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

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.