Effects of the stem barks aqueous extract of Anthocleista schweinfurthii Gilg (Loganiaceae) on acute and chronic gastric ulcers rats models

Anthocleista schweinfurthii is used in the traditional management of gastro-duodenal ulcers; this led us to evaluate the gastro-cytoprotective and healing effects of this plant. Anti-ulcer activity of the stem barks aqueous extract of A. schweinfurthii (EAS) was evaluated using five methods: HCl/ethanol; indomethacin-HCl/ethanol; absolute ethanol; pylorus-ligated (acute gastric lesions); and acetic acid-induced chronic ulcers in rats. The parameters assessed were mucus production, gastric ulcer index, pH, acid concentration and volume of gastric contents. Sucralfate, cimetidine and ranitidine were used as the reference anti-ulcer drugs. In all cases, oral administration of EAS (250 and 500 mg/kg), dose-dependently, prevented gastric lesion formation (p<0.001). Generally, this cytoprotective action was accompanied by significant increases in gastric mucus production. Intraperitoneal indomethacin (30 mg/kg) significantly reduced mucus production but did not reduce the cytoprotective effect. In pylorus ligation, the extract did not reduce acidity and volume of gastric juice compared to controls. All doses of the extract showed a highly significant (p<0.001) reduction of ulceration with a healing rate over 90%. This study indicates that A. schweinfurthii possesses significant anti-ulcer activity and these results are substantiated by the histopathological examination of the ulcerated stomachs.   Key words: Gastric, ulcer, cytoprotection, Anthocleista schweinfurthii, Loganiaceae.