Antihyperglycemic and antioxidative effects of ethanolic leaf extract of Croton zambesicus in streptozotocin induced diabetic rats

The aim of this study was to evaluate the antihyperglycemic and antioxidative effect of Croton zambesicus (C. zambesicus) leaf extract in experimentally induced diabetic rats. Seventy adult male wistar rats were divided into seven groups (n=10). Group A, control rats; Group B, untreated diabetic rats; Group C, diabetic rats in which C. zambesicus therapy started 2 weeks prior to induction of diabetes; Group D and Group E, diabetic rats administered orally with C. zambesicus leaf extract for 2 and 4 weeks respectively; Group F, normal rats administered orally with C. zambesicus; Group G, diabetic rats administered glimepiride (2 mg/kg/day). The animals were weighed and sacrificed. Serum was obtained for catalase (CAT), glutathione (GSH), superoxide dismutase (SOD), glutathione peroxidase (GPx) and thiobarbituric acid reactive substances (TBARS) analyses using respective diagnostic kits. The result showed a better remediation with early commencement of the extract treatment. C. zambesicus exhibited significant (p<0.05) reduction in blood glucose level in the extract treated group when compared with other groups. The result also presented an improvement in the CAT, GSH, SOD, GPx and a reduction in TBARS in the extract treated groups as against a reduction in the antioxidant level and an increase in TBARS concentration in the untreated diabetic group.In conclusion, this study demonstrated that C. zambesicus leaf extract possesses antihyperglycemic and antioxidative activities in streptozotocin (STZ) induced diabetic rats and by extension may be useful in the management of diabetes mellitus.