Antipyretic Effect of Azadirachta indica Leaf Extract (Neem Leaf Extract) on Albino Rats.

Evaluation of antipyretic activity of Neem Leaf Extract (NLE) by using Brewer’s yeast induced pyrexia model. In this study the albino rats were randomly divided into groups of six each group consisting of 6 rats. Group I: Control (distilled water 0.5ml/rat); Group II: Standard (Paracetamol 100mg/kg intraperitoneally); Group III, IV, V, VI (NLE 62.5, 125, 250, 500 mg/kg body weight intraperitoneally respectively). It is a randomized controlled experimental study. Fever was induced by injecting 20 ml/kg body weight of 20 % suspension of brewer’s yeast subcutaneously below the nape of neck. Those animals that had a constant rectal temperature or a variation of less than 1 o C were included in the study. Drugs were given after development of pyrexia and temperatures recorded. Paracetamol at 100mg/kg orally was taken as the standard drug. NLE 62.5 mg/kg body weight showed no significant fall in temperature, whereas NLE 125 mg/kg body weight decreased the temperature significantly from 4 th hour of its injection along with NLE 250 mg and 500 mg/kg body weight. NLE caused significant fall in temperature from 1 st hour onwards. Distilled water did not show any antipyretic effect on Yeast-induced pyrexia. Thus NLE exhibited significant (p<0.05) antipyretic activity with the progressive increase in dose.