ISOLATION OF STIGMASTEROL AND GASTROPROTECTIVE ACTIVITY OF THE ETHYL ACETATE PORTION FROM ACACIA NILOTICA LINN (FABACEAE) SEEDS

Acacia nilotica Linn is used traditionally in the treatment of various diseases, such as diarrhea, ulcer, dysentery, asthma, inflammation and cancer. The present study aimed at isolation and characterization of a steroidal compound and evaluating the gastroprotective activity of the ethyl acetate portion of A. nilotica seeds in indomethacin-induced ulcer model. Fractionation of the ethyl acetate portion using standard chromatographic techniques led to the isolation of a compound (B2-I) which on further purification and characterisation using physical, chemical and spectral analysis, and by comparison with literature values was identified as stigmasterol. The effect of ethyl acetate portion of A. nilotica on experimentally induced ulcer was dose-dependent with curative ratios of 40%, 60% and 75% at concentrations of 100, 200 and 300 mg/kg body weights respectively. It significantly (P<0.05) decreased free and total acidity and increased the pH of gastric juice with respect to the indomethacin treated group. This justifies the ethnomedicinal use of A. nilotica seed as an antiulcer agent. The study recommends that A. nilotica seeds be evaluated against other ulcer models such as ethanol and stress induced ulcers.