Abstract:
The study was to evaluate the acute toxicity, antihyperglycaemic and in vitro antioxidant activities of the methanolic stem bark extract of Cussonia arborea in alloxan-induced diabetic rat model.The extract did not produce any form of acute toxicity effect even at the highest dose of 3,200 mg/kg body weight. Phytochemical studies of the extract revealed the presence of saponin, glycosides, tannins and alkaloids. Cussonia. arborea extract at the dose of 500 mg/kg body weight significantly (p<0.05) reduced the blood glucose levels of the diabetic rats from 16.9±4.7 to 5.1±1.8 (72.4±2.9% reduction) six hours post extract administration. Upon screening of the four fractions obtained after column and thin layer chromatography, fraction 2 showed the highest antihyperglycaemic activity (75.2±2.1 % reduction). Fraction 2 on further phytochemical investigation, was found to contain mainly saponin.The extract showed concentration-dependent scavenging activity in DPPH photometric assay. The optimum percentage antioxidant activity was 55 at the concentration of 400 µg/ml. The ferric reducing antioxidant power (FRAP) value (1.6µm) of the extract at 400µg/ml was statistically comparable to that of 2 µm Ascorbic acid (reference standard).It was concluded that C .arborea extract is safe and has both antihyperglycaemic and antioxidant activities.
