An overview of Neem (Azadirachta indica) and its potential impact on health

The extracts of different parts of neem tree (Azadirachta indica) have been well documented for its pharmacological or medicinal properties and their wide applications by indigenous healthcare practices. Pharmacological properties exhibited by plant parts could be further explored for development of new herbal formulations and therapeutic agents. Pharmacological properties of neem tree are due to the presence of active phytochemicals like flavonoids, terpenoids, coumarins, alkaloids, tannins, sulphurous compounds, carbohydrates, proteins and minerals. Various medicinal properties and applications of neem tree have been well documented in ancient Indian system of medicine and scripts such as Susruta Samhita and Charak Samhita. Over 700 herbal preparations based on A. indica have been recognized in traditional system of medicine such as Unani, homoeopathy, Ayurveda and Siddha, and more than 160 local practices are known in different countries of the world in which neem contributes as a main or the sole constituent for curing various diseases. Neem displays various medicinal properties such as antioxidant, anti-inflammatory, antidiabetic, anticancer, antiviral, antibacterial, antigingivitis, antifungal, antiulcer, hepatoprotective, neuroprotective, antipyretic and wound healing activities. All the parts of neem tree have been used as traditional medicines. In addition to its therapeutic potential, neem is being extensively used as eco-friendly commercial agrochemicals and pesticides. The present chapter provides the critical description of phytochemistry and pharmacological properties of different parts of neem tree and its important natural bio-active compounds.

Bio-active Compounds Isolated from Neem Tree and Their Applications

Cancer is the second leading cause of morbidity and mortality worldwide. Although chemotherapy and radiotherapy enhance the survival rate of cancerous patients but they have several acute toxic effects. Therefore, there is a need to search for new anticancer agents having better efficacy and lesser side effects. In this regard, herbal treatment is found to be a safe method for treating and preventing cancer. Here, an attempt has been made to screen some less explored medicinal plants like Ammania baccifera, Asclepias curassavica, Azadarichta indica, Butea monosperma, Croton tiglium, Hedera nepalensis, Jatropha curcas, Momordica charantia, Moringa oleifera, Psidium guajava, etc. having potent anticancer activity with minimum cytotoxic value (IC50 >3μM) and lesser or negligible toxicity. They are rich in active phytochemicals with a wide range of drug targets. In this study, these medicinal plants were evaluated for dose-dependent cytotoxicological studies via in vitro MTT assay and in vivo tumor models along with some more plants which are reported to have IC50 value in the range of 0.019-0.528 mg/ml. The findings indicate that these plants inhibit tumor growth by targeting anti-proliferative, pro-apoptotic, anti-metastatic and anti-angiogenic molecular targets. They are widely used because of their easy availability, affordable price and having no or sometimes minimal side effects. This review provides a baseline for the discovery of anticancer drugs from medicinal plants having minimum cytotoxic value with minimal side effects and establishment of their analogues for the welfare of mankind.

Hongjuan Diao

Papers

A new cytotoxic salannin-class limonoid alkaloid from seeds of Azadirachta indica A. Juss