Antidiabetic and Pancreato-Hepato-Renal Protective Effects of Entada a fricana (Fabaceae) Stem Bark Aqueous Extract in Fructose/Sucrose and Streptozotocin-Induced Type 2 Diabetic Rat

Abstract

Background: Type 2 diabetes mellitus is a growing public health problem that can lead to multi-organ damage. This study assessed the antidiabetic and antioxidant effects of Entada africana stem bark aqueous extract on pancreatic, hepatic, and renal damage in type 2 diabetic rats. Methods: Qualitative phytochemical analyses and acute toxicity assessment of the extract were performed. Normal Wistar rats underwent oral glucose tolerance tests after single (75 - 300 mg/kg) and 28-day (300 mg/kg) pretreatment with the extract, and fasting blood glucose was monitored for 2.5 h. Type 2 diabetes was induced in other rats by administering 10% fructose by gavage and 10% sucrose in drinking water for 21 days, followed by streptozotocin (40 mg/kg; i.p. ) injections on days 22 and 57. Diabetic rats received daily doses (75 - 300 mg/kg) of the extract for 28 days. Body weight and non-fasting blood glucose were measured before treatment and weekly thereafter, and insulin sensitivity, serum and tissue biochemical, and histological parameters were assessed at the end. Glibenclamide (10 mg/kg) served as the standard. Results: E. africana stem bark aqueous extract contains mucilage, cardiac glycosides, reducing sugars, unsaturated sterols, free quinones, saponins, polyphenols, flavones, flavonols, gallic tannins and triterpenoids, and exhibited low toxicity. The extract (300 mg/kg) improved glucose tolerance (p < 0.05) after 28 days in normal rats. In diabetic rats, it significantly (p < 0.05-p < 0.001) improved blood glucose, insulin sensitivity, lipid profile, and atherogenic risk index; reduced serum ALT, AST, ALP, Bilirubin, Urea, Uric acid, and Creatinine; and increased liver glycogen, albumin and total protein levels. It also decreased MDA and increased SOD, CAT, and GSH levels in the liver, kidneys and pancreas, improving their integrity. Conclusion: The safety, antihyperglycemic, insulin-sensitizing, lipid-modifying, and antioxidant activities, along with pancreato-, hepato-, and nephroprotective effects of E. africana stem bark aqueous extract, likely mediated by its phytoconstituents, justify its traditional medicinal use.