Anti-Hyperglycaemic Effects of Ethanol Leaf Extract of Sphenocentrum jollyanum in Normal and Alloxan-Induced Diabetic Rabbits

The anti-hyperglycaemic activity of Sphenocentrum jollyanum (SJ) Pierre (Menispermaceae) was evaluated on alloxan-induced diabetic rabbits. The single extract dose in an oral tolerance test enhanced clearance of plasma glucose with decrease in the area under OGTT curve by 26.9% (P<0.05) compared to the untreated. In the alloxan-induced hyperglycaemic rabbits, the extract exerted significant blood glucose reduction in a dose dependent manner from day 3 of continuous oral administration. The maximum anti-hyperglycaemic effect was observed in the group that received 200 mg/kg with plasma glucose level of 200.2±2.6 mg/kg (42.8%) compared to glibenclamide (10 mg/kg) treated that showed maximum decrease of 158.5±5.0 mg/kg (54.8%). The photomicrograph of the extract treatment showed amorphous material resulting from necrosis with few surviving beta cells spotted at the periphery. It is apparent that the tissue histology indicated no evidence of beta cells regeneration. The decrease in glycaemia was therefore believed to have occurred through the extract potentiation of the survivor beta cells to facilitate insulin production.