Anti-ulcerogenic evaluation of the fractions of the ethanol layer of the chloroform-ethanol extract of the leaves of Dacryodes edulis

摘要

In traditional medicine, the leaves of Dacryodes edulis are utilised in the treatment of gastric ulcer and hence, the chloroform and ethanol layers of the chloroform-ethanol extract of the leaves of D. edulis were evaluated for their anti-oxidant vitamin contents and proximate compositions. Based on preliminary investigations, the more promising layer (ethanol layer) was further fractionated and the effects of the fractions on ulcer index and curative ratio of diclofenac-ulcerated Wistar rats were determined using standard methods. The anti-oxidant vitamin contents of the chloroform and ethanol layers showed the following: vitamins A (1.83 ± 0.08 and 1.79 ± 0.08 μg/100 g), C (0.62 ± 0.05 and 0.79 ± 0.03 mg/100 g) and E (1.17 ± 0.07 and 1.04 ± 0.05 mg/100 g) respectively. The proximate compositions of the chloroform and ethanol layers were: moisture (3.15 ± 0.11 and 4.08 ± 0.18%), crude fibre (5.41 ± 0.29 and 5.29 ± 0.27%), ash (5.09 ± 0.27 and 4.12 ± 0.18%), crude fats (4.43 ± 0.13 and 3.98 ± 0.12%), crude proteins (17.24 ± 0.43 and 17.80 ± 0.29%) and carbohydrates (64.68 ± 1.40 and 64.73 ± 1.35%) respectively. Each of the chloroform and ethanol layers of the chloroform-ethanol extract was found to be safe at a dose as high as 5000 mg/kg body weight (b.w). At the two doses (100 and 200 mg/kg b.w), the n-hexane, chloroform, ethyl acetate and methanol fractions of the ethanol layer dose-dependently decreased and increased the ulcer indices and curative ratios respectively of the rats in the test groups when compared with those of the rats in the ulcer-untreated group albeit these effects were not significant (p>0.05) except those of the methanol fraction at the dose of 200 mg/kg b.w. Results of the methanol fraction (200 mg/kg b.w only) were comparable to those of the standard anti-ulcer drug, ranitidine at the dose of 150 mg/kg b.w. The data of this study indicate that the methanol fraction of the ethanol layer of the chloroform-ethanol extract of the leaves of D. edulis possess remarkable anti-ulcerogenic effect and might serve as source of novel drugs for ulcers in future.