therapeutic activities, chemical modification of GL and GA has been performed. Deoxoglycyrrhetol (DG), homo- and heteroannular diene homologs of dihemiphthalates, showed a remarkable improvement in antiinflammatory, antiallergic, and antiulcer activities in animal experiments. Immunomodulating effects of GL, GA, and DG derivatives, which induce interferon-gamma and some other cytokines, have been demonstrated in relation with their antiviral activities. Antiinflammatory, antitumorigenic, and antimalarial effects of licorice flavonoids have also been investigated.
Glycyrrhetinic acid (GA) is known to inhibit glucocorticoid metabolism inhibiting 11beta-hydroxysteroid dehydrogenase (11beta-HSD). Moreover, GA administration to mice has been shown to affect the lymphoid organs through elevation of endogenous corticosterone concentration. The effect of GA administration on thymus has been demonstrated to show that considerable amounts of thymocytes undergo apoptosis by elevated levels of corticosterone in systemic circulation. However, the effect of GA administration on peripheral lymphocytes has remained unknown. In our current study, we demonstrated that a significant involution of spleen as well as thymus occurred within 24 h of a single administration of GA in mice. In addition, a flow cytometric analysis of the splenocytes taken from mice treated with GA showed a significant increase in the number of apoptotic cells which exhibited translocated phosphatidylserine outside the plasma membrane. Furthermore, considerable inhibition of 11beta-HSD activity in GA-treated mice was observed in liver and spleen, resulting in a significant increase in concentration of corticosterone in the blood. These facts showed that the apoptosis of splenocytes was the result of indirect effect of GA through elevated levels of corticosterone. We confirmed this using cultured splenocytes in vitro where no apoptotic effect of GA was observed. We concluded that GA administration induces cell death of not only thymocytes that are naive to corticosterone, but also splenocytes that are usually stable to its physiological concentrations.
Licorice root is one of the oldest and most frequently employed botanicals in Chinese medicine. In the United States, licorice products are most often used as flavoring and sweetening agents in food products. Constituents of licorice include triterpenoids, such as glycyrrhizin and its aglycone glycyrrhizic acid, various polyphenols, and polysaccharides. A number of pharmaceutical effects of licorice are known or suspected (anti-inflammatory, antivirus, antiulcer, anticarcinogenesis, and others). Licorice and its derivatives may protect against carcinogen-induced DNA damage and may be suppressive agents as well. Glycyrrhizic acid is an inhibitor of lipoxygenase and cyclooxygenase, inhibits protein kinase C, and downregulates the epidermal growth factor receptor. Licorice polyphenols induce apoptosis in cancer cells. These and other activities of licorice are reviewed, and a rationale is suggested for combinations of agents in preventive clinical trials.
The history of licorice as an officinal plant dates back thousands of years, and licorice is still appreciated as a medicinal root. Many of its endocrine properties can be derived from observations of Authors of the ancient world, when hormones were not known. Inappropriate use of licorice can produce pseudoaldosteronism, by inactivating 11beta-hydroxysteroiod-dehydrogenase and by binding to mineralocorticoid receptors. Licorice possesses many other therapeutic properties as to potentiate the action of cortisol, to reduce testosterone synthesis, especially in women, to exert an estrogen-like activity and to reduce body fat mass. The chronological development of research on these effects is described.
Stronger Neo-Minophagen C (SNMC) is an intravenous drug with glycyrrhizin as the principal ingredient. The efficacy and safety of SNMC at two doses were evaluated on 194 patients with chronic hepatitis B in nine hospitals in China. They all had serum levels of alanine aminotransferase (ALT) exceeding twice the upper limit of normal (>80 IU/l). SNMC daily 100 and 40 ml were given for 4 weeks to the patients randomized into Group A (N=99) and Group B (N=95), respectively. Thereafter, all patients received oral glycyrrhizin (GLYCYRON Tab) 9 tablets a day for an additional 4 weeks. Primary end-point was ALT<1.5 times the upper limit of normal (60 IU/l) at completion of the 8-week therapy, and it was achieved by 73 patients (74%) in Group A and 74 (79%) patients in Group B; normalization of ALT levels (<40 IU/l) was accomplished in 58 (58%) and 54 (57%) patients in Groups A and B, respectively. SNMC was withdrawn in four (2%) patients due to mild and reversible side effects. Based on these results, SNMC is safe and efficacious in lowering or normalizing ALT levels in patients with chronic hepatitis B in China, and an induction dose of 40 ml daily is efficient in achieving maximal effects.
The history of licorice, as a medicinal plant, is very old and has been used in many societies throughout the millennia. The active principle, glycyrrhetinic acid, is responsible for sodium retention and hypertension, which is the most common side-effect. We show an effect of licorice in reducing body fat mass. We studied 15 normal-weight subjects (7 males, age 22-26 yr, and 8 females, age 21-26 yr), who consumed for 2 months 3.5 g a day of a commercial preparation of licorice. Body fat mass (BFM, expressed as percentage of total body weight, by skinfold thickness and by bioelectrical impedance analysis, BIA) and extracellular water (ECW, percentage of total body water, by BIA) were measured. Body mass index (BMI) did not change. ECW increased (males: 41.8+/-2.0 before vs 47.0+/-2.3 after, p<0.001; females: 48.2+/-1.4 before vs 49.4+/-2.1 after, p<0.05). BFM was reduced by licorice: (male: before 12.0+/-2.1 vs after 10.8+/-2.9%, p<0.02; female: before 24.9+/-5.1 vs after 22.1+/-5.4, p<0.02); plasma renin activity (PRA) and aldosterone were suppressed. Licorice was able to reduce body fat mass and to suppress aldosterone, without any change in BMI. Since the subjects were consuming the same amount of calories during the study, we suggest that licorice can reduce fat by inhibiting 11beta-hydroxysteroid dehydrogenase Type 1 at the level of fat cells.
Short BCH codes for multimedia communication are examined in a typical fast fading channel. In adverse fading channel, burst errors degrade the quality of transmission badly. Generally, long BCH codes and large interleaving degree are adopted to improve the performance of system, thus causing inevitable long delay, which sometimes is fatal to multimedia data. We propose to employ short BCH codes (n<32) with medium interleaving depth on static images compressed by discrete-cosine-transformation (DCT), a widely used compression method in multimedia data. The structure of coding meets the rigorous delay request of multimedia communication. Simulation results amply demonstrate the validity of the proposed scheme in fading environment. The aspects of delay and reliability are both satisfied.
Determination of serum proteins by means of the biuret method
- Ag Gornall
- Cj
- David
- Mm
Gornall AG, Bardawill CJ, David MM. Determination of serum proteins by means of the biuret method. J Biol Chem 1949;177: 751–66.
Membrane potential of mitochondria measured with an electrode sensitive to tetraphenyl Fig
- N Kamo
- M Muratsugu
- R Hongoh
- Kobatake
Kamo N, Muratsugu M, Hongoh R, Kobatake Y. Membrane potential of mitochondria measured with an electrode sensitive to tetraphenyl Fig.