NEEM LEAF - For thousands of years the beneficial properties of Neem (Azadirachta indica A. Juss) have been recognized in the Indian tradition. Each part of the neem tree has some medicinal property. Biswas et al (2002) have recently reviewed the biological activities some of the neem compounds, pharmacological actions of the neem extracts, clinical study and plausible medicinal applications of neem along with their safety evaluation.
Neem has two closely related species: A. indica A. Juss and M. azedarac, the former is popularly known as Indian neem (margosa tree) or Indian lilac, and the other as the Persian lilac. Neem has been extensively used in ayurveda, unani and homoeopathic medicine.The Sanskrit name of neem tree is Arishtha meaning 'reliever of sickness' and hence is considered as Sarbaroganibarini. The tree is still regarded as 'village dispensary' in India. The importance of the neem tree has been recognized by US National Academy of Sciences, which published a report in 1992 entitled 'Neem – a tree for solving global problems'.
More than 135 compounds have been isolated from different parts of neem and several reviews have also been published on the chemistry and structural diversity of these compounds. The compounds have been divided into two major classes: isoprenoids (like diterpenoids and triterpenoids containing protomeliacins, limonoids, azadirone and its derivatives, gedunin and its derivatives, vilasinin type of compounds and C- secomeliacins such as nimbin, salanin and azadirachtin ) and non-isoprenoids, which are proteins (amino acids) and carbohydrates (polysaccharides), sulphurous compounds, polyphenolics such as flavonoids and their glycosides, dihydrochalcone, coumarin and tannins, aliphatic compounds, etc.