Antidiabetic and biochemical effect of the different fractions of methanol extract of Detarium microcarpum (Fabaceae) Guill and Perr stem bark on normal and alloxan induced diabetic rats

In this study, anti-diabetic activity of n-hexane fraction (HF) chloroform fraction (CF), diethyl ether fraction (DEF), ethyl acetate fraction (EAF) and methanol fraction (MF) of the methanol extract of Detarium microcarpum stem bark was investigated in normal and alloxan-induced dabetic rats. The fractions were screened for phytochemicals using standard methods. The acute toxicity (LD₅₀) of the fractions was determined in mice. The fractions were subjected to anti-diabetic study in alloxan-induced diabetic rats at two dose levels, 200 and 400 mg/kg. Diabetes was induced by a single ip injection of 120 mg/kg of alloxan monohydrate and glucose level was analyzed as indices of diabetes. Biochemical parameters, including glucose, urea, creatinine, serum cholesterol, serum triglyceride, high density lipoprotein (HDL), low density lipoprotein (LDL) haemoglobin and glycosylated haemoglobin were also assessed.The acute toxicity test showed that the fractions were safe at doses of up to 5 g/kg. The results indicated that intraperitoneal injection of CF, DEF, EAF and MF reversed the effect of alloxan in rats by different degrees. The anti-diabetic potency of fractions was in the order MF > CF >EAF > DEF and the activity of MF was comparable to that of the standard, glibenclamide (5 mg/kg). Treatment of diabetic rats with fractions of the methanol extract restored the elevated biochemical parameters significantly (p < 0.05) to the normal level. Histological studies showed a degenerative effect on the pancreatic islet cells of diabetic rats. The results suggested restorative (protective) effect of the MF on the pancreatic islet cells. The results of this study justify the use of this plant stem bark as traditional treatment for diabetes mellitus.