Gastroprotective and antioxidant potentials of ethanolic stem bark extract of Margaritaria discoidea (Euphorbiaceae) in rats

Abstract

Ethnopharmacological relevance: Decoctions prepared from the bark of Margaritaria discoidea (Baill.) G. L. Webster (Euphorbiaceae) are used in Nigeria and other parts of West Africa in the treatment of wounds and ulcers. The study was conducted to investigate the gastric ulcer protective effect of ethanolic stem bark extract of M. discoidea in rats.

Materials and methods: Antiulcer assays were performed using ethanol, indomethacin and pylorus ligation-induced ulcer models at the dose of 50, 100 and 150 mg/kg, p.o. The antioxidant effect of the extract was evaluated in vitro and by studying its effect on antioxidant enzymes (superoxide dismutase, catalase, and reduced glutathione) and lipid peroxidation in the stomach tissue of rats in ethanol-induced model. Solvent fractions (hexane, dichloromethane, ethyl acetate, butanol and aqueous) from the crude extract were investigated for antiulcerogenic effects in ethanol-induced ulcer model at the dose of 150 mg/kg. GC-MS analysis of the active hexane fraction was also carried out.

Results: The extract significantly (P<0.05) reduced gastric lesion in ethanol and indomethacin-induced ulcer models. The extract had significant influence on in vivo antioxidant status in ethanol-induced model. In pylorus ligation-induced model, only the dose of 150 mg/kg showed significant reduction (88.89%, P<0.05) of ulcer lesions. There was no significant reduction in the gastric juice volume and total acidity. The solvent fractions showed ulcer inhibition in varying degrees but significance (P<0.01) was only observed in the hexane fraction. Ethyl esters of palmitic and linoleic acids were found as the major compounds in the GC-MS analysis of the hexane fraction.

Conclusion: Our results suggest that M. discoidea possesses gastroprotective activity possibly mediated through antioxidant mechanism. The data obtained in this study provide some support to the traditional use of M. discoidea in the treatment of gastric ulcer.

Keywords: Antioxidant activity; Euphorbiaceae; Extract; Fractions; GC–MS; Gastroprotective activity; Margaritaria discoidea.