Protective effect of Enterococcus faecium against ethanol-induced gastric injury via extracellular vesicles

Recently, Enterococcus has been shown to have gastric protective functions, and the mechanisms by which Enterococcus modulates gastric function are still being investigated. Herein, we investigated how Enterococcus faecium (Efm) and E. faecium-derived extracellular vesicles (EVs) (EfmEVs) exert protective effect against ethanol-induced gastric injury by investigating the effect of EfmEVs on gastric mucosal ulcer scoring, histological lesion, mucosal glycoprotein production, acidity, anti-oxidative function, and inflammatory responses in rat. Pretreatment with Efm showed significant reduction of ethanol-induced gastric injury, as evidenced by the lowering of ulcer index, histological lesion, gastric pH, and inflammatory responses and the enhancement of mucosal glycoprotein production and anti-oxidative function. Further functional studies on three bioactive components [inactivated Efm, EfmEVs (EVs), and EV-free supernatants] of the bacterial culture showed that EVs are mostly responsible for the gastroprotective effect. Moreover, EV secretion is beneficial for the gastroprotective effect of Efm. Hence, EVs mediated the protective effect of Efm against ethanol-induced gastric injury by lowering inflammatory responses and enhancing anti-oxidative function and may be a potent anti-inflammatory and anti-oxidative strategy to alleviate hyperinflammatory gastrointestinal tract conditions.IMPORTANCEThis study indicated that Enterococcus faecium provided a protective effect against rat gastric injury, which involved improvement of the mucosal glycoprotein production, anti-oxidative function, and inflammatory responses. Furthermore, we confirmed that three bioactive components (inactivated Efm, extracellular vesicles, and EV-free supernatants) of E. faecium culture also contributed to the gastroprotective effect. Importantly, E. faecium-derived EVs showed an effective impact for the gastroprotective effect.

LC-MS-Based Metabolomics Reveals the Mechanism of Protection of Berberine against Indomethacin-Induced Gastric Injury in Rats

Berberine is a natural isoquinoline alkaloid with low toxicity, which exists in a wide variety of medicinal plants. Berberine has been demonstrated to exhibit potent prevention of indomethacin-induced gastric injury (GI) but the related mechanism remains unclear. In the present study, liquid chromatography-mass spectrometry (LC-MS)-based metabolomics was applied for the first time to investigate the alteration of serum metabolites in the protection of berberine against indomethacin-induced gastric injury in rats. Subsequently, bioinformatics was utilized to analyze the potential metabolic pathway of the anti-GI effect of berberine. The pharmacodynamic data indicated that berberine could ameliorate gastric pathological damage, inhibit the level of proinflammatory factors in serum, and increase the level of antioxidant factors in serum. The LC-MS-based metabolomics analysis conducted in this study demonstrated the presence of 57 differential metabolites in the serum of rats with induced GI caused by indomethacin, which was associated with 29 metabolic pathways. Moreover, the study revealed that berberine showed a significant impact on the differential metabolites, with 45 differential metabolites being reported between the model group and the group treated with berberine. The differential metabolites were associated with 24 metabolic pathways, and berberine administration regulated 14 of the 57 differential metabolites, affecting 14 of the 29 metabolic pathways. The primary metabolic pathways affected were glutathione metabolism and arachidonic acid metabolism. Based on the results, it can be concluded that berberine has a gastroprotective effect on the GI. This study is particularly significant since it is the first to elucidate the mechanism of berberine's action on GI. The results suggest that berberine's action may be related to energy metabolism, oxidative stress, and inflammation regulation. These findings may pave the way for the development of new therapeutic interventions for the prevention and management of NSAID-induced GI disorders.

Honokiol, an inducer of sirtuin-3, protects against non-steroidal anti-inflammatory drug-induced gastric mucosal mitochondrial pathology, apoptosis and inflammatory tissue injury

BACKGROUND AND PURPOSE

Mitochondrial oxidative stress, inflammation and apoptosis primarily underlie gastric mucosal injury caused by the widely used non-steroidal anti-inflammatory drugs (NSAIDs). Alternative gastroprotective strategies are therefore needed. Sirtuin-3 pivotally maintains mitochondrial structural integrity and metabolism while preventing oxidative stress; however, its relevance to gastric injury was never explored. Here, we have investigated whether and how sirtuin-3 stimulation by the phytochemical, honokiol, could rescue NSAID-induced gastric injury.

EXPERIMENTAL APPROACH

Gastric injury in rats induced by indomethacin was used to assess the effects of honokiol. Next-generation sequencing-based transcriptomics followed by functional validation identified the gastroprotective function of sirtuin-3. Flow cytometry, immunoblotting, qRT-PCR and immunohistochemistry were used measure effects on oxidative stress, mitochondrial dynamics, electron transport chain function, and markers of inflammation and apoptosis. Sirtuin-3 deacetylase activity was also estimated and gastric luminal pH was measured.

KEY RESULTS

Indomethacin down-regulated sirtuin-3 to induce oxidative stress, mitochondrial hyperacetylation, 8-oxoguanine DNA glycosylase 1 depletion, mitochondrial DNA damage, respiratory chain defect and mitochondrial fragmentation leading to severe mucosal injury. Indomethacin dose-dependently inhibited sirtuin-3 deacetylase activity. Honokiol prevented mitochondrial oxidative damage and inflammatory tissue injury by attenuating indomethacin-induced depletion of both sirtuin-3 and its transcriptional regulators PGC1α and ERRα. Honokiol also accelerated gastric wound healing but did not alter gastric acid secretion, unlike lansoprazole.

CONCLUSIONS AND IMPLICATIONS

Sirtuin-3 stimulation by honokiol prevented and reversed NSAID-induced gastric injury through maintaining mitochondrial integrity. Honokiol did not affect gastric acid secretion. Sirtuin-3 stimulation by honokiol may be utilized as a mitochondria-based, acid-independent novel gastroprotective strategy against NSAIDs.

Biological Potential of Kakkalide in medicine for the Treatment of Human disorders: An Overview of Pharmacological aspects

BACKGROUND

Pueraria lobata is an important herbal medicine of Fabaceae family that has been clinically used in Traditional Chinese Medicine to counteract human disorders and associated secondary complications. Kakkalide also called irisolidone 7-xylosylglucoside is an isoflavonoid of Puerariae flos, Pueraria lobata and Flos Puerariae. Moreover, Kakkalide has a wide range of bioactivities in medicine.

METHODS

Biological potential of kakkalide was investigated in the present work through scientific data analysis of different scientific research work on kakkalide in order to know its therapeutic potential in medicine. Scientific data on Pueraria lobata were collected and analyzed in the present work. All the scientific data were collected from Google, Google Scholar, Scopus, and Science Direct in the present work.

RESULTS

Scientific data analysis of kakkalide revealed its biological importance and therapeutic potential in medicine. The present investigation signified kakkalide's effectiveness in inflammatory diseases, prostaglandin E2 production, liver complication, gastric injury, alcoholism, insulin-resistant endothelial dysfunction, aldose reductase enzyme, hyperlipidemia, estrogenic activity, and stroke. In addition, the bioavailability of kakkalide was also discussed in the present paper. Present work also revealed the significance of analytical techniques for the separation, isolation and identification of kakkalide in different biological and non-biological samples.

CONCLUSION

Present paper signified the health-beneficial aspects of kakkalide in medicine.

Preparation of Corn Peptides with Anti-Adhesive Activity and Its Functionality to Alleviate Gastric Injury Induced by Helicobacter pylori Infection In Vivo

More than 50% of the world population is infected with Helicobacter pylori (H. pylori), which is classified as group I carcinogen by the WHO. H. pylori surface adhesins specifically recognize gastric mucosal epithelial cells' (GES-1 cells) receptor to complete the adhesion. Blocking the adhesion with an anti-adhesion compound is an effective way to prevent H. pylori infection. The present study found that corn protein hydrolysate, hydrolyzed by Neutral, effectively alleviated gastric injury induced by H. pylori infection through anti-adhesive and anti-inflammatory effects in vitro and in vivo. The hydrolysate inhibited H. pylori adhesion to GES-1 cells significantly, and its anti-adhesive activity was 50.44 ± 0.27% at 4 mg/mL, which indicated that the hydrolysate possessed a similar structure to the GES-1 cells' receptor, and exhibited anti-adhesive activity in binding to H. pylori. In vivo, compared with the H. pylori infection model group, the medium and high dose of the hydrolysate (400-600 mg/kg·bw) significantly decreased (p < 0.05) the amount of H. pylori colonization, pro-inflammatory cytokines (IL-6, IL-1β, TNF-α and MPO), chemokines (KC and MCP-1) as well as key metabolites of NF-κB signaling pathway levels (TLR4, MyD88 and NF-κB), and it increased antioxidant enzyme contents (SOD and GSH-Px) and the mitigation of H. pylori-induced pathological changes in the gastric mucosa. Taken together, these results indicated that the hydrolysate intervention can prevent H. pylori-induced gastric injury by anti-adhesive activity and inhibiting the NF-κB signaling pathway's induction of inflammation. Hence, the corn protein hydrolysate might act as a potential anti-adhesive agent to prevent H. pylori infection.

Rivastigmine ameliorates indomethacin experimentally induced gastric mucosal injury via activating α7nAChR with inhibiting oxidative stress and apoptosis

The current study aimed to investigate the potential ameliorative role of Rivastigmine (RIVA), the anti-Alzheimer drug, against the gastric mucosal injury caused by indomethacin (IND). The rats were divided into four groups: group I was given a vehicle as a control, group II was given RIVA (0.3 mg/kg) once daily intraperitoneal (ip) for 2 weeks, group III was given a single IP dose of 30 mg/kg IND, and group IV was given RIVA ip 2 weeks before the administration of IND. The gastric mucosal injury was detected by the estimation of ulcer index, gastric acidity, pepsin, and mucin concentrations. Malondialdehyde (MDA), superoxide dismutase (SOD), reduced glutathione (GSH), total nitrite/nitrate (NOx), and the expression of tumor necrosis factor-α (TNF-α), interleukin 6 (IL-6), nuclear factor kappa B (NF-κB), Hemoxygenase 1 (HO-1), and caspase-3 were all measured in gastric tissue. In addition, histological assessment and proliferating cell nuclear antigen (PCNA) immuno-expression were studied. Gastric mucosal injury induced by IND was indicated by both biochemical and histopathological assessments. RIVA Pretreatment reduced ulcer index, MDA, TNF-α, IL-6, NF-κB, and caspase-3 and increased SOD, GSH, NOx, and HO-1. RIVA improved the suppressed nuclear immunoreaction for PCNA observed with IND. The current findings provide novel evidence that RIVA possesses a prophylactic action against IND-induced gastric mucosal damage in rats. Despite being a cholinergic drug that is associated with increased pepsin and stomach acidity, RIVA protected against IND-induced gastric mucosal injury via activating α7nAChR and inhibiting oxidative stress and apoptosis.

Gonggan) Peel Extract on Ethanol/HCl-Induced Gastric Injury in Mice via an Anti-oxidative Mechanism

Gonggan (Citrus reticulata Blanco var. gonggan) is one of the most popular citruses. In this study, the effect of Gonggan peel extract (GPE) on gastric injury was investigated. The components in GPE were analysed by HPLC and the gastric injury model in mice was established by ethanol/hydrochloric acid. After treatment by GPE, the pathological changes of gastric tissue were observed by optical microscope. The levels of oxidative stress and inflammation were measure by kit. And the mRNA expression of related gene was determined by qPCR assay. HPLC result showed GPE mainly contained the flavonoids narirutin, hesperidin, nobiletin, tangeretin and 5-demethylnobiletin. Morphological and pathological analysis of gastric tissue revealed that GPE could relieve gastric injury. Also, GPE increased the levels of SOD, GSH-Px, and CAT and decreased the level of MDA. Moreover, GPE decreased the levels of the inflammatory cytokines TNF-α, IFN-γ, IL-1β, and IL-6 to suppress inflammation. In addition, the q-PCR results showed that GPE upregulated the mRNA expression of SOD1, SOD2, γ-GCS, GSH-Px, CAT, and IκBα and downregulated the mRNA expression of NF-κB. In conclusion, GPE alleviated gastric injury caused by ethanol/hydrochloric acid by inhibiting oxidative stress and the inflammatory response. The mechanism by which GPE protects gastric tissues may involve the antioxidative pathway. Therefore, GPE has great potential to be developed as a product to prevent gastric injury.

Non-Invasive Remote Ischemic Preconditioning May Protect the Gastric Mucosa Against Ischemia-Reperfusion-Induced Injury Through Involvement of Glucocorticoids

Remote ischemic preconditioning (RIPC) is one of the most effective approaches to attenuate tissue injury caused by severe ischemia-reperfusion (I/R). Experimental studies have demonstrated that RIPC is capable of producing a protective effect not only on heart, but also on brain, lungs, kidneys, liver, intestine, and stomach. We previously demonstrated that glucocorticoids participate in protective effect of local gastric ischemic preconditioning against I/R-induced gastric injury. In the present study we investigated whether RIPC may protect the gastric mucosa against I/R-induced injury through involvement of glucocorticoids. Anesthetized fasted Sprague Dawley male rats were exposed to prolonged gastric I/R (30 min occlusion of celiac artery followed by 3 h of reperfusion) alone or with preliminary brief RIPC (10 min non-invasive occlusion of right hind limb blood flow followed by reperfusion for 30 min). First, we investigated the effect of RIPC on I/R-induced injury by itself. Then to study the role of glucocorticoids similar experiments were carried out: 1) in rats pretreated with the inhibitor of glucocorticoid synthesis, metyrapone (30 mg/kg, i.p), and in control animals; 2) in adrenalectomized rats without or with corticosterone replacement (4 mg/kg, s.c.) and in sham-operated animals; 3) in rats pretreated with glucocorticoid receptor antagonist RU-38486 (20 mg/kg, s.c.) and in control animals. I/R induced corticosterone rise and resulted in the gastric erosion formation. RIPC significantly reduced the erosion area in control animals. Metyrapone injected shortly before RIPC caused a decrease in plasma corticosterone levels and prevented the gastroprotective effect of RIPC and, moreover, further aggravated the deleterious effect of I/R. Adrenalectomy performed 1 week before experiment created long-lasting corticosterone deficiency and had no effect on the gastroprotective effect of RIPC. Nevertheless, corticosterone replacement which mimics the corticosterone rise, similar to RIPS, significantly reduced erosion areas of gastric mucosa in adrenalectomized rats supporting the role of glucocorticoids in gastroprotection. RU-38486, which occupied glucocorticoid receptors, similar to metyrapone prevented the gastroprotective effect of RIPC and, moreover, further aggravated the deleterious effect of I/R. The results of the present study demonstrate for the first time that RIPC may protect the gastric mucosa against I/R-induced injury through involvement of glucocorticoids.

Gastroprotective effects of diosgenin against HCl/ethanol-induced gastric mucosal injury through suppression of NF-κβ and myeloperoxidase activities

Gastric mucosal injury is caused by an imbalance between the mucosal defense and gastro-irritants, leading to gastroenteritis. Diosgenin is a steroidal sapogenin found in the wild Yam plant that has been reported with several pharmacological properties. The aim of this study is to explore the gastroprotective role of diosgenin on gastric mucosal damage caused by HCl/ethanol in rats. Male Sprague-Dawley rats were intragastrically administered with diosgenin (20 mg/kg) before HCl/ethanol (0.15 M HCl in 98 % ethanol) administration. Omeprazole was used as a positive control. Diosgenin-attenuated oxidative stress by enhancing (p < 0.05) antioxidant enzymes, reducing lipid peroxidation (MDA), and modulating nitric oxide (NO) levels. Anti-inflammatory effects of diosgenin were observed by a reduction in pro-inflammatory cytokines (p < 0.05), decreased myeloperoxidase (MPO) activities (p < 0.05), and histopathological observation of gastric mucosal damage. Western blot analysis provided evidence on the downregulation of NF-κβ by diosgenin. The findings showed that diosgenin has a significant protective role on gastric injury caused by HCl/ethanol, through its antioxidant, anti-inflammatory role, and suppression of NF-κβ and MPO activities.

Lactobacillus plantarum HFY09 alleviates alcohol-induced gastric ulcers in mice via an anti-oxidative mechanism

The protective effect of Lactobacillus plantarum HFY09 (LP-HFY09) on alcohol-induced gastric ulcers was investigated. Gastric morphology observation and pathological tissue sections showed that LP-HFY09 effectively relieved gastric tissue injury. The biochemical indicator detection showed that LP-HFY09 increased superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), glutathione (GSH), prostaglandin E2 (PGE2), and somatostatin (SS) levels, and decreased malondialdehyde (MDA) levels. Moreover, LP-HFY09 inhibited the levels of inflammatory cytokines interleukin (IL)-1β, IL-6, and tumor necrosis factor-α (TNF-α), and elevated the level of anti-inflammatory cytokine IL-10. The quantitative polymerase chain reaction (q-PCR) examination revealed that LP-HFY09 enhanced the mRNA expression of nuclear factor E2-related factor 2 (Nrf2) and downstream genes, including copper/zinc superoxide dismutase (SOD1), heme oxygenase-1 (HO-1), gamma-glutamylcysteine synthetase (GSH1), manganese superoxide dismutase (SOD2), catalase (CAT), and GSH-Px. This study indicated that LP-HFY09 alleviated alcohol-induced gastric ulcers by increasing gastric mucosa defense factor, and inhibiting oxidative stress and the inflammatory response. PRACTICAL APPLICATIONS: LP-HFY09 has the potential to be investigated as a treatment for gastric injury induced by alcohol.

Pretreatment with Lactobacillus fermentum XY18 Relieves Gastric Injury Induced by HCl/Ethanol in Mice via Antioxidant and Anti-Inflammatory Mechanisms

Aim

Lactobacillus fermentum XY18 (LF-XY18) is a bacterial strain with satisfactory antioxidant properties in vitro that we previously isolated from Xinjiang yogurt. This article will explore the preventive effect of LF-XY18 on acute gastric injury and provide the basis for the innovative development and application of lactic acid bacteria (LAB).

Methods

Kunming mice underwent gastric injury induced by hydrochloric acid and ethanol. LF-XY18 isolated from yogurt in Xinyuan County in the Yili region of Xinjiang was subsequently administered intragastrically to mice for 2 weeks to explore the mechanism of LF-XY18 in preventing gastric injury via its antioxidant effects.

Results

There was decreased gastric juice volume, gastric injury area, and formation of gastric mucosal lesions in the LF-XY18 mice as compared to those in the control mice, while LF-XY18 prevented the decrease in the gastric juice pH value in mice. Compared with the gastric injury model group mice, LF-XY18 reduced the serum levels of motilin, substance P, interleukin-6, interleukin-12, tumor necrosis factor-α, and interferon-γ but increased the serum levels of somatostatin and vasoactive intestinal peptide. The activities of superoxide dismutase, glutathione peroxidase, glutathione, and nitric oxide were increased in the gastric tissue of the LF-XY18 mice compared with the control mice, but malondialdehyde activity was decreased in the LF-XY18 mice. Quantitative polymerase chain reaction analysis illustrated that in the gastric tissue of LF-XY18 mice, the messenger RNA (mRNA) expression of occludin, epidermal growth factor (EGF), EGF receptor, vascular EGF, inhibitor kappa-B-α, neuronal nitric oxide synthase, endothelial nitric oxide synthase, cuprozinc superoxide dismutase, manganese superoxide dismutase, and catalase was stronger than that in the control mice, but the mRNA expression of activated B cells (NF-κB), inducible nitric oxide synthase, and cyclooxygenase-2 was weaker than in the control mice.

Conclusion

These results indicate that LF-XY18 has a potential role in the prevention of gastric injury through antioxidant effects, and a high concentration (1.0 × 10⁹ CFU/kg b.w.) of LF-XY18 has a stronger anti-gastric injury effect than a low concentration (1.0 × 10⁸ CFU/kg b.w.).

Polysaccharides of Dendrobium officinale Kimura & Migo Leaves Protect Against Ethanol-Induced Gastric Mucosal Injury via the AMPK/mTOR Signaling Pathway in Vitro and vivo

Ethanol-induced gastric mucosal injury is a common gastrointestinal disorder. Polysaccharides separated from herbs have been shown to be effective for ethanol-induced gastric mucosal injury, but whether the polysaccharides from Dendrobium officinale Kimura & Migo leaves (LDOP-1) protected mucosa from ethanol-induced injury remains unknown. Thus, the present study carried out gastric mucosal protection and the mechanism of LDOP-1 in vivo and vitro. The chemical composition of LDOP-1 was a heteropolysaccharide comprising mannose, galacturonic acid, glucose, galactose, and arabinose at a molar ratio of 2.0:1.1:0.7:0.5:0.4. Pharmacological results showed that LDOP-1 significantly reduced gastric mucosal injury score and pathological injury, improved antioxidant capacity, reduced the level of reactive oxygen species, and reversed the apoptosis of GES-1 in vivo and vitro. Research showed that LDOP-1 pretreatment upregulated the expression level of p-AMPK, LC3β, HO-1, and Beclin-1; downregulated the expression level of p-mTOR and p62; and reversed the expression level of caspase3, Bax, and Bcl-2. This study was the first to demonstrate that LDOP-1 could protect against ethanol-induced gastric mucosal injury via the AMPK/mTOR signaling pathway in vitro and vivo.

Gastroprotective Effects of Cudrania tricuspidata Leaf Extracts by Suppressing Gastric cAMP and Increasing Gastric Mucins

Cudrania tricuspidata has been used as an East Asian folk remedy to treat various symptoms. Recently, scientific evidence of the efficacy of C. tricuspidata has emerged. The objective of this study was to elucidate protective role of C. tricuspidata in the gastric mucosa using pylorus-ligated Sprague-Dawley rats and primary parietal cells. C. tricuspidata ethanol extracts attenuated gastric mucosal damage, secretion, and juice acidity in pylorus-ligated rats; however, it did not affect expression of gastric acid-related genes [muscarinic acetylcholine receptor M3 receptor (M3R), histamine H2-receptors (H2R), and cholecystokinin-2/gastrin receptors (CCK2R)] or serum gastrin concentrations. Furthermore, extracts greatly reduced levels of gastric cyclic adenosine monophosphate (cAMP) and significantly increased mRNA levels of gastric-type mucins (MUC5AC and MUC6). To identify the mode of action of C. tricuspidata extract in regulating gastric acid secretion, intracellular cAMP and mRNA for H2R, M3R, and CCK2R were measured in primary parietal cells. mRNA levels of H2R, M3R, and CCK2R did not significantly differ following treatment with C. tricuspidata extract, whereas cAMP induced by the H2R-specific agonist was significantly decreased. C. tricuspidata may therefore reduce gastric acid secretion by inhibiting H2R activity rather than regulating mRNA expression. These finding suggest that ethanol extracts of C. tricuspidata inhibit H2R-related gastric acid secretion and increase gastric mucus to help prevent gastric mucosal damage. Therefore, C. tricuspidata extract has potential to be used in foods and medicines to prevent diseases related to gastric mucosal damage, such as gastritis and functional dyspepsia.

Upper gastrointestinal symptoms and associated endoscopic and histological features in patients receiving immune checkpoint inhibitors

Background: Immune checkpoint inhibitors (ICIs) have demonstrated effectiveness in treating many malignancies. Gastrointestinal (GI) adverse events are commonly reported; however, few reports describe upper GI tract toxic effects. We aimed to describe clinical features of upper GI injury related to ICI. Methods: We studied consecutive patients who received ICIs between April 2011 and March 2018 and developed upper GI symptoms requiring esophagogastroduodenoscopy (EGD). Results: Sixty patients developed upper GI symptoms between ICI initiation and 6 months after the last infusion. Among patients who had both EGD and colonoscopy (n = 38), 21 had endoscopic evidence of inflammation involving both the upper and lower GI tract. Overall, histological signs of inflammation of the stomach were evident in 83% of patients, but inflammation of the duodenum in 38%. Total of 42 patients had other risk factors of gastritis, i.e., chemotherapy, radiotherapy, and non-steroidal anti-inflammatory drugs. Only isolated gastric inflammation was seen on endoscopy in patients without these risk factors. The rates of ulceration were similar in the cohorts with and without other risk factors for gastritis. Isolated upper GI inflammation was related to anti-PD-1/L1 in 47% of patients. Immunosuppressive therapy in our cohort with upper GI toxicity consisted of steroids (42%) and infliximab or vedolizumab (23%). Most isolated upper GI symptoms were treated with proton pump inhibitors (65%) or H₂ blockers (35%). Conclusion: We observed a correlation between ICI use and onset of upper GI inflammation even when other risk factors were excluded. Gastric involvement was evident more often than duodenal involvement on endoscopic and histological level.

Preventive Effect of Raw Liubao Tea Polyphenols on Mouse Gastric Injuries Induced by HCl/Ethanol via Anti-Oxidative Stress

Liubao tea is a type of traditional Chinese tea, belonging to the dark teas. This study is a basic research of the contained polyphenols (active substances) and detected preventive effects of polyphenols of raw Liubao tea (PRLT) on mouse gastric injuries induced by HCl/ethanol. High-pressure liquid chromatography was used to analyze the components of PRLT. Furthermore, a mouse gastric injury model was established to observe the preventive effects. PRLT was shown to contain gallic acid, EGC (epigallocatechin), catechin, caffeine, EC (epicatechin), EGCG (epigallocatechin gallate), GCG (gallocatechin gallate), and ECG (epicatechin gallate). The results of the in vivo study indicate that PRLT can inhibit the observed increase of gastric juice volume and decrease of gastric juice pH caused by gastric injury. PRLT can decrease the serum levels of IL-6 (interleukin-6), IL-12 (interleukin-12), TNF-α (tumor necrosis factor-α), and IFN-γ (interferon-γ) in mice with gastric injuries. Moreover, it can also increase the serum levels of SS (somatostatin) and VIP (vasoactive intestinal peptide) and reduce the serum levels of both SP (substance P) and ET-1 (endothelin-1). PRLT was also shown to increase SOD (superoxide dismutase) and GSH (glutathione) levels and decrease MDA (malondialdehyde) level. The detection of mRNA and protein in gastric tissues indicates that PRLT could also up-regulate the expression of Cu/Zn-SOD (copper/zinc superoxide dismutase), Mn-SOD (manganese superoxide dismutase), CAT (catalase), nNOS (neuronal nitric oxide synthase), and eNOS (endothelial nitric oxide synthase) and down-regulate the expression of both iNOS (inducible nitric oxide synthase) and COX-2 (cyclooxygenase-2). Thus, PRLT possess a good preventive effect on gastric injury, which is directly related to the contained active substance. PRLT show good anti-oxidative and preventive effect in gastric injury and offer promising application value.

Pretreatment with Lactobacillus reuteri F-9-35 attenuates ethanol-induced gastric injury in rats

Background

Previous studies suggested that probiotics intervention may be one of the methods for preventing and/or treating gastric ulcer.

Objective

The aim of the study was to compare the preventive effects of a spaceflight mutant Lactobacillus reuteri F-9-35 and its wild type on ethanol-induced gastric injury in rats.

Design

Forty rats were randomly allocated into five groups: a normal group (NOR), ethanol group (EtOH), skim milk group (MILK), L. reuteri F-9-35 group (F935) and wild-type group (WT). The NOR and EtOH groups received 1 ml of distilled water by daily gavage for 14 days. The MILK group received 1 ml of skim milk alone, while the F935 and WT groups were administered 1 ml of skim milk containing the mutant and wild type (1 × 10¹⁰ colony-forming unit/ml) by daily gavage for 14 days, respectively. Acute gastric injury was induced by absolute alcohol 1 h after the final administration of different treatments, except for the NOR group.

Results

Pretreatment with L. reuteri F-9-35, but not milk alone or milk with the L. reuteri wild type, showed significant reduction of ethanol-induced gastric injury, as evidenced by lowering of ulcer index, ulcer area (%), and histological lesion. F-9-35 decreased the levels of lipid peroxidation and myeloperoxidase and increased mucus, glutathione, and nitric oxide levels in gastric tissue. Moreover, F-9-35 inhibited the expression of proinflammatory genes including gastric tumor necrosis factor-α, interleukin-1β, and cyclooxygenase-2 and decreased the activity of nuclear factor kappa B (NF-κB).

Conclusion

These findings indicated that L. reuteri F-9-35 pretreatment can attenuate ethanol-induced gastric injury in rats by inhibiting oxidative stress and inflammatory response. Together, L. reuteri F-9-35 has potential preventive efficacy on gastric ulcer.

Molecular Mechanisms of Melatonin Protection from Gastric Mucosal Apoptotic Injury in Experimental Burns

Melatonin, a basic secretory pineal gland product, is a nontoxic, multifunctional molecule. It has antioxidant and anti-apoptotic activities and protects tissues from injury. The objective of the present study was to determine the molecular mechanism of melatonin anti-apoptotic effect on gastric injury in a rat burn model. We hypothesized that melatonin gastric protection may be related to the activation of transcription erythroid 2-related factor 2 (Nrf2). Using a 30% total body surface area (TBSA) rat burn model, melatonin (10 mg/kg, i.p.) was injected immediately and 12 h after thermal skin injury. Via light immunohistochemistry, we determined the tissue level of 4-hydroxy-2-nonenal (4-HNE) as a marker of lipid peroxidation, Bcl-2 and Bax as apoptosis-related proteins, and Nrf2. Results are presented as medians (interquartile range (IQR)). Thermal trauma in burned animals, compared with the controls, increased the expression of pro-apoptotic Bax protein (1.37 (0.94–1.47)), decreased anti-apoptotic Bcl-2 protein (1.16 (1.06–1.23), p < 0.001) in epithelial cells, and elevated Bax/Bcl-2 ratios (p < 0.05). Tissue 4-HNE and Nrf2 levels were increased following severe burns (1.55 (0.98–1.61) and 1.16 (1.01–1.25), p < 0.05, respectively). Melatonin significantly decreased 4-HNE (0.87 (0.74–0.96), p < 0.01) and upregulated Nrf2 (1.55 (1.52–1.65), p < 0.001) levels. It also augmented Bax (1.68 (1.5–1.8), p < 0.001) and Bcl-2 expressions (1.96 (1.89–2.01), p < 0.0001), but reduced Bax/Bcl-2 ratios (p < 0.05). Our results suggest that experimental thermal trauma induces oxidative gastric mucosal injury. Melatonin manifests a gastroprotective effect through Nrf2 activation, lipid peroxidation attenuation, and Bax/Bcl-2 ratio modification as well.

Complementarity of in vitro and in vivo models for the evaluation of gastro-protective effects of pharmacological substances

Gastric mucosa is frequently exposed to various gastric irritants, and there is a continuing requirement to develop new gastro-protective agents. This study compares the effects of three such agents, sucralfate, rebamipide, and cimetidine in both in vivo and in vitro indomethacin-induced gastric damage models. For the in vivo approach, rats were orally administered sucralfate, rebamipide, and cimetidine at 300 mg/kg before an acute dose of indomethacin (30 mg/kg). Gastric lesions were then macroscopically examined. For the in vitro approach, gastric mucosal cells were incubated with sucralfate (3 and 5 mg/mL), rebamipide (0.3 and 1 mm), and cimetidine (10 and 50 μg/mL) before exposure to indomethacin (3.8 mm). The release of lactate dehydrogenase (LDH) and mitochondrial function were then measured. Sucralfate, rebamipide, and cimetidine displayed gastro-protective effects in vivo (decreased number of gastric ulcers: -50% P < 0.05, -22% NS, and -69% P < 0.05, respectively, and reduced length of gastric lesions: -62% P < 0.05, -29% NS, and -70% P < 0.001, respectively). Cell damage induced by indomethacin in vitro was inhibited by sucralfate (LDH release) and by rebamipide and cimetidine (mitochondrial function and LDH release). In contrast, sucralfate accentuated the indomethacin-induced decrease in mitochondrial function. Although cultured gastric cells offer a promising tool for evaluating the cytotoxic or protective effects of test compounds, data from in vivo models are still needed to confirm in vitro data. Using both approaches provides more comprehensive insight into the effects of test compounds on the gastric mucosa.

Lactobacillus fermentum Suo Attenuates HCl/Ethanol Induced Gastric Injury in Mice through Its Antioxidant Effects

The purpose of the study was to determine the inhibitory effects of Lactobacillus fermentum Suo (LF-Suo) on HCl/ethanol induced gastric injury in ICR (Institute for Cancer Research) mice and explain the mechanism of these effects through the molecular biology activities of LF-Suo. The studied mice were divided into four groups: healthy, injured, LF-Suo-L and LF-Suo-H group. After the LF-Suo intragastric administration, the gastric injury area was reduced compared to the injured group. The serum MOT (motilin), SP (substance P), ET (endothelin) levels of LF-Suo treated mice were lower, and SS (somatostatin), VIP (vasoactive intestinal peptide) levels were higher than the injured group mice. The cytokine IL-6 (interleukin 6), IL-12 (interleukin 12), TNF-α (tumor necrosis factor-α) and IFN-γ (interferon-γ) serum levels were decreased after the LF-Suo treatment. The gastric tissues SOD (superoxide dismutase), GSH-Px (glutathione peroxidase), NO (nitric oxide) and activities of LF-Suo treated mice were increased and MDA (malondialdehyde) activity was decreased compared to the injured group mice. By the RT-PCR assay, LF-Suo raised the occludin, EGF (epidermal growth factor), EGFR (epidermal growth factor receptor), VEGF (vascular endothelial growth factor), Fit-1 (fms-like tyrosine kinase-1), IκB-α (inhibitor kappaB-α), nNOS (neuronal nitric oxide synthase), eNOS (endothelial nitric oxide synthase), Mn-SOD, Cu/Zn-SOD, CAT (catalase) mRNA or protein expressions and reduced the COX-2, NF-κB (nuclear factor kappaB), and iNOS (inducible nitric oxide synthase) expressions in gastric tissues compared to the gastric injured group mice. A high concentration (1.0 × 10⁹ CFU/kg b.w.) of LF-Suo treatment showed stronger anti-gastric injury effects compared to a low concentration of (0.5 × 10⁹ CFU/kg b.w.) of LF-Suo treatment. LF-Suo also showed strong survival in pH 3.0 man-made gastric juice and hydrophobic properties. These results indicate that LF-Suo has potential use as probiotics for its gastric injury treatment effects.

The Realization of the Brain-Gut Interactions with Corticotropin-Releasing Factor and Glucocorticoids

BACKGROUND

The brain and the gut interact bi-directionally through the brain-gut axis. The interaction is mediated by the autonomic nervous system and the hypothalamic-pituitary-adrenocortical (HPA) system. The first brilliant demonstration of the brain-gut interactions was the cephalic phase of gastric and pancreatic secretion discovered by Ivan Pavlov, the first physiologist who was awarded the Nobel Prize for Physiology or Medicine in 1904. This review aims to identify the HPA system as a key hormonal branch of the brain-gut axis in stress.

METHODS

We first outlined main components of the brain-gut axis and then focused on the HPA system as a key hormonal branch of the brain-gut axis in stress. We undertook a structured search of bibliographic databases for peer-reviewed research literature using a focused review question.

RESULTS

Seventy-one articles were included in the review, the eleventh of them were articles of Filaretova L. and co-authors. We will discuss in our articles how an endocrinological approach to gastroenterological field can advance our understanding of the HPA axis role in regulation of gastric mucosal integrity and uncover new findings. According to these findings activation of the HPA system is gastroprotective component of the brain-gut axis in stress but not ulcerogenic one as it was generally accepted. Corticotropin-releasing factor (CRF) and glucocorticoids are important natural players provided gastroprotection. The results suggest that an initial action of endogenous glucocorticoids, including stress- and CRF-produced ones, as well as exogenous glucocorticoids, even used at pharmacological doses, is physiological gastroprotective. Prolongation of the hormonal action may lead to the transformation of gastroprotective hormonal effect to proulcerogenic one.

CONCLUSION

The findings of this review demonstrate that corticotropin-releasing factor and glucocorticoids contribute to the realization of the brain-gut interactions and that activation of the HPA system is gastroprotective component of this interaction in stress.

Gastroprotective activity of Annona muricata leaves against ethanol-induced gastric injury in rats via Hsp70/Bax involvement

The popular fruit tree of Annona muricata L. (Annonaceae), known as soursop and graviola, is a widely distributed plant in Central and South America and tropical countries. Leaves of A. muricata have been reported to possess antioxidant and anti-inflammatory activities. In this study, the gastroprotective effects of ethyl acetate extract of A. muricata leaves (EEAM) were investigated against ethanol-induced gastric injury models in rats. The acute toxicity test of EEAM in rats, carried out in two doses of 1 g/kg and 2 g/kg, showed the safety of this plant, even at the highest dose of 2 g/kg. The antiulcer study in rats (five groups, n=6) was performed with two doses of EEAM (200 mg/kg and 400 mg/kg) and with omeprazole (20 mg/kg), as a standard antiulcer drug. Gross and histological features showed the antiulcerogenic characterizations of EEAM. There was significant suppression on the ulcer lesion index of rats pretreated with EEAM, which was comparable to the omeprazole effect in the omeprazole control group. Oral administration of EEAM to rats caused a significant increase in the level of nitric oxide and antioxidant activities, including catalase, glutathione, and superoxide dismutase associated with attenuation in gastric acidity, and compensatory effect on the loss of gastric wall mucus. In addition, pretreatment of rats with EEAM caused significant reduction in the level of malondialdehyde, as a marker for oxidative stress, associated with an increase in prostaglandin E2 activity. Immunohistochemical staining also demonstrated that EEAM induced the downregulation of Bax and upregulation of Hsp70 proteins after pretreatment. Collectively, the present results suggest that EEAM has a promising antiulcer potential, which could be attributed to its suppressive effect against oxidative damage and preservative effect toward gastric wall mucus.

Hydroxyproline, a serum biomarker candidate for gastric ulcer in rats: a comparison study of metabolic analysis of gastric ulcer models induced by ethanol, stress, and aspirin

Gastrointestinal symptoms are a common manifestation of adverse drug effects. Non-steroid anti-inflammatory drugs (NSAIDs) are widely prescribed drugs that induce the serious side effect of gastric mucosal ulceration. Biomarkers for these side effects have not been identified and ulcers are now only detectable by endoscopy. We previously identified five metabolites as biomarker candidates for NSAID-induced gastric ulcer using capillary electrophoresis–mass spectrometry (CE–MS)-based metabolomic analysis of serum and stomach from rats. Here, to clarify mechanism of changes and limitations of indications of biomarker candidates, we performed CE–MS-based metabolomic profiling in stomach and serum from rats with gastric ulcers induced by ethanol, stress, and aspirin. The results suggest that a decrease in hydroxyproline reflects the induction of gastric injury and may be useful in identifying gastric ulcer induced by multiple causes. While extrapolation to humans requires further study, hydroxyproline can be a new serum biomarker of gastric injury regardless of cause.

Preventive effect of polysaccharides from the large yellow croaker swim bladder on HCl/ethanol induced gastric injury in mice

In the present study the preventive effect of polysaccharides from the large yellow croaker swim bladder (PLYCSB) on HCl/ethanol-induced gastric injury in ICR mice was investigated. A high dose of PLYCSB (50 mg/kg) was found to reduce the levels of the serum proinflammatory cytokines interleukin (IL)-1β, IL-6, IL-8, as well as increase the levels of IL-4 compared with those in mice treated with a low dose of PLYCSB (25 mg/kg) and control mice. The somatostatin and vasoactive intestinal peptide serum levels in PLYCSB-treated mice were higher compared with those in control mice, whilst motilin and substance P serum levels were lower compared with those in control mice. The extent of the gastric injury in the mice treated with PLYCSB was lower compared with that in the control mice; however, the results obtained for mice treated with a high dose of PLYCSB were similar to those for omeprazole-treated mice. In addition, the superoxide dismutase and glutathione peroxidase activities of PLYCSB-treated mice were higher compared with those of the control mice, and similar to those observed in normal and omeprazole-treated mice. Furthermore, PLYCSB-treated mice showed levels of nitric oxide and malondialdehyde that were similar to those in the normal group. Using PCR and western blot analysis, it was demonstrated that PLYCSB significantly inhibited inflammation in the tissues of the HCl/ethanol induced gastric injury mice by downregulating the expression of inducible nitric oxide synthase, cyclooxygenase-2, tumor necrosis factor-α and IL-1β. These results suggest that PLYCSB has an inhibitory effect against gastric injury that is comparable to that of the gastric injury drug omeprazole. Therefore, PLYCSB has the potential to be used as a natural therapeutic drug.

In vitro antioxidative activity of yellow tea and its in vivo preventive effect on gastric injury

Yellow tea is a traditional Chinese drink widely used in Asia. The aim of this study was to determine the antioxidant activity of yellow tea and its preventive effect on gastric injury. The antioxidant effects were determined by measuring the 1,1-diphenyl-2-picryhydrazyl (DPPH) free radical- and hydroxyl radical-scavenging activity. The yellow tea extract demonstrated high antioxidant activity in the assays of DPPH and hydroxyl radical-scavenging activity. Additionally, an animal model was used to investigate the preventive effect of yellow tea on gastric injury. High concentrations of yellow tea reduced the levels of the serum pro-inflammatory cytokines interleukin (IL)-6 and tumor necrosis factor (TNF)-α to a greater extent than low concentrations. The extent of the gastric injury was significantly reduced by yellow tea, which demonstrated its anti-inflammatory properties. Yellow tea demonstrated the strongest inhibitory effect (74.6%) against gastric injury when administered at a dose of 1,000 mg/kg by gavage. These results suggest that yellow tea possesses good antioxidant activity and a preventive effect on gastric injury in vivo.

Development and characterization of zein-based microcarrier system for sustained delivery of aceclofenac sodium

Nonsteroidal anti-inflammatory drugs (NSAIDs) induce gastric injury on long-term usage. This study aims at reducing the side effect of NSAIDs by encapsulating in zein, an acid-resistant biopolymer. Aceclofenac-loaded zein microspheres were prepared by emulsification and solvent evaporation method. The stability of zein microspheres at gastric pH retarded the release of the entrapped drug and hence reduces the possibility of gastric injury. However, the in vitro release of aceclofenac was sustained up to 72 h at intestinal pH. Thus, zein microspheres pave the way for the development of safe and sustained delivery system for NSAIDs thereby achieving the desired therapeutic potential with reduced side effects for chronic inflammatory disorders.

Transcriptome Analysis for Cytoprotective Actions of Rebamipide against Indomethacin-Induced Gastric Mucosal Injury in Rats

We have reported that rebamipide, a gastroprotective drug, suppresses indomethacin-induced gastric mucosal injury in humans and rats. However, the mechanisms of the cytoprotective actions of rebamipide have not been fully addressed. In the present study, we determined mRNA expression profile of the gastric mucosa treated with indomethacin in rats, and investigated the cytoprotective effects of rebamipide against indomethacin-induced injury with a high-density oligonucleotide array (Rat Toxicology U34 GeneChip array). Gastric epithelial cells were obtained by laser-assisted microdissection. Data analysis was performed with a GeneChip Operating Software, GeneSpring software 7.0, and Ingenuity Pathway Analysis. Among 1,031 probes, the expression of 160 probes (15.5%) showed at least 2.0-fold up-regulation (158 probes) and down-regulation (2 probes) 2 h after indomethacin administration in comparison with the vehicle-treated rats. The pathway analysis of the up-regulated 123 probes identified the network with a highly significant score, which consisted of known clusters of cell death, cancer, and endocrine system disorders. We succeeded in listing 10 genes that were up-regulated by the treatment with indomethacin and that were down-regulated by rebamipide, including growth arrest and DNA damage-induced 45α. In conclusion, we demonstrated that cell death, especially apoptosis, pathway is involved in the pathogenesis of indomethacin-induced gastric mucosal injury, and that inhibition of apoptosis-related genes is possibly important for the cytoprotective effect of rebamipide against this injury.

Prevention of Indomethacin-Induced Gastric Mucosal Injury in Helicobacter pylori-Negative Healthy Volunteers: A Comparison Study Rebamipide vs Famotidine

The clinical efficacy of gastroprotective drugs or low-dose H(2) receptor antagonists in the prevention of nonsteroidal anti-inflammatory drug (NSAID)-induced gastropathy is limited. The aim of the present study was to investigate efficacy of rebamipide and famotidine in Helicobacter pylori (H. pylori)-negative healthy volunteers taking NSAID. This study was a randomized, two way crossover study comparing the preventive effect rebamipide 100 mg, t.i.d. and famotidine 10 mg, b.i.d against indomethacin (25 mg, t.i.d.)-induced gastric mucosal injury in H. pylori-negative healthy volunteers. 12 subjects satisfied criteria and were randomized. Endoscopy was performed at baseline and again after the treatment for 7 days, and symptoms were recorded during the treatment. Tissue levels of lipid peroxides and myeloperoxidase and serum indomethacin concentrations were also measured. Subjective symptoms were developed in 58% (7/12) of the rebamipide group, and in 75% (9/12) of the famotidine group (no significant differences). The incidence of gastric lesions (modified Lanza score 2 or higher) was 17% (2/12) in the rebamipide group and 25% (3/12) in the famotidine group. Peptic ulcers did not occur in both groups. There were no significant differences in tissue levels of lipid peroxide and myeloperoxidase and serum level of indomethacin between two groups after the treatment. In conclusion, these data recommend rebamipide (100 mg, t.i.d.) or famotidine (10 mg, b.i.d.) for the prevention of acute gastric injury induced by NSAID in patients without a particular risk factor.

Congenital diaphragmatic hernia: Misdiagnosis in adolescence

We report 3 cases of congenital diaphragmatic hernia (CDH) in the second decade of life which were misdiagnosed on initial presentation. The first case had an iatrogenic gastric injury because of intercostal tube drainage for suspected pleural effusion. The second case was treated for pulmonary tuberculosis for 6 months before being diagnosed as a case of CDH. The third case presented as acute chest pain on the left side. It was treated accordingly for 1 month and was diagnosed as a CDH on a CT scan of the chest when seen by a surgeon.

New dogmas or old?

Recent experimental studies may undermine our understanding of the gastrointestinal side effects of non-steroidal anti-inflammatory drugs and cast a shadow on the original concept that underpins the development of the recent addition to the clinical anti-inflammatory armamentarium, the COX-2 selective inhibitors. But is this just a passing cloud or a total eclipse of the COX theory?