2008 Kyung Hee University Press 302 Oriental Pharmacy and Experimental Medicine 2008 8(3), 302-310 www.opem.org OPEM Effect of Azadirachta indica flower extract on basal and experimentally elevated blood glucose in rats S Waliullah 1 , Kalim Javed 2, * , MA Jafri 1 , and S Singh 3 1 Department of Ilmul Advia, Faculty of Medicine (U), Jamia Hamdard, New Delhi, India; 2 Department of Chemistry, Faculty of Science, Jamia Hamdard, New Delhi, India; 3 Department of Pharmacology, All India Institute of Medical Sciences, New Delhi, India Received for publication December 13, 2006; accepted December 27, 2007 SUMMARY Azadirachta indica A. Juss (N.O. Meliaceae), popularly known, as ‘Neem’ is an indigenous tree widely available in India. Almost every part of the tree has long been used in Unani system of medicine for the treatment of a variety of human ailments. The flowers have been mentioned as a remedy useful in controlling diabetes mellitus. The present study had been designed to investigate the hypoglycemic/anti-hyperglycemic effects of the methanolic extract of the flowers of A. indica (Gule-Neem) and its different fractions on normal, glucose fed hyperglycemic, adrenaline induced hyperglycemic and alloxan induced diabetic rats. The methanolic extract was resolved into water soluble and water insoluble fractions. Water soluble portion of the methanolic extract was found to possess significant blood sugar lowering effect in glucose-fed and adrenaline-induced hyperglycemic rats but it did not show such effect in normal and alloxan induced mild and severe diabetic rats. Water-soluble portion was fractionated by employing the polarity criterion with ethyl acetate and butanol. The ethyl acetate fraction was further fractionated into phenolic and non-phenolic fractions. Hypoglycemic effect of these fractions was also evaluated. The results suggest that the flowers of A. indica contain at least two different constituents, responsible for the said activity. These investigations validate the use of flowers of A. indica in diabetes by Unani physicians. Key words: Neem; Azadirachta indica; Anti-hyperglycemic; Diabetes; Adrenalineinduced hyperglycemia INTRODUCTION The tree Azadirachta indica A Juss (N.O. Meliaceae), popularly known as ‘Neem’, is an indigenous plant widely available in India. Almost every part of the tree has long been used in Unani system of medicine for the treatment of a variety of human ailments (Rahman and Jairajpuri, 1996). Flowers have been mentioned as a remedy useful in getting rid of intestinal worms, bile, phlegm, boils and bilious fever. Gargling of decoction of the flowers provides strength to gums and teeth. The flowers of this plant are valued for ophthalmic use also. Classical literature survey revealed that only the flowering part of this plant is reputed for controlling diabetes mellitus (Azam, 1899; Ghani, 1920). *Correspondence: Kalim Javed, Department of Chemistry, Faculty of Science, Jamia Hamdard, New Delhi - 110 062, India. E-mail: kjaved@jamiahamdard.ac.in, kjavedchem @yahoo.co.in DOI 10.3742/OPEM.2008.8.3.302