Pharmacologyonline 1: 474-485 (2008) Yadav et al. 474 ANTIHYPERGLYCAEMIC ACTIVITY OF ETHANOL EXTRACT OF PSIDIUM GUAJAVA LEAVES IN ALLOXAN INDUCED DIABETIC MICE. Bapuso V.Yadav 1 , Subhash L. Bodhankar 2 and Sunil R. Dhaneshwar. 1 * 1 Department of Pharmaceutical Chemistry, Poona College of Pharmacy, Bharati Vidyapeeth University, Erandwane, Pune - 411 038, India. 2 Department of Pharmacology, Poona College of Pharmacy, Bharati Vidyapeeth University, Erandwane, Pune – 411 038, India. Summary The antihyperglycaemic activity of the ethanol extract of Psidium guajava (EEPG) leaves was studied by administering three doses of EEPG (i. e.100,200 and 400 mg/kg, p. o.) to alloxan (70 mg/kg, i. v.) induced diabetic mice. The serum glucose levels and body weights of mice were determined. The acute oral toxicity study showed no mortality upto 5000 mg/kg p. o. dose of EEPG. In acute study the antihyperglycaemic effect was observed at 2h (78.25 mg/dl), peak at 6 h (197.03 mg/dl) but antihyperglycaemic effect vanished at 24 h. The subacute study was also carried out which showed maximum reduction in serum glucose level (311.22 mg/dl) at the dose of 200 mg/kg on 28 th day. The oral glucose tolerance test (OGTT) was carried out after administration of EEPG in non-diabetic and diabetic mice previously loaded with (2.5 g/kg, p. o.) glucose. EEPG (200 mg/kg) showed increased glucose threshold in non-diabetic mice. EEPG (800 mg/kg) showed increased glucose threshold in diabetic mice. EEPG (200 mg/kg) prevented the loss of body weight. These results indicated antihyperglycaemic activity of EEPG (200 mg/kg) in alloxan induced diabetic mice. The antihyperglycaemic activity of EEPG was comparable with glyburide. Keywords: Psidium guajava, Alloxan, Antihyperglycaemic, Body weight, Oral glucose tolerance test. *Address for Correspondence: Dr. Sunil R. Dhaneshwar, Professor & Head, Department of Pharmaceutical Chemistry, Poona College of Pharmacy,Bharati Vidyapeeth University, Erandwane, Pune – 411 038. Maharashtra, INDIA. E-mail – sunil.dhaneshwar@gmail.com Tel. No. : +91-20-25437237, 25436898 (Ext. 103), Fax No.: +91-20-25439383