Polyphenols with antiulcerogenic action from aqueous decoction of mango leaves (Mangifera indica L.).

This study was designed to determine the gastroprotective effect of a Mangifera indica leaf decoction (AD), on different experimental models in rodents. The administration of AD up to a dose of 5 g/kg (p.o.) did not produce any signs or symptoms of toxicity in the treated animals, while significantly decreasing the severity of gastric damage induced by several gastroprotective models. Oral pre-treatment with AD (250, 500 or 1000 mg/kg) in mice and rats with gastric lesions induced by HCl/ethanol, absolute ethanol, non-steroidal anti-inflammatory drug (NSAID) or stress-induced gastric lesions resulted in a significant decrease of said lesions. Phytochemical analyses of AD composition demonstrated the presence of bioactive phenolic compounds that represent 57.3% of total phenolic content in this extract. Two main phenolic compounds were isolated, specifically mangiferin (C-glucopyranoside of 1,3,6,7-tetrahydroxyxanthone) and C-glucosyl-benzophenone (3-C-beta-D-glucopyranosyl-4',2,4,6-tetrahydroxybenzophenone). These findings indicate the potential gastroprotective properties of aqueous decoction from M. indica leaves.

Byrsonima fagifolia: an integrative study to validate the gastroprotective, healing, antidiarrheal, antimicrobial and mutagenic action.

ETHNOPHARMACOLOGICAL RELEVANCE: Ethnopharmacological survey indicated leaves of Byrsonima fagifolia Nied. (Malpighiaceae) against gastrointestinal disorders. AIM OF THE STUDY: The methanolic extract from the leaves of Byrsonima fagifolia (denominated BF) was evaluated for toxic, mutagenic, gastroprotective, antidiarrheal, antibacterial and immunomodulatory activities. MATERIALS AND METHODS: The preventive and healing action of BF against gastric ulcer was evaluated in experimental models in rodents. We evaluated immunomodulatory (by murine peritoneal macrophages), antidiarrheal (by induced diarrhea with castor oil and intestinal motility) and antibacterial action of BF against standard strain of Escherichia coli, Staphylococcus aureus and Helicobacter pylori. The safety of use of BF was also evaluated by mutagenic (Ames assay) and by analyses of toxicity parameters. RESULTS: Phytochemical BF profile indicated the presence of phenolic compounds with antioxidant and radical-scavenging properties. BF significantly inhibited gastric lesions induced by ethanol and HCl/ethanol and endogenous mucosal sulphydryl groups (SHs) participated efficaciously in BF gastroprotection. BF blocked development of inflammation process and also has antidiarrheal actions. This extract accelerated the healing of the gastric ulcerated mucosa by stimulating proliferative factors and by increasing production of gastric mucus with no toxic action. The substances responsible for the protective action are concentrated in the ethyl acetate fraction that demonstrated no mutagenic action in vitro. CONCLUSIONS: Byrsonima fagifolia presents gastroprotective, healing and antidiarrheal activities supporting previous claims that its traditional use by Brazilians can treat these gastrointestinal ailments.

Constituents and antiulcer effect of Alchornea glandulosa: activation of cell proliferation in gastric mucosa during the healing process.

Alchornea glandulosa (Euphorbiaceae) is a plant used in folk medicine as an antiulcer agent. Rats pretreated with methanolic extract obtained from the leaves of A. glandulosa (AG) showed a dose-dependent effect and significant reduction of gastric ulcers induced by absolute ethanol at the doses of 500 (57%) and 1000 mg/kg (85%) in relation to the control group. Pretreatment of mice with AG (500, 1000 mg/kg, p.o.) showed dose-dependent activity and significantly decreased the severity of lesions caused by HCl/ethanol and by non steroidal anti inflammatory drug-induced gastric lesions. Pretreatment with AG also induced antisecretory action via local and systemic routes and a significant decrease in the total gastric acid content. The gastroprotective effects of AG involved the participation of nitric oxide and increased levels of endogenous sulfhydryl compounds, which are defensive mechanisms of the gastrointestinal mucosa against aggressive factors. The ability of AG to heal gastric ulcers was evaluated after 14 consecutive days of treatment. The results showed that single oral administrations of AG (250 mg/kg/once daily) potently stimulates gastric epithelial cell proliferation that contributes to the accelerated healing of gastric ulcers induced by acetic acid. In addition, no subacute toxicity (body weight gain, vital organs, and serum biochemical parameters) was observed during treatment with AG. Phytochemical investigation of AG led to the isolation of myricetin-3-O-alpha-L-rhamnopyranoside, quercetin-3-O-alpha-L-arabinopyranoside, quercetin-3-O-beta-D-galactopyranoside, quercetin, amentoflavone, methyl gallate, gallic acid, and pterogynidine. We also established the phytochemical profile of AG with the quantification of total phenolic compounds. These compounds may contribute to the observed antiulcerogenic effects of AG.