Azadirachta indica, Neem, Margosa (Meliaceae) is a medicinal plant used in traditional formulations for the treatment of various disease conditions. The physicochemical properties fluctuate with the season and in response to stress. To obtain the highest medicinal value, it is necessary to collect the plant raw material in the correct season. The present study aim to evaluate the physiochemical fluctuations in the leaves of Azadirachta indica and nimbin, an antidiabetic constituent in these leaves. Plant leaves were collected in every month of a year at different time and places. subjected to authentication and standardization. The leaves were evaluated for macroscopic and microscopic evaluation, quantitative microscopy, proximate phytochemical analysis, extractive values in petroleum ether, chloroform, ethyl acetate, ethanol, water, and determination of the concentration of the antidiabetic component nimbin. The leaves showed morphological and microscopical variations in different seasons. The phytochemical composition was the same in all season; however the levels of extractive values fluctuated in response to seasonal variations. Maximum levels of ethanol and water extract were obtained in winter and also the nimbin concentration was higher in this season.
GAUTAM SADASHIV PALSHIKAR (Mon,) studied this question.