0 Bajaj S Srinivasan BP 1999 Indian Journal of Pharmacology 31 2 4 Diabetes Mellitus/DT, Diabetes Mellitus, Insulin-Dependent, Non-Insulin-Dependent,Rats, Hyperglycemic Agents, Streptozocin/AD, Data Interpretation, Statistical,Animal, Male Objective: To investigate the anti-diabetic activity of Azadirachta Indica using IDDM and NIDDM animal models. Methods: Streptozotocin induced models of IDDM (65 mg/kg,iv) as well as NIDDM model (90 mg/kg,i.p in neonates) were given neem leaf extract (NLE, 1 g/kg, po) for 6 weeks and their anti-diabetic activity was assessed. Result: The treatment with insulin, aqueous NLE, aqueous NLE with insulin and insulin with aminoguanidine showed a fall in blood glucose levels of 80,45,4,38, 02 and 77-65 percent whereas in NIDDM model, a fall of 53.95 and 60.50 percent were observed with glibenclamide and NLE. Conclusion: Aqueous extract of NLE has a good therapeutic potential as anti-hyperglycaemic agent in IDDM and NIDDM.