Effect of resveratrol on Helicobacter pylori-induced interleukin-8 secretion, reactive oxygen species generation and morphological changes in human gastric epithelial cells

Antitumor Effects of Resveratrol Opposing Mechanisms of Helicobacter pylori in Gastric Cancer

Gastric cancer is an aggressive and multifactorial disease. Helicobacter pylori (H. pylori) is identified as a significant etiological factor in gastric cancer. Although only a fraction of patients infected with H. pylori progresses to gastric cancer, bacterial infection is critical in the pathology and development of this malignancy. The pathogenic mechanisms of this bacterium involve the disruption of the gastric epithelial barrier and the induction of chronic inflammation, oxidative stress, angiogenesis and metastasis. Adherence molecules, virulence (CagA and VacA) and colonization (urease) factors are important in its pathogenicity. On the other hand, resveratrol is a natural polyphenol with anti-inflammatory and antioxidant properties. Resveratrol also inhibits cancer cell proliferation and angiogenesis, suggesting a role as a potential therapeutic agent against cancer. This review explores resveratrol as an alternative cancer treatment, particularly against H. pylori-induced gastric cancer, due to its ability to mitigate the pathogenic effects induced by bacterial infection. Resveratrol has shown efficacy in reducing the proliferation of gastric cancer cells in vitro and in vivo. Moreover, the synergistic effects of resveratrol with chemotherapy and radiotherapy underline its therapeutic potential. However, further research is needed to fully describe its efficacy and safety in treating gastric cancer.

Helicobacter bilis infection induces oxidative stress in and enhances the proliferation of human cholangiocytes

BACKGROUND

Helicobacter bilis, an enterohepatic Helicobacter species, represents a carcinogenic risk factor for cholangiocytes owing to the prevalence of infections in patients with biliary tract cancer, cholecystitis, and pancreaticobiliary maljunction. However, the effect of H. bilis infection on cholangiocytes and the process and mechanism of carcinogenesis are not known. We aimed to determine the effects of H. bilis on cholangiocytes, focusing on inflammation and oxidative stress.

MATERIALS AND METHODS

Helicobacter bilis and MMNK-1 cells were cocultured for 24 h and inflammatory cytokine secretion was evaluated. Furthermore, MMNK-1 cell proliferation, intracellular reactive oxidant species (ROS) production, and DNA damage caused by ROS were investigated. All factors were compared with and without H. bilis infection.

RESULTS

Interleukin (IL)-6 and IL-8 secretion were significantly increased in MMNK-1 cocultures with H. bilis (IL-6, 24.3 ± 12.2 vs. 271.1 ± 286.4 pg/ml; IL-8, 167.6 ± 78.7 vs. 1085.1 ± 1047.1 pg/ml, p < .05). MMNK-1 proliferation was also significantly higher in H. bilis cocultures (1.05 ± 0.02 vs. 1.00-fold, respectively; p < .05). Coculturing enhanced the production of ROS in MMNK-1 cells depending on the cell concentration of H. bilis (1.0 vs. 1.17 ± 0.06, p < .05); however, DNA injury was not observed in cocultures with H. bilis (5.35 ± 0.87 vs. 6.08 ± 0.55 pg/μl, p = .06).

CONCLUSIONS

Helicobacter bilis infection induced ROS production in and enhanced the proliferation of cholangiocytes.

Quinone Derivatives as Promising Anti-Helicobacter pylori Agents from Aerial Parts of Mitracarpus hirtus

Seven new naphthoquinone diglycosides (1-7), three new anthraquinones (8-10), and eight known analogues were obtained from the aerial parts of Mitracarpus hirtus collected from West Africa in a bioassay-guided phytochemical investigation. All isolated compounds were elucidated by comparison with the literature and interpretation of spectroscopic data, and the absolute configurations of the new naphthoquinone diglycosides (1-10) were confirmed by chemical methods and ECD calculations. Notably, compound 1 was found to be the first naphthoquinone diglycoside containing carboxylic acid and isopentenyl side chains isolated from a species in the genus Mitracarpus. Compounds 6-18 showed antibacterial activity against multiple Helicobacter pylori strains with MIC values ranging from 0.0625 to 64 μg/mL. Particularly, 1-hydroxybenzoisochromanquinone (17) and benzo[g]isoquinoline-5,10-dione (18), with MIC values of 0.0625 and 0.125 μg/mL, displayed 32-512-fold higher potencies than a positive control, metronidazole. Compound 18 also demonstrated high antibiofilm activity and killed biofilm-encased Helicobacter pylori cells more effectively than metronidazole.

Pimarane-derived diterpenoids with anti-Helicobacter pylori activity from the tuber of Icacina trichantha

Two novel diterpenoids and ten known analogs were obtained from the tuber of Icacina trichantha. All compounds exhibited antibacterial activity against Helicobacter pylori strains with MIC values ranging from 8 to 64 μg mL⁻¹.

Mechanisms of resveratrol in the prevention and treatment of gastrointestinal cancer

Gastrointestinal (GI) cancer is one of the leading causes of cancer-related deaths worldwide. According to the Global Cancer Statistics, colorectal cancer is the second leading cause of cancer-related mortality, closely followed by gastric cancer (GC). Environmental, dietary, and lifestyle factors including cigarette smoking, alcohol intake, and genetics are the most important risk factors for GI cancer. Furthermore, infections caused by Helicobacter pylori are a major cause of GC initiation. Despite improvements in conventional therapies, including surgery, chemotherapy, and radiotherapy, the length or quality of life of patients with advanced GI cancer is still poor because of delayed diagnosis, recurrence and side effect. Resveratrol (3, 4, 5-trihydroxy-trans-stilbene; Res), a natural polyphenolic compound, reportedly has various pharmacologic functions including anti-oxidant, anti-inflammatory, anti-cancer, and cardioprotective functions. Many studies have demonstrated that Res also exerts a chemopreventive effect on GI cancer. Research investigating the anti-cancer mechanism of Res for the prevention and treatment of GI cancer has implicated multiple pathways including oxidative stress, cell proliferation, and apoptosis. Therefore, this paper provides a review of the function and molecular mechanisms of Res in the prevention and treatment of GI cancer.

Stilbenoids: A Natural Arsenal against Bacterial Pathogens

The escalating emergence of resistant bacterial strains is one of the most important threats to human health. With the increasing incidence of multi-drugs infections, there is an urgent need to restock our antibiotic arsenal. Natural products are an invaluable source of inspiration in drug design and development. One of the most widely distributed groups of natural products in the plant kingdom is represented by stilbenoids. Stilbenoids are synthesised by plants as means of protection against pathogens, whereby the potential antimicrobial activity of this class of natural compounds has attracted great interest in the last years. The purpose of this review is to provide an overview of recent achievements in the study of stilbenoids as antimicrobial agents, with particular emphasis on the sources, chemical structures, and the mechanism of action of the most promising natural compounds. Attention has been paid to the main structure modifications on the stilbenoid core that have expanded the antimicrobial activity with respect to the parent natural compounds, opening the possibility of their further development. The collected results highlight the therapeutic versatility of natural and synthetic resveratrol derivatives and provide a prospective insight into their potential development as antimicrobial agents.

Grape seed extract: having a potential health benefits

Grapes are one of the most highly consumed fruits across the world. In ancient Europe the leaves and the sap of grape plants has been used in traditional treatment for ages. Besides being a wellspring for vitamins and fibre, the skin and seeds of grapes are highly rich in Polyphenols specifically proanthocyanidins, which can be used as a functional ingredient to address various health issues by boosting the natural bio-processes of the body. Since, grape seeds are by product of wine making companies therefore can be easily procured. The present review article briefly describes the various pharmacological activities of grape seed extract and different experimental studies were done which supports the beneficial health qualities of the extract. Through different and various studies, it was proved that the proanthocyanidin rich grape seed extract provides benefits against many diseases i.e. inflammation, cardiovascular disease, hypertension, diabetes, cancer, peptic ulcer, microbial infections, etc. Therefore, beside from using it as a nutraceutical or cosmeceutical, as a result they may have a potential to substitute or complement in currently used drugs in the treatment of diseases by developing it into other successful pharmaceutical formulations for better future prospective.

Can Diet Modulate Helicobacter pylori-associated Gastric Pathogenesis? An Evidence-Based Analysis

Helicobacter pylori is involved in the pathogenesis of gastritis, peptic ulcer, and gastric cancer. The infection is prevalent in more than half of the world's population. Although the infection may lead to detrimental consequences, still the majority of the infected individuals only develop mild gastritis. Several factors are behind this paradoxical outcome including virulence of the infecting H. pylori strains, genetic background of the host, and factors related to lifestyle such as dietary habits. Among these, lifestyle including dietary factors was not in the limelight, until recently, as one of the important factors that could modulate H. pylori-linked gastric diseases. This review is directed to gather and elucidate the role of dietary components in augmenting or attenuating pathological processes initiated by H. pylori. Available evidence strongly supports the notion that the diet may play a critical role in defining the final outcome of H. pylori infection particularly if certain dietary components are taken on a regular basis for a long time. Despite a recent surge in research related to the role of dietary ingredients, further studies involving large-scale clinical trials are required to gain a better understanding of the precise role played by the dietary ingredients in H. pylori-associated pathogenesis.

New natural amino acid-bearing prodrugs boost pterostilbene's oral pharmacokinetic and distribution profile

The biomedical effects of the natural phenol pterostilbene are of great interest but its bioavailability is negatively affected by the phenolic group in position 4' which is an ideal target for the conjugative enzymes of phase II metabolism. We report the synthesis and characterization of prodrugs in which the hydroxyl moiety is reversibly protected as a carbamate ester linked to the N-terminus of a natural amino acid. Prodrugs comprising amino acids with hydrophobic side chains were readily absorbed after intragastric administration to rats. The Area Under the Curve for pterostilbene in blood was optimal when prodrugs with isoleucine or β-alanine were used. The prodrug incorporating isoleucine was used for further studies to map distribution into major organs. When compared to pterostilbene itself, administration of the isoleucine prodrug afforded increased absorption, reduced metabolism and higher concentrations of pterostilbene, sustained for several hours, in most of the organs examined. Experiments using Caco-2 cells as an in vitro model for human intestinal absorption suggest that the prodrug could have promising absorption profiles also in humans; its uptake is partly due to passive diffusion, and partly mediated by H⁺-dependent transporters expressed on the apical membrane of enterocytes, such as PepT1 and OATP.

Review of the Pharmacological Effects of Vitis vinifera (Grape) and its Bioactive Constituents: An Update

Vitis vinifera fruit (grape) contains various phenolic compounds, flavonoids and stilbenes. In recent years, active constituents found in the fruits, seeds, stems, skin and pomaces of grapes have been identified and some have been studied. In this review, we summarize the active constituents of different parts of V. vinifera and their pharmacological effects including skin protection, antioxidant, antibacterial, anticancer, antiinflammatory and antidiabetic activities, as well as hepatoprotective, cardioprotective and neuroprotective effects in experimental studies published after our 2009 review. Clinical and toxicity studies have also been examined. Copyright © 2016 John Wiley & Sons, Ltd.

Helicobacter pylori associated Asian enigma: Does diet deserve distinction?

Helicobacter pylori (H. pylori) is one of the most widespread infections in humans worldwide that chronically infects up to 50% of the world’s population. The infection is involved in the pathogenesis of chronic active gastritis, peptic ulcer, mucosa-associated lymphoid tissue lymphoma and gastric cancer, therefore, it has been classified as class I definite carcinogen by the World Health Organization. Despite the established etiological role of H. pylori, its actual distribution and association with related diseases is controversial and there is a large intercountry variation especially among Asian countries. H. pylori infection is more frequent in developing countries like India, Pakistan, and Bangladesh as compared to developed Asian countries like Japan, China and South Korea. However, the frequency of gastric cancer is comparatively lower in India, Pakistan, and Bangladesh with that of Japan, China and South Korea. Such phenomenon of clinical diversity, defined as enigma, is judged by genetic variability of the infecting H. pylori strains, differences in the host genetic background in various ethnic groups, and environmental factors such as dietary habits. Most of the studies have so far focused on the bacterial factor while environmental issues, including dietary components, were not given due attention as one of the factors related with H. pylori associated gastric carcinogenesis. The dietary factor has been suggested to play an important role in H. pylori related carcinogenesis, and in this respect several studies have corroborated the intake of various dietary components as modulatory factors for gastric cancer risk. In this review, such studies, from in vitro experiments to clinical trials, are being focused in detail with respect to enigma associated with H. pylori. It may be conceivably concluded from the available evidence that dietary factor can be a game changer in the scenario of Asian enigma, particularly in high risk population infected with virulent H. pylori strains, however further affirmation studies are desperately needed to achieve conclusive outcomes.

Anti-inflammatory effect of cinnamaldehyde in Helicobacter pylori induced gastric inflammation

Cinnamomum cassia is widely employed for gastrointestinal complaints such as dyspepsia, flatulence, diarrhea, and vomiting. Studies report cinnamaldehyde (CM) as a major active constituent of cinnamon. The aim of this study was to evaluate the anti-inflammatory mechanism of CM on Helicobacter (H.) pylori-infected gastric epithelial cells in order to validate cinnamon traditional use in gastrointestinal (GI)-related disorders. AGS/MKN-45 cells and H. pylori (193C) were employed for co-culture experiments. Anti-H. pylori cytotoxic and anti-adhesion activity of CM were determined. Enzyme linked immunosorbent assay, real time polymerase chain reaction analysis and immunoblotting were used to measure the effect on interleukin-8 (IL-8) secretion/expression. The effect on activation of nuclear factor kappa B (NF-κB) was determined by immunoblot analysis. The non-cytotoxic CM (≤125 µM) was also non-bactericidal at the given time, suggesting the effect in H. pylori/cell co-culture system was not due to alteration in H. pylori viability or the toxicity to the cells. Also, CM did not show any anti-adhesion effect against H. pylori/cell co-culture. However, pre-incubation of the cells with CM significantly inhibited the IL-8 secretion/expression from H. pylori-infected cells (p<0.01). In addition, CM suppressed H. pylori-induced NF-κB activation and prevented degradation of inhibitor (I)-κB This study provides evidence that the anti-inflammatory effect of C. cassia on H. pylori-infected gastric cells is due to blockage of the NF-κB pathway by cinnamaldehyde. This agent can be considered as a potential candidate for in vivo and clinical studies against various H. pylori related gastric pathogenic processes.

Glutamine Deprivation Causes Hydrogen Peroxide-induced Interleukin-8 Expression via Jak1/Stat3 Activation in Gastric Epithelial AGS Cells

BACKGROUND

The Janus kinase (Jak)/Signal transducers of activated transcription (Stat) pathway is an upstream signaling pathway for NF-κB activation in Helicobacter pylori-induced interleukin (IL)-8 production in gastric epithelial AGS cells. H. pylori activates NADPH oxidase and produces hydrogen peroxide, which activates Jak1/Stat3 in AGS cells. Therefore, hydrogen peroxide may be critical for IL-8 production via Jak/Stat activation in gastric epithelial cells. Glutamine is depleted during severe injury and stress and contributes to the formation of glutathione (GSH), which is involved in conversion of hydrogen peroxide into water as a cofactor for GSH peroxidase.

METHODS

We investigated whether glutamine deprivation induces hydrogen peroxide-mediated IL-8 production and whether hydrogen peroxide activates Jak1/Stat3 to induce IL-8 in AGS cells. Cells were cultured in the presence or absence of glutamine or hydrogen peroxide, with or without GSH or a the Jak/Stat specific inhibitor AG490.

RESULTS

Glutamine deprivation decreased GSH levels, but increased levels of hydrogen peroxide and IL-8, an effect that was inhibited by treatment with GSH. Hydrogen peroxide induced the activation of Jak1/Stat3 time-dependently. AG490 suppressed hydrogen peroxide- induced activation of Jak1/Stat3 and IL-8 expression in AGS cells, but did not affect levels of reactive oxygen species in AGS cells.

CONCLUSIONS

In gastric epithelial AGS cells, glutamine deprivation increases hydrogen peroxide levels and IL-8 expression, which may be mediated by Jak1/Stat3 activation. Glutamine supplementation may be beneficial for preventing gastric inflammation by suppressing hydrogen peroxide-mediated Jak1/Stat3 activation and therefore, reducing IL-8 production. Scavenging hydrogen peroxide or targeting Jak1/Stat3 may also prevent oxidant-mediated gastric inflammation.

Role of dietary polyphenols in the management of peptic ulcer

Peptic ulcer disease is a multifactorial and complex disease involving gastric and duodenal ulcers. Despite medical advances, the management of peptic ulcer and its complications remains a challenge, with high morbidity and death rates for the disease. An accumulating body of evidence suggests that, among a broad reach of natural molecules, dietary polyphenols with multiple biological mechanisms of action play a pivotal part in the management of gastric and duodenal ulcers. The current review confirmed that dietary polyphenols possess protective and therapeutic potential in peptic ulcer mediated by: improving cytoprotection, re-epithelialization, neovascularization, and angiogenesis; up-regulating tissue growth factors and prostaglandins; down-regulating anti-angiogenic factors; enhancing endothelial nitric oxide synthase-derived NO; suppressing oxidative mucosal damage; amplifying antioxidant performance, antacid, and anti-secretory activity; increasing endogenous mucosal defensive agents; and blocking Helicobacter pylori colonization associated gastric morphological changes and gastroduodenal inflammation and ulceration. In addition, anti-inflammatory activity due to down-regulation of proinflammatory cytokines and cellular and intercellular adhesion agents, suppressing leukocyte-endothelium interaction, inhibiting nuclear signaling pathways of inflammatory process, and modulating intracellular transduction and transcription pathways have key roles in the anti-ulcer action of dietary polyphenols. In conclusion, administration of a significant amount of dietary polyphenols in the human diet or as part of dietary supplementation along with conventional treatment can result in perfect security and treatment of peptic ulcer. Further well-designed preclinical and clinical tests are recommended in order to recognize higher levels of evidence for the confirmation of bioefficacy and safety of dietary polyphenols in the management of peptic ulcer.

Resveratrol suppresses the inflammatory responses of human gingival epithelial cells in a SIRT1 independent manner

BACKGROUND AND OBJECTIVE

In periodontitis, chronic infection by periodontopathic bacteria induces uncontrolled inflammation, which leads to periodontal tissue destruction. Human gingival epithelial cells (HGECs) constitute a critical first line of defense against periodontopathic bacteria, both as a physical barrier and as regulators of inflammation. Resveratrol, a polyphenol found in grapes and red wine, reportedly has anti-inflammatory properties. Therefore, we investigated the effects of resveratrol on the Porphyromonas gingivalis-induced inflammatory responses of HGECs and their mechanism.

MATERIAL AND METHODS

We stimulated the HGEC line, epi 4, with live or heat-killed P. gingivalis in the presence of resveratrol, and analyzed expressions of the interleukin-8, monocyte chemoattractant protein-1 and interleukin-1β genes. We determined the involvement of SIRT1 in the effect of resveratrol using sirtinol (a SIRT1 inhibitor) or SIRT1 knockdown. We also examined whether the effects were mediated by activation of AMP-activated kinase, suppression of reactive oxygen species, or inhibition of nuclear factor-κB (NF-κB).

RESULTS

Resveratrol treatment decreased the expression of inflammatory cytokines and slightly increased the expression of SIRT1. However, neither SIRT1 inhibition nor SIRT1 knockdown counteracted its anti-inflammatory effects. Although resveratrol did not affect AMP-activated kinase activation or reactive oxygen species production, it slightly suppressed NF-κB translocation when cells were stimulated with heat-killed P. gingivalis.

CONCLUSION

Resveratrol suppressed the inflammatory responses of P. gingivalis-stimulated HGECs, probably by inhibiting NF-κB signaling but independent of SIRT1.

Overview of the phytomedicine approaches against Helicobacter pylori

Helicobacter pylori (H. pylori) successfully colonizes the human stomach of the majority of the human population. This infection always causes chronic gastritis, but may evolve to serious outcomes, such as peptic ulcer, gastric carcinoma or mucosa-associated lymphoid tissue lymphoma. H. pylori first line therapy recommended by the Maastricht-4 Consensus Report comprises the use of two antibiotics and a proton-pomp inhibitor, but in some regions failure associated with this treatment is already undesirable high. Indeed, treatment failure is one of the major problems associated with H. pylori infection and is mainly associated with bacterial antibiotic resistance. In order to counteract this situation, some effort has been allocated during the last years in the investigation of therapeutic alternatives beyond antibiotics. These include vaccines, probiotics, photodynamic inactivation and phage therapy, which are briefly revisited in this review. A particular focus on phytomedicine, also described as herbal therapy and botanical therapy, which consists in the use of plant extracts for medicinal purposes, is specifically addressed, namely considering its history, category of performed studies, tested compounds, active principle and mode of action. The herbs already experienced are highly diverse and usually selected from products with a long history of employment against diseases associated with H. pylori infection from each country own folk medicine. The studies demonstrated that many phytomedicine products have an anti-H. pylori activity and gastroprotective action. Although the mechanism of action is far from being completely understood, current knowledge correlates the beneficial action of herbs with inhibition of essential H. pylori enzymes, modulation of the host immune system and with attenuation of inflammation.

Helicobacter pylori infection: A brief overview on alternative natural treatments to conventional therapy

Helicobacter pylori is a human gastric pathogen considered as the etiologic agent of several gastric disorders, that may range from chronic gastritis to more severe outcomes, including gastric cancer. The current therapeutic scheme relies on the combination of several pharmacological substances, namely antibiotics and proton pump inhibitors. However, the cure rates obtained have been declining over the years, mostly due to bacterial resistance to antibiotics. In this context, the use of non-antibiotic substances is of the utmost importance regarding H. pylori eradication. In this review, we present different classes of compounds obtained from natural sources that have shown to present anti-H. pylori potential; we briefly highlight their possible use in the context of developing new therapeutic approaches.

Evaluation of the effect of cagPAI genes of Helicobacter pylori on AGS epithelial cell morphology and IL-8 secretion

Helicobacter pylori cagPAI genes play an important role in pathogenesis, however little is known about their functions in isolates from Turkish patients. We aimed to evaluate the intactness and the effect of the cagPAI genes (cagT, cagM, cagE, cagA) and cagA EPIYA motifs on the AGS morphological changes and IL-8 induction. Of 53 patients 38 were found infected with H. pylori. PCR amplification of the cagPAI genes showed 42.1 % intact, 39.5 % partially deleted and 18.4 % with complete deletions. Isolates from gastritis, duodenal and gastric ulcer patients with intact and partially deleted cagPAI genes induced higher IL-8 secretion than those with complete deletions. Isolates from gastritis patients had higher deletion frequencies of the cagT and cagM genes than the other two genes. Infection of AGS cells with isolates that possess intact cagPAI and EPIYA-ABC resulted in the formation of the hummingbird phenotype. The cagA positive isolates induced higher IL-8 secretion than cagA negative isolates. Isolates from DU patients with more than one EPIYA-C motif induced higher concentrations of IL-8 than those with EPIYA-ABC. In conclusion, the intactness of the cagPAI in our isolates from different patients was not conserved. An intact cagPAI was found to play an important role in the pathogenesis of DU but not GU or gastritis. The cagA gene, but not other cagPAI genes, was associated with the induction of IL-8 and the morphological changes of the AGS cells. An increase in the number of EPIYA-C motifs had noticeable effect on the formation of the hummingbird phenotype.

Scientific evaluation of edible fruits and spices used for the treatment of peptic ulcer in traditional Iranian medicine

In traditional Iranian medicine (TIM), several edible fruits and spices are thought to have protective and healing effects on peptic ulcer (PU). The present study was conducted to verify anti-PU activity of these remedies. For this purpose, edible fruits and spices proposed for the management of PU in TIM were collected from TIM sources, and they were searched in modern medical databases to find studies that confirmed their efficacy. Findings from modern investigations support the claims of TIM about the efficacy of many fruits and spices in PU. The fruit of Phyllanthus emblica as a beneficial remedy for PU in TIM has been demonstrated to have antioxidant, wound healing, angiogenic, anti-H. pylori, cytoprotective, antisecretory, and anti-inflammatory properties. The fruit of Vitis vinifera has been found to be anti-H. pylori, anti-inflammatory, wound healing, angiogenic, cytoprotective, and antioxidant. The fruit and aril of seed from Myristica fragrans exert their beneficial effects in PU by increasing prostaglandin, modulation of nitric oxide and inflammatory mediators, wound healing, antisecretory, antacid, antioxidant, and anti-H. pylori activities, and improving angiogenesis. Pharmacological and clinical studies for evaluation of efficacy of all TIM fruits and spices in PU and their possible mechanisms of action are recommended.

Effects of radix curcumae-derived diterpenoid C on Helicobacter pylori-induced inflammation and nuclear factor kappa B signal pathways

AIM: To study effect of diterpenoid C extracted from radix curcumae on Helicobacter pylori (H. pylori)-infected inflammation, intestinal metaplasia, and nuclear factor kappa B (NF-κB) signaling pathway in vitro.

METHODS: We used I-type H. pylori to infect human gastric epithelial gastric epithelium cell line (GES-1) cell lines, and then H. pylori-infected GES-1 cells were treated with radix curcumae (RC)-derived diterpenoid C of different concentrations (5, 10, 20 μg/mL) and amoxicillin. The expression of p65, IκB kinase (IKK) α and IKKγ proteins was detected with Western blotting, and the expression of interleukin (IL)-8, IL-6 and IL-4 was determined with enzyme-linked immunosorbent assay method. Data were analyzed using SPSS software ver18.0. For comparisons between groups of more than two unpaired values, one-way analysis of variance (ANOVA) was used. If an ANOVA F value was significant, post hoc comparisons were performed between groups. If results were not normally distributed, the Mann-Whitney U test was used to compare two groups of unpaired values, whereas for comparisons between groups of more than two unpaired values, the Kruskal-Wallis H test was used. Statistical significance was established at P < 0.05.

RESULTS: The MTT assay results revealed the inhibited rate of GES-1, and indicated that the IC5 of RC-derived diterpenoid C and amoxicillin all were 5 μg/mL for gastric GES-1 cells. The expression of IL-8 was significantly increased, especially at 12 h time point; and the expression of IL-4 was decreased in H. pylori-infected GES-1 cells. After H. pylori-infected GES-1 cells were treated with RC-derived diterpenoid C of different concentrations and amoxicillin, the expression of IL-8 was decreased at 12, 24, 48, 72 h points (P < 0.01), especially in high-concentration diterpenoid C (20 μg/mL) group; and the expression of IL-4 was increased, especially in moderate and high-concentration diterpenoid C (10 and 20 μg/mL) groups. RC-derived diterpenoid C had the inhibitory effects on H. pylori-induced p65 translocation from cytoplasm into cell nucleus, H. pylori-stimulant IkBα degradation, the phosphorylation of p65 and IkBα, and the expression of IKKα and IKKβ proteins.

CONCLUSION: RC-derived diterpenoid C can block NF-κB signal pathway, effectively reducing the secretion of H. pylori-induced proinflammatory cytokine and increasing the secretion of anti-inflammatory cytokine.

Anthocyanins from black soybean inhibit Helicobacter pylori-induced inflammation in human gastric epithelial AGS cells

Infection with Helicobacter pylori leads to gastritis, peptic ulcers and gastric cancer. Moreover, when the gastric mucosa is exposed to H. pylori, gastric mucosal inflammatory cytokine interleukin-8 (Il-8) and reactive oxygen species increase. Anthocyanins have anti-oxidative, antibacterial and anti-inflammatory properties. However, the effect of anthocyanins in H. pylori-infected cells is not yet clear. In this study, therefore, the effect of anthocyanins on H. pylori-infected human gastric epithelial cells was examined. AGS cells were pretreated with anthocyanins for 24 hrs followed by H. pylori 26695 infection for up to 24 hrs. Cell viability and ROS production were examined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and 2',7'-dichlorofluorescein diacetate assay, respectively. Western blot analyses and RT-PCR were performed to assess gene and protein expression, respectively. IL-8 secretion in AGS cells was measured by ELISA. It was found that anthocyanins decrease H. pylori-induced ROS enhancement. Anthocyanins also inhibited phosphorylation of mitogen-activated protein kinases, translocation of nuclear factor-kappa B and Iκβα degradation. Furthermore anthocyanins inhibited H. pylori-induced inducible nitric oxide synthases and cyclooxygenase-2 mRNA expression and inhibited IL-8 production by 45.8%. Based on the above findings, anthocyanins might have an anti-inflammatory effect in H. pylori-infected gastric epithelial cells.

Resveratrol induces long-lasting IL-8 expression and peculiar EGFR activation/distribution in human keratinocytes: mechanisms and implications for skin administration

Anti-inflammatory and skin tumour preventing effects of resveratrol have been extensively studied pre-clinically and resveratrol has been proposed for clinical investigations. To provide a basis or/and limitations for topical administration to human skin, molecular mechanisms underlying resveratrol effects towards normal human epidermal keratinocytes (NHEK) were evaluated. NHEK were challenged by either resveratrol alone or by its combination with TNFalpha or TGFalpha, and time-dependent molecular events were monitored. Interleukin 8 (IL-8) expression and its mRNA stability, ERK1/2, p65/RelA, and EGFR phosphorylation were determined. Intracellular distribution of EGFR/P-EGFR was measured in the membrane, cytoplasmic, and nuclear fractions. Specific DNA binding activity of NFκB (p65/RelA) and AP-1(c-Fos), NHEK proliferation, and molecular markers of apoptosis/cell cycle were detected. Resveratrol induced delayed, long-lasting and steadily growing IL-8 gene and protein over-expression as well as enhanced EGFR phosphorylation, both abrogated by the EGFR kinase inhibitor PD168393. However, resveratrol did not act as a phosphatase inhibitor. ERK phosphorylation was transiently inhibited at early time-points and activated at 6–24 h. Accordingly, c-Fos-specific DNA binding was increased by resveratrol. Cellular distribution of EGFR/P-EGFR was shifted to membrane and nucleus while cytosolic levels were reduced concomitant with enhanced degradation. Notwithstanding high nuclear levels of EGFR/P-EGFR, spontaneous and TGFalpha-triggered cell proliferation was strongly suppressed by resveratrol mainly through cell cycle arrest.

Anti-inflammatory Effect of Oyster Shell Extract in LPS-stimulated Raw 264.7 Cells

This study was designed to investigate the anti-inflammatory effect of oyster shell extract on the production of pro-inflammatory factors [NO, reactive oxygen species (ROS), nuclear factor-kappa B (NF-κB), inducible nitric oxide synthase (iNOS) and cycloxygenase-2 (COX-2)] and pro-inflammatory cytokines [Interleukin-1β (IL-1β), Interleukin-6 (IL-6) and TNF-α] in the lipopolysaccharide (LPS)-stimulated Raw 264.7 cells. Cell viability, as measured by the MTT assay, showed that oyster shell extract had no significant cytotoxicity in Raw 264.7 cells. The treatment with oyster shell extract decreased the generation of intracellular reactive oxygen species dose dependently and increased antioxidant enzyme activities, such as SOD, catalase, GSH-px in LPS-stimulated macrophage cells. Oyster shell extract significantly suppressed the production of NO and also decreased the expressions of iNOS, COX-2 and NF-κB. Additionally, oyster shell extract significantly inhibited the production of IL-1β, IL-6, and TNF-α in LPS-stimulated Raw 264.7 cells. Thus, these results showed that the oyster shell extract had an anti-inflammatory effect on LPS-stimulated Raw 264.7 cells.

Molecular mechanisms of chemopreventive phytochemicals against gastroenterological cancer development

Cancer is one of the leading causes of death worldwide. Commonly used cancer treatments, including chemotherapy and radiation therapy, often have side effects and a complete cure is sometimes impossible. Therefore, prevention, suppression, and/or delaying the onset of the disease are important. The onset of gastroenterological cancers is closely associated with an individual’s lifestyle. Thus, changing lifestyle, specifically the consumption of fruits and vegetables, can help to protect against the development of gastroenterological cancers. In particular, naturally occurring bioactive compounds, including curcumin, resveratrol, isothiocyanates, (-)-epigallocatechin gallate and sulforaphane, are regarded as promising chemopreventive agents. Hence, regular consumption of these natural bioactive compounds found in foods can contribute to prevention, suppression, and/or delay of gastroenterological cancer development. In this review, we will summarize natural phytochemicals possessing potential antioxidant and/or anti-inflammatory and anti-carcinogenic activities, which are exerted by regulating or targeting specific molecules against gastroenterological cancers, including esophageal, gastric and colon cancers.

The anti-inflammatory effects of platinum nanoparticles on the lipopolysaccharide-induced inflammatory response in RAW 264.7 macrophages

OBJECTIVE

Platinum nanoparticles (nano-Pt) have been reported to possess anti-oxidant and anti-tumor activities. However, the biological activity and mechanism of action of nano-Pt in inflammation are still unknown. The present study was designed to determine the in-vitro anti-inflammatory effects of nano-Pt on lipopolysaccharide (LPS)-stimulated RAW 264.7 cells.

METHODS

RAW 264.7 macrophages were used for the study. The LPS-induced production of reactive oxygen species (ROS) was determined by flow cytometry. The prostaglandin E(2) (PGE(2)) concentration was measured using a PGE(2) assay kit. The protein levels and mRNA expression of the pro-inflammatory cytokines [tumor necrosis factor-α, interleukin (IL)-1β and IL-6], along with cyclooxygenase (COX-2) and inducible nitric oxide synthase, were analyzed by Western blotting and reverse transcription-polymerase chain reaction analysis. The phosphorylation of extracellular signal regulated kinase (ERK1/2) and Akt, and the phosphorylation and degradation of inhibitory kappa B-alpha (IκB-α) was determined by Western blot analysis.

RESULTS

Nano-Pt significantly reduced the LPS-induced production of intracellular ROS and inflammatory mediators. In addition, nano-Pt suppressed the phosphorylation of ERK1/2 and Akt, and significantly inhibited the phosphorylation/degradation of IκB-α as well as nuclear factor kappa-B (NFκB) transcriptional activity.

CONCLUSION

These results suggest that the anti-inflammatory properties of nano-Pt may be attributed to their downregulation of the NFκB signaling pathway in macrophages, thus supporting the use of nano-Pt as an anti-inflammatory agent.

Anti-inflammatory and cytoprotective effects of selected Pakistani medicinal plants in Helicobacter pylori-infected gastric epithelial cells

ETHNOPHARMACOLOGICAL RELEVANCE

Helicobacter pylori infection is associated with gastritis, peptic ulcer, and gastric cancer. Due to its high global prevalence and uprising resistance to available antibiotics, efforts are now directed to identify alternative source to treat and prevent associated disorders. In the present study, effect of selected indigenous medicinal plants of Pakistan was evaluated on the secretion of interleukin-8 (IL-8) and generation of reactive oxygen species (ROS) in a bid to rationalize their medicinal use and to examine the anti-inflammatory and cytoprotective effects in gastric epithelial cells.

MATERIALS AND METHODS

AGS cells and clinically isolated Helicobacter pylori strain (193C) were employed for co-culture experiments. Anti-Helicobacter pylori activity and cytotoxic effects of the selected plants were determined by serial dilution method and DNA fragmentation assay respectively. ELISA and flow cytometry were performed to evaluate the effect on IL-8 secretion and ROS generation in Helicobacter pylori-infected cells.

RESULTS

At 100μg/ml, extracts of Alpinia galangal, Cinnamomum cassia, Cinnamomum tamala, Mentha arvensis, Myrtus communis, Oligochaeta ramose, Polygonum bistorta, Rosa damascena, Ruta graveolens, Syzygium aromaticum, Tamarix dioica, and Terminalia chebula exhibited strong inhibitory activity against IL-8 secretion. Of these, four extracts of Cinnamomum cassia, Myrtus communis, Syzygium aromaticum, and Terminalia chebula markedly inhibited IL-8 secretion at both 50 and 100μg/ml. Cinnamomum cassia was further assessed at different concentrations against Helicobacter pylori and TNF-α stimulated IL-8 secretion, which displayed significant suppression of IL-8 in a concentration-dependent-manner. Among the plants examined against ROS generation, Achillea millefolium, Berberis aristata, Coriandrum sativum, Foeniculum vulgare, Matricaria chamomilla and Prunus domestica demonstrated significant suppression of ROS from Helicobacter pylori-infected cells (p<0.01).

CONCLUSION

Results of the study revealed anti-inflammatory and cytoprotective effects of selected medicinal plants which could partially validate the traditional use of these plants in GI disorders particularly associated with Helicobacter pylori. Furthermore, results obtained may lead to possible future candidates of chemoprevention against peptic ulcer or gastric cancer.

Alternative therapies for Helicobacter pylori: probiotics and phytomedicine

Helicobacter pylori is a common human pathogen infecting about 30% of children and 60% of adults worldwide and is responsible for diseases such as gastritis, peptic ulcer and gastric cancer. Treatment against H. pylori is based on the use of antibiotics, but therapy failure can be higher than 20% and is essentially due to an increase in the prevalence of antibiotic-resistant bacteria, which has led to the search for alternative therapies. In this review, we discuss alternative therapies for H. pylori, mainly phytotherapy and probiotics. Probiotics are live organisms or produced substances that are orally administrated, usually in addition to conventional antibiotic therapy. They may modulate the human microbiota and promote health, prevent antibiotic side effects, stimulate the immune response and directly compete with pathogenic bacteria. Phytomedicine consists of the use of plant extracts as medicines or health-promoting agents, but in most cases the molecular mode of action of the active ingredients of these herbal extracts is unknown. Possible mechanisms include inhibition of H. pylori urease enzyme, disruption of bacterial cell membrane, and modulation of the host immune system. Other alternative therapies are also reviewed.

Interleukin-8 is the single most up-regulated gene in whole genome profiling of H. pylori exposed gastric epithelial cells

BACKGROUND

The association between Helicobacter pylori infection and upper gastrointestinal disease is well established. However, only a small fraction of H. pylori carriers develop disease, and there are great geographical differences in disease penetrance. The explanation to this enigma lies in the interaction between the bacterium and the host. H. pylori Outer Membrane Phospholipase A (OMPLA) has been suggested to play a role in the virulence of this bacterium. The aim of this study was to profile the most significant cellular pathways and biological processes affected in gastric epithelial cells during 24 h of H. pylori exposure, and to study the inflammatory response to OMPLA⁺ and OMPLA⁻ H. pylori variants.

RESULTS

Interleukin-8 was the most significantly up-regulated gene and appears to play a paramount role in the epithelial cell response to H. pylori infection and in the pathological processes leading to gastric disease. MAPK and NF-kappaB cellular pathways were powerfully activated, but did not seem to explain the impressive IL-8 response. There was marked up-regulation of TP53BP2, whose corresponding protein ASPP2 may interact with H. pylori CagA and cause marked p53 suppression of apoptosis. Other regulators of apoptosis also showed abberant regulation. We also identified up-regulation of several oncogenes and down-regulation of tumor suppressor genes as early as during the first 24 h of infection. H. pylori OMPLA phase variation did not seem to influence the inflammatory epithelial cell gene response in this experiment.

CONCLUSION

In whole genome analysis of the epithelial response to H. pylori exposure, IL-8 demonstrated the most marked up-regulation, and was involved in many of the most important cellular response processes to the infection. There was dysregulation of apoptosis, tumor suppressor genes and oncogenes as early as in the first 24 h of H. pylori infection, which may represent early signs of gastric tumorigenesis. OMPLA⁺/⁻ did not affect the acute inflammatory response to H. pylori.

The role of CXC chemokines in the transition of chronic inflammation to esophageal and gastric cancer

Chronic inflammation may increase the risk to develop cancer, for instance esophagitis or gastritis may lead to development of esophageal or gastric cancer, respectively. The key molecules attracting leukocytes to local inflammatory sites are chemokines. We here provide a systematic review on the impact of CXC chemokines (binding the receptors CXCR1, CXCR2, CXCR3 and CXCR4) on the transition of chronic inflammation in the upper gastrointestinal tract to neoplasia. CXCR2 ligands, including GRO-α,β,γ/CXCL1,2,3, ENA-78/CXCL5 and IL-8/CXCL8 chemoattract pro-tumoral neutrophils. In addition, angiogenic CXCR2 ligands stimulate the formation of new blood vessels, facilitating tumor progression. The CXCR4 ligand SDF-1/CXCL12 also promotes tumor development by stimulating angiogenesis and by favoring metastasis of CXCR4-positive tumor cells to distant organs producing SDF-1/CXCL12. Furthermore, these angiogenic chemokines also directly enhance tumor cell survival and proliferation. In contrast, the CXCR3 ligands Mig/CXCL9, IP-10/CXCL10 and I-TAC/CXCL11 are angiostatic and attract anti-tumoral T lymphocytes and may therefore mediate tumor growth retardation and regression. Thus, chemokines exert diverging, sometimes dual roles in tumor biology as described for esophageal and gastric cancer. Therefore extensive research is needed to completely unravel the complex chemokine code in specific cancers. Possibly, chemokine-targeted cancer therapy will have to be adapted to the individual's chemokine profile.

Effect of Trans-resveratrol on Rotenone-induced Cytotoxicity in Human Breast Adenocarcinoma Cells

Rotenone, a botanical insecticide is known to cause apoptosis in various cell types. Trans-resveratrol, a natural phytophenol present in red grapes and wine, is also well documented for its antioxidant, anti-inflammatory, anti-mutagenic, and anticarcinogenic activities. Therefore, the present investigations were carried out to assess the protective effect of trans-resveratrol against rotenone-induced cell death in human breast adenocarcinoma (MCF-7) cells. MCF-7 cells were exposed with various concentrations of rotenone for 24 h, and the loss in percent cell viability was evaluated by MTT [3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide] and neutral red uptake (NRU) assays. A significant decrease in percent cell viability in MCF-7 cells was observed at 50 μM and above concentrations of rotenone, as compared to untreated control. Furthermore, various concentrations (5, 10, and 25 μM) of trans-resveratrol were used to see its protective role on cell viability in rotenone-induced cell death in MCF-7 cells. Pre- or post- treatment of trans-resveratrol for 24 h was given to the cells. The data exhibited a significant dose dependent increase in the percent cell viability under pre- and post-treatment conditions. However, post-treatment of trans-resveratrol for 24 h after rotenone exposure to the cells was relatively less effective. Overall, the results suggest that trans-resveratrol significantly protects MCF-7 cells from rotenone-induced cell death. This model can be used as an effective and economical alternative to animal models for screening the antioxidant activity of a variety of natural compounds/drugs.

Immunomodulation of Autoimmune Arthritis by Herbal CAM

Rheumatoid arthritis (RA) is a debilitating autoimmune disease of global prevalence. The disease is characterized by synovial inflammation leading to cartilage and bone damage. Most of the conventional drugs used for the treatment of RA have severe adverse reactions and are quite expensive. Over the years, increasing proportion of patients with RA and other immune disorders are resorting to complementary and alternative medicine (CAM) for their health needs. Natural plant products comprise one of the most popular CAM for inflammatory and immune disorders. These herbal CAM belong to diverse traditional systems of medicine, including traditional Chinese medicine, Kampo, and Ayurvedic medicine. In this paper, we have outlined the major immunological pathways involved in the induction and regulation of autoimmune arthritis and described various herbal CAM that can effectively modulate these immune pathways. Most of the information about the mechanisms of action of herbal products in the experimental models of RA is relevant to arthritis patients as well. The study of immunological pathways coupled with the emerging application of genomics and proteomics in CAM research is likely to provide novel insights into the mechanisms of action of different CAM modalities.

Resveratrol modulates RTX toxin-induced cytotoxicity through interference in adhesion and toxin production

Host-parasite contact is a prerequisite for the acute cytotoxicity of Vibrio vulnificus, which is mediated primarily by RtxA1, a repeat in toxin (RTX) toxin. We found that resveratrol (at 10 or 30 microM), a natural polyphenol, protected HeLa cells from V. vulnificus cytotoxicity. To further characterize the underlying mechanism, the effect of resveratrol was investigated at the level of the host-microbe interactions. We studied the effects of resveratrol on adhesion, motility, cytotoxicity, and RtxA1 toxin expression of V. vulnificus. In addition, the effect of resveratrol on mouse mortality caused by V. vulnificus was investigated. Resveratrol inhibited V. vulnificus motility and the microbe adhesion to host cells, critical virulence traits for many bacteria. Resveratrol also down-regulated the expression of RtxA1 toxin at the transcriptional level and thereby protected the host cells from becoming rounded and damaged. In addition, resveratrol (20mg/kg) protected CD-1 mice from V. vulnificus infection. Taken together, these results suggest that resveratrol, a modulator of host-microbe interactions, has potential for development as a new paradigm drug to treat infectious diseases.