The effect of metformin on indomethacin-induced gastric ulcer: Involvement of nitric oxide/Rho kinase pathway

Comparative effectiveness of sodium-glucose cotransporter-2 inhibitors for new-onset gastric cancer and gastric diseases in patients with type 2 diabetes mellitus: a population-based cohort study

OBJECTIVE

To compare the risks of gastric cancer and other gastric diseases in patients with type-2 diabetes mellitus (T2DM) exposed to sodium-glucose cotransporter 2 inhibitors (SGLT2I), dipeptidyl peptidase-4 inhibitors (DPP4I) or glucagon-like peptide-1 receptor agonists (GLP1a).

DESIGN

This was a population-based cohort study of prospectively collected data on patients with T2DM prescribed SGLT2I, DPP4I or GLP1a between January 1st 2015 and December 31st 2020 from Hong Kong. The outcomes were new-onset gastric cancer, peptic ulcer (PU), acute gastritis, non-acute gastritis, and gastroesophageal reflux disease (GERD). Propensity score matching (1:1) using the nearest neighbour search was performed, and multivariable Cox regression was applied. A three-arm comparison between SGLT2I, DPP4I and GLP1a was conducted using propensity scores with inverse probability of treatment weighting.

RESULTS

A total of 62,858 patients (median age: 62.2 years old [SD: 12.8]; 55.93% males; SGLT2I: n = 23,442; DPP4I: n = 39,416) were included. In the matched cohort, the incidence of gastric cancer was lower in SGLT2I (Incidence rate per 1000 person-year, IR: 0.32; 95% confidence interval, CI 0.23-0.43) than in DPP4I (IR per 1000 person-year: 1.22; CI 1.03-1.42) users. Multivariable Cox regression found that SGLT2I use was associated with lower risks of gastric cancer (HR 0.30; 95% CI 0.19-0.48), PU, acute gastritis, non-acute gastritis, and GERD (p < 0.05) compared to DPP4I use. In the three-arm analysis, GLP1a use was associated with higher risks of gastric cancer and GERD compared to SGLT2I use.

CONCLUSIONS

The use of SGLT2I was associated with lower risks of new-onset gastric cancer, PU, acute gastritis, non-acute gastritis, and GERD after matching and adjustments compared to DPP4I use. SGLT2I use was associated with lower risks of GERD and gastric cancer compared to GLP1a use.

Concomitant Effects of Metformin and Vitamin C on Indomethacin-Induced Gastric Ulcer in Rats: Biochemical and Histopathological Approach

INTRODUCTION

Gastric ulcer is one of the most common and serious conditions in the gastrointestinal tract. One of the main causes of gastric ulcers is using of non-steroidal anti-inflammatory drugs (NSAIDs) which have limited their use in clinical practice. Several studies have revealed that metformin and Vitamin C (Vit C) exhibit protective effects against gastric mucosal damage in different animal models. However, no studies indicate their combination's effect on gastric ulcer models. Therefore, this study aims to investigate the protective effects of metformin and Vit C combination on indomethacin-induced gastric ulcers.

MATERIAL AND METHODS

In total, thirty rats were divided into six groups, including the control group, rats received indomethacin (50 mg/kg, i.p.), rats received indomethacin and pretreated with ranitidine (100 mg/kg), metformin (100 mg/kg, i.p.), Vit C (100 mg/kg), or metformin combined with Vit C. Four hours after indomethacin administration, rats were euthanized, and gastric tissues were removed for macroscopic, histopathologic, and biochemical examinations.

RESULTS

All therapeutics used in this study were found to alleviate gastric mucosal injury caused by indomethacin, as observed in histopathologic and macroscopic evaluations. Both Vit C and metformin were observed to significantly decrease lipid peroxidation and enhance the activity of anti-oxidative enzymes, SOD, GPx, and catalase. However, a more significant effectiveness was observed in catalase and GPx activities when Vit C was co-administered with metformin.

CONCLUSIONS

In conclusion, the present study revealed that metformin and Vit C combination therapy could potentially treat gastric ulcers associated with indomethacin.

Protective effect of astaxanthin on indomethacin-induced gastric ulcerations in mice

Gastric ulcer disease remains one of the common medical burdens affecting millions worldwide due to its prevalent risk factors with the chronic usage of non-steroidal anti-inflammatory drugs at the top, reportedly through the stimulation of oxidative stress and triggering of inflammatory and apoptotic cascades in the gastric mucosa. Astaxanthin, a dietary keto-carotenoid derived from marine organisms is gaining a wide interest as a nutraceutical for its pronounced antioxidant properties. Here, we aim to examine the potential modulatory role of astaxanthin on indomethacin-induced gastric ulceration in experimental mice. Twenty-four Swiss albino mice were randomly distributed into four groups: a control group, an indomethacin group, and two groups pre-treated with either omeprazole or astaxanthin. The gastric tissues were assessed using gross morphology, ulcer scoring, gastric juice acidity, as well as reduced glutathione (GSH) and malondialdehyde (MDA) levels. Histopathological examination and immunostaining for nuclear factor-kappa B (NF-κB) and caspase-3 levels were also employed. Indomethacin group tended to show a higher number of mucosal ulcerations relative to control and pre-treated groups. The indomethacin group also showed significantly lower GSH levels and higher MDA levels relative to control. Immunostaining of gastric tissue sections showed a higher reactivity to NF-κB and caspase-3 in indomethacin group. Astaxanthin pre-treatment significantly elevated gastric juice pH, normalized GSH levels, and lowered the indomethacin-induced elevations in MDA, NF-κB, and caspase-3 levels. These results indicate that astaxanthin exhibits a comparable protective effect to omeprazole, against indomethacin-induced gastric ulceration. This anti-ulcerogenic effect could be mediated through its antioxidant, anti-inflammatory, and anti-apoptotic modulatory activities.

A comprehensive review on potential drug-drug interactions of proton pump inhibitors with antidiabetic drugs metformin and DPP-4 inhibitors

A drug interaction is a condition in which two or more drugs are taken at the same time. Type 2 diabetes mellitus is a significant contributor to polypharmacy. Proton pump inhibitors (PPIs) are often prescribed in combination with metformin or DPP-4 inhibitors (sitagliptin, saxagliptin, linagliptin, and alogliptin) or a combined dose of metformin and DPP-4 inhibitor to treat gastritis in diabetic patients. This review article mainly focused on evaluating the potential drug-drug interactions (DDIs) between PPIs (i.e. esomeprazole, lansoprazole, omeprazole, pantoprazole, and rabeprazole) with metformin and PPIs with DPP-4 inhibitors. The findings demonstrated the existence of pharmacokinetic and pharmacodynamic DDIs between the aforementioned PPIs with metformin and DPP-4 inhibitors, which could impact the biological activities (i.e., hypoglycemia) of these drugs. Moreover, this review suggested that esomeprazole could be the best drug in the PPI group to be prescribed simultaneously with metformin and DPP-4 inhibitors, as most of the antidiabetic drugs of this study did not show any interaction with esomeprazole. The findings of this study also revealed that both antidiabetic drugs and PPIs could have positive interactions as PPIs have the potential to lessen the gastrointestinal side effects of metformin and DPP-4 inhibitors. To achieve the greatest therapeutic impact with the fewest side effects, careful dose control of these drugs is required. So, more extensive research on both human and animal subjects are needed to ascertain the veracity of this hypothesis.

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.

A Gellan Gum/Sodium Alginate-based gastric-protective hydrogel loaded with a combined herbal extract consisting of Panax notoginseng, Bletilla striata and Dendrobium officinale

One Chinese herbal combination consisting of Panax notoginseng, Bletilla striata and Dendrobium officinale (PBD) is an effective Traditional Chinese Medicine (TCM) prescription and is widely used in clinics to treat gastric ulcers due to their safety and effectiveness compared with chemical agents, such as aspirin and omeprazole. Herein, an in situ forming gel (ISFG) based on Gellan Gum (GG) and Sodium Alginate (SA) was designed to deliver extracts of PBD prescription (EPBDP). The central composite design optimized prescription dosage was 0.1 % w/v of GG and 0.5 % w/v of SA. Gels prepared with this formulation demonstrated outstanding fluidity and instantaneous gel formation. In vitro release data showed that sustained drug release occurred in the gel, and the gel was pH-sensitive. The rheological tests confirmed the formation of stable gel, which exhibited strong viscosity and elasticity. In vitro adhesion assays revealed that the gel had strong gastric mucosal adhesion, while in vivo residual rate experiments of active ingredients revealed that the gel might greatly improve the gastric retention of active ingredients. Animal studies demonstrated that the gel was effective in treating gastric ulcers. Hence, the results of the study show that EPBDP-ISFG, a highly pH-sensitive sustained-release system, is effective.

The Effect of Metformin on Chemotherapy-Induced Toxicities in Non-diabetic Breast Cancer Patients: A Randomised Controlled Study

BACKGROUND AND OBJECTIVE

Breast cancer patients treated with adriamycin-cyclophosphamide plus paclitaxel (AC-T) are often challenged with serious adverse effects for which no effective therapies are available. Here, we investigated whether metformin, an antidiabetic drug with additional pleiotropic effects could favourably offset AC-T induced toxicities.

PATIENTS AND METHODS

Seventy non-diabetic breast cancer patients were randomised to receive either AC-T (adriamycin 60 mg/m² + cyclophosphamide 600 mg/m² × 4 cycles Q21 days, followed by weekly paclitaxel 80 mg/m² × 12 cycles) alone or AC-T plus metformin (1700 mg/day). Patients were assessed regularly after each cycle to record the incidence and severity of adverse events based on the National Cancer Institute Common Terminology Criteria for Adverse Events (NCI-CTCAE), version 5.0. Moreover, baseline echocardiography and ultrasonography were done and repeated after the end of neoadjuvant therapy.

RESULTS

Addition of metformin to AC-T resulted in significantly less incidence and severity of peripheral neuropathy, oral mucositis, and fatigue (p < 0.05) compared to control arm. Moreover, the left ventricular ejection fraction (LVEF%) in the control arm dropped from a mean of 66.69 ± 4.57 to 62.2 ± 5.22% (p = 0.0004) versus a preserved cardiac function in the metformin arm (64.87 ± 4.84 to 65.94 ± 3.44%, p = 0.2667). Furthermore, fatty liver incidence was significantly lower in metformin compared with control arm (8.33% vs 51.85%, p = 0.001). By contrast, haematological disturbances caused by AC-T were preserved after concurrent metformin administration (p > 0.05).

CONCLUSION

Metformin offers a therapeutic opportunity for controlling toxicities caused by neoadjuvant chemotherapy in non-diabetic breast cancer patients.

TRIAL REGISTRATION

This randomised controlled trial was registered on November 20, 2019 in ClinicalTrials.gov under registration number: NCT04170465.

Interactions between phenolic constituents of Scutellaria salviifolia and key targets associated with inflammation: network pharmacology, molecular docking analysis and in vitro assays

Scutellaria salviifolia Benth. (SS), an endemic plant for Turkey, is used for gastric ailments as folk medicine. In this study, we aimed to uncover the underlying molecular mechanisms with the help of network pharmacology and molecular docking analysis in the inflammation processes of gastric ailments. Gene enrichment analysis and target screening were carried out. Experimental validation was performed via cytokines of nitric oxide (NO) and interleukin-6 (IL-6) in LPS stimulated RAW 264.7 cells. Furthermore, antioxidant activity studies were performed by radical scavenging effects on different radicals. A total of 144 targets were listed for the isolated compounds where 26 of them were related to selected inflammation targets. According to the gene enrichment analysis, HIF1 signaling pathway and TNF signaling pathway were found to be involved in inflammation. We also defined AKT1, TNF, EGFR, and COX2 as key targets due to the protein-protein interactions of 26 common targets. The extract inhibited NO and IL-6 production at 100 and 200 µg/mL, while flavonoid-rich fraction possessed significant anti-inflammatory activity at the concentration of 50 and 100 µg/mL via NO and IL-6 production, respectively. It is thought that the anti-inflammatory effects of extracts, fractions and pure compounds were achieved by reducing NO and IL-6 levels via regulating the NF-κB pathway or reducing NO production by suppressing iNOS through the HIF-1 pathway when evaluated together with the results of network analysis and literature. Anti-inflammatory activities of the extract and fractions were promising and comparably with S. baicalensis, commonly used for its anti-inflammatory activity.

Ferulic Acid Treats Gastric Ulcer via Suppressing Oxidative Stress and Inflammation

(1) Background: The aim of the present study was to evaluate the gastroprotective potential of ferulic acid (FA) on indomethacin-induced gastric ulcers in rats with macroscopic and microscopic examinations along with biochemical assays. (2) Methods: After 24 h starvation, the ulcer was induced in male Sprague-Dawley rats by subcutaneous indomethacin (25 mg/kg) injection. Fifteen minutes after ulcer induction, rats were treated with either tween 80 or FA. FA was given by oral gavage at 100 mg/kg, 250 mg/kg, and 500 mg/kg. In the fourth hour, rats were euthanized and collected gastric samples were evaluated macroscopically and microscopically. Antioxidant parameters including malondialdehyde (MDA), glutathione (GSH), superoxide dismutase (SOD), and inflammatory parameters comprising of myeloperoxidase (MPO), Tumor Necrosis Factor (TNF)-α, Interleukin (IL)-1β, IL-6 and Nuclear Factor Kappa-B (NF-κB) p65 levels were also determined. (3) Results: Indomethacin injection significantly increased the macroscopic and microscopic scores. In addition, it increased the gastric MDA, MPO, TNF-α, IL-1β, IL-6, and NF-κB p65 levels but reduced SOD and GSH content. Treatment with FA significantly improved the gastric injury macroscopically and microscopically. Moreover, FA displayed a marked decrease in the gastric levels of MDA, MPO, TNF-α, IL-1β, IL-6, and NF-κB p65 and a significant increase in SOD and GSH compared to the INDO group. Ultimately, 250 mg/kg FA was determined as the most effective dose. (4) Conclusion: Our results revealed that FA has a gastroprotective effect against indomethacin-induced gastric ulcers in rats due to its antioxidant and anti-inflammatory properties. As a result, FA may be a potential treatment choice for gastric ulcers.

Decreased xCT activity in patients associated with Helicobacter pylori infection

Objective: In animals, Helicobacter pylori (Hp)-induced gastric injury is accompanied by a decrease in the activity of the cysteine/glutamate transporter (xCT), which regulates extracellular glutamate levels. However, the impact of xCT activity in patients with Hp infection remains unclear. This study aims to investigate variations of xCT activity in the gastric mucosa of patients with Hp infection and to provide a clinical basis for identifying targets related to Hp infection. Methods: Our study included a total of 67 patients with gastritis, which consisted of 44 Hp-negative and 23 Hp-positive peptic ulcer cases. The inclusion criteria used to select patients were as follows: gastric histology was determined with a gastroscope, antral biopsies were taken for urease tests, and pathology and culture were performed for analysis of Hp-colonization. The clinical characteristics of the patients were obtained, the expressions of microRNAs and xCT protein were detected using immune histochemical analysis, and the concentration of glutamate in their gastric secretion was determined. Results: The findings revealed that xCT expression was significantly lower in Hp-positive patients as compared to Hp-negative individuals, which was accompanied by a decrease in glutamate concentration in gastric juice. We also discovered a high expression of microRNAs that have been shown to negatively regulate xCT expression, in Hp-positive patients. Conclusion: Reduced xCT activity in patients may play an important role in gastric ulcers caused by Hp infection. Our findings suggest that the microRNA/xCT pathway could be a potential treatment target for Hp-infection-related ulcers.

Protective effects of metformin against aluminum phosphide-induced acute hepato-renal damage in rats: An experimental approach

Phosphine (PH3), from hydrolysis of magnesium, zinc, and aluminum phosphide (AlP), is a rodenticide and insecticide which is used to avoid losses of the agriculture products. However, using of this agent may affect the human health, in a way that poisoning with AlP has a high rate of mortality and morbidities. This study determined the ameliorative effects of metformin (MET) on AlP-induced hepato- and nephro-toxicity in Wistar rats. Male rats were randomly divided into four experimental groups. Group I was the control group received coconut oil by oral gavage, group II was the model group received AlP (12 mg/kg) distributed in coconut oil by oral gavage, group III received MET (200 mg/kg; i.p.), and group IV received MET (200 mg/kg; i.p.) 30 min after intoxication. After 24 h, the serum, liver and kidney tissues were collected for histopathological and biochemical investigations. The levels of kidney function markers, blood urea nitrogen and creatinine, and liver function markers, ALP, AST and ALT, in the plasma were increased significantly followed by AlP intoxication. The results revealed that phosphine causes a significant enhancement of lipid peroxidation, while decreases the activity of superoxide dismutase in both liver and kidney tissues. Furthermore, phosphine significantly induced the up-regulation of TNF-α and phosphorylation of NF-κB in target tissues. Overall, treatment with MET abolished aforementioned alterations resulted by AlP intoxication. Furthermore, histological evaluation indicated a deleterious effect of AlP on the liver and kidney tissues along with marked increase in kidney and liver injury scores, which is mitigated by MET administration. According to our results, although metformin could not bring the changes to the level of the control group, it was indicated that this drug might possess a protective effect against AlP-induced hepato and nephrotoxicity by inhibiting inflammatory responses and oxidative stress.

The effects of dragon fruit (Hylocereus polyrhizus) extract on indomethacin-induced stomach ulcer in rats

The aim of this study was to investigate the effects of red dragon fruit (Hylocereus polyrhizus) extract (DFE) on the stomach in ulcer model induced by indomethacin in rats. Effects of DFE were evaluated in indomethacin-induced gastric damage model on Sprague-Dawley rats. Experimental model: all rats were fasted for 24 h. At the end of this period, DFE was administered to the ulcer-induced groups. One hour after this application, a dose of 25 mg/kg of indomethacin was applied by oral gavage to all groups except the HEALTHY and DFE1000 groups. Six hours after indomethacin administration, the rats were euthanized with high-dose anesthesia and the experiment was terminated. Macroscopic and microscopic analyses for investigating ulcerative area, molecular and biochemical analyses for oxidative damages investigation and molecular analyses for the effect mechanism of indomethacin and DFE were conducted on stomach tissues in the study. While oxidative stress-associated markers such as MDA, BAX, and Caspase 3 increased dramatically in the indomethacin group, GSH antioxidant levels decreased. It was observed that these parameters were significantly improved in DFE 500 mg/kg and DFE 1000 mg/kg groups compared to ulcer group, and the results of especially DFE 1000 mg/kg group were similar to famotidine group. We observed that our histopathological findings also supported all our other findings. Dragon fruit extract was protected against indomethacin-induced ulcer damage by decreased MDA levels, increased GSH levels, and inhibition of Caspase 3, BAX, and Cox-2, and activation of Cox-1. PRACTICAL APPLICATIONS: People of all ages around the world suffer from gastric ulcer which is one of the most common gastrointestinal ailments. The etiological factors of the disease are using of cigarette and alcohol, nutritional deficiencies, infections, and using non-steroidal anti-inflammatory drugs which use frequent and indiscriminate. Indomethacin is one of the NSAIDs and is commonly preferred to induce ulcer modeling in rats due to its gastric toxicity potential. Current anti-ulcer drugs have many serious side effects. Patients who suffered from gastric ulcer tend to discontinue the drug because of side effects. Therefore, patients need new agents that are non-toxic, have few side effects, and are easily accessible anti-ulcer drugs. Dragon fruit, as a medicinal herb, is highly valuable and widely used in traditional medicine, and may provide gastroprotective activity. Studies have shown that H. polyrhizus has antioxidant activities. We consider the effects of dragon fruit extract (DFE) to be a therapeutic drug for an indomethacin-induced ulcer model.

Probiotics for the Treatment of Gastric Diseases

Common gastric diseases include chronic gastritis, gastric ulcers and gastric cancer. The etiology of gastric diseases is complicated, including genetics, diet, excessive smoking and drinking, environmental factors, and bacterial infections. As live microorganisms, probiotics can confer health benefits to the host. At present, probiotics have been widely used in the preparation of foods, health products, and medicines. Due to their positive effects in improving diarrhea, constipation, alleviating allergies, enhancing immunity, and maintaining intestinal homeostasis, studies worldwide have focused on whether probiotics also provide therapeutic effects on gastric diseases. Thus, this review summarizes the possible mechanism of probiotics in the treatment of gastric diseases and provides a reference for expanding not only their application but also that of other microecological agents.

Mitigation of Gastric Damage Using Cinnamomum cassia Extract: Network Pharmacological Analysis of Active Compounds and Protection Effects in Rats

Gastritis is a common disease worldwide that is caused by various causes such as eating habits, smoking, severe stress, and heavy drinking, as well as Helicobacter pylori infections and non-steroidal anti-inflammatory drugs. Cinnamomum cassia is a tropical aromatic evergreen tree commonly used as a natural medicine in Asia and as a functional food ingredient. Studies have reported this species' anti-obesity, anti-diabetic, and cardiovascular disease suppression effects. We evaluated the potential effects of C. cassia using non-steroidal anti-inflammatory drugs (NSAIDs), ethanol (EtOH), and ethanol/hydrochloric acid (HCl)-induced gastric mucosal injury models. C. cassia extracts reduced the area of gastric mucosa injury caused by indomethacin, NSAID, EtOH, and EtOH/HCl. We also applied a network pharmacology-based approach to identify the active compounds, potential targets, and pharmacological mechanisms of C. cassia against gastritis. Through a network pharmacology analysis, 10 key components were predicted as anti-gastritis effect-related compounds of C. cassia among 51 expected active compounds. The NF-κB signaling pathway, a widely known inflammatory response mechanism, comprised a major signaling pathway within the network pharmacology analysis. These results suggest that the anti-gastritis activities of C. cassia may be induced via the anti-inflammatory effects of key components, which suppress the inflammation-related genes and signaling pathways identified in this study.

Gastroprotective action of the ethanol extract of Leonurus sibiricus L. (Lamiaceae) in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Leonurus sibiricus L. (Lamiaceae) is a medicinal plant known in Brazil as "rubim" or "erva de macaé". It is used for various purposes, including stomach disorders.

AIM OF THE STUDY

To evaluate the effect of the ethanol extract of the aerial parts of L. sibiricus (EELs) in models of gastric damage in mice.

MATERIAL AND METHODS

The effect of EELs (50, 100 and 300 mg/kg, p.o., 1 h before induction) was tested on acidified ethanol (ACEt)-induced gastric ulcers. Additionally, we tested the effect of EELs (by intraduodenal administration) in the pylorus ligation (PL) model.

RESULTS

Pretreatment with EELs, at 300 mg/kg, but not 50 and 100 mg/kg, reduced the relative area of gastric ulcers induced by ACEt (p < 0.01) and lipoperoxidation (p < 0.001), and increased the sulfhydryl content (p < 0.01) in the stomach in comparison with the vehicle group. Pretreatment with N-ethylmaleimide (a blocker of non-protein sulfhydryl groups, 10 mg/kg, i.p.) or glibenclamide (a K_ATP channel blocker, 10 mg/kg, i.p.) inhibited the gastroprotective response caused by EELs (300 mg/kg; p < 0.001), but there were no alterations due to pretreatments with inhibitors of the synthesis of prostaglandins (indomethacin, 10 mg/kg), nitric oxide (L-NAME, 70 mg/kg) or hydrogen sulfide (DL-propargylglycine, 10 mg/kg). Treatment with EELs (300 mg/kg) reduced mucus production (p < 0.001) and the volume of gastric secretion (p < 0.001) after PL without affecting gastric acidity or pH.

CONCLUSIONS

These results provide evidence that EELs exerts gastroprotective action in mice, with the participation of oxidative stress and mediation of NP-SH, K_ATP channels and mucus production.

Glycopeptides from Paecilomyces sinensis ameliorate ethanol-induced gastric ulcers via anti-inflammation and the miR-9-5p-MEK/ERK signaling pathway

The aim of this study was to investigate the immunomodulatory effect and mechanism of the glycopeptides from Paecilomyces sinensis (CPS-II) on ethanol induced ulcers in mice. In this study, histopathological evaluation (H&E staining) and the gastric ulcer score, ulcer index, total acid secretion and gastric pH value were used to determine the anti-ulcer activity. The expression levels of interleukin (IL)-6, interleukin (IL)-10 and tumor necrosis factor-α (TNF-α) were detected by ELISA. The contents of superoxide dismutase (SOD), malondialdehyde (MDA) and epidermal growth factor (PEG2) in serum were measured according to the instructions for the reagents. Western blotting was used to detect the effect of CPS-II on the MEK/ERK pathway. The results showed that CPS-II could inhibit the ulcer score and ulcer index compared with the disease control group. CPS-II could significantly increase gastric pH and decrease gastric acid secretion in mice. The ELISA analysis showed that the expression levels of IL-6 and TNF-α in the CPS-II treatment group were significantly decreased, while the expression levels of IL-10 were significantly increased in the CPS-II treatment group. In the resveratrol treatment group, the content of MDA in serum was decreased, and the level of PEG2 and the activity of SOD in serum were significantly increased, which indicated that CPS-II has immunoregulation and anti-ulcer properties. The CPS-II treatment group could reduce the expression level of miR-9-5p in gastric tissue. pEGFR had been identified as a potential target of miR-9-5p. Western blot analysis showed that CPS-II could up-regulate the relative protein expression of pEGFR/EGFR, pRaf/Raf, pMEK/MEK, pERK/ERK, and ZO-1. The results showed that CPS-II could reduce oxidative stress and inflammatory response by regulating the miR-9-5p-MEK/ERK signaling pathway, thus protecting the gastric mucosa and improving stress gastric ulcers.

Protective and therapeutic effects of the flavonoid "pinocembrin" in indomethacin-induced acute gastric ulcer in rats: impact of anti-oxidant, anti-inflammatory, and anti-apoptotic mechanisms

Peptic ulcer including gastric and duodenal ulcers is a common gastro-intestinal disorder worldwide, associated with a significant mortality due to bleeding and perforation. Numerous efforts are being exerted to look for natural drugs that lack the potential side effects but still keep beneficial effects for treatment and/or prevention of gastric ulcer. Pinocembrin (PINO) is a natural flavonoid retaining anti-microbial, anti-oxidant, and anti-inflammatory activities. The present study was conducted to investigate the protective and therapeutic effects of PINO against indomethacin (INDO)-induced gastric ulcer in rats and the possible underlying mechanisms. PINO (25 and 50 mg/kg) promoted mucus secretion, decreased ulcer index, and inhibited histopathological changes induced by INDO. Further investigation of possible mechanisms showed that PINO significantly attenuated INDO-induced oxidative and inflammatory responses in both doses when administrated before or after ulcer induction. PINO downregulated mRNA expression level of p38-mitogen-activated protein kinase (p38-MAPK) which subsequently inhibited NF-κB activation and inflammatory cytokine release including tumor necrosis factor-α (TNF-α) and interleukin-1beta (IL-1β). Additionally, PINO inhibited apoptotic activity which was confirmed by downregulation of caspase-3 transcription. The current results demonstrated the promising therapeutic activity of PINO against INDO-induced gastric ulcer due to-at least partly-its anti-oxidant, anti-inflammatory, and anti-apoptotic effects.