Antiulcer effects of the aqueous and organic extracts of the stem bark of Anthocleista vogelii in rats

The aqueous, hexane, acetone, and methanol extracts of the stem bark of Anthocleista vogelii Planch. (Loganiaceae) were screened for antiulcerogenic activity using HCl/ethanol gastric necrotizing solution. The methanol extract showed 100% inhibition at a dose of 500 mg/kg compared with the aqueous, hexane, and acetone extracts, which produced 87.91%, 61.39%, and 76.89%, respectively. The methanol and aqueous extracts were further tested against ulceration induced by indomethacin (30 mg/kg) and pylorus ligation at doses of 125, 250, and 500 mg/kg. The aqueous extract at a dose of 500 mg/kg significantly (p <= 0.01) reduced indomethacin-induced gastric lesions by 78.62% while the methanol extract at the same dose completely inhibited the action of indomethacin. The aqueous extract of A. vogelii at doses of 250 and 500 mg/kg induced a decrease of about 15% and 40%, respectively, of the surface area in the pylorus-ligated rats. Similarly, the methanol extract at doses 250 and 500 mg/kg produced a decrease of almost 25% and 70%, respectively. The gastric juice secretion increased significantly (p <= 0.05) at a dose of 500 mg/kg in the aqueous extract while the gastric acidity significantly (p <= 0.01) decreased at doses of 125 and 500 mg/kg in aqueous and methanol extracts as compared with the control group. These findings show that the aqueous and organic extracts of the stem bark of Anthocleista vogelii possess potent antiulcer properties thereby lending support to the ethnomedical uses of the plant in the treatment of stomachache.