Protective roles of Vigna subterranea (Bambara nut) in rats with aspirin-induced gastric mucosal injury.

Vigna subterranea is widely consumed as a traditional staple food in Nigeria and some West African countries. The ethanolic seed extract of V. subterranea (EEVS) was investigated for its gastroprotective effects on aspirin plus pylorus ligation-induced gastric ulcerated rats using an in vivo assay.

Gastric mucosal ulceration was induced experimentally in Groups 2 to 5 using aspirin plus pylorus ligation. Rats in Group 1 were orally pretreated with 3% Tween 80 only as normal control. Groups 2 to 5 were pretreated with 3% Tween 80 (ulcer group), 20 mg/kg of omeprazole (positive group), and 200 and 400 mg/kg of EEVS (experimental groups), respectively, once daily for 21 days before ulcer induction. Parameters including those for gastric secretions, ulcerated areas and gastric wall histology were assessed. Levels of superoxide dismutase (SOD), glutathione peroxidase (GPX), and malondialdehyde (MDA) in the gastric tissue homogenate were also determined.

Pretreatment with EEVS significantly (P < 0.05) reduced the ulcer index, gastric volume and total acidity in rats with aspirin plus pylorus ligation-induced ulcer. The pH and mucus of gastric content increased significantly (P < 0.05) while the levels of SOD and GPX were observed to be elevated with a reduced amount of MDA. Significant severe gastric mucosal injury was exhibited in the ulcer group and EEVS or omeprazole offered significant (P < 0.05) protection against mucosal ulceration. Histologically, the gastric submucosal layer showed remarkable decrease in edema and leucocytes infiltration compared with ulcer group.

The study suggests that EEVS offered a protective action against aspirin plus pylorus ligation-induced gastric ulcers in Wistar rats. The protective effect might be mediated via antisecretory, cytoprotective and antioxidative mechanisms.