Antidiabetic potentials of the methanol leaf extract of Oxytenanthera abyssinica

Oxytenathera abyssinica is used for the treatment of diabetes mellitus in folklore medicine in Nigeria. In this study, we evaluated its antidiabetic activity in alloxan-induced diabetic mice. Diabetes was induced in the mice by a single intraperitoneal injection of alloxan monohydrate and the fasting blood glucose (FBG) levels measured with blood from the tail snip at 0, 1, 3 and 6 h. The activity was compared with reference drug, glibenclamide (2 mg/kg) and negative control. Oral glucose tolerance test (OGTT) was evaluated by loading glucose to rats at the dose of 2,000 mg/kg and checking their FBG at 0, 60 and 180 min. Antioxidant activity was evaluated using ferric reducing antioxidant power (FRAP) and 1, 1- diphenyl-2- hydrazyl (DPPH) photometric assay. The extract and the reference drug caused a significant (P < 0.02–P < 0.002) time and dose dependent decrease in the FBG levels of the mice when compared to the negative control; the extract (500 mg/kg) reduced FBG by 38.0 % at the 6th hr as against 45.6 % by glibenclamide. In OGTT the extract caused a time dependent decrease in the blood glucose level up to 33.3 % at 180 min at the dose of 300 mg/kg. The extract also caused a concentration dependent increase in antioxidant activity having 91 % increase and 1.95 total antioxidant activities at a concentration of 400 μg/ml. Extract of Oxythenanthera abyssinica showed significant antidiabetic activity.