Antihyperglycaemic and antioxidant potentials of Cussonia arborea in alloxan-induced diabetic rats

Abstract

This study was to evaluate the anti-hyperglycaemic potential of the methanolic stem bark extract of Cussonia arborea in alloxan-induced diabetic rat model. C. arborea extract was well tolerated by the rats at the highest dose of 3,200 mg/kg. The extract at the dose of 500 mg/kg body weight significantly (p < 0.05) reduced the blood glucose levels of diabetic rats from 16.9 ± 4.7 to 5.1 ± 1.8 (72.4 ± 2.9 % reduction) 6 h post-extract administration. Upon screening of the four fractions obtained after chromatographic techniques, fraction 2 showed the highest anti-hyperglycaemic activity (75.2 ± 2.1 % reduction). Further phytochemical studies on fraction 2 revealed that it contains mainly saponin. Fraction 2 showed concentration-dependent antioxidant scavenging activity in 1,1-diphenyl-2-picrynyl phenyl hydrazyl photometric assay. The optimum percentage antioxidant activity was 55 % at the concentration of 400 μg/ml. Ferric reducing antioxidant power (FRAP) value (1.6 μm) of the fraction at 400 μg/ml was statistically comparable to that of 2 μm ascobic acid (reference standard).). It was concluded that the anti-hyperglycaemic property of the extract is attributable to fraction 2. The anti-hyperglycaemic activities of C. arborea could also be attributed to its antioxidant potentials.