Hypoglycaemic effects of Mammea africana (Guttiferae) in diabetic rats

Stem bark of Mammea africana is used in traditional medicine in tropical Africa, here we report a new property: stem bark extract can reduce hyperglycaemia in diabetic rats. The stem bark of Mammea africana Sabine (Guttiferae) is used in African rain forest to treat various diseases, including diabetes mellitus. We investigated whether Mammea africana extract induced hypoglycaemic activity in rats. We tested the effects of acute (5 h) and sub-acute (21 days) oral administrations of the CH 2Cl 2–MeOH stem bark extract of Mammea africana (19–300 mg/kg body weight) on blood glucose levels of normal and streptozotocin (STZ)-induced type 1 diabetic rats. The effects were compared with those of glibenclamide. Acute administration reduced blood glucose in the diabetic rats only (33.87%, P < 0.01). Sub-acute treatment for 21 days also reduced blood glucose level in diabetic rats (73.29%, P < 0.01). A reduction or stabilization in total serum protein, triglyceride, cholesterol and alanine amino transferase levels was also observed. No effect was observed on body weight loss but food and water intakes were significantly reduced ( P < 0.01) in diabetic rats. The maximal anti-diabetic effect was obtained with the dose of 75 mg/kg and was more important than that of glibenclamide. It can be concluded that extracts of Mammea africana exhibited a significant anti-hyperglycaemic activity and improved the metabolic alterations in STZ-diabetic rats. These results provide a rationale for the use of Mammea africana to treat diabetes mellitus and hypercholesterolemia.