Gastric antisecretory and antiulcer activity of bovine hemoglobin

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.

Gastroprotective effects of Caragana ambigua stocks on ethanol-induced gastric ulcer in rats supported by LC-MS/MS characterization of formononetin and biochanin A

BACKGROUND

Caragana ambigua has been the part of the dietary routines of the regional people in south-west Pakistan and has traditionally been used for the treatment of diabetes there. There is an increased production of reactive oxygen species in diabetics, leading to gastrointestinal disorders. Natural antioxidants exhibit gastroprotective effects owing to their free-radical scavenging action. C. ambigua possesses appreciable phenolic and flavonoid content; thus, it has the potential to protect against gastrointestinal disorders (e.g. gastric ulcer).

RESULTS

This study reports the anti-ulcer potential of C. ambigua. Four different fractions (chloroform, ethyl acetate, butanol, and aqueous) of plant were compared against omeprazole. Ulcer index, ulcer inhibition percentage, gastric pH and volume, total acidity, gastric protein, gastric wall mucus, and histopathology of gastric walls of rats were assessed. All fractions exhibited a reduction in ulcer index and promotion of percentage of ulcer inhibition compared with the ulcer control group. Furthermore, the fractions revealed a significant (P < 0.001) diminution in gastric volume and total acidity with an increase in pH. Among the fractions investigated, the chloroform fraction unveiled the most promising anti-ulcer activity, which is comparable to omeprazole. Liquid chromatography-tandem mass spectrometry screening of fractions revealed the presence of formononetin and biochanin A (isoflavones reported to have anti-ulcer properties) in the chloroform fraction.

CONCLUSION

This study establishes that C. ambigua possesses significant potential in reducing gastric ulcer progression. Formononetin and biochanin A are chiefly responsible for the stated bioactivity due to the fact that these compounds were solely present in the chloroform fraction. © 2022 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Novokinin inhibits gastric acid secretion and protects against alcohol-induced gastric injury in rats

Novokinin (Arg-Pro-Leu-Lys-Pro-Trp), a potent vasorelaxing and hypotensive peptide modified from ovokinin, exhibits highly selective affinity for the AT₂ receptor. However, its role in gastrointestinal functions is still not fully understood. In this study, we found that novokinin inhibited basal gastric acid secretion and protected gastric mucosa from alcohol-induced injury in a dose-related manner in rats after intracerebroventricular (i.c.v.) administration. Novokinin significantly decreased basal gastric acid output at the dose of 50 and 100 nmol/rat. The effect of novokinin on gastric acid secretion was reversed by central injection of PD 123319 (10 nmol/rat), an AT₂ receptor antagonist, and peripheral injection of indomethacin (10 mg/kg), an inhibitor of prostaglandin synthesis. Meanwhile, pre-treatment with novokinin at doses of 10, 50, and 100 nmol/rat significantly reduced the alcohol-induced gastric mucosal injury compared to the ulcer-control group, which was inhibited by indomethacin (10 mg/kg). The result showed a remarkable increase in the level of prostaglandin E2 (PGE₂), glutathione (GSH), and a decrease in malondialdehyde (MDA) after i.c.v. administration of novokinin. These findings suggest that the inhibitory effect of novokinin on gastric acid secretion is probably mediated via an AT₂ receptor-prostaglandins (PGs) pathway. The gastroprotective effect of novokinin might be attributed to the inhibition of acid secretion, the cytoprotection of PGs, and the antioxidant property.

Vanillin abrogates ethanol induced gastric injury in rats via modulation of gastric secretion, oxidative stress and inflammation

Vanillin is commonly used as an additive in food, medicine and cosmetics, but its effect has not yet been studied in gastric injury. Therefore the effect of vanillin was studied in experimental gastric ulcer. Gastric secretion and acidity were studied in pylorus ligated rats. Ulcer index, levels of gastric mucus, malondialdehyde (MDA), myeloperoxidase activity (MPO), expression of nuclear factor kappa B (NF-κB) p65, and histopathological changes were determined in ethanol induced gastric ulcer. Pre treatment with vanillin significantly reduced gastric secretion (P < 0.001) and acidity (P < 0.0001) and gastric ulcer index scores (P < 0.001). and augmented the gastric mucosal defense. Vanillin significantly restored the depleted gastric wall mucus levels (P < 0.0001) induced by ethanol and also significantly attenuated ethanol induced inflammation and oxidative stress by the suppression of gastric MPO activity (P < 0.001), reducing the expression of NF-κB p65 and the increased MDA levels (P < 0.001). Vanillin was also effective in alleviating the damage to the histological architecture and the activation of mast cells induced by ethanol.

Together the results of this study highlight the gastroprotective activity of vanillin in gastric ulcers of rats through multiple actions that include inhibition of gastric secretion and acidity, reduction of inflammation and oxidative stress, suppression of expression of NF-κB, and restoration of the histological architecture.

Aripiprazole an atypical antipsychotic protects against ethanol induced gastric ulcers in rats

The present investigation was undertaken, to study the gastro-protective potential of aripiprazole (ARI) an atypical antipsychotic drug in ethanol induced gastric ulcers in rats. ARI (10, 30, 100 mg/kg) was tested for gastric secretion and antiulcer activity in different groups of male Sprague Dawley rats. Gastric secretion and acidity studies were performed in pylorus ligated rats while indices of gastric ulcers were measured in ethanol (1 ml-100%) induced gastric ulcers. Histological changes and the levels of gastric wall mucus, malondialdehyde (MDA), non-protein sulfhydryls (NP-SH), myeloperoxidase (MPO), and serotonin were used to assess ethanol induced gastric mucosal injuries. Exposure of rats to ethanol resulted in gastric mucosal injury and a high index of ulcer. Pretreatment with ARI significantly (P < 0.001), reduced the gastric lesions induced by ethanol and also resulted in a significant decrease in the gastric secretion, and total acidity in pylorus ligated rats. ARI also significantly attenuated the ethanol induced reduction in the levels of gastric wall mucus, and NP-SH (P < 0.001). The histological changes and the increased MDA and MPO activity were also significantly (P < 0.001) inhibited by ARI. Ethanol induced depletion in the levels of serotonin in the gastric tissue were also significantly restored by pretreatment with ARI (p < 0.001). ARI showed significant antiulcer and gastroprotective activity against ethanol induced gastric ulcers. The gastroprotective effects of ARI may be due to its anti-secretory, antioxidant and anti-inflammatory action and also due to the restoration of the depleted gastric serotonin levels.

Gastroprotective effect of minocycline in experimentally induced gastric ulcers in rats

Minocycline (MCN), a semi-synthetic tetracycline derivative possesses pleiotropic effects and provides protection against a number of disease models. However its effect on gastric ulcers has not been studied. The present investigation was undertaken, to study the gastro-protective potential of MCN in experimentally induced gastric ulcers in rats. MCN (10, 30, 100 mg/Kg) was tested for gastric secretion and antiulcer activity in different groups of Wistar rats. Gastric secretion and acidity studies were performed in pylorus ligated rats while indices of gastric ulcers were measured in ethanol (1 ml-100%) and indomethacin (30 mg/kg), induced gastric ulcers. Histological changes and the levels of gastric wall mucus, malondialdehyde (MDA), non-protein sulfhydryl (NP-SH), and myeloperoxidase (MPO), were used to assess ethanol induced gastric mucosal injuries. Exposure of rats to ulcerogens resulted in gastric mucosal injury and a significant increase in the indices of ulcer. MCN conferred a protective effect against ethanol, and indomethacin induced gastric mucosal injuries. Treatment with MCN, resulted in a significant decrease in the amount of gastric secretion, and total acidity and significantly (P<0.001), reduced the gastric lesions induced by ethanol and indomethacin. MCN also significantly attenuated the ethanol induced reduction in the levels of gastric wall mucus, and NP-SH (P<0.001). The histological changes and the increased MDA and MPO activity were also significantly (P<0.001) inhibited by MCN. Minocycline showed significant antiulcer and gastroprotective activity against experimentally induced gastric ulcers. The gastroprotective effects of minocycline may be due to its anti-secretory, antioxidant and anti inflammatory action.