In vivo antidiabetic activity of the aqueous leaf extract of Croton macrostachyus in alloxan induced diabetic mice

Abstract

The folklore reports from traditional medical practitioners that Croton macrostachyus has bioactivity against several diseases including diabetes mellitus have not been scientifically evaluated. The aim of this study was to determine the in vivo hypoglycemic activity of aqueous leaf extracts of this plant in male swiss white albino mice. Aqueous leaf extract of Croton macrostachyus was intraperitoneally and orally administered to alloxan (180.9 mg/ kg; intraperitoneally)-induced diabetic mice at different doses of 25 mg/kgbwt, 48.4 mg/kgbwt, 93.5 mg/kgbwt, 180.9 mg/kgbwt and 350 mg/kgbwt and the effects on blood glucose levels investigated. The treatments effects were compared with three controls (normal, diabetic and diabetic treated with a standard antidiabetic drugs (insulin administered intraperitoneally at 1 IU/kg body weight in 0.1 ml physiological saline or glibenclamide administered orally at 3 mg/kg body weight in 0.1 ml physiological saline). Phytochemical composition of the leaf extracts were qualitatively assessed using standard procedures.The diabetic control mice showed significantly (p<0.05) higher fasting blood glucose when compared with normal control mice. Treatment of diabetic mice with doses of the leaf extract resulted in significantly (p<0.05) lower levels of fasting blood glucose. The effects of the leaf extract were comparable with the conventional drugs. However, the glucose lowering potency of this plant extract was dose independent. The aqueous leaf extracts contained tannins, flavonoids, saponins, sterols, anthraquinones and alkaloids. The observed hypoglycemic activity could be associated with the phytochemicals present in this plant extract. Therefore, the results suggest that Croton macrostachyus leaf extract is a potent hypoglycemic agent and this validates their folkloric usage. Further studies to investigate the mechanism of action for hypoglycemic activity for these plant species should be done in order to explore possibilities of developing a drug that can function by similar mode of action as the plant extract.