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The gastroprotective potential of silibinin against Helicobacter pylori infection and gastric tumor cells
Abstract
Aims
Silibinin is the major component of flavonolignans complex mixture (Silymarin), which is obtained from Silybum marianum (L.) Gaertn. Despite several reports about silibinin, little is known about its effects on gastric diseases. Then, the present study aims to evaluate the silibinin effect against Helicobacter pylori infection, gastric tumor cells and immunomodulation.
Main methods
The anti-H. pylori effect was performed on 43,504 and 43,629 strains by minimum inhibitory concentration (MIC) determination, observing morphological alterations by scanning electron microscopy and in silico evaluation by molecular docking. Immunomodulatory activity (Interleukins-6 and 10, TNF-α and NO inhibition) was determined in H. pylori-stimulated macrophages and the cytotoxic activity on gastric adenocarcinoma cells prior and after metabolization by S9 fraction.
Key findings
Silibinin showed anti-H. pylori activity with MIC of 256 μg/mL, promoted important morphological changes in the bacterial cell wall, as blebs and clusters, suggesting interaction with Penicillin Binding Protein (PBP) subunits. Immunomodulatory potential was observed at 50 μg/mL with the inhibition of produced cytokines and NO by H. pylori-stimulated macrophages of 100% for TNF-ɑ, 56.83% for IL-6, and 70.29% for IL-10 and 73.33% for NO. Moreover, silibinin demonstrated significant cytotoxic activity on adenocarcinoma cells (CI50: 60.17 ± 0.95 μg/mL) with a higher selectivity index (SI: 1.52) compared to cisplatin. After metabolization silibinin showed an increase of cytotoxicity with a CI50 six-fold decrease (10.46 ± 0.25).
Significance
The use of silibinin may become an important alternative tool in the prevention and treatment of H. pylori infection and, consequently, in gastric cancer.
... (CXCL-16;Chen et al., 2020). Silibinin, derived from milk thistle seeds, possesses potent anti-Helicobacter and anti-gastric tumor cell properties (Bittencourt et al., 2020). This chemical affects Penicillin Binding Protein (PBP) and interferes with wall formation, resulting in changes in the bacterial structure. ...
... This chemical affects Penicillin Binding Protein (PBP) and interferes with wall formation, resulting in changes in the bacterial structure. It also has anti-inflammatory properties by decreasing cytokine release by inhibiting macrophages activated by H. pylori (Bittencourt et al., 2020;Cho et al., 2021). Vergara et al. (2005) found that eradicating H. pylori was successful in NSAID-naive users but not in chronic users. ...
... L. acidophilus strain LB Greater rate of H. pylori eradicationCanducci et al. (2000) Adding nonviable L. reuteri to triple therapy Decrease the abdominal distention al.(2021) and Magdy et al. (2023) Okinawamozuku Inhibition of H. pylori attachment to the mucous layer of the gut Tomori et al. (2019) and Tomori et al. (2021) Propolis Destruction of the bacterial membrane Romero et al. (2019) and Song et al. (2020) Vegetable oils (EOCs) Unknown Ruiz-Rico et al. (2020) and Guerra-Valle et al. (2022) Cranberry Inhibition of H. pylori attachment to the mucous layer of the gut Howell (2020), Nikbazm et al. (2022), and Wang et al. (2023) Apple peel Inhibition of urease activity Yang et al. (2022) and Kumari et al. (n.interleukin 8 (IL-8) and chemokine 16 (CXCL-16)Chen et al.(2020) Silibinin Inhibition of wall synthesis by PBP inhibitionBittencourt et al. (2020) andSalatin et al. ...
Gastric ulcers and gastric cancer are brought on by the Helicobacter pylori bacteria, which colonizes under the stomach mucous membrane. Different medication regimens are used to remove it, but the illness returns and becomes more resistant, which lowers the treatment rates. Additionally, this bacterium now exhibits a skyrocketing level of multi-drug resistance, necessitating recurrent therapeutic treatments. The negative effects of synthetic medications in comparison to conventional therapies are another significant factor in favor of non-pharmacological therapy. The most significant side effects of popular anti-gastric ulcer medications include nausea, vomiting, and diarrhea. Stomach ulcers have previously been treated with herbal remedies and complementary treatments like probiotics. When probiotics are ingested, the host experiences several advantages that may be brought about by altering the bacterial flora in the digestive system. Additionally, stronger-acting chemical compounds and plant extracts can be employed to treat patients. In this article, we look at the substances and medications that are utilized in place of synthetic stomach ulcer-curing treatments.
... Studies have shown that silibinin has significant cytotoxic activity on gastric adenocarcinoma cells (CI50: 60.17 ± 0.95 µg/mL) with a higher selectivity index compared with cisplatin. After metabolization silibinin showed an increase of cytotoxicity with a CI50 six-fold decrease (10.46 ± 0.25) [55]. ...
... Nobiletin has been confirmed to inhibit Hp infection and prevent Hp-mediated GC [65]. Notably, silymarin has 100% inhibitory effect on cytokines and NO related to Hp infection [55]. ...
The lack of new drugs and resistance to existing drugs are serious problems in gastric cancer(GC) treatment. The research found polyphenols possess anti-Helicobacter pylori(Hp) and antitumor activities and may be used in the research and development of drugs for cancer prevention and treatment. However, polyphenols are affected by their chemical structures and physical properties, which leads to relatively low bioavailability and bioactivity in vivo. The intestinal flora can improve the absorption, utilization, and biological activity of polyphenols, whereas polyphenol compounds can increase the richness of the intestinal flora, reduce the activity of carcinogenic bacteria, stabilize the proportion of core flora, and maintain homeostasis of the intestinal microenvironment. Our review summarizes the gastrointestinal flora-mediated mechanisms of polyphenol against GC.
... Several studies have been conducted with natural compounds that have the potential to influence the morphological conversion of H. pylori. Bittencourt et al. showed that silibinin affected the morphological conversion of H. pylori [45]. Abouwarda et al. compared the binding of fosfomycin and six antibiotics used to treat H. pylori infection to the MurA homologous model of H. pylori and concluded that fosfomycin had the highest binding affinity for MurA and enhanced the effectiveness of the antibiotics used [46]. ...
Background: The coccoid form of Helicobacter pylori (H. pylori) is resistant to antibiotics. There are only a few studies that have analyzed the frequency of coccoid H. pylori in patients with gastritis. The aim of this work was to examine the correlation between the H. pylori form and the pathohistological characteristics of the stomach in patients with gastritis. Materials and methods: This research was cross-sectional and focused on the gastric mucosa samples of 397 patients from one general hospital in Croatia. Two independent pathologists analyzed the samples regarding the pathohistological characteristics and the form of H. pylori. Results: There was a statistically significant difference in the gender of patients with H. pylori gastritis. Only the coccoid form of H. pylori was present in 9.6% of patients. There was a statistically significant difference in the frequency of a certain form of the bacterium depending on its localization in the stomach. The intensity of the bacterium was low in the samples where only the coccoid or spiral form was described. In cases of infection in the antrum, premalignant lesions and the coccoid form of H. pylori were more often present. Conclusion: In the diagnosis of H. pylori infection, the determination of the form of the bacterium via immunohistochemistry should be included to increase the rate of eradication therapy and reduce the incidence of gastric malignancy.
... It has been found that the mechanism of killing H. pylori is to cause changes in the visual morphology [37] of the bacterium and the integrity of the bacterial cell membrane [38][39][40]. CPC is an amphiphilic chemical that disrupts cytoplasmic membranes in bacteria as part of its recognized mechanism of action [16]. ...
The primary treatment method for eradicating Helicobacter pylori ( H . pylori ) infection involves the use of antibiotic-based therapies. Due to the growing antibiotic resistance of H . pylori , there has been a surge of interest in exploring alternative therapies. Cetylpyridinium chloride (CPC) is a water-soluble and nonvolatile quaternary ammonium compound with exceptional broad-spectrum antibacterial properties. To date, there is no documented or described specific antibacterial action of CPC against H . pylori . Therefore, this study aimed to explore the in vitro activity of CPC against H . pylori and its potential antibacterial mechanism. CPC exhibited significant in vitro activity against H . pylori , with MICs ranging from 0.16 to 0.62 μg/mL and MBCs ranging from 0.31 to 1.24 μg/mL. CPC could result in morphological and physiological modifications in H . pylori , leading to the suppression of virulence and adherence genes expression, including flaA , flaB , babB , alpA , alpB , ureE , and ureF , and inhibition of urease activity. CPC has demonstrated in vitro activity against H . pylori by inhibiting its growth, inducing damage to the bacterial structure, reducing virulence and adherence factors expression, and inhibiting urease activity.
... The mechanism of killing H. pylori involved inducing alterations in the visual morphology of the bacterium as well as disrupting the integrity of its cell membrane (Bittencourt et al., 2020). For morphological observations, after 24 h of treatment at the MIC, the SEM results indicated a significant alteration in the morphology of H. pylori and interference with the integrity of its cell membrane caused by HZQYF, which might lead to alternations of osmotic pressure and thereby induce bleb formation and cell lysis . ...
Background
Helicobacter pylori (H. pylori) is thought to primarily colonize the human stomach and lead to various gastrointestinal disorders, such as gastritis and gastric cancer. Currently, main eradication treatment is triple or quadruple therapy centered on antibiotics. Due to antibiotic resistance, the eradication rate of H. pylori is decreasing gradually. Therefore, searching for anti-H. pylori drugs from herbal sources has become a strategy for the treatment. Our team proposed a Hezi Qingyou Formula (HZQYF), composed of Chebulae Fructus, Ficus hirta Vahl and Cloves, and studied its anti-H. pylori activity and mechanism.
Methods
Chemical components of HZQYF were studied using UHPLC–MS/MS and HPLC. Broth microdilution method and agar dilution method were used to evaluate HZQYF’s antibacterial activity. The effects of HZQYF on expression of adhesion genes (alpA, alpB, babA), urease genes (ureE, ureF), and flagellar genes (flaA, flaB) were explored using Reverse Transcription-quantitative Polymerase Chain Reaction (RT-qPCR) technology. Effects on morphology and permeability of the extracellular membrane were studied using scanning electron microscopy (SEM) and N-phenylnaphthalen-1-amine (NPN) uptake. Effect on urease activity was studied using a urease kinetics analysis in vitro. Immunofluorescence staining method was used to examine the effect on adhesion. Western blot was used to examine the effect on cagA protein.
Results
Minimum inhibitory concentration (MIC) values of the formula against H. pylori clinical strains and standard strains were 80–160 μg/mL, and minimum bactericidal concentration (MBC) values were 160–320 μg/mL. The formula could down-regulate the expression of adhesion genes (alpA, alpB, babA), urease genes (ureE, ureF) and flagellar genes (flaA, flaB), change the morphology of H. pylori, increase its extracellular membrane permeability, and decrease its urease activity.
Conclusion
Present studies confirmed that HZQYF had promising in vitro anti-H. pylori activities and demonstrated its possible mechanism of action by down-regulating the bacterial adhesion, urease, and flagellar gene expression, which provided scientific bases for further clinical investigations.
... Полифенолы обладают подтвержденными антибактериальными свойствами [108], благодаря которым способны модулировать состав кишечной микрофлоры. Так, силибинин может подавлять рост H. pylori в культуре, вызывая изменения в морфологии клеток и ингибируя их деление [109]. Байкалин и байкалеин продемонстрировали антибактериальную активность в отношении этого микроорганизма не только in vitro, но и in vivo, уменьшая бактериальную нагрузку инфицированных мышей за счет снижения адгезивности и инвазивности бактериальных клеток [110]. ...
Genetic apparatus of human cells is constantly affected by a broad spectrum of mutagenic factors, both exogenous and
endogenous. Genetic and epigenetic disorders, which emerge as a result of this influence, become the main cause of the
majority of malignant neoplasias. Several different approaches were proposed to prevent these disorders, including the
suppression of the activity of mutagenic factors by treatment with certain chemical compounds. Plant polyphenols are
promising candidates for the development of chemopreventive drugs, as they exert the ability to regulate the metabolic activation of procarcinogens and modulate the cellular oxidative stress. In the present review, classification of plant
phenolic compounds and their interactions with biological macromolecules are described, along with the molecular
mechanisms of their influence on the enzymes and regulatory pathways of phase I xenobiotic metabolism, and the prevention of oxidative stress. Interactions between natural polyphenols and patient’s microbiota is also described.
... Plant polyphenols have antibacterial properties [292], which allow them to modulate the intestinal microflora. Silibinin was able to suppress the H. pylori culture growth by promoting changes in bacterial morphology and suppressing cell division [293]. Kaempferol and (-)-epicatechin demonstrated antibacterial and bacteriostatic effects towards this pathogen in vitro [294]. ...
Malignant tumors remain one of the main sources of morbidity and mortality around the world. A chemotherapeutic approach to cancer treatment poses a multitude of challenges, primarily due to the low selectivity and genotoxicity of the majority of chemotherapeutic drugs currently used in the clinical practice, often leading to treatment-induced tumors formation. Highly selective antitumor drugs can largely resolve this issue, but their high selectivity leads to significant drawbacks due to the intrinsic tumor heterogeneity. In contrast, plant polyphenols can simultaneously affect many processes that are involved in the acquiring and maintaining of hallmark properties of malignant cells, and their toxic dose is typically much higher than the therapeutic one. In the present work we describe the mechanisms of the action of polyphenols on cancer cells, including their effects on genetic and epigenetic instability, tumor-promoting inflammation, and altered microbiota.
... Silibinin (molecular formula: C 25 H 22 O 10 , molecular weight: 482.4 g/mol) is the main active component extracted from the seed of Silybum marianum (milk thistle) or artichoke (Cynara scolymus) (Bittencourt et al. 2020), which has anti-oxidant, anti-inflammation, and anti-apoptosis properties (Tong et al. 2018). In mice with myocardial I/R injury, silibinin improved cardiac function, limited infarct size, and inhibited myocardial fibrosis and remodeling. ...
Cardiovascular diseases (CVDs) are a leading cause of global mortality and have a high incidence rate worldwide. The function of inflammasomes in CVDs has received a lot of attention recently, and the nucleotide-binding domain and leucine-rich repeat protein 3 (NLRP3) inflammasome may be a new target for the prevention and treatment of CVDs. Flavonoids, which are found in food and plant extracts, inhibited inflammation in CVDs by regulating the NLRP3 inflammasome. CB-Dock was used to investigate whether 34 flavonoids from natural products acted on NLRP3 inflammasome. In brief, the PDB format of NLRP3 was selected as a protein file, and 34 flavonoids in SDF format were selected as the ligand file, and then input to CB-Dock for molecular docking. The docking results showed that epigallocatechin-3-gallate (EGCG), amentoflavone, baicalin, scutellarin, vitexin, silibinin, and puerarin had good binding affinities to NLRP3, which could be used as NLRP3 inhibitors, and aid in the discovery of lead compounds for the design and development of CVDs.
... While screening medicinal plants for anti-metastasis research, it was found that the inhibitory effect of milk thistle (Cirsium japonicum) extract was excellent. The silibinin employed in this study corresponds to 50-70% of the three isomers of silymarin which makes up roughly 2% of milk thistle's active component [2]. It has been known to have a role in the anti-tumor drug cisplatin's hepatoprotection, antioxidation, anti-angiogenesis, inhibition of inflammation, and nephrotoxicity [3]. ...
Background and aims:
Normal cells become tumorigenic owing to mutations in oncogenes and tumor suppressor genes modulating cell division. Cancer cells break down extracellular matrix to metastasize other tissues. Therefore, the development of natural and synthetic substances that suppress metastatic enzymes such as matrix metalloproteinase (MMP)-2 and MMP-9 is useful to inhibit metastasis. Silibinin is the main ingredient of silymarin extracted from the seeds of milk thistle plants having lung cancer-suppressing effects and liver protection. The purpose of this study was to investigate the inhibitory effect of silibinin on the invasion of human fibrosarcoma cells.
Methods:
The effect of silibinin on cell viability was measured in HT1080 cells using an MTT assay. The MMP-9 and MMP-2 activities were analyzed using a zymography assay. The expression of proteins in cytoplasm related to metastasis was examined by western blot analysis and immunofluorescence assay.
Results:
In this study, silibinin above 20 μM showed growth inhibitory effects. Silibinin above 20 μM remarkably inhibited the levels of MMP-2 and MMP-9 activation under phorbol myristate acetate (PMA) treatment conditions. Furthermore, silibinin at 25 μM reduced the levels of MMP-2, IL-1β, ERK-1/2, and p-p38 expression and silibinin above 10 μM inhibited cell invasion on HT1080 cells.
Conclusions:
These findings indicate that silibinin may have an inhibitory effect on the enzymes involved in invasion, hence it might influence the metastatic ability of tumor cells.
... Besides, considering that silymarin has antioxidant, antiinfammatory, immunomodulatory, antifbrotic, and hepatoprotective activities and stimulates protein synthesis and liver tissue regeneration [88], silymarin may be used for the treatment of NAFLD. Notably, it seems that silymarin can also inhibit H. pylori activity [89][90][91][92]. Terefore, it may be hypothesized that silymarin can be helpful for the treatment of NAFLD and H. pylori infection. ...
Background and aims:
Helicobacter pylori (H. pylori) and nonalcoholic fatty liver disease (NAFLD) have become increasingly recognized, both of which affect human health globally. The association of H. pylori infection with NAFLD remains unclear.
Methods:
PubMed, EMBASE, and Cochrane Library databases were searched. Only a random-effects model was used. Odds ratios (ORs) and risk ratios (RRs) with 95% confidence intervals (CIs) were calculated for the combined estimates of raw data. Adjusted ORs (aORs) and hazard ratios (aHRs) with 95% CIs were calculated for the combined estimates of data adjusted for confounders.
Results:
Thirty-four studies with 218573 participants were included. Based on unadjusted data from 26 cross-sectional studies and 3 case-control studies, H. pylori infection was significantly associated with the presence of NAFLD (OR = 1.26, 95% CI = 1.17-1.36, P < 0.001). Based on adjusted data from 15 cross-sectional studies and 1 case-control study, H. pylori infection was significantly associated with the presence of NAFLD (aOR = 1.25, 95% CI = 1.08-1.44, P < 0.001). Compared with control subjects without NAFLD, patients with moderate (OR = 1.67, 95% CI = 1.17-2.39, P = 0.005) and severe (OR = 1.71, 95% CI = 1.30-2.24, P < 0.001) NAFLD, but not those with mild NAFLD (OR = 1.14, 95% CI = 0.9-1.45, P = 0.286), had significantly higher proportions of H. pylori infection. The association of H. pylori infection with the occurrence of NAFLD was statistically significant based on adjusted data from 3 cohort studies (aHR = 1.18, 95% CI = 1.05-1.34, P = 0.007), but not based on unadjusted data from 3 cohort studies (RR = 1.41, 95% CI = 0.80-2.48, P = 0.237).
Conclusion:
H. pylori infection is associated with NAFLD, especially moderate and severe NAFLD. The impact of H. pylori eradication on the prevention of NAFLD should be further explored.
... Such compounds with an enhanced binding potential with PBP2a compared to oxacillin have already been published (summarized e.g. by [63]). The interaction of silybin with PBP2a was also suggested by Bittencourt et al. [64]. ...
Antibiotic resistance is currently a serious health problem. Since the discovery of new antibiotics no longer seems to be a sufficient tool in the fight against multidrug-resistant infections, adjuvant (combination) therapy is gaining in importance as well as reducing bacterial virulence. Silymarin is a complex of flavonoids and flavonolignans known for its broad spectrum of biological activities, including its ability to modulate drug resistance in cancer. This work aimed to test eleven, optically pure silymarin flavonolignans for their ability to reverse the multidrug resistance phenotype of Staphylococcus aureus and reduce its virulence. Silybin A, 2,3-dehydrosilybin B, and 2,3-dehydrosilybin AB completely reversed antibiotic resistance at concentrations of 20 µM or less. Both 2,3-dehydrosilybin B and AB decreased the antibiotic-induced gene expression of representative efflux pumps belonging to the major facilitator (MFS), multidrug and toxic compound extrusion (MATE), and ATP-binding cassette (ABC) families. 2,3-Dehydrosilybin B also inhibited ethidium bromide accumulation and efflux in a clinical isolate whose NorA and MdeA overproduction was induced by antibiotics. Most of the tested flavonolignans reduced cell-to-cell communication on a tetrahydrofuran-borate (autoinducer-2) basis, with isosilychristin leading the way followed by 2,3-dehydrosilybin A and AB, which halved communication at 10 µM. Anhydrosilychristin was the only compound that reduced communication based on acyl-homoserine lactone (autoinducer 1), with an IC50 of 4.8 µM. Except for isosilychristin and anhydrosilychristin, all of the flavonolignans inhibited S. aureus surface colonization, with 2,3-dehydrosilybin A being the most active (IC50 10.6 µM). In conclusion, the selected flavonolignans, particularly derivatives of 2,3-dehydrosilybin B, 2,3-dehydrosilybin AB, and silybin A are non-toxic modulators of S. aureus multidrug resistance and can decrease the virulence of the bacterium, which deserves further detailed research.
... The flavonoid silibinin showed anti-H. pylori activities [180]. Mechanistically, silibinin had the potential to interact with H. pylori Penicillin Binding Protein (PBP), causing its suppression and, thus, promoted significant morphological changes in the bacterial cell wall. ...
Flavonoids are a group of polyphenolic compounds which are ubiquitously found in plants and are consumed as part of the human diet in substantial amounts. The verification of flavonoids' cancer chemopreventive benefits has led to a significant interest in this field. Gut microbiota includes a diverse community of microorganisms and has a close relationship with cancer development. Increasing evidence has indicated that flavonoids exert anticarcinogenic effects by reshaping gut microbiota. Gut microbiota can convert flavonoids into bioactive metabolites that possess anticancer activity. Here, we present a brief introduction to gut microbiota and provide an overview of the interplay between gut microbiota and cancer pathogenesis. We also highlight the crucial roles of flavonoids in preventing cancer based on their regulation of gut microbiota. This review would encourage research on the flavonoid-intestinal microbiota interactions and clinical trials to validate the chemotherapeutic potentials of targeting gut microbiota by dietary bioactive compounds.
... Considering the unavoidable side effects of the synthetic antibiotics, we have been interested in searching for some phytochemicals with anti-inflammatory and antioxidative properties as alternatives for the management H. pylori-induced gastritis and gastric cancer. One of the candidates is silibinin which is a component of silymarin mixture [13,34]. ...
More than half of the world's populations are considered to be infected by Helicobacter pylori. It causes a chronic inflammation of the stomach, which is implicated in the pathogenesis of gastric ulcer and cancer. Silibinin, a polyphenolic flavonoid derived from milk thistle, has been known for its hepatoprotective effects, and recent studies have revealed its chemopreventive potential. In the present study, we examined the anti-inflammatory effects of silibinin in human gastric cancer MKN-1 cells and in the stomach of C57BL/6 mice infected by H. pylori. Pretreatment with silibinin attenuated the up-regulation of COX-2 and inducible nitric oxide synthase (iNOS) in H. pylori-infected MKN-1 cells and mouse stomach. In addition, the elevated translocation and DNA binding of NF-κB and STAT3 induced by H. pylori infection were inhibited by silibinin treatment. Moreover, H. pylori infection in combination with high salt diet resulted in dysplasia and hyperplasia in mouse stomach, and these pathological manifestations were substantially mitigated by silibinin administration. Taken together, these findings suggest that silibinin exerts anti-inflammatory effects against H. pylori infection through suppression of NF-κB and STAT3 and subsequently, expression of COX-2 and iNOS.
... Another explanation regarding the effect of polyphenols upon morphological changes in H. pylori cell wall underlaid the interaction with penicillin-binding protein subunits (PBP). This mechanism has been recently described for silybin (Bittencourt et al., 2020). However, other mechanisms could not be ruled out. ...
The full UHPLC-MS metabolome fingerprinting and anti-Helicobacter pylori effect of Gunnera tinctoria (Molina) Mirb. (Nalca) total extract (GTE) and fractions prepared from its edible fresh petioles were evaluated. The activity of G. tinctoria against H. pylori strains ATCC 45504 and J99 was assessed in vitro by means of agar diffusion assay, Minimum Inhibition Concentration (MIC), and Minimum Bactericidal Concentration (MBC), while killing curve and transmission electronic microscopy (TEM) were conducted in order to determine the effect of the plant extract on bacterial growth and ultrastructure. Additionally, the inhibitory effect upon urease was evaluated using both the Jack Bean and H. pylori enzymes. To determine which molecules could be responsible for the antibacterial effects, tentative identification was done by ultra-high performance liquid chromatography coupled with high-resolution mass spectrometry (UHPLC-Q-Orbitrap®-HR-MS). Furthermore, the total G. tinctoria extract was fractionated using centrifugal partition chromatography (CPC), giving four active fractions (1–4). It was determined that the crude extract and centrifugal partition chromatography fractions of G. tinctoria have a bactericidal effect being the lowest MIC and MBC = 32 μg/ml. In the killing curves, fraction one acts faster than control amoxicillin. In the urease assay, F3 exhibited the lowest IC50 value of 13.5 μg/ml. Transmission electronic microscopy showed that crude G. tinctoria extract promotes disruption and separation of the cellular wall and outer membrane detachment on H. pylori causing bacterial cell death.
Inflammation is a vital defense mechanism, creating hostile conditions for pathogens, preventing the spread of tissue infection and repairing damaged tissues in humans and animals. However, when inflammation resolution is delayed or compromised as a result of its misregulation, the process proceeds from the acute phase to chronic inflammation, leading to the development of various chronic illnesses. It is proven that redox balance disturbances and oxidative stress are among major factors inducing NF-κB and leading to over-inflammation. Therefore, the anti-inflammatory properties of various natural antioxidants have been widely tested in various in vitro and in vivo systems. Accumulating evidence indicates that silymarin (SM) and its main constituent silibinin/silybin (SB) have great potential as an anti-inflammation agent. The main anti-inflammatory mechanism of SM/SB action is attributed to the inhibition of TLR4/NF-κB-mediated signaling pathways and the downregulated expression of pro-inflammatory mediators, including TNF-α, IL-1β, IL-6, IL-12, IL-23, CCL4, CXCL10, etc. Of note, in the same model systems, SM/SB was able to upregulate anti-inflammatory cytokines (IL-4, IL-10, IL-13, TGF-β, etc.) and lipid mediators involved in the resolution of inflammation. The inflammatory properties of SM/SB were clearly demonstrated in model systems based on immune (macrophages and monocytes) and non-immune (epithelial, skin, bone, connective tissue and cancer) cells. At the same time, the anti-inflammatory action of SM/SB was confirmed in a number of in vivo models, including toxicity models, nonalcoholic fatty liver disease, ischemia/reperfusion models, stress-induced injuries, ageing and exercising models, wound healing and many other relevant model systems. It seems likely that the anti-inflammatory activities of SM/SB are key elements on the health-promoting properties of these phytochemicals.
Silybum Marianum (SM) belongs to the family Asteraceae, which holds therapeutic significance in medicinal chemistry. Phytochemistry analysis revealed an abundance of active constituents, particularly silymarin, composed of polyphenols and flavonolignans. Silymarin is majorly found in leaves, seeds, and fruits and is comprised of seven flavonolignans. Silymarin derivatives, specifically silybin, were reported for their medicinal properties. This review summarizes the studies conducted to evaluate SM's pharmacological properties and proposed mechanisms. SM exhibited anticancer properties due to being capable of modifying the induction of apoptosis, inhibiting the STAT3 pathway, decreasing the transcription of various growth factors, impeding the growth of 4T1 cells and inducing cell cycle arrest in various types of cancers, i.e., skin cancer, liver cancer, breast cancer, ovarian cancer etc. Silymarin and its derivatives protect the liver and ameliorate various immune-mediated and autoimmune hepatic diseases. Moreover, antimicrobial, antidiabetic, cardioprotective, nephroprotective, and neuroprotective activities were also reported. Based on testified in vitro and in vivo studies, SM can serve as an alternative to cure various pathological ailments.
Background Silibinin is a single compound of silymarin that is obtained from the seeds of milk thistle plants. Their natural compound has an alternative function to suppress lung cancer and liver protection. Normal cells are converted into cancer cells due to defects in the genes that regulate cell division. Cancer cells break down vascular walls and basal membranes to obtain sufficient oxygen and nutrients, causing metastasis to other tissues. Therefore, the development of natural substances to suppress metastasis through MMPs, the metastatic enzymes, is necessary. Our investigation aimed to study the activation of silibinin on metastasis inhibition of human cancer fibrosarcoma cells.
Methods and Results The cytotoxicity of silibinin in HT1080 cells was measured by MTT assay. The gelatinolytic activities of MMP-2 and MMP-9 expression were determined by using a gelatin zymography assay. Western blot analysis and immunofluorescence assay was performed to investigate the protein expression of silibinin on metastasis inhibition. Silibinin above 5 μM showed reducing power activity. Even though the cell cytotoxicity was measured in the presence of silibinin below 5 μM, the cell cytotoxicity of silibinin was shown above 15 μM. Silibinin above 20 μM remarkably inhibited the levels of MMP-2 and MMP-9 activation under PMA treatment conditions. Furthermore, silibinin at 25 μM suppressed metastasis by reducing the levels of TIMP-1, MMP-2, IL-1β, ERK1/2, and p-p38 expression and silibinin above 10 μM inhibited cell invasion on HT1080 cells.
Conclusion These results suggest that silibinin could exert an excellent effect on the suppression of metastatic enzymes, leading to the inhibition of cell invasion.
Gastric cancer (GC) is one of the most prevalent cancer types worldwide and one of the leading causes of cancer-related deaths. Gastric cancer is an aggressive and heterogeneous disease with a poorly understood carcinogenesis at the molecular level. Therefore, the research for effective drug therapy strategies plays a significant role in treating the disease. One of these effective treatment strategies is herbal-based therapeutics, which have low side effects and contain many biologically active compounds. In this study, the effect of U.dioica, S. marianum and C. scolymus herbal extracts on cell viability in L929, AGS and SH-SY5Y cell lines was analyzed by XTT test to evaluate the anticancer activities. Antibacterial and antioxidant activities of extracts were determined by the agar well diffusion test and CUPRAC method, respectively. We found that U. dioica and S. marianum extracts showed no significant effect on the viability of AGS and SH-SY5Y cancer cells. C. scolymus extract demonstrated strong anticancer activity on AGS cancer cells at all concentrations but had no effect on SH-SY5Y cells. U. dioica and C. scolymus exhibited antibacterial activity against S. aureus and B. cereus, respectively. No antibacterial activity was found in S. marianum extract. U. dioica and S. marianum extracts have shown strong antioxidant activity in CUPRAC assay. In conclusion, the obtained results revealed the antibacterial and anticancer therapeutic potential of C. scolymus extract known as artichoke in gastric cancer cells. However, more research is required to better explain the therapeutic properties of these extracts.
Silibinin is a natural polyphenolic flavonoid, isolated from the seeds of the milk thistle of Silybum marianum (L.) Gaertn. Silibinin has been widely used clinically as a traditional medicine for liver diseases. This study investigated the protective role of silibinin in ethanol- or acetaldehyde-induced apoptosis in human carcinomatous liver HepG2 cells and immortalized liver HL7702 cells, focusing on elucidation of the underlying mechanism in vitro. The toxicity of ethanol or acetaldehyde was evaluated by MTT assay. Apoptosis-related proteins, mitochondrial fission-associated proteins and mitochondrial fusion-associated proteins were analyzed by western blotting and immunofluorescence microscopy. Present experimental results demonstrated that silibinin improved cell viability, reduced the enzyme activities of AST/ALT and ALDH/ADH, inhibited apoptosis and recovered mitochondrial function in ethanol- or acetaldehyde-treated HepG2 or HL7702 cells. Silibinin reduced the expression of mitochondrial fission-associated proteins, dynamin-related protein 1 (DRP1), but increased mitochondrial fusion-associated proteins, optic atrophy 1 (OPA1) and mitofusin 1 (MFN1). Accordingly, inhibition of DRP1 activity with its pharmacological inhibitor or siDRP1 efficiently attenuated ethanol- or acetaldehyde-induced apoptosis, whereas activation of DRP1 by using staurosporine (STS) further increased apoptosis in ethanol- or acetaldehyde-treated HepG2 or HL7702 cells. The results show that silibinin protects cells against ethanol- or acetaldehyde-induced mitochondrial fission that results in apoptosis.
The co-culture strategy, which mimics natural ecology by constructing an artificial microbial community, is a useful tool to activate the biosynthetic gene clusters to generate new compounds. However, without optimization of fermentation conditions, the antagonism between the microbes often interferes with the production of secondary metabolites. In this study, the fermentation conditions of co-culture of Aspergillus sydowii and Bacillus subtilis were optimized by response surface methodology to increase the production of active metabolites against Staphylococcus aureus. After optimization, the inhibitory rate of the co-culture extract was 74.62%, which was 29.20% higher than that of the initial conditions. Meanwhile, a total of 15 newly biosynthesized metabolites were detected only in optimized co-culture, occupying 13.2% of all detected metabolites. The structures of the 12 metabolites with high variable importance in projection score were elucidated by the established LC-MS/MS approach integrated with various metabonomic tools. Among them, 7 metabolites were newly induced and the content of other 5 metabolites increased by 1.1–2.4 folds in optimized co-culture. The bioassay of metabolites in co-culture against S. aureus indicated that compounds (−)- (7S)- 10-hydroxysydonic acid, serine sydonate and macrolactin U’ contributed much to the increment of antibacterial activity. This study demonstrated that optimizing the fermentation conditions of co-culture was beneficial to changing the metabolite profile and effective to induce the biosynthesis of active metabolites.
Gastric cancer is the fourth most common cause of cancer-linked deaths in the world. Gastric tumor cells have biological characteristics such as rapid proliferation, high invasiveness, and drug resistance, which result in recurrence and poor survival. Helicobacter pylori (H. pylori) has been proposed as a first‐class carcinogen for gastric cancer according to the 1994 world health organization (WHO) classification. One of the important mechanisms by which H. pylori affects the gastric environment and promotes carcinogenesis is triggering inflammation. H. pylori induces an inflammatory response and a plethora of different signal transduction processes, leading to gastric mucosal disturbance, chronic gastritis, and a multi-step complex pathway that initiates carcinogenesis. It seems undeniable that the interaction between various cell types, including immune cells, gastric epithelium, glands, and stem cells, is vital for the progression and development of carcinogenesis concerning H. pylori. The interactions of H. pylori with surrounding cells play a key role in cancer progression. In this review, we discuss the interplay between H. pylori and tumor-supportive cells, including mesenchymal stem cells (MSCs), cancer-associated fibroblasts (CAFs), tumor-associated macrophages (TAMs), and myeloid derived-suppressor cells (MDSCs) in gastric cancer. It is hoped that clarifying the specific mechanisms for ‘cross-talk’ between H. pylori and these cells will provide promising strategies for developing new treatments.
Twenty‐three benzoxazole derivatives were prepared through two‐step reaction strategy. The precursor, 2‐mercapto benzoxazole was synthesized by reacting 2‐amino phenol with carbon disulfide in the presence of potassium hydroxide. Then, 2‐mercapto benzoxazole was further reacted with substituted phenacyl/benzyl bromide to afford a range of substituted 2‐mercapto benzoxazole analogs. All compounds were characterized by different spectroscopic techniques including mass spectrometry and nuclear magnetic resonance spectroscopy, and investigated against urease enzyme. All analogs revealed good to moderate urease inhibition, ranging from IC50 = 17.50±0.10 to 42.50±0.44 μM. Few derivatives showed superior activity than thiourea (IC50=21.50±0.47 μM), standard inhibitor of urease enzyme. Structure‐activity relationship (SAR) revealed the crucial participation of various structural features in the inhibitory process. Compounds bearing methoxy and halogen substituents were found to show more potency as compared with other molecules. Molecular docking showed various interesting interactions established by molecules (ligand) with the active pocket of urease enzyme.
Cytokine therapy, which activates the host immune system, has become an important and novel therapeutic approach to treat various cancers. Recent studies have shown that IL‐6 is an important cytokine that regulates the homeostasis in vivo. However, excessive IL‐6 plays a pathological role in a variety of acute and chronic inflammatory diseases, especially in cancer. IL‐6 can transmit signals through JAK/STAT, RAS /MAPK, PI3K/ Akt, NF‐κB, and other pathways to promote cancer progression. Phenolic compounds can effectively regulate the level of IL‐6 in tumor cells and improve the tumor microenvironment. This article focuses on the phenolic compounds through the regulation of IL‐6, participate in the prevention of cancer, inhibit the proliferation of cancer cells, reduce angiogenesis, improve therapeutic efficacy, and reduce side effects and other aspects. This will help to further advance research on cytokine therapy to reduce the burden of cancer and improve patient prognosis. However, current studies are mostly limited to animal and cellular experiments, and high‐quality clinical studies are needed to further determine their antitumor efficacy in humans.
Background and aims
Silybum marianum (SM) is an herbal product with cytoprotective and antioxidant properties. We have previously demonstrated that SM ameliorates ventricular remodeling and improves cardiac performance. Here, we evaluated whether SM could exert beneficial effects against cardiac lipotoxicity in a pig model of closed-chest myocardial infarction (MI).
Methods
Study 1 investigated the effect of SM administration on lipid profile and any potential SM-related adverse effects. Animals received SM or placebo during 10 days and were afterward sacrificed. Study 2 evaluated the effectiveness of SM daily administration in reducing cardiac lipotoxicity in animals subjected to a 1.5h myocardial infarction (MI), who were subsequently reperfused for 2.5h and euthanized or kept under study for three weeks and then euthanized.
Results
Animals administered a 10-day SM regime presented a sharp decline in plasma triglyceride levels vs. controls, with no other modifications in lipid profile. The decrease in triglyceride concentration was accompanied by a marked reduction in triglyceride intestinal absorption and glycoprotein-P expression. Three weeks post-MI the triglyceride content in the ischemic myocardium of the SM-treated animals was significantly lower than in the ischemic myocardium of placebo-controls. This effect was associated with an enhanced cardiac expression of PPARγ and triglyceride clearance receptors. This long-term SM-administration induced a lower expression of lipid receptors in the subcutaneous adipose tissue. No SM-related side-effects were registered.
Conclusion
SM administration reduces plasma triglyceride levels through attenuation of triglyceride intestinal absorption and modulates cardiac lipotoxicity in the ischemic myocardium, likely contributing to improve ventricular remodeling.
Microbial resistance to classical antibiotics and its rapid progression have raised serious concern in the treatment of infectious diseases. Recently, many studies have been directed towards finding promising solutions to overcome these problems. Phytochemicals have exerted potential antibacterial activities against sensitive and resistant pathogens via different mechanisms of action. In this review, we have summarized the main antibiotic resistance mechanisms of bacteria and also discussed how phytochemicals belonging to different chemical classes could reverse the antibiotic resistance. Next to containing direct antimicrobial activities, some of them have exerted in vitro synergistic effects when being combined with conventional antibiotics. Considering these facts, it could be stated that phytochemicals represent a valuable source of bioactive compounds with potent antimicrobial activities.
Helicobacter pylori is a Gram-negative, microaerophilic bacterium colonising the gastric mucosa. Normally, this bacterium has a spiral shape, which is crucial for proper colonisation of the stomach and cork-screwing penetration of dense mucin covering this organ. However, H. pylori may also form curved/straight rods, filamentous forms and coccoid forms. This morphological variability affects nutrient transport and respiration processes, as well as motility, the ability to form aggregates/biofilms, and resistance to adverse environmental factors. For this reason, a more accurate understanding of the molecular determinants that control the morphology of H. pylori seems to be crucial in increasing the effectiveness of antibacterial therapies directed against this microorganism. This article focuses on the molecular factors responsible for peptidoglycan and cytoskeleton rearrangements affecting H. pylori morphology and survivability. In addition, the existence of proteins associated with modifications of H. pylori morphology as potential targets in therapies reducing the virulence of this bacterium has been suggested. Citation: Krzyżek P., Gościniak G. Morphology of Helicobacter pylori as a result of peptidoglycan and cytoskeleton rearrangements. Prz Gastroenterol 2018; 13(3): 182-195.
Gastrointestinal cancer (GI) is a major health problem. Patients with gastric, pancreatic, colorectal, bile duct and gall bladder cancer often have advanced disease at the time of diagnosis and are generally difficult to cure, resulting in a dismal prognosis for most patients. Inflammation plays an important role in the development and growth of cancer, which has led to a growing interest in the pro-inflammatory cytokine interleukin 6 (IL-6).
The aim of the present review was to evaluate the clinical use of IL-6 as a biomarker or therapeutic target in patients with GI cancer. We did a systematic review of studies (1993–2018), to assess the clinical use of IL-6 as a diagnostic, prognostic or predictive tumor biomarker or as a potential therapeutic target.
This review includes 48 studies and 5316 patients. Circulating IL-6 levels appear to be an independent prognostic biomarker in patients with GI cancer, with high IL-6 levels associated with short overall survival (OS). The results for colorectal cancer were too ambiguous to give conclusive results. IL-6 seemed to be a marker for some of the clinical characteristics of GI cancer, and may have a role in the diagnostic workup in general practice. No published studies have examined the use of IL-6 as a therapeutic target in pancreatic, gastric, bile duct or colorectal cancer.
In conclusion, high circulating IL-6 was associated with short OS in most studies in GI cancer patients. Whether inhibition of IL-6 would decrease GI cancer symptoms and increase quality of life is unknown.
Milk thistle (Silybum marianum) is a medicinal plant that has been used for thousands of years as a remedy for a variety of ailments. The main component of S. marianum fruit extract (silymarin) is a flavonolignan called silybin, which is not only the major silymarin element but is also the most active ingredient of this extract, which has been confirmed in various studies. This compound belongs to the flavonoid group known as flavonolignans. Silybin’s structure consists in two main units. The first is based on a taxifolin, the second a phenyllpropanoid unit, which in this case is conyferil alcohol. These two units are linked together into one structure by an oxeran ring. Since the 1970s, silybin has been regarded in official medicine as a substance with hepatoprotective properties. There is a large body of research that demonstrates silybin’s many other healthy properties, but there are still a lack of papers focused on its molecular structure, chemistry, metabolism, and novel form of administration. Therefore, the aim of this paper is a literature review presenting and systematizing our knowledge of the silybin molecule, with particular emphasis on its structure, chemistry, bioavailability, and metabolism.
Helicobacter pylori is a Gram-negative, microaerophilic bacterium that infects the stomach and can lead to, among other disorders, the development of gastric cancer. The inability of the host to clear the infection results in a chronic inflammatory state with continued oxidative stress within the tissue. Reactive oxygen species and reactive nitrogen species produced by the immune and epithelial cells damage the host cells and can result in DNA damage. H. pylori has evolved to evoke this damaging response while blunting the host’s efforts to kill the bacteria. This long-lasting state with inflammation and oxidative stress can result in gastric carcinogenesis. Continued efforts to better understand the bacterium and the host response will serve to prevent or provide improved early diagnosis and treatment of gastric cancer.
AIM: Helicobacter pylori causes gastric mucosal inflammation and immune reaction. However, the increase of IL-10, MMP-7, and MMP-7 levels in the serum is still controversial. The objective of this study was to investigate the serum levels of IL-10, MMP-7 & MMP-9 in gastritis patients with H. pylori infection.
MATERIALS AND METHODS: A cross-sectional study was done on seventy gastritis patients that consecutive admitted to endoscopy units. The diagnosis of gastritis was made based on histopathology and diagnosis of H. pylori infection was based on rapid urease test. Serum samples were obtained to determine to circulate IL-10, MMP-7, and MMP-9 level. Univariate and bivariate analysis were done by SPSS version 22.
RESULTS: Forthy percentages of the patients were infected with H. pylori. The IL-10 level was significantly higher in H. pylori-infected patients compared to non-infected patients. However, there were no differences between serum levels of MMP-7 and MMP-9 in infected and non-infected H. pylori patients.
CONCLUSIONS: The immune response to H. pylori promotes systemic inflammation, which was reflected by the increased levels of serum IL-10. However, there were no significant differences in MMP-7 and MMP-9 serum levels between positive and negative infected H. pylori patients.
The bacterial pathogen Helicobacter pylori commonly colonizes the human gastric mucosa during early childhood and persists throughout life. The organism has evolved multiple mechanisms for evading clearance by the immune system and, despite inducing inflammation in the stomach, the majority of infections are asymptomatic. H. pylori is the leading cause of peptic ulcer disease and gastric cancer. However, disease outcomes are related to the pattern and severity of chronic inflammation in the gastric mucosa, which in turn is influenced by both bacterial and host factors. Despite over 2 decades of intensive research, there remains an incomplete understanding of the circumstances leading to disease development, due to the fascinating complexity of the host–pathogen interactions. There is accumulating data concerning the virulence factors associated with increased risk of disease, and the majority of these have pro-inflammatory activities. Despite this, only a small proportion of those infected with virulent strains develop disease. Several H. pylori virulence factors have multiple effects on different cell types, including the induction of pro- and anti-inflammatory, immune stimulatory, and immune modulatory responses. The expression of multiple virulence factors is also often linked, making it difficult to assess the meaning of their effects in isolation. Overall, H. pylori is thought to usually modulate inflammation and limit acute damage to the mucosa, enabling the bacteria to persist. If this delicate balance is disturbed, disease may then develop.
The present study showed that silymarin, a polyphenolic flavonoid isolated from milk thistle (Silybum marianum), inhibited lipopolysaccharide (LPS)-induced morphological changes in the mouse RAW264.7 macrophage cell line. We also showed that silymarin inhibited the nuclear translocation and transactivation activities of nuclear factor-kappa B (NF-κB), which is important for macrophage activation-associated changes in cell morphology and gene expression of inflammatory cytokines. BAY-11-7085, an NF-κB inhibitor, abrogated LPS-induced morphological changes and NO production, similar to silymarin. Treatment of RAW264.7 cells with silymarin also inhibited LPS-stimulated activation of mitogen-activated protein kinases (MAPKs). Collectively, these experiments demonstrated that silymarin inhibited LPS-induced morphological changes in the RAW264.7 mouse macrophage cell line. Our findings indicated that the most likely mechanism underlying this biological effect involved inhibition of the MAPK pathway and NF-κB activity. Inhibition of these activities by silymarin is a potentially useful strategy for the treatment of inflammation because of the critical roles played by MAPK and NF-κB in mediating inflammatory responses in macrophages.
Prevalence of chronic gastritis has markedly declined in developed populations during the past decades. However, chronic gastritis is still one of the most common serious pandemic infections with such severe killing sequelae as peptic ulcer or gastric cancer. Globally, on average, even more than half of people may have a chronic gastritis at present. Helicobacter pylori infection in childhood is the main cause of chronic gastritis, which microbial origin is the key for the understanding of the bizarre epidemiology and course of the disease. A life-long and aggressive inflammation in gastritis results in destruction (atrophic gastritis) of stomach mucosa with time (years and decades). The progressive worsening of atrophic gastritis results subsequently in dysfunctions of stomach mucosa. Atrophic gastritis will finally end up in a permanently acid-free stomach in the most extreme cases. Severe atrophic gastritis and acid-free stomach are the highest independent risk conditions for gastric cancer known so far. In addition to the risks of malignancy and peptic ulcer, acid-free stomach and severe forms of atrophic gastritis may associate with failures in absorption of essential vitamins, like vitamin B12, micronutrients (like iron, calcium, magnesium and zinc), diet and medicines.
Helicobacter pylori-induced gastric mucosal inflammation is mediated by proinflammatory and anti-inflammatory cytokines. Polymorphisms in genes that code cytokines influence cytokine secretion levels and appear to contribute to the risk of gastric diseases. In this sense, we performed this study to identify the polymorphisms in the IL-6, IL-8, and IL-10 genes and their associations with H. pylori infection and gastric pathologies.
Gastric biopsy samples of 151 patients infected with H. pylori and 76 uninfected individuals were used. Helicobacter pylori infection was diagnosed by histological examination and the detection of the ureA and glmM genes. The polymorphisms in the IL-6 (at position -174), IL-8 (at position -251), and IL-10 (at position -819) were detected by polymerase chain reaction-restriction fragment length polymorphism.
Among the genetic polymorphisms studied, we observed that only the presence of the A allele at position -251 of the IL-8 gene was significantly associated with H. pylori infection. In addition, patient carriers of the A/A genotype at position -251 of the IL-8 gene and carriers of the T allele at position -819 of the IL-10 gene had an increased risk of peptic ulcer disease in the presence of H. pylori infection. We did not find a correlation between polymorphisms in the IL-6, IL-8, and IL-10 genes and a higher risk of gastric carcinoma.
We demonstrated that polymorphisms in the IL-8 gene was significantly associated with H. pylori infection. Furthermore, polymorphisms in the IL-8 and IL-10 genes were associated with an enhanced risk of peptic ulcer disease in H. pylori-positive patients.
Copyright © 2015. Published by Elsevier B.V.
Silymarin is a standardized extract from the dried seeds of the milk thistle (Silybum marianum L. Gaertn.) clinically used as an antihepatotoxic agent. The aim of this study was to investigate the antibacterial and antifungal activity of silymarin and its major constituent (silibinin) against different microbial strains and their modulatory effect on drugs utilized in clinical practice. Silymarin demonstrated antimicrobial activity of little significance against the bacterial strains tested, with MIC (minimum inhibitory concentration) values of 512 í µí¼g/mL. Meanwhile, silibinin showed significant activity against Escherichia coli with a MIC of 64 í µí¼g/mL. The results for the antifungal activity of silymarin and silibinin demonstrated a MIC of 1024 í µí¼g/mL for all strains. Silymarin and silibinin appear to have promising potential, showing synergistic properties when combined with antibacterial drugs, which should prompt further studies along this line.
Helicobacter pylori is one of the most common causes of chronic gastritis. With the development of the disease cellular inflammatory infiltrates composed of lymphocytes, plasma cells, and macrophages are formed in epithelium and lamina propria of the stomach. These cells are capable of secreting a number of active substances, including inducible nitric oxide synthase (iNOS). We examined the relationship between H. pylori and secretion of iNOS by cells of inflammatory infiltrates in chronic gastritis by light microscopy and immunohistochemistry. The data obtained indicate that stimulation of H. pylori immune system cells of the host organism during development of chronic gastritis causes increase in number of macrophages and lymphocytes in the inflammatory infiltrate of the gastric mucosa. This is accompanied with increased expression of inducible NO-synthase with excess free radicals in the tissues, which leads to secondary alterations and exacerbates the inflammation with impaired regeneration processes.
Interleukin 6 (IL-6), promptly and transiently produced in response to infections and tissue injuries, contributes to host defense through the stimulation of acute phase responses, hematopoiesis, and immune reactions. Although its expression is strictly controlled by transcriptional and posttranscriptional mechanisms, dysregulated continual synthesis of IL-6 plays a pathological effect on chronic inflammation and autoimmunity. For this reason, tocilizumab, a humanized anti-IL-6 receptor antibody was developed. Various clinical trials have since shown the exceptional efficacy of tocilizumab, which resulted in its approval for the treatment of rheumatoid arthritis and juvenile idiopathic arthritis. Moreover, tocilizumab is expected to be effective for other intractable immune-mediated diseases. In this context, the mechanism for the continual synthesis of IL-6 needs to be elucidated to facilitate the development of more specific therapeutic approaches and analysis of the pathogenesis of specific diseases.
Silymarin, a mixture of flavonolignans exhibiting many pharmacological activities, is obtained from the fruits of milk thistle
(Silybum marianum L. Gaertner). Due to the high lipid content in thistle fruits, the European Pharmacopoeia recommends a two-step process of
its extraction. First, the fruits are defatted for 6 h, using n-hexane; second, silymarin is extracted with methanol for 5 more hours. The presented data show that this extremely long traditional
Soxhlet extraction process can be shortened to a few minutes using pressurized liquid extraction (PLE). PLE also allows to
eliminate the defatting stage required in the traditional procedure, thus simplifying the silymarin extraction procedure and
preventing silymarin loss caused by defatting. The PLE recoveries obtained under the optimized extraction conditions are clearly
better than the ones obtained by the Pharmacopoeia-recommended Soxhlet extraction procedure. The PLE yields of silychristin,
silydianin, silybin A, silybin B, isosilybin A and isosilybin B in acetone are 3.3, 6.9, 3.3, 5.1, 2.6 and 1.5 mg/g of the
non-defatted fruits, respectively. The 5-h Soxhlet extraction with methanol on defatted fruits gives only ∼72% of the silymarin
amount obtained in 10 min PLE at 125°C.
Helicobacter pylori (H. pylori) infection underlies gastric ulcer disease, gastric cancer and duodenal ulcer disease. The disease expression reflects the pattern and extent of gastritis/gastric atrophy (i.e., duodenal ulcer with non-atrophic and gastric ulcer and gastric cancer with atrophic gastritis). Gastric and duodenal ulcers and gastric cancer have been known for thousands of years. Ulcers are generally non-fatal and until the 20th century were difficult to diagnose. However, the presence and pattern of gastritis in past civilizations can be deduced based on the diseases present. It has been suggested that gastric ulcer and duodenal ulcer both arose or became more frequent in Europe in the 19th century. Here, we show that gastric cancer and gastric ulcer were present throughout the 17th to 19th centuries consistent with atrophic gastritis being the predominant pattern, as it proved to be when it could be examined directly in the late 19th century. The environment before the 20th century favored acquisition of H. pylori infection and atrophic gastritis (e.g., poor sanitation and standards of living, seasonal diets poor in fresh fruits and vegetables, especially in winter, vitamin deficiencies, and frequent febrile infections in childhood). The latter part of the 19th century saw improvements in standards of living, sanitation, and diets with a corresponding decrease in rate of development of atrophic gastritis allowing duodenal ulcers to become more prominent. In the early 20th century physician's believed they could diagnose ulcers clinically and that the diagnosis required hospitalization for "surgical disease" or for "Sippy" diets. We show that while H. pylori remained common and virulent in Europe and the United States, environmental changes resulted in changes of the pattern of gastritis producing a change in the manifestations of H. pylori infections and subsequently to a rapid decline in transmission and a rapid decline in all H. pylori-related diseases.
We demonstrate herein that silibinin, a polyphenolic flavonoid compound isolated from milk thistle (Silybum marianum), inhibits LPS-induced activation of macrophages and production of nitric oxide (NO) in RAW 264.7 cells. Western blot analysis showed silibinin inhibits iNOS gene expression. RT-PCR showed that silibinin inhibits iNOS, TNF-α, and IL1β. We also showed that silibinin strongly inhibits p38 MAPK phosphorylation, whereas the ERK1/2 and JNK pathways are not inhibited. The p38 MAPK inhibitor abrogated the LPS-induced nitrite production, whereas the MEK-1 inhibitor did not affect the nitrite production. A molecular modeling study proposed a binding pose for silibinin targeting the ATP binding site of p38 MAPK (1OUK). Collectively, this series of experiments indicates that silibinin inhibits macrophage activation by blocking p38 MAPK signaling.
In view of the world wide prevalence of Helicobacter pylori infection, its potentially serious consequences, and the increasing emergence of antibiotic resistant H. pylori strains there is an urgent need for the development of alternative strategies to combat the infection. In this study it has been demonstrated that polyethyleneimine (PEI) functionalized zinc oxide (ZnO) nanoparticles (NPs) inhibit the growth of a metronidazole-resistant strain of H. pylori and the molecular basis of the anti-bacterial activity of ZnO-PEI NP has been investigated. The ZnO-PEI NP was synthesized using a wet chemical method with a core size of approximately 3-7 nm. Internalization and distribution of ZnO-PEI NP without agglomeration was observed in H. pylori cytosol by electron microscopy. Several lines of evidence including scanning electron microscopy, propidium iodide uptake and ATP assay indicate severe membrane damage in ZnO-PEI NP treated H. pylori. Intracellular ROS generation increased rapidly following the treatment of H. pylori with ZnO-PEI NP and extensive degradation of 16S and 23S rRNA was observed by quantitative reverse-transcriptase PCR. Finally, considerable synergy between ZnO-PEI NP and antibiotics was observed and it has been demonstrated that the concentration of ZnO-PEI NP (20 µg/ml) that is non-toxic to human cells could be used in combination with sub-inhibitory concentrations of antibiotics for the inhibition of H. pylori growth.
Natural compounds commonly found in foods may contribute to protect cells against the deleterious effects of inflammation. These anti-inflammatory properties have been linked to the modulation of transcription factors that control expression of inflammation-related genes, including the inducible nitric oxide synthase (iNOS), rather than a direct inhibitory action on these proteins. In this study, forty two natural dietary compounds, known for their ability to exert an inhibitory effect on the expression of iNOS, have been studied in silico as docking ligands on two available 3D structures for this protein (PDB ID: 3E7G and PDB ID: 1NSI). Natural compounds such as silibinin and cyanidin-3-rutinoside and other flavonoids showed the highest theoretical affinities for iNOS. Docking affinity values calculated for several known iNOS inhibitors significatively correlated with their reported half maximal inhibitory concentrations (R = 0.842, P < 0.0001), suggesting the computational reliability of the predictions made by our docking simulations. Moreover, docking affinity values for potent iNOS inhibitors are of similar magnitude to those obtained for some studied natural products. Results presented here indicate that, in addition to gene expression modulation of proteins involved in inflammation, some chemicals present in food may be acting by direct binding and possible inhibiting actions on iNOS.
Tumor necrosis factor (TNF)-alpha is one of the pro-inflammatory cytokines highly expressed in Helicobacter pylori that inhibits gastric acid secretion. In this study we determined the effect of silibinin on TNF-alpha-induced MMP-9 expression in gastric cancer cell lines. MMP-9 mRNA and protein expression was dose-dependently increased by TNF-alpha in SNU216 and SNU668 gastric cancer cells. On the other hand, TNF-alpha-induced MMP-9 expression was dose-dependently suppressed by silibinin. To verify the regulatory mechanism of silibinin on TNF-alpha-induced MMP-9 expression, the gastric cancer cell lines were pretreated with silibinin prior to TNF-alpha. TNF-alpha-induced MMP-9 expression was inhibited by the MEK1/2 specific inhibitor, UO126. Finally, we investigated the effect of adenoviral constitutively active (CA)-MEK and CA-Akt on MMP-9 expression. The expression of MMP-9 was significantly increased by CA-MEK overexpression, but not by CA-Akt overexpression. Taken together, we suggest that silibinin down-regulates TNF-alpha- induced MMP-9 expression through inhibition of the MEK/ERK pathway in gastric cancer cells.
The production of tumour necrosis factor alpha (TNF alpha) and interleukin-6 by human antral mucosa during short term culture in vitro has been measured by enzyme linked immunosorbent assay. TNF alpha and interleukin-6 concentrations in culture supernatants were significantly greater (p less than 0.001) in patients infected with Helicobacter pylori, all of whom had chronic gastritis, than in patients who were H pylori negative with histologically normal gastric mucosa. Among H pylori colonised patients, TNF alpha concentrations were significantly higher in those with active gastritis and neutrophil infiltration into the epithelium than in those with inactive gastritis. In contrast, interleukin-6 concentrations were raised in both active and inactive gastritis. This study shows that H pylori gastritis is associated with increased gastric mucosal production of TNF alpha and interleukin-6 and that the nature of the mucosal cytokine response varies with the immunohistology of the disease. Inflammatory cytokines generated locally within the gastric mucosa could be relevant to the gastric physiology of H pylori infection.
Helicobacter pylori is a gram-negative bacterium which causes chronic gastritis and plays important roles in peptic ulcer disease, gastric carcinoma, and gastric lymphoma. H. pylori has been found in the stomachs of humans in all parts of the world. In developing countries, 70 to 90% of the population carries H. pylori. In developed countries, the prevalence of infection is lower. There appears to be no substantial reservoir of H. pylori aside from the human stomach. Transmission can occur by iatrogenic, fecal-oral, and oral-oral routes. H. pylori is able to colonize and persist in a unique biological niche within the gastric lumen. All fresh isolates of H. pylori express significant urease activity, which appears essential to the survival and pathogenesis of the bacterium. A variety of tests to diagnose H. pylori infection are now available. Histological examination of gastric tissue, culture, rapid urease testing, DNA probes, and PCR analysis, when used to test gastric tissue, all require endoscopy. In contrast, breath tests, serology, gastric juice PCR, and urinary excretion of [15N]ammonia are noninvasive tests that do not require endoscopy. In this review, we highlight advances in the detection of the presence of the organism and methods of differentiating among types of H. pylori, and we provide a background for appropriate chemotherapy of the infection.
The penicillin-binding proteins (PBPs) of helical (log-phase) Helicobacter pylori ATCC 43579 were identified by using biotinylated ampicillin. The major PBPs had apparent molecular masses of 47, 60, 63, and 66 kDa; an additional minor PBP of 95 to 100 kDa was also detected. The relative affinities of various beta-lactams for these PBPs were tested by competitive-binding assays. Only PBP63 appeared to be significantly bound to each of the competing antibiotics, whereas PBP66 strongly bound mezlocillin, oxacillin, amoxicillin, and ceftriaxone. Whereas most of the beta-lactams significantly bound two or more PBPs, aztreonam specifically targeted PBP63. The influence of sub-MICs of these beta-lactams on the morphologies of log-phase H. pylori was observed at both the phase-contrast and transmission electron microscopy levels. Each of the eight beta-lactams examined induced blebbing and sphere formation, whereas aztreonam was the only antibiotic studied which induced pronounced filamentation in H. pylori. Finally, studies comparing the PBPs of helical (log-phase) cultures with those of coccoid (7-, 14-, and 21-day-old) cultures of H. pylori revealed that the major PBPs at 60 and 63 kDa seen in the helical form were almost undetectable in the coccoid forms, whereas PBP66 remained the major PBP in the coccoid forms, although somewhat reduced in level compared to the helical form. PBP47 was present in both forms at approximately equal concentrations. These studies thus identified the major PBPs in both helical and coccoid forms of H. pylori and compared the relative affinities of seven different beta-lactams for the PBPs in the helical forms and their effects on bacterial morphology.
H. pylori is one of the most common bacterial infections in human beings, and its discovery 20 years ago altered the diagnosis and treatment of gastroduodenal disease. This review considers current knowledge about the epidemiology and transmission of H. pylori, as well as the role of this infectious agent in the pathogenesis of upper gastrointestinal tract disease. Diagnostic approaches, indications for therapy, and measures of therapeutic efficacy are reviewed.
Silibinin is a major component of Silymarin mixture (Silybum marianum), which has traditionally been used to treat a wide range of liver diseases. Recently, Silibinin and its flavonoid derivatives in several in vitro models have shown a significant inhibitory effect in different types of tumors including skin, breast, lung, colon, bladder, prostate, kidney and liver. The chemo-preventive potentials of this flavonoid are promoted by inducing apoptosis, enhancing tumor suppressor and cell cycle inhibitors, inhibiting growth factors, attenuating proliferative mediators, and having anti-angiogenic properties. In the present review study, a summary of the main molecular mechanisms involved in Silibinin anti-cancer effects, up to date utilities and important clinical trials have been presented. In the near future, the results of these studies will provide a more comprehensive perspective of Silibinin and help to optimize its pharmaceutical properties in cancer chemotherapeutic regimens.
Acidification of the gastric lumen poses a barrier to transit of potentially pathogenic bacteria and enables activation of pepsin to complement nutrient proteolysis initiated by salivary proteases. Histamine-induced activation of the protein kinase A signaling pathway in gastric corpus parietal cells causes insertion of proton pumps into their apical plasma membranes. Parietal cell secretion and homeostasis are regulated by signaling pathways that control cytoskeletal changes required for apical membrane remodeling and organelle and proton pump activities. Helicobacter pylori colonization of human gastric mucosa affects gastric epithelial cell plasticity and homeostasis, promoting epithelial progression to neoplasia. By intervening in proton pump expression, H pylori regulates the abundance and diversity of microbiota that populate the intestinal lumen. We review stimulation-secretion coupling and renewal mechanisms in parietal cells and the mechanisms by which H pylori toxins and effectors alter cell secretory pathways (constitutive and regulated) and organelles to establish and maintain their inter- and intra-cellular niches. Studies of bacterial toxins and their effector proteins have provided insights into parietal cell physiology and the mechanisms by which pathogens gain control of cell activities, increasing our understanding of gastrointestinal physiology, microbial infectious disease, and immunology.
Milk thistle (MT; Silybum marianum), a member of the Asteraceae family, is a therapeutic herb with a 2,000‐year history of use. MT fruits contain a mixture of flavonolignans collectively known as silymarin, being silybin (also named silibinin) the main component. This article reviews the chemistry of MT, the pharmacokinetics and bioavailability, the pharmacologically relevant actions for liver diseases (e.g., anti‐inflammatory, immunomodulating, antifibrotic, antioxidant, and liver‐regenerating properties) as well as the clinical potential in patients with alcoholic liver disease, nonalcoholic fatty liver disease, viral hepatitis, drug‐induced liver injury, and mushroom poisoning. Overall, literature data suggest that, despite encouraging preclinical data, further well‐designed randomized clinical trials are needed to fully substantiate the real value of MT preparations in liver diseases.
Gastric cancer (GC) is the 3rd leading cause of tumor‑associated mortality worldwide. The efficacy of paclitaxel, a frequently used GC chemotherapeutic agent, is hindered due to drug resistance, dose‑induced toxicity and adverse side effects. Silibinin, an active compound of a widely consumed dietary supplement, milk thistle extract, has recently been demonstrated to have strong antitumor efficacy in a human GC cell model. Thus, to enhance the efficacy of GC treatment, the present study evaluated whether silibinin exerted a synergistic therapeutic effect with paclitaxel. It was observed that the combination of silibinin‑paclitaxel was able to trigger cell cycle arrest and apoptosis. The cell cycle arrest assay indicated that silibinin and paclitaxel alone induced a G2/M phase arrest, and the silibinin‑paclitaxel combination strongly inhibited G2/M cells from entering the S phase. The apoptosis assay and western blot analysis of poly‑ADP‑ribose polymerase, pro‑caspase 3 and pro‑caspase 8 demonstrated that silibinin synergized with paclitaxel in promoting SGC‑7901 GC cell apoptosis. Furthermore, upregulation of the ratio of apoptosis regulator Bcl‑2/apoptosis regulator BAX and tumor necrosis factor receptor superfamily member 6 (Fas)/Fas ligand indicated that the silibinin‑paclitaxel combination activated the death receptor‑mediated pathway in SGC‑7901 cells. The results of the present study suggested that silibinin enhanced the therapeutic potential of paclitaxel against human GC SGC‑7901 cells.
Purpose:
To investigate the effects of silibinin, a natural compound, on the proliferation and apoptosis of BGC-823 gastric cancer cell line and to figure out the relevant pathways.
Methods:
BGC-823 gastric cancer cells were treated with silibinin at various concentrations (0,25,50,100,150 and 200μM). Zero μM was the control group and the other concentrations were defined as the experimental groups. The effects of silibinin on the proliferation of BGC-823 gastric cancer cells were explored through methylthiazolyldiphenyltetrazolium bromide (MTT). Silibinin's toxic effects were detected through determination of the concentration of lactic dehydrogenase (LDH). Flow cytometry was performed to explore the effects of silibinin on apoptosis of these cells. Western blotting was conducted to study the relevant pathways acting on the BGC-823 cells.
Results:
MTT assay showed that with the increase in silibinin concentration and extension of exposure time, the inhibitory effect silibinin on cell proliferation was enhanced in an obvious time-dosage pattern. The results of LDH detection showed that the toxicity of silibinin to cells was enhanced in an obvious time-dosage pattern with the increase in drug concentration and extension of exposure time. Flow cytometry revealed that with the increase in drug concentration, gradual increase in the proportion of early and late of apoptotic cells took place, and the comparison between the experimental and the control group showed that the difference had statistical significance. Western blotting indicated that silibinin could upregulate the expression of mitochondrial apoptosis-associated proteins, and the difference in comparison with the control group had statistical significance.
Conclusion:
Silibinin can inhibit the proliferation of BGC- 823 gastric cancer cells, and such an inhibitory effect is time- and concentration-dependent. Additionally, silibinin can promote the apoptosis of BGC-823 gastric cancer cells, which may be realized through mitochondrial apoptosis.
Background:
Although many epidemiologic studies have evaluated the effect of Helicobacter pylori eradication on gastric cancer, the effect is still uncertain in general populations. We evaluated whether H. pylori eradication would affect the incidence of gastric cancer in healthy asymptomatic populations.
Materials and methods:
We performed a retrospective cohort study in 38 984 asymptomatic individuals, who underwent health screening examinations more than twice between 2005 and 2016. We investigated the incidence of gastric cancer among 3 groups: those without H. pylori infection (Hp-negative group), those with H. pylori eradication (eradication group), and those without H. pylori eradication (non-eradication group).
Results:
The cumulative incidence of gastric cancer was 54.5 cases per 100 000 person-years during a median of 6.4 years. In a multivariate analysis using the Cox proportional hazard model, the cumulative incidence of gastric cancer in the non-eradication group was significantly higher than those in the Hp-negative (hazard ratio [HR] 4.12, P < .001) and eradication groups (HR 2.73, P = .001). However, the cumulative incidence of gastric cancer was not significantly different between the eradication and Hp-negative groups. Other risk factors for gastric cancer occurrence were age, smoking, family history of gastric cancer, and gastric atrophy. The standardized incidence ratios of the age groups above 40 and below 70 in the eradication group were all significantly decreased.
Conclusions:
Helicobacter pylori eradication reduced the cumulative incidence of gastric cancer in healthy asymptomatic population, and the effect of H. pylori eradication on the prevention of gastric cancer was observed in all ages.
Silibinin is the major active component of silymarin, extracted from medicinal plant Silybum marianum. Silibinin has potent antibacterial activity; however, the exact mechanism underlying its activity has not been elucidated. Here, we investigated the novel mechanism of silibinin against Escherichia coli. Time-kill kinetic assay showed that silibinin possess a bactericidal effect at minimal inhibitory concentration (MIC) and higher concentrations (two and four-fold MIC). At the membrane depolarization and increased intracellular Ca²⁺ levels were observed, considered as characteristics of bacterial apoptosis. Additionally, cells treated with MIC and higher concentrations showed apoptotic features like DNA fragmentation, phosphatidylserine exposure, and caspase-like protein expression. Generally, apoptotic death is closely related with ROS generation, however, silibinin did not induce ROS generation but acted as a scavenger of intracellular ROS. These results indicate that silibinin dose-dependently induces bacterial apoptosis-like death and affected by ROS depletion, suggesting that silibinin is a potential candidate for controlling bacteria.
The objective of the present study was to observe the effects of silibinin and the p38 mitogen-activated protein kinase (MAPK) signaling pathway inhibitor SB203580 on the migra- tion and invasion capabilities of SGC7901 cells, and to explore the underlying associated mechanisms. Scratch, Transwell and Matrigel invasion assays were performed to study the effects of silibinin on cell migration and invasion. Western blot analysis was used to determine the expression levels of p38MAPK, phos- phorylated (p-)p38MAPK, matrix metalloproteinase (MMP)-2 and MMP-9. At the genomic level, quantitative polymerase chain reaction was performed to evaluate the expression levels of MMP-2 and MMP-9. The results of scratch assay indicated that silibinin inhibited the migration capabilities of human gastric cancer SGC7901 cells in a dose-dependent manner. Additionally, Matrigel invasion and Transwell migration assays revealed that silibinin and SB203580 combined treatment significantly reduced the number of invasive cells. Western blot analysis indicated a reduced phosphorylation of p38MAPK without marked changes in p38MAPK expression. In addition, the expression of MMP-2 and MMP-9 significantly decreased in the presence of silibinin, SB203580, and the combination of silibinin and SB203580. In summary, silibinin decreased the invasion and migration abilities of SGC7901 cells by downregu- lating the expression of MMP-2 and MMP-9 through inhibiting p38MAPK signaling cascades.
The extract from milk thistle (Silybum marianum (L.) Gaertn. (Asteraceae)), known as silymarin, contains a variety of flavonolignans and displays antioxidant, anti-inflammatory, immunomodulatory and hepatoprotective properties. As silybin is the main component of silymarin, the literature mainly focuses on this compound, ignoring all other components. This leads to problems in reproducibility of scientific results, as the exact composition of silymarin is often unknown and can vary to a certain degree depending on the processing, chemo-variety of the plant used and climatic conditions during the plant growth. There are studies dealing with the analytical separation and quantification of silymarin components as well as studies focused on silymarin content in clinically used drugs, in various plant parts, seasons, geographic locations etc. However, no comparison of detail flavonolignan profiles in various silymarin preparations is available to date. Also, as a result of the focus on the flavonolignans; the oil fraction, which contains linoleic, oleic and palmitic acids, sterols, tocopherol (vitamin E) and phospholipids, has been neglected. Due to all these factors, the whole plant is used e.g. as animal feed, the leaves can be eaten in salads and seed oil, besides culinary uses, can be also utilized for biodiesel or polymer production. Various HPLC separation techniques for the determination of the content of the flavonolignans have been vastly summarized in the present review.
Limited treatment options in infectious diseases caused by resistant microorganisms created the need to search new approaches. Several herbal extracts are studied for their enormous therapeutic potential. Silymarin extract, from Silybum marianum (milk thistle), is an old and a new remedy for this goal. The purpose of this study is to evaluate the antibacterial and antiadherent effects of silymarin besides biofilm viability activity on standard bacterial strains. Minimal inhibitory concentration (MIC), minimal bactericidal concentration (MBC), antiadherent/antibiofilm activity, and effects on biofilm viability of silymarin were evaluated against standard bacterial strains. MIC values were observed between 60 and >241 μg/mL (0.25->1 mmol/L). Gram-positive bacteria were inhibited at concentrations between 60 and 120 μg/mL. Gram-negative bacteria were not inhibited by the silymarin concentrations included in this study. MBC values for Gram-positive bacteria were greater than 241 μg/mL. Adherence/biofilm formations were decreased to 15 μg/mL silymarin concentration when compared with silymarin-untreated group. Silymarin reduced the biofilm viabilities to 13 and 46 % at 1 and 0.5 mmol/L concentrations, respectively. We demonstrated that silymarin shows antibacterial and antiadherent/antibiofilm activity against certain standard bacterial strains which may be beneficial when used as a dietary supplement or a drug.
Background:
To investigate the effect of silibinin on proliferation and apoptosis in human gastric cancer cell line MGC803 and its possible mechanisms.
Materials and methods:
Human gastric cancer cell line MGC803 cells were treated with various concentration of silibinin. Cellular viability was assessed by CCK-8 assay and apoptosis and cell cycle distribution by flow cytometry. Protein expression and mRNA of STAT3, and cell cycle and apoptosis regulated genes were detected by Western blotting and real-time polymerase chain reaction, respectively.
Results:
Silibinin inhibits growth of MGC803 cells in a dose- and time-dependent manner. Silibinin effectively induces apoptosis of MGC803 cells and arrests MGC803 cells in the G2/M phase of the cell cycle, while decreasing the protein expression of p-STAT3, and of STAT3 downstream target genes including Mcl-1, Bcl-xL, survivin at both protein and mRNA levels. In addition, silibinin caused an increase in caspase 3 and caspase 9 protein as well as mRNA levels. Silibinin caused G2/M phage arrest accompanied by a decrease in CDK1 and Cyclin B1 at protein and mRNA levels..
Conclusions:
These results suggest that silibinin inhibits the proliferation of MGC803 cells, and it induces apoptosis and causes cell cycle arrest by down-regulating CDK1, cyclinB1, survivin, Bcl-xl, Mcl-1 and activating caspase 3 and caspase 9, potentially via the STAT3 pathway.
Background
Helicobacter pylori infection is a strong risk factor for gastric cancer, likely due to the extensive inflammation in the stomach mucosa caused by these bacteria. Many studies have reported an association between IL10 polymorphisms, the risk of gastric cancer, and IL-10 production. The aim of the study was to evaluate the association between IL10 genetic variants, Helicobacter pylori infection, and IL-10 production by peripheral blood leukocytes in children.Materials and Methods
We genotyped a total of 12 single nucleotide polymorphisms in IL10 in 1259 children aged 4–11 years living in a poor urban area in Salvador, Brazil, using TaqMan probe based, 5′ nuclease assay minor groove binder chemistry. Association tests were performed by logistic regression for Helicobacter pylori infection and linear regression for IL-10 spontaneous production (whole-blood cultures) including sex, age, and principal components for informative ancestry markers as covariates, using PLINK.ResultsOur results shown that IL10 single nucleotide polymorphisms rs1800896 (OR = 1.63; 95% CI = 1.11–2.39), rs3024491 (OR = 1.71; 95% CI = 1.14–2.57), rs1878672 (OR = 1.79; 95% CI = 1.19–2.68), and rs3024496 (OR = 1.48; 95% CI = 1.05–2.08) were positively associated with Helicobacter pylori infection. Eight single nucleotide polymorphisms were associated with spontaneous production of IL-10 in culture, of which three (rs1800896 and rs1878672, p = .04; rs3024491, p = .01) were strongly associated with infection by Helicobacter pylori.Conclusions
Our results indicate that IL10 variants rs1800896, rs3024491, rs1878672, and rs3024496 are more consistently associated with the presence of anti-H. pylori IgG by inducing increased production of IL-10. Further studies are underway to elucidate the role of additional genetic variants and to investigate their impact on the occurrence of gastric cancer.
Sphingoid bases found in the outer layers of the skin exhibit antimicrobial activity against gram-positive and gram-negative bacteria. We investigated the uptake of several sphingoid bases by Escherichia coli and Staphylococcus aureus, and assessed subsequent ultrastructural damage. E. coli and S. aureus were incubated with D-sphingosine, dihydrosphingosine, or phytosphingosine at ten times their MIC for 0.5 and 4 h, respectively, to kill 50% of viable bacteria. Treated bacterial cells were immediately prepared for SEM, TEM, and analyzed for lipid content by QTLC. E. coli and S. aureus treated with sphingoid bases were distorted and their surfaces were concave and rugate. Significant differences were observed in the visual surface area relative to controls for both E. coli and S. aureus when treated with dihydrosphingosine and sphingosine (p < 0.0001) but not phytosphingosine. While sphingoid base-treated S. aureus exhibited disruption and loss of cell wall and membrane, E. coli cytoplasmic membranes appeared intact and the outer envelope uncompromised. Both E. coli and S. aureus cells contained unique internal inclusion bodies, likely associated with cell death. QTLC demonstrated extensive uptake of sphingoid bases by the bacteria. Hence, sphingoid bases induce both extracellular and intracellular damage and cause intracellular inclusions that may reflect lipid uptake.
The cytotoxic activities of crude extract and pure licamichauxiioic-B compound from stem and root parts of Licania michauxii Prance (LMP) plant were evaluated against brine shrimp larvae and cell cultures. Under in vivo. shrimp assay, both crude extract and the purified compound were active with ED50 values of 122.5 and 32.1 µg/ml, respectively. When tested in four human cancer cell lines, namely, CL-187 (colon adenocarcinoma), MCF-7 (hormone-dependent breast carcinoma), MDA-MB-231 (hormone-independent breast carcinoma), and CRL-2547 (pancreatic carcinoma), the pure compound exhibited 1.5- to about 3-times greater cytotoxic activity than the crude extract. In all cancer cell lines, the LD50 values of crude extract ranged from 33.8 ± 0.9 to 88.1 ± 3.6 µg/ml, while with pure compound the values ranged from 21.6 ± 1.2 to 31.8 ± 4.2 µg/ml. In a noncancerous normal mouse adipose areolar (CCL-1 NCTC clone 929) cell line, the pure compound was found to have an LD50 value greater than 100 µg/ml. Comparison of cytotoxic results of cell cultures revealed that the pure licamichauxiioic-B compound was relatively inactive in noncancerous cell line. The selectivity index for the pure licamichauxiioic-B compound is greater than 3.14 in all cancer cell lines tested.
Silibinin, a flavonoid compound, has shown to be of chemopreventive potential against many cancers. However, its efficacy against gastric cancer has not been well elucidated. Here, we assessed the activity of Silibinin on apoptosis and cell-cycle arrest in human gastric cells culture system using SGC-7901 as the model. Silibinin treatment could inhibit the cell growth and cause a prominent G(2) phase arrest and apoptosis in dose- and time-dependent manner. In mechanistic studies, Silibinin decreased the protein level of p34cdc2, which might be the possible molecular mechanism of Silibinin efficacy on the growth inhibition in SGC-7901 cells. In addition, Silibinin caused an increase in p53 and p21 protein level as well as mRNA levels. Interestingly, Silibinin-induced apoptosis in SGC-7901 cells was independent of caspases activation. These results indicated that Silibinin is a cell-cycle regulator and apoptosis inducer in human gastric carcinoma SGC-7901 cells and might be used as a candidate chemopreventive agent for gastric carcinoma prevention and intervention. Copyright © 2012 John Wiley & Sons, Ltd.
The probable cross talk among large numbers of inflammatory and angiogenic parameters in indomethacin (IND)-induced gastropathy and the associated signaling mechanism were studied in a mouse model. A single dose of IND (18 mg/kg, po) produced robust gastric ulceration in mice without any mortality, which peaked on the third day, but started healing from the fifth day onward. The ulceration was associated with increased myeloperoxidase activity and expression of proinflammatory (TNF-α, adhesion molecules, COX-2) and antiangiogenic (endostatin) parameters. The levels of proangiogenic factors such as COX-1, prostaglandin E, VEGF, and von Willebrand factor VIII were downregulated by IND. Our results revealed that although the maximal and minimal levels of these parameters were attained sequentially at different time points, TNF-α upregulation was the primary event to initiate and induce gastric ulceration. IND also activated NF-κB and all the MAP kinases, but only the inhibitors of TNF-α, NF-κB, and JNK MAP kinase could abrogate the IND-induced damages. Further TNF-α inhibition also reduced the IND-mediated activation of NF-κB and JNK MAP kinase. All this evidence strongly suggests that mitigation of TNF-α may offer a potential solution to IND-mediated gastropathy.
Some natural products consisting of the alkaloids yohimbine and vincamine (indole-type), scopolamine and atropine (tropane-type), colchicine (tropolone-type), allantoin (imidazolidine-type), trigonelline (pyridine-type) as well as octopamine, synephrine, and capsaicin (exocyclic amine-type); the flavonoid derivatives quercetin, apigenin, genistein, naringin, silymarin, and silibinin; and the phenolic acids namely gallic acid, caffeic acid, chlorogenic acid, and quinic acid, were tested for their in vitro antiviral, antibacterial, and antifungal activities and cytotoxicity.
Antiviral activity of the compounds was tested against DNA virus herpes simplex type 1 and RNA virus parainfluenza (type-3). Cytotoxicity of the compounds was determined using Madin-Darby bovine kidney and Vero cell lines, and their cytopathogenic effects were expressed as maximum non-toxic concentration. Antibacterial activity was assayed against following bacteria and their isolated strains: Escherichia coli, Pseudomonas aeruginosa, Proteus mirabilis, Klebsiella pneumoniae, Acinetobacter baumannii, Staphylococcus aureus, Enterococcus faecalis, and Bacillus subtilis, although they were screened by microdilution method against two fungi: Candida albicans and Candida parapsilosis.
Atropine and gallic acid showed potent antiviral effect at the therapeutic range of 0.8-0.05 µg ml(-1), whilst all of the compounds exerted robust antibacterial effect.
Antiviral and antimicrobial effects of the compounds tested herein may constitute a preliminary step for further relevant studies to identify the mechanism of action.
Silybum marianum or milk thistle (MT) is the most well-researched plant in the treatment of liver disease. The active complex of MT is a lipophilic extract from the seeds of the plant and is composed of three isomer flavonolignans (silybin, silydianin, and silychristin) collectively known as silymarin. Silybin is a component with the greatest degree of biological activity and makes up 50% to 70% of silymarin. Silymarin is found in the entire plant but it is concentrated in the fruit and seeds. Silymarin acts as an antioxidant by reducing free radical production and lipid peroxidation, has antifibrotic activity and may act as a toxin blockade agent by inhibiting binding of toxins to the hepatocyte cell membrane receptors. In animals, silymarin reduces liver injury caused by acetaminophen, carbon tetrachloride, radiation, iron overload, phenylhydrazine, alcohol, cold ischaemia and Amanita phalloides. Silymarin has been used to treat alcoholic liver disease, acute and chronic viral hepatitis and toxin-induced liver diseases.
The Helicobacter pylori HP-NAP is a dodecameric protein with a three-dimensional structure similar to that of bacterioferritins. Originally defined as neutrophil-activating protein, because of its ability to stimulate neutrophils to produce oxygen radicals, HP-NAP is now considered a crucial factor in driving the Th1 inflammation in H. pylori infection. This review summarizes recent studies that have provided a deeper understanding of the pro-inflammatory and immune modulatory properties of HP-NAP. We first examine the role of this protein in the H. pylori-associated disease, and then we discuss recent findings that support the possibility for HP-NAP to become a new tool for therapeutic strategies aimed at redirecting Th2 into Th1 responses, for example in atopy, vaccinology and cancer immunotherapy.
Biopsy specimens were taken from intact areas of antral mucosa in 100 consecutive consenting patients presenting for gastroscopy. Spiral or curved bacilli were demonstrated in specimens from 58 patients. Bacilli cultured from 11 of these biopsies were gram-negative, flagellate, and microaerophilic and appeared to be a new species related to the genus Campylobacter. The bacteria were present in almost all patients with active chronic gastritis, duodenal ulcer, or gastric ulcer and thus may be an important factor in the aetiology of these diseases.
A tetrazolium salt has been used to develop a quantitative colorimetric assay for mammalian cell survival and proliferation. The assay detects living, but not dead cells and the signal generated is dependent on the degree of activation of the cells. This method can therefore be used to measure cytotoxicity, proliferation or activation. The results can be read on a multiwell scanning spectrophotometer (ELISA reader) and show a high degree of precision. No washing steps are used in the assay. The main advantages of the colorimetric assay are its rapidity and precision, and the lack of any radioisotope. We have used the assay to measure proliferative lymphokines, mitogen stimulations and complement-mediated lysis.
Prediction of small molecule binding modes to macromolecules of known three-dimensional structure is a problem of paramount importance in rational drug design (the "docking" problem). We report the development and validation of the program GOLD (Genetic Optimisation for Ligand Docking). GOLD is an automated ligand docking program that uses a genetic algorithm to explore the full range of ligand conformational flexibility with partial flexibility of the protein, and satisfies the fundamental requirement that the ligand must displace loosely bound water on binding. Numerous enhancements and modifications have been applied to the original technique resulting in a substantial increase in the reliability and the applicability of the algorithm. The advanced algorithm has been tested on a dataset of 100 complexes extracted from the Brookhaven Protein DataBank. When used to dock the ligand back into the binding site, GOLD achieved a 71% success rate in identifying the experimental binding mode.
Silymarin is an antihepatotoxic substance isolated from fruits of Silybum marianum. Possibly due to their antioxidant and membrane stabilizing properties, the compounds have been shown to protect different organs and cells against a number of insults. The content and composition of main silymarin components (silybin, isosilybin, silydianin and silychristin) in various pharmaceuticals were analysed using HPLC and newly developed capillary zone electrophoresis method. Antioxidant properties expressed as total antioxidant status (TAS) of silymarin components were studied. Results of TAS were correlated with electropherograms and chromatograms.
The Chemscore function was implemented as a scoring function for the protein-ligand docking program GOLD, and its performance compared to the original Goldscore function and two consensus docking protocols, "Goldscore-CS" and "Chemscore-GS," in terms of docking accuracy, prediction of binding affinities, and speed. In the "Goldscore-CS" protocol, dockings produced with the Goldscore function are scored and ranked with the Chemscore function; in the "Chemscore-GS" protocol, dockings produced with the Chemscore function are scored and ranked with the Goldscore function. Comparisons were made for a "clean" set of 224 protein-ligand complexes, and for two subsets of this set, one for which the ligands are "drug-like," the other for which they are "fragment-like." For "drug-like" and "fragment-like" ligands, the docking accuracies obtained with Chemscore and Goldscore functions are similar. For larger ligands, Goldscore gives superior results. Docking with the Chemscore function is up to three times faster than docking with the Goldscore function. Both combined docking protocols give significant improvements in docking accuracy over the use of the Goldscore or Chemscore function alone. "Goldscore-CS" gives success rates of up to 81% (top-ranked GOLD solution within 2.0 A of the experimental binding mode) for the "clean list," but at the cost of long search times. For most virtual screening applications, "Chemscore-GS" seems optimal; search settings that give docking speeds of around 0.25-1.3 min/compound have success rates of about 78% for "drug-like" compounds and 85% for "fragment-like" compounds. In terms of producing binding energy estimates, the Goldscore function appears to perform better than the Chemscore function and the two consensus protocols, particularly for faster search settings. Even at docking speeds of around 1-2 min/compound, the Goldscore function predicts binding energies with a standard deviation of approximately 10.5 kJ/mol.
Silybin has a potent antibacterial activity, more potent than silymarin II, against gram-positive bacteria without hemolytic activity, whereas it has no antimicrobial activity against gram-negative bacteria or fungi. The mode of action of silybin against the gram-positive bacterial cell was examined by investigating the change in plasma membrane dynamics of bacterial cells using 1,6-diphenyl-1,3,5-hextriene (DPH) as a membrane probe and by assessing the inhibition of macromolecular synthesis using radiolabeled incorporation assay. The results showed that silybin inhibited RNA and protein synthesis on gram-positive bacteria.
Two pairs of diastereoisomeric flavonolignans, silybin A, silybin B, isosilybin A, and isosilybin B, were successfully separated from Silybum marianum by sequential silica gel column chromatography, preparative reversed-phase HPLC, and recrystallization. Complete stereochemical assignments at C-2, C-3, C-7', and C-8' of these flavonolignans have been achieved. On the basis of X-ray crystallographic analysis and optical rotation data, coupled with comprehensive (1)H and (13)C NMR spectral data interpretation including COSY, HMQC, and HMBC, the stereochemistry of these diastereoisomers was determined unambiguously as silybin A (4), 2R, 3R, 7'R, 8'R; silybin B (5), 2R, 3R, 7'S, 8'S; isosilybin A (6), 2R, 3R, 7'R, 8'R; and isosilybin B (7), 2R, 3R, 7'S, 8'S.