Antidiabetic Effects of Aqueous and Dichloromethane/Methanol Stem Bark Extracts of Pterocarpus soyauxii Taub (Papilionaceae) on Streptozotocin-induced Diabetic Rats

AIM OF THE STUDY: The aim is to evaluate the hypoglycemic and antidiabetic effects of aqueous and CH(2)Cl(2)/CH(3)OH stem bark extracts of Pterocarpus soyauxii Taub in normal and diabetic rats. MATERIALS AND METHODS: Streptozotocin (STZ)-induced diabetic and normal adult Wistar rats were orally administered with aqueous and CH(2)Cl(2)/CH(3)OH plant extracts of P. soyauxii at various doses (38–300 mg/kg) in a single administration. In addition, STZ-induced diabetic rats received prolonged daily administration for 14 days. Glibenclamide (GB) (10 mg/kg) was used as reference treatment. In acute test, fasting blood glucose was followed for 5 h. In subacute test, body weight, food and water intakes, and blood glucose were followed weekly and serum biochemical parameters evaluated after 14 days treatment. RESULTS: Acute administration of aqueous and CH(2)Cl(2)/CH(3)OH stem bark extracts moderately decreased fasting blood glucose compared to GB, significantly in normal rats (P < 0.05 to P < 0.01) but, as GB, not significantly in diabetic rats. Prolonged treatments in diabetic rats with aqueous and CH(2)Cl(2)/CH(3)OH extracts reduced blood glucose to an extent, respectively, superior or similar to GB. Moreover, P. soyauxii also significantly (P < 0.01) reduced weight loss, and diabetes increased serum triglycerides, total cholesterol, and transaminases (alanine aminotransferase/aspartate aminotransferase) elevations. CONCLUSION: P. soyauxii Taub stem bark extracts have possible value for antidiabetic oral medication. SUMMARY: Aqueous and Dichloromethane/Methanol stem bark extracts of Pterocarpus soyauxii Taub have potent (compared to Glibenclamide) antidiabetic effects in STZ-diabetic rats, with specific kinetics and dose-responses. Moderate hypoglycemia effects upon acute P. soyauxii administration. Potent anti-hyperglycemic effects of sub-acute P. soyauxii administration in STZ-diabetic rats. Potent anti-hyperlipidemic effects of sub-acute P. soyauxii administration in STZ-diabetic rats. Improved hepatic and renal serum parameters after sub-acute P. soyauxii administration in STZ-diabetic rats. P. soyauxii extracts may be useful for oral treatment of diabetes and related metabolic disorders. [Image: see text] Abbreviations Used: CH2Cl2/CH3OH: Dichloromethane/Methanol; STZ: Streptozotocin; GB: Glibenclamide; AE: Aqueous extract; OE: Organic extract; FeCl3: Iron (III) chloride; NaCl: Sodium chloride; K3Fe(CN)6: Potassium ferricyanide; ALT: Alanine aminotransferase; AST: Aspartate aminotransferase; H: Hour; BW: Body weight, W1 and W2: Weeks 1 and 2; CHOD: Cholesterol oxidase; GPO: Glycerol-3 Phosphate oxidase; PAP: Phenol + Aminophenazone