Evaluation of Toddalia asiatica (L.) Lam. leaf extracts for antidiabetic activity

Objective: The objective of this investigation was to ascertain the scientific basis for the use of Toddalia asiatica (L.) Lam. belongs to family Rutaceae (commonly called: Wild orange tree or Forest pepper; in Odia: Tunda poda) in controlling diabetes, using streptozotocin induced diabetic rats.Methods: T. asiatica (L.) Lam. leaves was collected from Athamallik forest region in Angul district, Odisha, in the month of January ? February and extracted successively with petroleum ether (60-80 0C) and methanol. The antihyperglycaemic activity was evaluated in normal, glucose-loaded and Streptozotocin-induced hyperglycaemic rats (single and multi dose treatment).Results: In normoglycaemic rats, the test extracts showed progressive fall of blood glucose level till the end of 8 h. In glucose loaded animals (OGTT), reduction in blood glucose level was observed after 60 minutes of administration of the test substances. The maximum reduction was observed at 4 h with methanol extract exhibiting maximum improvement in glucose tolerance. The extracts produced significant decrease in the blood glucose level in STZ-induced hyperglycaemic rats when compared with the diabetic control group in the single dose treatment study at the tested dose level of 400 mg/kg of body weight. In multi-dose treated hyperglycaemic rats, both the extracts showed various degree of blood glucose reduction, among which methanol extract exhibited highest percentage of reduction in blood glucose level. Continuous administration of extracts for 14 days leads to significant decrease in serum total cholesterol, triglycerides, LDL and VLDL levels, while increase in total protein and HDL levels was recorded. The in vitro study showed an increased utilization of the glucose by α-amylase inhibition assay in presence of methanol extract which suggests that the test extract may inhibit the digestion and absorption of glucose through intestine.Conclusions: These findings suggest that the plant may be a potential source for the development of new oral antihyperglycaemic agent.