Antidiabetic and anti-oxidant activities of the methanol leaf extract of <i>Vernonia amygdalina</i> in alloxan-induced diabetes in Wistar rats

The methanolic leaf extract of Vernonia amygdalina (MLVA) was assessed to evaluate its antidiabetic potential in rats. Diabetes was induced in male Wistar rats by the administration of alloxan monohydrate at 100 mg/kg of body weight. After 48 h, rats with fasting blood glucose levels of 200 mg/dL and above were considered diabetic and used for the study. The experimental animals were grouped into five groups (A–E) of 10 animals each. Group A rats were non-diabetic normal control, Group B consisted of diabetic control rats that received no treatment, groups C, D and E rats were diabetic rats but treated with glibenclamide, 200 and 400 mg/kg doses of MLVA respectively. Blood samples were collected at days 14 and 28 after induction for haematological and serum biochemical indices such as triglycerides, LDL, cholesterols etc. The intestine was collected and intestinal homogenate was prepared for the antioxidant studies. The extract at 200 mg/kg and 400 mg/kg doses significantly (p < 0.05) reduced blood glucose levels in extract-treated diabetic rats and also significantly increased weight gain in these rats. Most haematological parameters in treated rats experienced, while platelets and neutrophils were decreased. Biochemical indices measured were reduced in MLVA-treated groups compared with diabetic control. Treatment with MLVA also produced significant (p < 0.05) decrease in markers of oxidative stress but increased levels of enzymic and non-enzymic antioxidant markers in intestinal homogenates of treated groups compared with diabetic control. This study showed that V. amygdalina has antihyperglycaemic and in vivo antioxidant effects