Neem — Omnipotent tree
The Neem tree Azadirachta indica (Syn. Melia azadirachta L. ; Margosa tree; in French – le Margousier) is a tropical evergreen tree native to Indian sub-continent and is also found in other southeast countries. It’s a common roadside and front yard tree bearing medium to dark green leaflets, small, white and sweet scented flowers and glabrous olive-like fruits. The oil obtained by crushing the dried kernel has a garlic-like odour, and a bitter taste. The neem tree is noted for its drought resistance. Normally it thrives in areas with sub-arid to sub-humid conditions. Neem can grow in many different types of soil, but it thrives best on well drained deep and sandy soils. It is a typical tropical/subtropical tree and exists at annual mean temperatures between 21-32 °C. It can tolerate high to very high temperatures. It does not tolerate temperature below 4 °C.
Neem in Ancient history
Indian Ayurvedic texts have described the Neem tree by associating its remarkable healing properties from as far back as 5000 BC. Its leaves were first founded at the excavation of Mohanjodaro in the era of Australoid and Dravidian (2000 BC). Ayurvedic texts in sanskrit describes neem as ‘Sarva roga nivarini’ – (the universal healer or curer of all ailments), ‘Arishtha’ (perfect, complete and imperishable) and ‘Nimba’ from the term ‘Nimbati Syasthyamdadati’ which means ‘to give good health’. Even today, rural Indians refer neem as their ‘village pharmacy”. It’s a tree of unbelievable wonders that it is deeply imbued with spiritual meaning. Hindu mythology attributes its curative properties to the fact that a few drops of Amrita (the elixir of immortality, sacred nectar) was dropped or sprinkled by the celestial committee which gave rise to neem tree. There are many stories muttered in the past of Ancient India history that this tree should be of divine origin. A lot of records are available in the books that were accepted as the basis of the Indian system of natural treatment. Interesting..? . Please refer to this page if you want them to know them in detail.
Rediscovery of Neem in Modern world
In search of useful plants, especially the herbals, scientists use to explore the inaccessible hot-spots and the reserves of tropical rain forest. But one such plant, Neem, grows abundantly in the front yards and all along the road side throughout south Asia and Africa. This familiarity of neem should have hidden its real wonders until a few scientists took a closer look at this ancient tree of miracles. A series of research is now going on world wide to discover the hundreds of active compounds it produces and try to determine the role of each of the chemical compound. In recent days, growing interest in organic agriculture has identified the importance of neem. That’s why most of the research studies were oriented in agriculture field.
Neem is a bio-chemical factory that contains several thousands of chemical constituents that are attributable to its miracles. Of them, the terpenoids are of special importance. More than 70 terpenoids are available in different parts of the neem plants and living tissues. Recently, a special type of “secretory” cells has been identified to be the site of synthesis and accumulation of these chemicals. These cells are abundant in the kernel and naturally the terpenoids are more concentrated in the seeds. Of all these terpenoids, Azadirachtin, the astringent is the most active and well studied compound. Several kinds of Azadirachtin (A to K) have been isolated while the most abundant is the Azadirachtin-A. The concentration of Azadirachtin in neem kernels depends on the combination of environmental and genetic factors. The content may go as high as 10 g/kg of seed kernels and a single tree may yield about 2 kg of kernels each year.
Still today, the process of isolating Azadirachtin from the natural sources is too expensive that the scientists have made some attempts to synthesize the molecule. This process has frustrated several chemical labs and its eminent organic chemists. After 22 years of research, certain labs boast to have synthesized the molecule. Steven Ley, University of Cambridge, UK accepts that it’s by far the hardest molecule they have ever worked on and he ranks Azadirachtin has one of the very toughest syntheses so far reported. But the efficacy and stability of this synthesized molecule in its commercial formulations has been not yet proved. Also synthesizing the whole molecule is more expensive for now at least than isolating the product from the natural sources. This source happened to be the neem which contains several thousand of chemical constituents like Azadirachtin and a number of potent compounds from its root to its spreading crown. In most of the traditional preparations of neem, as a pesticide or as a medicine, a mixture of all these constituents is present and provides the necessary results. We can thus broadly classify the applications of neem products and its bye products for the three fields – Agriculture, medicines and cosmetics.