The Azhadirachtin in Indian society has been considered higher than kalpavriksha, the mythological and ethanobotanical beneficial properties. The efficacy of neem as a medicine has been documented in several different ancient treatments like the Atharvana Veda, the Ghrhyasutra and Sutragrantha and in puranas. The acidic principles in neem as margosic acid with three acetive constituents, viz., nimbin, nimbidin and nimbinene. Chemically related and biogenetically derivable from a tetracyclicterpene are the key features of them. These chemicals, for example, pesticides, antifeedants and cytotoxic properties, also show a whole range of biological activity.