Protective effect and mechanisms of action of Mongolian medicine Sulongga-4 on pyloric ligation-induced gastroduodenal ulcer in rats

Liuwei Anxiao San protects gastric mucosa from gastric ulcer in rats by regulating the JAK2/STAT3 pathway

Mongolian medicine prescriptions are recognized as promising gastroprotective agents. This study is to explore the effects and mechanisms of Liuwei Anxiao San (LAS) in gastric ulcer (GU). GU rat models were established using acetic acid, followed by treatment with LAS at different doses and/or the JAK2 agonist Coumermycin A1 (CA1). The ulcerous area and inhibition rates were calculated. The mucosal damage and cell apoptosis in gastric tissues were assessed by H&E and TUNEL staining. The activities of SOD, GSH-Px, and CAT, and MDA levels were measured. The levels of pro-inflammatory and anti-inflammatory factors were determined by ELISA. The activation of the JAK2/STAT3 pathway was determined by Western blot. As the results suggested, LAS dose-dependently ameliorated gastric mucosal damage and inhibited oxidative stress and inflammatory response, evidenced by increased activities of SOD, GSH-Px, and CAT, decreased MDA level, increment of anti-inflammatory factors and decrement of pro-inflammatory factors, and inhibited the activation of the JAK2/STAT3 pathway in GU rats. CA1 partly abolished the function of LAS on gastric mucosal injury, oxidative stress, and inflammation in GU rats. In conclusion, LAS protects against gastric mucosal injury in GU rats through inhibition of oxidative stress and inflammation by suppressing the JAK2/STAT3 pathway.

Mongolian medicine formulae Ruda-6 alleviates indomethacin-induced gastric ulcer by regulating gut microbiome and serum metabolomics in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Ruda-6 (RD-6), a typical traditional Mongolian medicine formulae consisting of 6 herbs, has been traditionally used in treating gastric disorders. Even though it has been shown to protect against gastric ulcers (GU) in animal models, the gut microbiome and serum metabololite-related mechanisms that prevent GU are not well understood.

AIM OF THE STUDY

This study was conducted to evaluate the gastroprotective mechanism of RD-6 associated with the alteration of the gut microbiome and serum metabolic profiles in GU rats.

MATERIALS AND METHODS

RD-6 (0.27, 1.35 and 2.7 g/kg) or ranitidine (40 mg/kg) were orally administered in rats for three weeks before the induction of gastric ulcer using indomethacin (30 mg/kg, single oral dose). The gastric ulcer index, ulcer area, H&E staining, and the levels of TNF-α, iNOS, MPO and MDA were quantified to evaluate the ulcer inhibitory effects of RD-6. Then, 16S rRNA gene sequencing combined with LC-MS metabolic profiling was performed to investigate the effect of RD-6 on the gut microbiota and serum metabolites in rats. Moreover, a spearman analysis was used to calculate the correlation coefficient between the different microbiota and the metabolites.

RESULTS

RD-6 inhibited the gastric lesion damage caused by indomethacin in rats, decreased the ulcer index by 50.29% (p < 0.05), reduced the levels of TNF-α, iNOS, MDA and MPO in gastric tissue. Additionally, RD-6 reshaped the diversity and microbial composition, and reversed the reduced bacteria including [Eubacterium]_xylanophilum group, Sellimonas, Desulfovibrio, and UCG-009, and the increased bacteria Aquamicrobium caused by indomethacin induction. Furthermore, RD-6 regulated the levels of metabolites including amino acids and organic acids, and these affected metabolites were involved in taurine and hypotaurine metabolism and tryptophan metabolism. Spearman analysis revealed that the perturbed gut microbiota were closely related to the changes in differential serum metabolites.

CONCLUSION

In view of the 16S rRNA gene sequencing and LC-MS metabolic results, the present study suggests the mechanism of RD-6 ameliorating GU via modulating intestinal microbiota and their metabolites.

RNA-Seq Reveals Protective Mechanisms of Mongolian Medicine Molor-Dabos-4 on Acute Indomethacin-Induced Gastric Ulcers in Rats

This study aimed to apply transcriptomics to determine how Molor-Dabos-4 (MD-4) protects healthy rats against indomethacin (IND)-induced gastric ulcers and to identify the mechanism behind this protective effect. Rats were pretreated with MD-4 (0.3, 1.5, or 3 g/kg per day) for 21 days before inducing gastric ulcers by oral administration with indomethacin (30 mg/kg). Unulcerated and untreated healthy rats were used as controls. Effects of the treatment were assessed based on the ulcer index, histological and pathological examinations, and indicators of inflammation, which were determined by enzyme-linked immunosorbent assay. Transcriptomic analysis was performed for identifying potential pharmacological mechanisms. Eventually, after identifying potential target genes, the latter were validated by quantitative reverse-transcription polymerase chain reaction (qRT-PCR). After pretreatment with MD-4, gastric ulcers, along with other histopathological features, were reduced. MD-4 significantly (p < 0.05) increased the superoxide dismutase (SOD) levels in ulcers and reduced pepsin, TNF-α, and IL-6 levels. RNA-seq analysis identified a number of target genes on which MD-4 could potentially act. Many of these genes were involved in pathways that were linked to anti-inflammatory and antioxidant responses, and other protective mechanisms for the gastric mucosa. qRT-PCR showed that altered expression of the selected genes, such as Srm, Ryr-1, Eno3, Prkag3, and Eef1a2, was consistent with the transcriptome results. MD-4 exerts protective effects against IND-induced gastric ulcers by reducing inflammatory cytokines and pepsin and increasing the expression of SOD levels. Downregulation of Srm, Ryr-1, Eno3, Prkag3, and Eef1a2 genes involved in regulating arginine and proline metabolism, calcium signaling pathway, HIF-1 signaling pathway, oxytocin signaling pathway, and legionellosis are possibly involved in MD-4-mediated protection against gastric ulcers.

Antisecretory and antioxidative effects of the antidepressants fluvoxamine and mirtazapine on water immersion stress and pyloric ligation-induced gastric ulcer in rats

OBJECTIVES

Although there are numerous drugs available for the treatment of gastric ulcers (GU), these drugs are not always effective. Antidepressant medications have been used for a variety of non-psychiatric indications, including antiulcer activity in various ulcer models. The purpose of this study was to compare the antiulcer effects of fluvoxamine and mirtazapine in two rat GU experimental models and to determine their relationship to antioxidant and antisecretory mechanisms.

MATERIALS AND METHODS

The antiulcer activities of various doses of fluvoxamine and mirtazapine on water immersion restraint stress (WIRS) and pyloric ligation-induced GU in rats have been studied against the positive control antiulcer drug famotidine. Various oxidative stress markers were evaluated.

RESULTS

Fluvoxamine and mirtazapine significantly protected against WIRS and pyloric ligation-induced gastric lesions, as evidenced by a dose-dependent decrease in ulcer index, myeloperoxidase (MPO) activity, lipid peroxidation, and an increase in prostaglandin E2, nitric oxide (NO), and reduced glutathione levels, as well as increased antioxidant enzyme activity. In the pyloric ligation model, fluvoxamine and mirtazapine improved GU more than famotidine. Furthermore, a 30 mg/kg dose of mirtazapine significantly improves both NO levels and MPO activity compared to famotidine.

CONCLUSIONS

The results highlighted the relationship in correlating the antiulcer effect of drugs from different antidepressant classes across two animal GU models, implying that antidepressants that affected both norepinephrine and serotonin levels (mirtazapine) had a more potent antiulcer effect in WIRS-induced gastric model than drugs that only affected serotonin levels (fluvoxamine).

Emodin Improves Intestinal Health and Immunity through Modulation of Gut Microbiota in Mice Infected by Pathogenic Escherichia coli O1

The effect of emodin on the intestinal mucosal barrier of a mouse E. coli O₁-induced diarrhea model was observed. Following successful establishment of a diarrhea model, the mice were treated with drugs for seven days. Intestinal lesions and the shape and the number of goblet cells were assessed via hematoxylin-eosin and periodic-acid-Schiff staining, while changes in inflammatory factors, ultrastructure of the small intestine, expression of MUC-2, and changes in the intestinal microbiota were analyzed via RT-PCR, electron microscopy, immunofluorescence, and 16S rRNA sequencing. Examination showed that emodin ameliorated pathological damage to the intestines of diarrheic mice. RT-PCR indicated that emodin reduced TNF-α, IL-β, IL-6, MPO, and COX-2 mRNA levels in duodenal tissues and increased the levels of sIgA and MUC-2 and the number of goblet cells. Microbiome analysis revealed that Escherichia coli O₁ reduced bacterial richness and altered the distribution pattern of bacterial communities at the phylum and order levels in cecum contents. Notably, pathogenic Clostridiales and Enterobacteriales were significantly increased in diarrheic mice. However, emodin reversed the trend. Thus, emodin protected against intestinal damage induced by E. coli O₁ and improved intestinal mucosal barrier function in mice by increasing the abundance of beneficial intestinal microbiota and inhibiting the abundance of harmful bacteria, thereby alleviating diarrhea.