Protective effect of methanol-methylene chloride extract of Terminalia glaucescens leaves on streptozotocin-induced diabetes in mice

Abstract

Purpose : Terminalia glaucescens (Combretaceae) is traditionally used in Cameroon in the treatment of diabetes. The anti-hyperglycemic effect of the methanol-methylene chloride extract of the leaves of this plant was investigated in streptozotocin (STZ)-induced diabetic mice. Methods : Diabetes was induced in mice by a daily dose of STZ (45 mg kg -1 body weight i.p.) for 5 days. From one day before STZ injection, normal and diabetic-test mice received one oral dose of the extract (100 mg kg -1 or 300 mg kg -1 body weight) daily for 15 days. The effect of the extract on body weight gain, food and water intake, plasma metabolites (glucose and lipids) and insulin levels was investigated. Results : Diabetic control mice and diabetic mice pre-treated with 100 mg kg -1 extract showed body weight loss, marked (P< 0.001) polyphagia and polydipsia, high plasma metabolites and glucose (P< 0.001), non-esterified fatty acids (NEFA) (P< 0.05), triglycerides (TG) (P< 0.05), and cholesterol (P< 0.05) and low insulin (P< 0.001) levels. Normal control, i.e., normal treated mice and 300 mg kg -1 extract pre-treated diabetic mice, presented normal weight gain, normal food and water intake, normal plasma metabolites and insulin levels, and did not exhibit very significant changes (P<0.1) in blood glucose level.. Conclusion : These results indicate that the extract of T. glaucescens leaf at a dose of 300 mg kg -1 protects against STZ-induced diabetic effects and could explain the traditional use of this plant in the management of diabetes.