Acid regulates inflammatory response in a rat model of induction of gastric ulcer recurrence by interleukin 1beta

Huang-Qi-Jian-Zhong-Tang accelerates healing of indomethacin-induced gastric ulceration in rats via anti-inflammatory and antioxidant mechanisms

ETHNOPHARMACOLOGICAL RELEVANCE

Huang-Qi-Jian-Zhong-Tang (HQJZT) is a canonical traditional Chinese medicine (TCM) formula that has been widely used in both the prevention and treatment of gastrointestinal diseases, including gastric ulcer, duodenal ulcer, and chronic atrophic gastritis, in China.

AIM OF THE STUDY

In the present study, we investigated the gastroprotective potential of HQJZT in a rat model of indomethacin (IND)-induced gastric ulcer and explained the biochemical, cellular, and molecular mechanisms involved.

MATERIALS AND METHODS

Observations were conducted at the macroscopic level to ascertain the ulcer index (UI) and the curative index (CI). Histopathological examinations were conducted, and a microscopic score (MS) was computed. The gastric juice volume, total acidity, pH value, and pepsin activity were quantified. Antioxidant and oxidative parameters were assessed, namely GSH, CAT, SOD, and MDA content. The RFLSI Pro instrument was employed to measure the blood flow within the gastric mucosa continuously. The mRNA levels of the inflammatory cytokines were assessed using droplet digital PCR (ddPCR). Molecular docking was employed to examine the interaction between representative active components of HQJZT and the binding sites associated with the NF-κB and STAT signaling pathways. The protein expression and localization of p-JAK, p-STAT, p-IκBβ, and p-NF-κB were evaluated through immunofluorescence analysis.

RESULTS

The administration of HQJZT treatment demonstrated a significant reduction in gastric lesions induced by IND, leading to a notable decrease in the UI. Additionally, HQJZT treatment significantly decreased gastric juice volume, acidity, and pepsin activity, accompanied by increased pH value. IND-treated stomachs exhibited severe hemorrhagic necrosis, submucosal edema, and epithelial cell destruction. However, the administration of HQJZT effectively counteracted these pathological changes. Furthermore, HQJZT administration significantly increased blood flow to the gastric mucosa. HQJZT enhanced antioxidant defenses and modulated oxidative stress by increasing SOD, CAT, and GSH activities while reducing MDA levels. Moreover, HQJZT reversed IND-induced increases in mRNA expression levels of inflammatory cytokines. Molecular docking analysis revealed that the representative active components of HQJZT could bind to the NF-κB and STAT signaling pathways. In addition, immunofluorescence microscopy revealed that HQJZT markedly attenuated the phosphorylation of IκΒβ, NF-κB, JAK, and STAT.

CONCLUSIONS

The therapeutic and protective effect of HQJZT on gastric ulcers is attributed to its ability to suppress gastric acid secretion, enhance antioxidative defenses and blood flow, mitigate proinflammatory cytokines, and inhibit the activation of NF-κB and STAT signaling pathways.

Piper sarmentosum Roxb. methanolic extract prevents stress-induced gastric ulcer by modulating oxidative stress and inflammation

This study investigated the gastroprotective effect of Piper sarmentosum (PS) on stress-induced gastric ulcers in rats by measuring its effect on oxidative stress, gastric mucosal nitric oxide (NO), and inflammatory biomarkers. Twenty-eight male Wistar rats were randomly divided into four groups; two control groups (non-stress and stress) and two treated groups supplemented with either methanolic PS extract (500 mg/kg body weight) or omeprazole (OMZ; 20 mg/kg) orally. After 28 days of treatment, the stress control, PS, and OMZ groups were subjected to water-immersion restrain stress (WIRS) for 3.5 h. Gastric tissue malondialdehyde (MDA), NO, superoxide dismutase (SOD), inducible NO synthase (iNOS), SOD mRNA, tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6 levels were measured. WIRS significantly increased gastric MDA, NO, and pro-inflammatory cytokine levels compared to the non-stressed control group. PS and omeprazole supplementation significantly reduced WIRS-exposure-induced gastric ulcers and MDA, iNOS, and IL-1β levels. However, only PS reduced NO, TNF-α, and IL-6 levels, which were upregulated in this ulcer model. In conclusion, the gastroprotection afforded by PS is possibly mediated by gastric mucosal NO normalization through reduced iNOS expression and attenuation of inflammatory cytokines. PS showed a greater protective effect than omeprazole in reducing gastric lesions and NO, TNF-α, and IL-6 levels, and iNOS expression.

Geraniol accelerates the gastric healing, minimizes ulcers recurrence, and reduces anxiolytic-like behavior in ulcerated rodents by oral or inhaled route

BACKGROUND

Geraniol (GE) is dietary acyclic monoterpene alcohol found in essential oils from aromatic plants with therapeutic value against gastric ulcers already described.

HYPOTHESIS/PURPOSE

To assess whether oral GE accelerates gastric healing or prevents ulcer recurrence, and to evaluate the hypothesis that GE promotes antiulcer effects by the inhaled route and that promotes changes in the behavior of ulcerated rodents.

METHODS

Gastric healing effects, underlining mechanisms, and behavioral changes were measured in80% acetic acid-induced gastric ulcer model in rats receiving GE by oral (30 mg/kg) or inhaled route (1 mg/L of air/min); whereas the effects of GE to avoid ulcer recurrence was evaluated in mice submitted to 10% acetic acid plus IL-1β ulcer.

RESULTS

GE administered by both routes accelerates gastric healing, increasing mucin and GSH levels, CAT, and GST activities, and reducing MPO activity. Moreover, oral, and inhaled GE minimized ulcer recurrence reducing gastric TNF and IL-6 levels and preserving mucin levels. Interestingly, the inhalation or oral intake of GE promotes anxiolytic-like effects in ulcerated rats.

CONCLUSION

Data altogether suggest that the GE accelerates gastric healing through the strengthening of protective factors of the gastric mucosa, promoting a quality healing that reduces the recurrence of the lesion. Besides, the anxiolytic-like effect of GE may also contribute to its gastric healing action since anxiety is recognized as one of the etiologic agents of ulcers.

Opioid Use in Murine Model Results in Severe Gastric Pathology that May Be Attenuated by Proton Pump Inhibition

Opioids are the gold standard for chronic and acute pain management; however, their consequence on gastric function is relatively understudied. Opioid users have a higher incidence of gastric dysfunction, worse quality of life, increased hospitalizations, and increased use of antiemetic and pain modulator medications. The current study shows that morphine treatment in the murine model results in greater disruption of gastric epithelial cell morphology, increased gastric cell apoptosis, elevated inflammatory cytokines, and matrix metallopeptidase-9 secretion. Morphine treatment also increases gastric acid secretion and causes delays in gastric emptying. Moreover, morphine treatment causes an increase in systemic IL-6 level, which plays an important role in morphine-induced delayed gastric emptying and gastric damage. IL-6 knockout mice show a significant level of reduction in morphine-induced gastric delaying, acid retention, and gastric damage. Thus, morphine-mediated gastric damage is a consequence of the accumulation of acid in the stomach due to increased gastric acid secretion and delayed gastric emptying. Treatment with a proton pump inhibitor resulted in a significant reduction in morphine-induced gastric inflammation, gastric delaying, and improved morphine tolerance. Hence, these studies attribute morphine-mediated induction in gastric acidity and inflammatory cytokines as drivers for morphine-associated gastric pathology and show the therapeutic use of proton pump inhibitors as an inexpensive approach for clinical management of morphine-associated pathophysiology and analgesic tolerance.

Preventive and therapeutic effects of Lactobacillus rhamnosus SHA113 and its culture supernatant on alcoholic gastric ulcers

BACKGROUND

Alcoholic gastric ulcers are currently a common upper gastrointestinal disease with a high recurrence rate, causing gastric perforation or even gastric cancer in severe cases. Lactobacillus rhamnosus was previously found to prevent alcoholic gastric ulcers, but its therapeutic effects were not illustrated.

AIMS

This study aims to illustrate the preventive and therapeutic effects of L. rhamnosus SHA113 cells and their culture supernatant on alcoholic gastric ulcers and explore the related mechanisms.

METHODS

An alcoholic gastric ulcer model was established by feeding mice with 75% ethanol once at a dosage of 10 ml per kg body weight. The L. rhamnosus SHA113 cells (SHA) and their culture supernatant (SHA-FS) were separately used to feed mice for 2 weeks before ethanol injury in preventive experiments and for 2 days after ethanol injury in therapeutic experiments. The mechanisms were analyzed in view of anti-oxidant and anti-inflammatory activities and intestinal barrier functions.

RESULTS

The preventive effects of SHA-FS were much better than those of SHA via similar mechanisms, such as promoting the secretion of mucus, improving the antioxidant capacity of the gastric mucosa, and inhibiting inflammation. In terms of the therapeutic effects, SHA-FS and SHA could accelerate the healing of damaged ulcers by improving the secretion of tight junction proteins and mucus proteins, increasing angiogenesis, and inhibiting the apoptosis of gastric epithelial cells.

CONCLUSION

L. rhamnosus SHA113 and its culture supernatant had preventive and therapeutic effects on alcoholic gastric ulcers via anti-oxidant and anti-inflammatory pathways and the promotion of healing of damaged ulcers by enhancing intestinal barrier functions, respectively.

Polygonum hydropiper extract attenuates ethanol-induced gastric damage through antioxidant and anti-inflammatory pathways

The present study was conducted to investigate the underlying mechanisms and effective components of Polygonum hydropiper in ethanol-induced acute gastric mucosal lesions. The ethanol extract was purified on an AB-8 macroporous resin column and eluted with 60% ethanol and was then injected into the HPLC system for quantitative analysis. Sprague-Dawley rats were orally pretreated with P. hydropiper extract (PHLE; 50, 100, and 200 mg/kg) for 5 days and then absolute ethanol was administered to induce gastric mucosal damage. One hour after ethanol ingestion, the rats were euthanized and stomach samples were collected for biochemical analysis. Antioxidant enzymes and anti-inflammatory cytokines were quantified. Western blotting was used to detect the expression levels of proteins. Cell proliferation was assayed by CCK-8 assays. The proportion of total flavonoids in the final extract of P. hydropiper was 50.05%, which contained three major bioactive flavonoid constituents, including rutin, quercitrin, and quercetin. PHLE significantly increased cell viability and effectively protected human gastric epithelial cells-1 against alcohol-induced damage in vitro. PHLE pretreatment attenuated gastric mucosal injuries in a dose-dependent manner in rats, and increased the activity of superoxide dismutase, glutathione peroxidase, and glutathione, and decreased the levels of malondialdehyde in gastric tissue. Pretreatment with PHLE also reduced the generation of the pro-inflammatory cytokines tumor necrosis factor-α and interleukin-1β in gastric tissue by downregulating the expression of nuclear factor-kappa B. PHLE exerted protective effects against gastric injury through antioxidant and anti-inflammatory pathways. Flavonoids might be the main effective components of P. hydropiper against gastric mucosal injury.

Cashew apple byproduct: Gastroprotective effects of standardized extract

ETHNOPHARMACOLOGICAL RELEVANCE

The incidence of gastric mucosa lesions in the adult population has increased mainly due to the continued use of nonsteroidal anti-inflammatory drugs (NSAIDs). The cashew (Anacardium occidentale L.) is a tropical tree, cultivated in several countries, whose barks, leaves and pseudofruit (cashew apple) are popularly used in traditional medicine for the treatment of many diseases, including gastric ulcer.

AIM

Our study evaluated the potential gastroprotective effect of the carotenoid and anacardic acids-enriched aqueous extract (CAE), prepared from cashew apple pomace, in the dose-repeated acetylsalicylic acid (ASA)-induced gastric lesions model in rats.

MATERIAL AND METHODS

After randomly distribution into five group (G1 - G5, n = 8 animals/group), male Wistar rats were daily treated with ASA solution (200 mg/kg, 5 ml/kg, G2 - G5) or potable water (Satellite group, G1) during 14 days. From 8th to 14th experimental day, rats in G3 - G5 groups were orally treated with CAE (50, 100 and 500 mg/kg, 5 ml/kg, respectively). Body weight was measured on 0, 7th and 14th day. On the 14th experimental day, all surviving animals were euthanized for macroscopic evaluation of the inner organs and stomach removal. After weighting, each stomach was properly prepared for biochemical analysis [myeloperoxidase activity (MPO), reduced glutathione analysis (GSH), IL-1β, CXCL2/MIP-2, TNF-α and IL-10 levels].

RESULTS

At the most efficient dose (100 mg/kg, p.o.), CAE-treated animals showed a slight improvement in the macroscopic aspect of gastric mucosa associated with significant (p < 0.05) reduced levels of IL-1β, CXCL2/MIP-2, and MPO activity besides increased levels of GSH (partially), and IL-10 in stomach tissues.

CONCLUSIONS

The present study demonstrated that the carotenoid and anacardic acids-enriched extract obtained from cashew apple pomace is a promising raw material for the development of herbal medicine and/or functional food supplements for the adjuvant treatment of NSAIDs-induced gastric ulcers.

The effects and mechanism of Kangfuxin on improving healing quality and preventing recurrence of gastric ulcer

This study investigated the gastroprotective effects and possible mechanism of Kangfuxin (KFX), an ethanol extract of Periplaneta americana L. (Dictyoptera; Blattidae), on improving healing quality and preventing recurrence of gastric ulcer. The effects of KFX were investigated in patients treated with endoscopic submucosal dissection (ESD), gastric ulcer animal model, and rat gastric mucosal cells and fibroblasts. Moreover, the relationship between KFX and p38/NF-κB pathway were explored both in vivo and in vitro. In patients, KFX exhibited protective effects against gastric ulcers and resulted in a decrease in the CD3 expression. In vivo animal experiments confirmed that KFX accelerated ulcer healing by promoting neovascularization (increased CD34 expression), suppressing inflammation (decreased interleukin-1β (IL-1β), myeloperoxidase (MPO), tumor necrosis factor α (TNF-α), intercellular adhesion molecule-1 (ICAM-1), and IL-8 expression), and enhancing growth factor expression, including the epidermal growth factor receptor (EGFR) and hepatocyte growth factor (HGF). In vitro experiments demonstrated that treatment with 10% KFX rat serum decreased IL-1β, IL-1Ra, SIL-1RAP, TNF-α, and ICAM-1 expression in rat gastric mucosal cells or fibroblasts and increased IL-1R expression compared to that in the group treatment with 10% normal rat serum. Furthermore, KFX inhibited the activation of p38/NF-κB pathway both in vivo and in vitro. In conclusion, KFX treatment could effectively improve healing quality and prevent gastric ulcer recurrence, which might be attributed to neovascularization, suppressed inflammation, and enhanced growth factor expression. The p38/NF-κB pathway may be one of important mechanism to mediate the effects of KFX.

Proton pump inhibitors for chronic obstructive pulmonary disease

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a common and progressive disease characterised by chronic cough, airflow limitation and recurrent exacerbations. Since COPD exacerbations are linked to rising mortality and reduced quality of life, the condition poses a substantial burden on individuals, society and the healthcare system. Effective management of COPD exacerbations that includes treatment of related conditions in people with COPD is thus recognised as a relevant clinical question and an important research topic. Gastroesophageal reflux disease (GERD) is a known comorbidity of COPD, and pulmonary microaspiration of gastric acid is thought to be a possible cause of COPD exacerbations. Therefore, reducing gastric acid secretion may lead to a reduction in COPD exacerbations. Proton pump inhibitors (PPIs) are one of the most commonly prescribed medications and are recommended as first-line therapy for people with GERD because of their inhibitory effects on gastric acid secretion. Treatment with PPIs may present a viable treatment option for people with COPD.

OBJECTIVES

To evaluate the efficacy and safety of PPI administration for people with COPD, focusing on COPD-specific outcomes.

SEARCH METHODS

We searched the Cochrane Airways Register of Trials and conventional clinical trial registers from inception to 22 May 2020. We also screened bibliographies of relevant studies.

SELECTION CRITERIA

Parallel-group and cluster-randomised controlled trials (RCTs) that compared oral PPIs versus placebo, usual care or low-dose PPIs in adults with COPD were eligible for inclusion. We excluded cross-over RCTs, as well as studies with a duration of less than two months.

DATA COLLECTION AND ANALYSIS

Two independent review authors screened search results, selected studies for inclusion, extracted study characteristics and outcome data, and assessed risk of bias according to standard Cochrane methodology. We resolved discrepancies by involving a third review author. Primary outcomes of interest were COPD exacerbations, pneumonia and other serious adverse events. Secondary outcomes were quality of life, lung function test indices, acute respiratory infections and disease-specific adverse events. We extracted data on these outcome measures and entered into them into Review Manager software for analysis.

MAIN RESULTS

The search identified 99 records, and we included one multicentre RCT that randomised 103 adults with COPD. The 12-month RCT compared an oral PPI (lansoprazole) and usual care versus usual care alone. It was conducted at one tertiary care hospital and three secondary care hospitals in Japan. This study recruited participants with a mean age of 75 years, and excluded people with symptoms or history of GERD. No placebo was used in the usual care arm. Among the primary and secondary outcomes of this review, the study only reported data on COPD exacerbations and acute respiratory infections (the common cold). As we only included one study, we could not conduct a meta-analysis. The included study reported that 12 of the 50 people on lansoprazole had at least one exacerbation over a year, compared to 26 out of 50 on usual care (risk ratio 0.46, 95% CI 0.26 to 0.81). The frequency of COPD exacerbations per person in a year was also lower in the PPI plus usual care group than in the usual care alone group（0.34 ± 0.72 vs 1.18 ± 1.40; P < 0.001). The number of people with at least one cold over the year was similar in both groups: 26 people on lansoprazole and 27 people in the usual care group. We judged the evidence to be of low to very low certainty, according to GRADE criteria. The study reported no data on pneumonia and other serious adverse events, quality of life, lung function test indices or disease-specific adverse events. The risk of bias was largely low or unclear for the majority of domains, though the performance bias was a high risk, as the study was not blinded.

AUTHORS' CONCLUSIONS

Evidence identified by this review is insufficient to determine whether treatment with PPIs is a potential option for COPD. The sample size of the included trial is small, and the evidence is low to very low-certainty. The efficacy and safety profile of PPIs for people with COPD remains uncertain. Future large-scale, high-quality studies are warranted, which investigate major clinical outcomes such as COPD exacerbation rate, serious adverse events and quality of life.

Short Chain Fatty Acid Acetate Protects against Ethanol-Induced Acute Gastric Mucosal Lesion in Mice

Short chain fatty acids acetate and propionate have been demonstrated protective function in the intestinal mucosa. However, their impact on gastric mucosa has not yet been elucidated. The current study aimed to investigate the potential protective effects of acetate and propionate against ethanol-induced gastric mucosal lesion and the underlying mechanism in mice. ICR mice were orally treated with acetate and propionate, respectively, 30 min prior to the establishment of gastric mucosal injury model by challenge with absolute ethanol. The gastric samples were collected for the detection of oxidative, inflammatory and apoptotic related parameters. Acetate, but not propionate, attenuated the severity of gastric mucosal damage as evidenced by the gross changes of gastric mucosa, pathological aberrations. Acetate alleviated oxidative stress as shown by the increase in glutathione (GSH) content and superoxide dismutase (SOD) activities, and the decrease of malondialdehyde (MDA) level. The elevated concentrations of interleukin (IL)-1β, tumor necrosis factor (TNF)-α and IL-6, and the activation of nuclear factor-kappaB (NF-κB) p65 by ethanol stimulation was also reduced by acetate. Moreover, the anti-inflammatory factors, IL-4, LXA4 and IL-10, were up-regulated in acetate treated group. With respect to gastric mucosal apoptosis, acetate suppressed caspase-3 activity and BAX expression in favor of cell survival. These favorable actions were maybe associated with up-regulation of the gastric MUC5AC, the key defense factor of gastric mucosal system. These findings accentuate the gastroprotective actions of acetate in ethanol-induced gastric injury which were mediated via concerted multi-prolonged actions, including suppression of gastric oxidation, inflammation and apoptosis and promotion of MUC5AC expression.

Potential role of probiotics in the management of gastric ulcer

Gastric ulcer is one of the most common chronic gastrointestinal diseases characterized by a significant defect in the mucosal barrier. Helicobacter pylori (H. pylori) infection and the frequent long-term use of non-steroidal anti-inflammatory drugs are major factors involved in gastric ulcer development. Acid inhibitors and antibiotics are commonly used to treat gastric ulcer. However, in the last few decades, the accumulating evidence for resistance to antibiotics and the side effects of antibiotics and acid inhibitors have drawn attention to the possible use of probiotics in the prevention and treatment of gastric ulcer. Probiotics are live microorganisms that when administered in adequate amounts confer health benefits on the host. Currently, the available experimental and clinical studies indicate that probiotics are promising for future applications in the management of gastric ulcers. This review aims to provide an overview of the general health benefits of probiotics on various systemic and gastrointestinal disorders with a special focus on gastric ulcer and the involved cellular and molecular mechanisms: i) Protection of gastric mucosal barrier; ii) upregulation of prostaglandins, mucus, growth factors and anti-inflammatory cytokines; iii) increased cell proliferation to apoptosis ratio; and iv) induction of angiogenesis. Finally, some of the available data on the possible use of probiotics in H. pylori eradication are discussed.

Mechanisms of NLRP3 inflammasome activation and its role in NSAID-induced enteropathy

Nonsteroidal anti-inflammatory drugs (NSAIDs) induce cytokines, including tumor necrosis factor-α and interleukins (ILs), in the small intestine via a Toll-like receptor 4 (TLR4)-dependent pathway, leading to intestinal ulceration. Activation of the inflammasome promotes pro-caspase-1 cleavage, leading to pro-IL-1β maturation. We examined the role of NLRP3 inflammasome in NSAID-induced enteropathy. Small intestinal damage developed 3 h after indomethacin administration, accompanied by increases in IL-1β and NLRP3 mRNA expression and mature caspase-1 and IL-1β levels. In vivo blocking of IL-1β using neutralizing antibodies attenuated indomethacin-induced damage, whereas exogenous IL-1β aggravated it. NLRP3(-/-) and caspase-1(-/-) mice exhibited resistance to the damage with reduction of mature IL-1β production. This resistance was abolished by exogenous IL-1β. TLR4 deficiency prevented intestinal damage and inhibited upregulation of NLRP3 and IL-1β mRNAs and maturation of pro-caspase-1 and pro-IL-1β, whereas TLR4 activation by its agonists exerted opposite effects. Apyrase, an adenosine triphosphate (ATP) scavenger, or Brilliant Blue G, a purinergic P2X7 receptor antagonist, inhibited the damage as well as caspase-1 activation and IL-1β processing, despite there being sufficient amounts of pro-IL-1β and NLRP3. These results suggest that NLRP3 inflammasome-derived IL-1β plays a crucial role in NSAID-induced enteropathy and that both TLR4- and P2X7-dependent pathways are required for NLRP3 inflammasome activation.

Preventive Effects of Tocotrienol on Stress-Induced Gastric Mucosal Lesions and Its Relation to Oxidative and Inflammatory Biomarkers

This study aimed to investigate the possible gastroprotective effect of tocotrienol against water-immersion restraint stress (WIRS) induced gastric ulcers in rats by measuring its effect on gastric mucosal nitric oxide (NO), oxidative stress, and inflammatory biomarkers. Twenty-eight male Wistar rats were randomly assigned to four groups of seven rats. The two control groups were administered vitamin-free palm oil (vehicle) and the two treatment groups were given omeprazole (20 mg/kg) or tocotrienol (60 mg/kg) orally. After 28 days, rats from one control group and both treated groups were subjected to WIRS for 3.5 hours once. Malondialdehyde (MDA), NO content, and superoxide dismutase (SOD) activity were assayed in gastric tissue homogenates. Gastric tissue SOD, iNOS, TNF-α and IL1-β expression were measured. WIRS increased the gastric MDA, NO, and pro-inflammatory cytokines levels significantly when compared to the non-stressed control group. Administration of tocotrienol and omeprazole displayed significant protection against gastric ulcers induced by exposure to WIRS by correction of both ulcer score and MDA content. Tissue content of TNF-α and SOD activity were markedly reduced by the treatment with tocotrienol but not omeprazole. Tocotrienol significantly corrected nitrite to near normal levels and attenuated iNOS gene expression, which was upregulated in this ulcer model. In conclusion, oral supplementation with tocotrienol provides a gastroprotective effect in WIRS-induced ulcers. Gastroprotection is mediated through 1) free radical scavenging activity, 2) the increase in gastric mucosal antioxidant enzyme activity, 3) normalisation of gastric mucosal NO through reduction of iNOS expression, and 4) attenuation of inflammatory cytokines. In comparison to omeprazole, it exerts similar effectiveness but has a more diverse mechanism of protection, particularly through its effect on NO, SOD activity, and TNF-α.

The preventive effect of β3 adrenoceptor stimulation against experimentally induced reflux esophagitis

A β3 adrenoceptor agonist plays an important regulatory role in stimulation of thermogenesis and lipolysis and it appears to have anti-ulcer and spasmolytic effects. So the present aim was to examine the effect of BRL 37344 (a selective B3 adrenoceptor agonist) on reflux esophagitis.

METHODS

Forty-eight rats were divided into twelve sham-operated with BRL 37344 and/or omeprazole with or without indomethacin. RE was induced in rats, then gastric acid output, pH, plasma nitric oxide (NO), esophageal PGE2, malondialdehyde (MDA) and reduced glutathione (GSH) were measured and the esophageal injury was assessed by macroscopic damage score.

RESULTS

Pretreatment with BRL significantly increased plasma NO, GSH, decreased acid output, esophageal MDA and esophageal injury in comparison to pretreatment. In addition, there was a no significant increase in esophageal PGE2.

CONCLUSION

It can be concluded that BRL 37344 has an anti-oxidant protective effect in rats with RE.

Toll-like receptor 2 mediates ischemia-reperfusion injury of the small intestine in adult mice

Toll-like receptor 2 (TLR2) recognizes conserved molecular patterns associated with both gram-negative and gram-positive bacteria, and detects some endogenous ligands. Previous studies demonstrated that in ischemia-reperfusion (I/R) injury of the small intestine, the TLR2-dependent signaling exerted preventive effects on the damage in young mice, but did not have a significant effect in neonatal mice. We investigated the role of TLR2 in adult ischemia-reperfusion injury in the small intestine. Wild-type and TLR2 knockout mice at 16 weeks of age were subjected to intestinal I/R injury. Some wild-type mice received anti-Ly-6G antibodies to deplete circulating neutrophils. In wild-type mice, I/R induced severe small intestinal injury characterized by infiltration by inflammatory cells, disruption of the mucosal epithelium, and mucosal bleeding. Compared to wild-type mice, TLR2 knockout mice exhibited less severe mucosal injury induced by I/R, with a 35%, 33%, and 43% reduction in histological grading score and luminal concentration of hemoglobin, and the numbers of apoptotic epithelial cells, respectively. The I/R increased the activity of myeloperoxidase (MPO), a marker of neutrophil infiltration, and the levels of mRNA expression of tumor necrosis factor-α (TNF-α), intercellular adhesion molecule-1 (ICAM-1), and cyclooxygenase-2 (COX-2) in the small intestine of the wild-type mice by 3.3-, 3.2-, and 13.0-fold, respectively. TLR2 deficiency significantly inhibited the I/R-induced increase in MPO activity and the expression of mRNAs for TNF-α and ICAM-1, but did not affect the expression of COX-2 mRNA. I/R also enhanced TLR2 mRNA expression by 2.9-fold. TLR2 proteins were found to be expressed in the epithelial cells, inflammatory cells, and endothelial cells. Neutrophil depletion prevented intestinal I/R injury in wild-type mice. These findings suggest that TLR2 may mediate I/R injury of the small intestine in adult mice via induction of inflammatory mediators such as TNF-α and ICAM-1.

Gastric mucosal injury induced by dual antiplatelet drugs in rats

AIM: To investigate the effect of different antiplatelet drugs on gastric mucosal injury in rats and the possible mechanisms involved.

METHODS: Eighty 6-7-week-old male SD rats were randomly allocated into four groups. Except a negative control group, the other three groups were given clopidogrel [7.81 mg/(kg•d), n = 20], aspirin [10.41 mg/(kg•d), n = 20] and clopidogrel plus aspirin (n = 20), respectively. The drugs were intragastrically administered once daily, and the negative control group was given normal saline (n = 20). All rats received operation after the final intragastric administration to observe gastric injury. The degree of gastric and small intestinal mucosal injury was assessed by HE staining, and the expression of tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) in gastric mucosal cells was detected by immunohistochemistry.

RESULTS: The scores of gross and pathological lesions were significantly higher in each drug treatment group than in the negative control group (P < 0.01), in the aspirin group than in the clopidogrel group (13.4000 ± 3.28634 vs 8.8000 ± 1.48324, P < 0.01), and in the combination group than in the two monotherapy groups (P < 0.01). Immunohistochemistry analysis revealed that the expression of TNF-α and IL-1β in the gastric and small intestinal mucosa was significantly higher in each drug treatment group than in the negative control group (P < 0.01), in the aspirin group than in the clopidogrel group (P < 0.01), and in the combination group than in the two monotherapy groups (P < 0.01).

CONCLUSION: Routine doses of antiplatelet drugs can cause gastrointestinal injury in rats, and the combination of antiplatelet drugs aggravates the injury compared with monotherapy. The high expression of TNF-α and IL-1β may be involved in mucosal injury induced by antiplatelet drugs.

Nonsteroidal anti-inflammatory drug induces proinflammatory damage in gastric mucosa through NF-κB activation and neutrophil infiltration: anti-inflammatory role of heme oxygenase-1 against nonsteroidal anti-inflammatory drug

Nonsteroidal anti-inflammatory drug (NSAID)-induced mitochondrial oxidative stress (MOS) is an important prostaglandin (PG)-independent pathway of the induction of gastric mucosal injury. However, the molecular mechanism behind MOS-mediated gastric pathology is still obscure. In various pathological conditions of tissue injury oxidative stress is often linked with inflammation. Here we report that MOS induced by indomethacin (an NSAID) induces gastric mucosal inflammation leading to proinflammatory damage. Indomethacin, time dependently stimulated the expression of proinflammatory molecules such as intercellular adhesion molecule 1(ICAM-1), vascular cell adhesion molecule 1(VCAM-1), interleukin1β (IL-1β), and monocyte chemotactic protein-1 (MCP-1) in gastric mucosa in parallel with the increase of neutrophil infiltration and injury of gastric mucosa in rat. Western immunoblotting and confocal microscopic studies revealed that indomethacin induced nuclear translocation of nuclear factor kappa-B (NF-κB) in gastric mucosal cells, which resulted in proinflammatory signaling. The prevention of MOS by antioxidant tryptamine-gallic acid hybrid (SEGA) inhibited indomethacin-induced expression of ICAM-1, VCAM-1, IL-1β, and MCP-1. SEGA also prevented indomethacin-induced NF-κB activation and neutrophil infiltration as documented by chromatin immunoprecipitation studies and neutrophil migration assay, respectively. Heme oxygenase-1 (HO-1), a cytoprotective enzyme associated with tissue repair mechanisms is stimulated in response to oxidative stress. We have investigated the role of HO-1 against MOS and MOS-mediated inflammation in recovering from gastropathy. Indomethacin stimulated the expression of HO-1 and indomethacin-stimulated HO-1 expression was reduced by SEGA, an antioxidant, which could prevent MOS. Thus, the data suggested that the induction of HO-1 was a protective response against MOS developed by indomethacin. Moreover, the induction of HO-1 by cobalt protoporphyrin inhibited inflammation and chemical silencing of HO-1 by zinc protoporphyrin aggravated the inflammation by indomethacin. Thus, NSAID by promoting MOS-induced proinflammatory response damaged gastric mucosa and HO-1 protected NSAID-induced gastric mucosal damage by preventing NF-κB activation and proinflammatory activity.

Local protective effects of oral 45S5 bioactive glass on gastric ulcers in experimental animals

Bioactive glass has been shown to stimulate bone regeneration and soft tissue healing. In this study, we evaluated the local protective effects of bioactive glass on experimental gastric ulcers, in comparison with omeprazole and hydrotalcite. Single and multiple gavage of 45S5 bioactive glass dose-dependently protected stress ulcers in mice and chronic ulcers in rats. Multi-daily gavage of bioactive glass for 7 days prevented chronic ulcer recurrence by 50 %. Bioactive glass ionic dissolution produced marked proliferation of ethanol-injured GES-1 human gastric mucosa epithelial cells 48 and 72 h after exposure. Bioactive glass was shown to be hardly absorbed after single or multi-daily gavage. This study, for the first time, demonstrates that bioactive glass is effective in protecting against gastric ulcers, with its high efficacy comparable to omeprazole and superior to hydrotalcite. The lack of oral absorption makes bioactive glass a potential for treatment of peptic ulcers omitting systemic toxicity or side-effects.

Progression of specialized intestinal metaplasia at the cardia to macroscopically evident Barrett's esophagus: an entity of concern in the ProGERD study

OBJECTIVES AND AIMS

Histological Barrett's esophagus, defined as specialized intestinal metaplasia (SIM+) at the cardia without endoscopic suspicion of columnar epithelium, is found frequently in biopsies at the gastro-esophageal junction although its clinical relevance is unknown. The authors aim was to evaluate prospectively the progression of SIM+ to macroscopically evident Barrett's esophagus (BE/SIM+), and to identify risk factors for this progression.

METHODS

Data were obtained from a sub-group of patients (no visible BE at presentation, but SIM+) included in the ProGERD study, a prospective evaluation of the clinical course of GERD under routine clinical care. They had esomeprazole 20-40 mg/day for 2-8 weeks. Symptom assessment was performed annually, and endoscopy with biopsy was planned at baseline, after healing treatment and after 2 and/or 5 years.

RESULTS

128 of 171 (74.8%) patients with unequivocal SIM at the z-line after healing were biopsied again after 2 and/or 5 years. At follow-up, 33 (25.8%) of these patients showed progression to BE/SIM+. Factors significantly associated with progression were smoking, a long history of GERD and severe esophagitis at baseline. Patients who had progressed to BE/SIM+ already at 2 years showed consistent findings at 5 years.

CONCLUSION

More than 20% of GERD patients with SIM+ in this study were found to have BE/SIM+ within 2-5 years. This finding supports the hypothesis that SIM+ at the cardia could be the missing link explaining increased cancer risk in GERD patients without overt BE and merits further investigation in a prospective study.

Quality of ulcer healing in gastrointestinal tract: Its pathophysiology and clinical relevance

In this paper, we review the concept of quality of ulcer healing (QOUH) in the gastrointestinal tract and its role in the ulcer recurrence. In the past, peptic ulcer disease (PUD) has been a chronic disease with a cycle of repeated healing/remission and recurrence. The main etiological factor of PUD is Helicobacter pylori (H. pylori), which is also the cause of ulcer recurrence. However, H. pylori-negative ulcers are present in 12%-20% of patients; they also recur and are on occasion intractable. QOUH focuses on the fact that mucosal and submucosal structures within ulcer scars are incompletely regenerated. Within the scars of healed ulcers, regenerated tissue is immature and with distorted architecture, suggesting poor QOUH. The abnormalities in mucosal regeneration can be the basis for ulcer recurrence. Our studies have shown that persistence of macrophages in the regenerated area plays a key role in ulcer recurrence. Our studies in a rat model of ulcer recurrence have indicated that proinflammatory cytokines trigger activation of macrophages, which in turn produce increased amounts of cytokines and chemokines, which attract neutrophils to the regenerated area. Neutrophils release proteolytic enzymes that destroy the tissue, resulting in ulcer recurrence. Another important factor in poor QOUH can be deficiency of endogenous prostaglandins and a deficiency and/or an imbalance of endogenous growth factors. Topically active mucosal protective and antiulcer drugs promote high QOUH and reduce inflammatory cell infiltration in the ulcer scar. In addition to PUD, the concept of QOUH is likely applicable to inflammatory bowel diseases including Crohn’s disease and ulcerative colitis.

Accelerated Ulcer Healing and Resistance to Ulcer Recurrence with Gastroprotectants in Rat Model of Acetic Acid-induced Gastric Ulcer

Quality of ulcer healing (QOUH) is defined as ideal ulcer healing featuring with the fine granular ulcer scar, high functional restoration and the resistance to recurrence. This study was designed to compare the rates of QOUH achievement in rat gastric ulcer model between acid suppressant treated group and gastroprotectant treated group accompanied with elucidations of molecular mechanisms. Serosal injection of acetic acids for generating gastric ulcer and intraperitoneal (ip) injection of recombinant interleukin 1-beta (IL-1β) for recurring healed ulcer was done in SD rats. The 72 rats were divided into three groups according to treatment as follows; Group I, no further treatment, Group II, 8 weeks treatment of omeprazole, and Group III, 8 weeks of gastroprotectant treatment. IL-1β was administered for ulcer recurrence after 28 weeks of acetic acid injection. At four weeks after gastric ulcerogenesis, 58.3% (7/12) of active gastric ulcer were converted to healing stage in Group III, but 16.7% (2/12) in Group II and none in Group I, for which significant levels of epidermal growth factor, mucin, and pS2/trefoil peptide1 were contributive to these accelerated healings of Group III. ip injections of rIL-1β (200 µg/kg) at 28 weeks after acetic acid injection led to 100% of ulcer recurrence in Group I and 75.0% in Group II, but only 16.7% of Group III rats showed ulcer recurrence. Significantly attenuated levels of inflammatory cytokines including IL-2, transforming growth factor-alpha (TNF-α), cyclooxygenase-2 (COX-2), nitrotyrosine were responsible for the resistance to ulcer recurrence in Group III. Conclusively, gastroprotectant might be prerequisite in order to achieve ideal QOUH through significant inductions of remodeling.

Nutritional Composition, Antioxidant Activities, and Antiulcer Potential of Lentinus squarrosulus (Mont.) Mycelia Extract

Water extract of Lentinus squarrosulus mycelia was analysed for nutritional content, antioxidant capacity, and antiulcer ability. The extract contains high protein (57.6 g/100 g) and low total fat (0.5 g/100 g) and is rich in magnesium (0.4 g/100 g), potassium (3.8 g/100 g), vitamins B₁ (1.42 mg/100 g), and B₃ (194.29 mg/100 g) with total phenolic content of 39.16 mg/100 g. The cupric reducing antioxidant capacity and 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity of the extract were A₄₅₀ of 0.20 ± 0.03 at 0.5 mg/ml and IC₅₀ of 14.29 mg/ml, respectively. Oral feeding of L. squarrosulus extract (250 mg/kg) offered significant gastric mucosal protection of Sprague-Dawley rats compared to cimetidine (50 mg/kg). The ulcer healing rate of ulcerated rats after 24, 48, and 72 hours of treatment was 82%, 90%, and 100%, respectively. The IL-1β level in the serum and the NF-κB level in the tissues indicate that the healing potential was associated with attenuation of proinflammatory cytokines.

A new strategy with proton pump inhibitors for the prevention of acute exacerbations in COPD

Acute exacerbations of chronic obstructive pulmonary disease (COPD), an acute worsening of respiratory symptoms, generally result in a poor prognosis. Successful prevention and management of such exacerbations is thus important for patient care. Viral infection, primarily with rhinovirus (RV), is the foremost cause of exacerbations in COPD patients. Proton pump inhibitors (PPIs) have been reported to inhibit RV infection in human airway epithelial cells in vitro. Furthermore, clinical trials of PPIs in patients with COPD resulted in a reduction in rates of both common cold and COPD exacerbations. In this review, we discuss the significance of COPD exacerbations, summarize a published trial of the effect of low-dose PPIs on COPD exacerbations, and postulate a mechanism for this effect.

Enhancement of gastric ulcer healing and angiogenesis by cochinchina Momordica seed extract in rats

Cochinchina momordica seed is the dried ripe seed of Momordica cochinchinensis, a perennial vine. The antiulcer effect of an extract from cochinchina momordica seeds (SK-MS10) was evaluated in a rat model of acetic acid-induced gastric ulcers. Gastric ulcers were produced by subserosal injection of acetic acid. SK-MS10 (200 mg/kg) or vehicle was administered orally once per day for 14 days after the acetic acid injection. The stomach was removed and the ulcer size measured at day 7 and 14 of the treatment. Expression of vascular endothelial growth factor (VEGF) was assessed by real-time RT-PCR and Western blot analysis. In addition, the microvasculature density (MVD) adjacent to the ulcer margin was examined by immunohistochemistry. The treatment with SK-MS10 for 7 and 14 days significantly accelerated ulcer healing and increased the expression of mRNA (at day 7) as well as VEGF protein (at day 14) compared to the vehicle-treated rats. The MVD for factor VIII was also higher in the SK-MS10 treatment group compared to the vehicle-treated rats; however, these differences were not statistically significant. These results suggest that SK-MS10 treatment accelerates the healing of gastric ulcers via upregulation of VEGF and angiogenesis in an acetic acid rat model.

A randomized, single-blind study of lansoprazole for the prevention of exacerbations of chronic obstructive pulmonary disease in older patients

OBJECTIVES

To investigate whether proton pump inhibitor (PPI) therapy reduces the frequency of common colds and exacerbations in patients with chronic obstructive pulmonary disease (COPD).

DESIGN

Twelve-month, randomized, observer-blind, controlled trial.

SETTING

A university hospital and three city hospitals in Miyagi prefecture in Japan.

PARTICIPANTS

One hundred patients with COPD (mean age +/- SD 74.9 +/- 8.2) participated. They were all ex-smokers and had received conventional therapies for COPD, including smoking cessation and bronchodilators. Patients with gastroesophageal reflux disease or gastroduodenal ulcer were excluded.

INTERVENTION

Patients were randomly assigned to conventional therapies (control group) or conventional therapies plus PPI (lansoprazole 15 mg/d; PPI group) and observed for 12 months.

MEASUREMENTS

Frequency of common colds and COPD exacerbations.

RESULTS

The number of exacerbations per person in a year in the PPI group was significantly lower than that in the control group (0.34 +/- 0.72 vs 1.18 +/- 1.40; P<.001). The adjusted odds ratio with logistic regression for having exacerbation (> or =once/year) in the PPI group compared with the control group was 0.23 (P=.004). In contrast, there was no significant difference in the numbers of common colds per person per year between the PPI group and the control group (1.22 +/- 2.09 vs 2.04 +/- 3.07; P=.12). PPI therapy significantly reduced the risk of catching frequent common colds (> or =3 times/year), the adjusted odds ratio of which was 0.28 (P=.048).

CONCLUSION

In this single-blind, nonplacebo-controlled trial, lansoprazole was associated with a significant decrease in COPD exacerbations. More definitive clinical trials are warranted.

Effect of some natural products either alone or in combination on gastritis induced in experimental rats

Gastritis, an inflammatory state in gastric mucosa, can be induced experimentally in various ways. The present study considered the iodoacetamide model (Iodo). Omega-3 fatty acids (fish oil), black seed oil, and curcuminoids (natural products) in addition to omeprazole (synthetic proton-pump inhibitor) were tested. Supplementation of 0.1% iodoacetamide to drinking water of experimental rats for two consecutive weeks resulted in: (i) increased serum nitric oxide (NO) and gastrin, and decreased pepsinogen, (ii) depletion of gastric mucosal glutathione (GSH), and (iii) increased gastric mucosal lipid peroxidation (MDA), but failed to affect gastric mucosal myeloperoxidase (MPO) activity. Histological examination showed marked neutrophilic infiltration after 1 week of iodoacetamide administration and shedding of apical cell layer with pale edematous vacuolated gastric gland cells and thickening of muscularis mucosa after 2 weeks of iodoacetamide intake. Individual administration of omega-3 fatty acids 12 mg/kg, black seed oil 50 mg/kg, and curcuminoids 50 mg/kg body weight orally daily for 3 weeks decreased MDA, gastrin, and NO, and normalized mucosal GSH but failed to affect serum pepsinogen level. Combined administration of these natural products for 3 weeks normalized MPO activity, and other effects were nearly the same as with individual use. Omeprazole administration 30 mg/kg body weight orally daily for 3 weeks induced a similar response except for an observed increase in serum gastrin and pepsinogen levels.

Anti-inflammatory effects of pravastatin on Helicobacter pylori-induced gastritis in mice

Pravastatin, an HMG-CoA reductase inhibitor, exerts anti-inflammatory effects via several mechanisms including induction of endothelial nitric oxide synthase (eNOS). We investigated the effect of pravastatin on Helicobacter pylori-induced gastritis in mice. Mice with or without H. pylori infection received intraperitoneal pravastatin daily for 1 week. Expression of eNOS mRNA and tumor necrosis factor-alpha mRNA and myeloperoxidase activity in gastric tissue was determined. Myeloperoxidase activity was reduced in a dose-dependent manner by pravastatin, with activity inhibited by 53.5 and 73.7% at doses of 0.3 and 1 mg/kg, respectively. At a dose of 1 mg/kg, pravastatin reduced the level of tumor necrosis factor-alpha mRNA by 52.7%, while it did not affect eNOS expression. Pravastatin had no effects on these inflammatory parameters in uninfected mice. Pravastatin did not affect the viability of H. pylori. In conclusion, pravastatin exerts an anti-inflammatory effect on H. pylori-induced gastritis in mice without affecting eNOS expression.

Different effects of polymorphisms of tumor necrosis factor-alpha and interleukin-1 beta on development of peptic ulcer and gastric cancer

BACKGROUND AND AIM

In Western countries, polymorphism of pro-inflammatory cytokine genes is associated with the development of gastric cancer and duodenal ulcer. The aim of this study was to clarify the association of polymorphisms of interleukin (IL)-1beta and tumor necrosis factor (TNF)-alpha with susceptibility to peptic ulcer diseases and gastric cancer in Japan.

METHODS

The IL-1beta-511/-31 and TNF-alpha-308/-857/-863/-1031 genotypes were determined in Helicobacter pylori-positive patients with gastritis only (n = 164), gastric ulcers (n = 110), duodenal ulcers (n = 94), or gastric cancers (n = 105), and in H. pylori-negative controls (n = 172).

RESULTS

Carriage of the alleles TNF-alpha-857 T (odd ratio [OR], 1.826; 95% confidence interval [CI], 1.097-3.039), TNF-alpha-863 A (OR, 1.788; 95% CI, 1.079-2.905) and TNF-alpha-1031 C (OR, 1.912; 95% CI, 1.152-3.171) was associated with increased risk for gastric ulcer development. Carriage of the alleles TNF-alpha-857 T (OR, 1.686; 95% CI, 1.003-2.832), TNF-alpha-863 A (OR, 1.863; 95% CI, 1.118-3.107) and TNF-alpha-1031 C (OR 2.074; 95% CI, 1.244-3.457) was also associated with increased risk of gastric cancer development. There was no relationship between the development of H. pylori-related diseases and polymorphisms of IL-1beta-511/-31 and TNF-alpha-308. The simultaneous carriage of three different high-producer alleles of TNF-alpha-857/-863/-1031 significantly increased the risk of gastric ulcer (OR, 6.57; 95% CI, 2.34-18.40) and gastric cancer (OR, 5.20; 95% CI, 1.83-14.78).

CONCLUSIONS

Polymorphisms in TNF-alpha rather than IL-1beta are associated with increased risk for gastric ulcers and gastric cancer in Japan. The simultaneous carriage of more than one high-producer allele of TNF-alpha further increased the risks for gastric ulcer and cancer.

Roles of cyclooxygenase 2 and microsomal prostaglandin E synthase 1 in rat acid reflux oesophagitis

BACKGROUND

Although prostaglandin E2 (PGE2), cyclooxygenase 2 (COX-2), and microsomal prostaglandin E synthase 1 (mPGES-1) are known to play a role in various inflammatory events, their roles in the pathogenesis of gastro-oesophageal reflux disease are not known.

AIMS

We examined the dynamics of COX-1, COX-2, mPGES-1, mPGES-2, cytosolic PGES (cPGES), and PGE2 synthetic activity in rat acid reflux oesophagitis and the effects of COX-2 inhibitors on the severity of oesophagitis.

METHODS

Acid reflux oesophagitis was induced by ligating the transitional region between the forestomach and the glandular portion and wrapping the duodenum near the pylorus. Rats were killed on day 3 (acute phase) or day 21 (chronic phase) after induction of oesophagitis.

RESULTS

Expression of COX-2 and mPGES-1 was markedly increased in oesophagitis while modest changes in COX-1, cPGES, and mPGES-2 expression were observed. COX-2 and mPGES-1 were colocalised in epithelial cells of the basal layer, as well as inflammatory and mesenchymal cells in the lamina propria and submucosa. COX-2 inhibitors significantly reduced the severity of chronic oesophagitis but did not affect acute oesophageal lesions. COX-2 inhibitors significantly inhibited the increase in PGE2 synthesis in oesophageal lesions on both days 3 and 21. Epithelial proliferation was significantly increased in the basal layer on day 21. Inflammatory cells and epithelial cells of the basal layer exhibited reactions for EP4 in oesophagitis.

CONCLUSION

PGE2 derived from COX-2 and mPGES-1 plays a significant role in the pathogenesis of chronic acid reflux oesophagitis, and possibly in basal hyperplasia and persistent inflammatory cell infiltration.

Of microbe and man: determinants ofHelicobacter pylori-related diseases

The human gastric pathogen Helicobacterpylori infects the human gastric mucus layer of approximately half of the world's population. Colonization with this bacterium results in superficial gastritis without clinical symptoms, but can progress into gastric or duodenal ulcers, gastric malignancies and mucosa-associated lymphoid tissue-lymphomas. Disease outcome is affected by a complex interplay between host, environmental and bacterial factors. Irrespective of disease outcome, the majority of H. pylori infected individuals remain colonized for life. Changing conditions in the human gastric mucosa may alter gene expression and/or result in the outgrowth of more fit H. pylori variants. As such, H. pylori is a highly flexible organism that is optimally adapted to its host. the heterogeneity in H. pylori populations make predictions on H. pylori-related pathogenesis difficult. In this review, we discuss host, environmental and bacterial factors that are important in disease progression. Moreover, H. pylori adaptive mechanisms, which allow its life-long survival and growth in the gastric mucosa are considered.

Rebamipide reduces recurrence of experimental gastric ulcers: role of free radicals and neutrophils

Mucosal inflammation is a crucial factor for the recurrence of peptic ulcer. In this study, we examined the effect of rebamipide on neutrophils infiltration, lipid peroxidation, and antioxidative enzyme activities in the recurrence of experimental gastric ulcer. Ulcer recurrence was examined at 60, 100, and 140 days after production of acetic acid-induced gastric ulcers in rats. Gastric neutrophil infiltration, lipid peroxidation, and antioxidative enzyme activities were determined by analyses of myeloperoxidase (MPO) activity, thiobarbituric acid reactive substance (TBARS) levels, and glutathione peroxidase (GSHpx) and superoxide dismutase (SOD) activities in the ulcer region, respectively. The effect of rebamipide, an antigastric-ulcer agent, on ulcer recurrence was assessed following oral administration at 60 mg/kg/day from day 20. In the control and rebamipide groups, gastric ulcer indices were reduced on day 100 compared with day 60; however, increases were observed on day 140, indicating ulcer recurrence. In the rebamipide group, the ulcer index was smaller than in the control group at each time point and the effect was significant on day 140. Although marked elevation of MPO activities was observed in the control group during the experiment, no significant elevations were seen in the rebamipide group on days 100 and 140. TBARS levels were significantly elevated in the control group on day 140, but not in the rebamipide group. Rebamipide suppressed the decrease in GSHpx activity on day 60. These results suggest that lipid peroxidation of gastric tissue mediated by free radicals from neutrophils is responsible for the recurrence of acetic acid-induced gastric ulcers in rats, and that the elimination of free radicals by rebamipide may contribute to the reduction of severity in ulcer recurrence.

15th anniversary of rebamipide: looking ahead to the new mechanisms and new applications

Rebamipide, a gastro-protective drug, was developed in Japan for the treatment of peptic ulcer disease. It was proven superior to the former same category drug cetraxate in a randomized, controlled, double-blind, comparative clinical study in 1989. Rebamipide's mechanisms of actions are different from anti-secretory drugs; it accelerates and improves the quality of ulcer healing and reduces ulcer recurrence rate. Numerous studies have been conducted to explain the mechanisms responsible for these actions, 37 papers were published by 1998. Major properties of rebamipide include: stimulation of prostaglandin and mucus glycoprotein synthesis, inhibition of reactive oxygen species, inflammatory cytokines and chemokines, and inhibition of neutrophils activation. Since 1998, 107 papers were published, clarifying further effects of rebamipide on cyclooxygenase-2, prostaglandin E receptors, growth factors (i.e., HGF, EGF, and VEGF), heat-shock proteins, nitric oxide, adhesion molecules, neutrophils, and Helicobacter pylori- and NSAID-related pathology. Moreover, inhibitory action of rebamipide on gastric cancer growth has also been shown. In this issue we reviewed recent advances in understanding of rebamipide's mechanism of action and its newest clinical applications.

Effect of Jianweiyuyang granule on gastric ulcer recurrence and expression of VEGF mRNA in the healing process of gastric ulcer in rats

AIM: To investigate the effect of Jianweiyuyang (JWYY) granule on gastric ulcer recurrence and its mechanism in the treatment of gastric ulcer in rats.

METHODS: Gastric ulcer in rats was induced according to Okeba’s method with minor modification and the recurrence model was induced by IL-1β. The expression of vascular endothelial growth factor mRNA (VEGF mRNA) was examined by reverse transcription polymerase chain reaction in gastric ulcer and microvessel density (MVD) adjacent to the ulcer margin was examined by immunohistochemistry.

RESULTS: MVD was higher in the JWYY treatment group (14.0±2.62) compared with the normal, model and ranitidine treatment groups (2.2±0.84, 8.8±0.97, 10.4±0.97) in rats (P<0.01). The expression level of VEGF mRNA in gastric tissues during the healing process of JWYY treatment group rats significantly increased compared with other groups (normal group: 0.190±0.019, model group: 0.642±0.034, ranitidine group: 0.790±0.037, P<0.01).

CONCLUSION: JWYY granules can stimulate angiogenesis and enhance the expression of VEGF mRNA in gastric ulcer rats. This might be the mechanism for JWYY accelerating the ulcer healing, and preventing the recurrence of gastric ulcer.

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The proton pump inhibitor lansoprazole inhibits rhinovirus infection in cultured human tracheal epithelial cells

To examine the effects of lansoprazole, a proton pump inhibitor, on rhinovirus infection in airways, human tracheal epithelial cells were infected with a major subgroup of rhinoviruses, type 14 rhinovirus. Rhinovirus increased the mRNA expression of intercellular adhesion molecule-1 (ICAM-1) in the cells, the major rhinovirus receptor, and the content of the soluble form of ICAM-1 (sICAM-1) and cytokines in supernatants. Lansoprazole reduced supernatant titers and RNA of rhinovirus, the susceptibility to rhinovirus infection, the ICAM-1 mRNA production, the number and fluorescence intensity of acidic endosomes in the cells, and supernatants sICAM-1 and cytokine concentrations including interleukin-1beta. Antibody to interleukin-1beta reduced baseline and rhinovirus-induced ICAM-1 production. These results suggest that lansoprazole inhibits rhinovirus infection by reducing ICAM-1 via partly endogenous production of interleukin-1beta, and by blocking the rhinovirus RNA entry into the endosomes. Lansoprazole may modulate airway inflammation by reducing the production of cytokines and ICAM-1 in rhinovirus infection.

The interleukin-1 RN polymorphism and Helicobacter pylori infection in the development of duodenal ulcer

BACKGROUND

The host genetic factors that determine the clinical outcomes for Helicobacter pylori-infected individuals remain unclear.

AIMS

To elucidate the relations among interleukin-1 locus polymorphisms, and H. pylori infection in the development of duodenal ulcers.

MATERIALS AND METHODS

In a case-control study involving 168 control subjects and 147 patients with duodenal ulcer, biallelic polymorphisms of two interleukin-1 loci, IL-1B(-511) and IL-1B(+3954), as well as the penta-allelic variable number of tandem repeats of interleukin-1 receptor antagonist IL-1RN, were genotyped, and the H. pylori states of controls and patients were examined.

RESULTS

Helicobacter pylori infection, male gender and the carriage of IL-1RN*2 independently increased the risk of duodenal ulcer with odds ratios of 6.4 (95% confidence interval, 3.7-11.0), 1.9 (95% confidence interval, 1.1-3.4) and 2.7 (95% confidence interval, 1.1-6.8), respectively. Statistical analysis revealed an interaction between IL-1RN*2 and H. pylori infection with the duodenal ulcer risk conferred by the H. pylori infection substantially increased (odds ratios, 22.6; 95% confidence interval, 5.9-86.5) by the carriage of IL-1RN*2. In addition, a synergistic interaction between IL-1RN*2 and blood group O existed. The combined risk of H. pylori infection, the carriage of IL-1RN*2 and blood group O for duodenal ulcer was 27.5 (95% confidence interval, 3.1-243.6).

CONCLUSIONS

This work is the first to verify IL-1RN*2 as an independent factor that governs the development of duodenal ulcers. Our data indicate that H. pylori infection and IL-1RN*2 synergistically determine susceptibility to duodenal ulcer. The blood group phenotype is possibly a crucial determinant for the outcome of the impact of an interleukin-1 locus polymorphism on H. pylori-infected individuals.

Monocyte chemotactic protein-1 regulates leukocyte recruitment during gastric ulcer recurrence induced by tumor necrosis factor-alpha

TNF-alpha has numerous biological activities, including the induction of chemokine expression, and is involved in many gastric injuries. C-C chemokines [monocyte chemotactic protein (MCP)-1 and macrophage inflammatory protein (MIP)-1alpha] and C-X-C chemokines [MIP-2 and cytokine-induced neutrophil chemoattractant (CINC)-2alpha] mediate chemotaxis of monocytes and neutrophils, respectively. We examined the roles of TNF-alpha and dynamics of chemokine expression in gastric ulceration including ulcer recurrence and indomethacin-induced injury. Rats with healed chronic gastric ulcers received intraperitoneal TNF-alpha to induce ulcer recurrence. Some rats were given neutralizing antibodies against neutrophils or MCP-1 together with TNF-alpha. In a separate experiment, rats were orally administered 20 mg/kg indomethacin with or without pretreatment with pentoxifylline (an inhibitor of TNF-alpha synthesis) or anti-MCP-1 antibody. TNF-alpha (1 microg/kg) induced gastric ulcer recurrence after 48 h, which was completely prevented by anti-neutrophil antibody. TNF-alpha increased the number of macrophages and MCP-1 mRNA expression in scarred mucosa from 4 h, whereas it increased MPO activities (marker of neutrophil infiltration) and mRNA expression of MIP-2 and CINC-2alpha from 24 h. Anti-MCP-1 antibody inhibited leukocyte infiltration with reduction of the levels of C-X-C chemokines and prevented ulcer recurrence. Indomethacin treatment increased TNF-alpha/chemokine mRNA expression from 30 min and induced macroscopic erosions after 4 h. Pentoxifylline inhibited the indomethacin-induced gastric injury with reduction of neutrophil infiltration and expression of chemokine (MCP-1, MIP-2, and CINC-2alpha). Anti-MCP-1 antibody also inhibited the injury and these inflammatory responses but did not affect TNF-alpha mRNA expression. In conclusion, increased MCP-1 triggered by TNF-alpha may play a key role in gastric ulceration by regulating leukocyte recruitment and chemokine expression.

Impaired gastric ulcer healing in diabetic rats: role of heat shock protein, growth factors, prostaglandins and proinflammatory cytokines

Gastric mucosa of diabetic rats is highly vulnerable to acute injury, but little is known about the influence of diabetic conditions on the healing of gastric ulcers. In this study, streptozotocin (70 mg/kg injected intraperitoneally) was used to induce diabetes mellitus in rats. Four weeks after streptozotocin injection, gastric ulcers were induced using the acetic acid method, and 10 days later, the healing rate and the gastric blood flow (GBF) were measured by planimetry and hydrogen (H(2))-gas clearance method, respectively. Six major groups of rats with gastric ulcers were used: (1) vehicle (saline); (2) streptozotocin alone; (3) insulin (4 IU/day intraperitoneally); (4) streptozotocin plus insulin; (5) pentoxifylline, an inhibitor of synthesis and release of tumor necrosis factor-alpha (TNF alpha); and (6) aspirin, a non-selective inhibitor of cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2), and rofecoxib, the highly selective COX-2. In the diabetic rats, a significant delay in ulcer healing ( approximately by 300%), accompanied by a decrease in the gastric mucosal blood flow was observed. The prolongation of the healing in diabetic animals was associated with an increase in gastric mucosal expression and release of TNFalpha, interleukin-1 beta (IL-1 beta), suppression of the vascular endothelial growth factor (VEGF), platelet endothelial cell adhesion molecule-1 (PECAM-1) and the mucosal overexpression of heat shock protein 70 (HSP 70). Administration of insulin reversed the delay in ulcer healing and significantly decreased the expression of IL-1 beta and TNF-alpha, while producing the rise in the expression of VEGF and PECAM. Pentoxifylline, an inhibitor of TNF-alpha, which by itself accelerated ulcer healing in non-diabetic rats, counteracted the increase in the area of gastric ulcer induced by streptozotocin, raised significantly gastric blood flow and suppressed the plasma TNF-alpha levels. Aspirin and rofecoxib, that significantly suppressed the mucosal prostaglandin E(2) generation in ulcer area, delayed significantly the rate of ulcer healing and decreased the GBF at ulcer margin in non-diabetic rats, and these changes were significantly augmented in diabetic animals. We conclude that: (1) Experimental diabetes dramatically impairs ulcer healing, depending upon the increased release of proinflammatory cytokines and the attenuation of angiogenesis that can limit the ulcer healing effects of locally produced HSP 70 and TNF-alpha. (2) Insulin reversed this impairment of ulcer healing in diabetic rats, mainly due to the enhancement of angiogenesis and reduction in expression of cytokines in the ulcer area. (3) Classic non-steroidal anti-inflammatory drugs such as aspirin prolonged ulcer healing under diabetic conditions due to suppression of endogenous prostaglandins and the fall in the microcirculation at the ulcer margin and these effects were mimicked by selective, so called "safe" COX-2 inhibitor, rofecoxib, suggesting that both COX isoforms are important sources of prostaglandins that are essential in the ulcer healing in diabetes.

Increased expression of cytokines and adhesion molecules in rat chronic esophagitis

BACKGROUND/AIMS

Cytokines and adhesion molecules regulate many inflammatory processes in several gastrointestinal diseases. The dynamics of cytokines and adhesion molecules in reflux esophagitis are unknown in detail. We examined the expression and dynamics of interleukin-1beta (IL-1beta), tumor necrosis factor-alpha (TNF-alpha), monocyte chemotactic protein-1 (MCP-1), macrophage inflammatory protein-1alpha (MIP-1alpha), MIP-2, GRO/cytokine-induced neutrophil chemoattractant-2alpha (CINC-2alpha), intercellular adhesion molecule-1 (ICAM-1), leukocyte function-associated antigen 1 (LFA-1; CD11a/CD18), and Mac-1 (CD11b/CD18) in rat chronic reflux esophagitis.

METHODS

Chronic acid reflux esophagitis was induced in Wistar rats by ligating the transitional region between the forestomach and the glandular portion and wrapping the duodenum near the pylorus with a small piece of an 18-Fr Nélaton catheter. Rats were killed 3 or 21 days after operation. The levels of mRNA expression of cytokines and ICAM-1 were determined by real-time quantitative RT-PCR. Localization of adhesion molecules and cytokines was investigated by immunohistochemical staining, and numbers of LFA-1- or Mac-1-positive cells were quantified.

RESULTS

IL-1beta, TNF-alpha, MCP-1, MIP-1alpha, MIP-2, CINC-2alpha, and ICAM-1 mRNA expression was significantly increased in esophageal lesions compared with normal esophagus. There were few these cytokines- or adhesion molecule-positive cells in normal esophagus. In regions of esophagitis, numerous inflammatory leukocytes in lamina propria and the submucosal layer exhibited positive reactions for these cytokines and endothelial cells were intensely stained for ICAM-1. Numbers of LFA-1- and Mac-1-positive cells were significantly increased in rat chronic esophagitis. Treatment with rabeprazole almost completely inhibited development of chronic acid reflux esophagitis and significantly decreased expression of cytokines and ICAM-1 mRNA in esophageal tissue compared with control.

CONCLUSION

Cytokines and adhesion molecules play important roles in the pathogenesis of chronic reflux esophagitis in this rat model.

Inhibition of small-conductance Cl- channels by the interleukin-1beta-stimulated production of superoxide in rabbit gastric parietal cells

We have shown previously that the G protein-coupled production of superoxide anion (O2-) leads to closure of small-conductance Cl- channels (0.3-0.4 pS) in the basolateral membrane of rabbit parietal cells. In the present study, effects of interleukin-1beta (IL-1beta) on the Cl- channel were investigated. In the whole-cell patch-clamp recording, IL-1beta (0.3-10 ng ml-1) inhibited the whole-cell Cl- current recorded from a parietal cell within isolated rabbit gastric glands. Variance noise analysis of the whole-cell Cl- current showed that the single channel conductance of the Cl- channel that is sensitive to IL-1beta is 0.37 pS. The IL-1beta (1 ng ml-1)-induced decrease of the Cl- current was abolished by anti-IL-1beta antibody (2 microg ml-1), recombinant IL-1 receptor antagonist (500 ng ml-1), GDPbetaS (500 microM) and superoxide dismutase (100 units ml-1), a scavenger of O2-. Northern blot analysis showed that the mRNA of the IL-1 receptor was selectively expressed in rabbit gastric parietal cells. In the dihydrofluorescein diacetate-loaded single parietal cells in gastric glands, IL-1beta (0.3-10 ng ml-1) stimulated the production of oxygen radicals. Y-27632 (1-10 microM), a specific Rho-kinase inhibitor, and fluvastatin (10 microM), an indirect inhibitor for Rho proteins, significantly inhibited the IL-1beta-induced effects on the channel activity and production of oxygen radicals. IL-1beta (0.3-10 ng ml-1) activated Rho in the parietal cells. These results indicate that IL-1beta binds to the IL-1 receptor of gastric parietal cells and inhibits the small-conductance Cl- channel via the G protein-mediated Rho/Rho-kinase-dependent production of O2-.

Helicobacter pylori: resurrection of the cancer link

Helicobacter pylori is one of the most common pathogenic bacterial infections, colonizing an estimated half of all humans. In a subset of individuals, the infection leads to serious gastroduodenal disease such as peptic ulcers and gastric adenocarcinoma. The factors contributing to skewing this, in most cases benign, relationship into disease development are largely unknown. However, factors emanating from the bacterium, host and the environment have been shown to affect the risk for disease, although no factor can be singled out to be most important. The known factors are associated with affecting the risk of disease, and are not absolute. Virulence of H. pylori is affected by the existence and regulation of certain genes present in the bacterial population in a stomach. The effects of H. pylori on gastric cancer development have been challenged and the risk associated with infection with virulent (i.e. Cag PAI positive) H. pylori has likely been underestimated.

Peptic ulcer disease

The introduction of the "Maastricht 2-2000" document provides some guidance with regard to the management of Helicobacter pylori infection in both primary and specialist practice settings, albeit primarily in the European setting. The putative role of H. pylori in gastric carcinogenesis was supported by a further study. Studies on the natural history of peptic ulcer disease (PUD) highlight the particular vulnerability of the elderly patient to PUD and its complications, and focus attention on targeted intervention in this group, particularly the avoidance of nonsteroidal antiinflammatory drugs (NSAID). Little has evolved with regard to the introduction of new NSAID, but reports indicate the potential association of cyclooxygenase-2 (COX 2)-selective agent use with an increased risk of cardiovascular events. The role of H. pylori and NSAID as risk factors for peptic ulcer disease and its complications is again explored, and both meta-analysis and clinical studies provide some evidence of their synergistic effect. The introduction of esomeprazole, the S-isomer of omeprazole, has widened the clinician's therapeutic choice; the true value of this agent remains to be determined.

Interleukin 1beta polymorphisms increase risk of hypochlorhydria and atrophic gastritis and reduce risk of duodenal ulcer recurrence in Japan

BACKGROUND & AIMS

Interleukin-1 beta (IL-1beta) polymorphisms are associated with increased risk of gastric cancer in whites. This study aimed to examine effects of these polymorphisms on gastric acid secretion, atrophic gastritis, and risk of peptic ulcer in Japan.

METHODS

We determined IL-1B-511/-31 and IL-1RN genotypes and measured gastric juice pH, serum pepsinogen (PG) I and II levels, and gastritis and atrophy scores in Helicobacter pylori-positive patients with gastritis only, gastric ulcers, or duodenal ulcers (DUs), and H. pylori-negative controls.

RESULTS

In the H. pylori-positive group, subjects with the proinflammatory IL-1B-511 T/T genotype had the highest atrophy and gastritis scores, the highest median gastric juice pH, and the lowest median serum PG I/PG II ratios. Although gastric juice pH significantly increased and serum PG I and PG I/PG II ratios significantly decreased in the IL-1B-511 T/T genotype group with age, no such age-dependent changes were observed in the C/C genotype group. Changes in the C/T genotype group were intermediate. In the H. pylori-negative group, the IL-1 loci had no effect on any of the physiologic or morphologic parameters. Carriage of IL-1RN allele 2 significantly protected against DU disease while the IL-1B-511 T/T genotype significantly protected against DU recurrence in patients older than 60 years.

CONCLUSIONS

Proinflammatory IL-1beta polymorphisms are associated with hypochlorhydria and atrophic gastritis in Japan. The effects are dependent on H. pylori infection and become more significant with advancing age. This may explain the high incidence of gastric cancer in Japan and also the age-dependent decrease in DU recurrence in infected subjects.