Antidiabetic effects of aqueous extract of Baillonella toxisperma Pierre (Sapotacae) in streptozotocin-induced diabetic rats

Abstract

Baillonella toxisperma stem bark is used in Cameroonian traditional medicine to control many ailments such as diabetes mellitus. The present study was designed to evaluate the anti-diabetic potential of Baillonella toxisperma stem-barks aqueous extract on STZ-induced type 1 diabetes in rats. Experimental diabetes was induced by intravenous (penile vein) injection of 55 mg/kg of streptozotocin. Animal received distilled water (10 mL/kg), insulin (10 UI/kg) or the aqueous extract of B. toxisperma (100 mg/kg, 200 mg/kg and 300 mg/kg). Hypoglycemic effect was assessed by a single oral administration of the extract to normal and diabetic rats and anti-diabetic effect evaluated by administrating daily doses to diabetic rats for 28 days. At the end of experimental period, blood pressure was recorded and serum (blood glucose levels, total cholesterol, triglycerides, LDL-cholesterol, LDL-cholesterol, AST, ALT, creatinine, sodium, calcium and urea), urinary (creatinine, sodium, calcium, urea and protein) biochemical parameters were evaluated. Some oxidative stress parameters were evaluated, and histomorphometry of the pancreas performed. A single oral administration of the plant extract significantly reduced blood glucose levels in both normal and diabetic rat with a marked effect at higher dose. Injection of streptozotocin induced chronic hyperglycaemia accompanied by polyphagia, polydipsia, polyuria, weight loss, dyslipidemia, oxidative stress, rising on blood pressure, liver, kidney damages and degenerative changes in pancreas. The administration of Baillonella toxisperma stem-barks aqueous extract (200 mg/kg and 300 mg/kg) significantly decreased blood glucose levels and blood pressure parameters as compared to diabetic control 28 days post-treatment. Furthermore, the extract improved lipidemia, liver, renal parameters, and countered oxidative stress. Similarly, the plant extract improved morphological changes in pancreas by increased the area of islets cells of Langerhans as compared to diabetic control. These findings suggest that Baillonella toxisperma stem-barks aqueous extract exerts its anti-diabetic property by its hypolipidemic and anti-oxidative effects. These results justify the use of this extract in the management of diabetic condition.