Establishment of in vitro cultures of Azadirachta Indica A. Juss. and Spilanthes acmella Murr. and their potential for the production of secondary Metablites
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Medicinal plants have always had an important place in the therapeutic arsenal of mankind. In the last few years as the demand for medicinal plants is increasing; their exploitation by the local population as well as pharmaceutical companies is also increasing continuously. It is, therefore, imperative to develop efficient methods for its large scale propagation. Besides micropropagation, in vitro production of useful bioactive compounds, their identification as well as quantification is also highly warranted. In this context, plant cell cultures have been proved handy for the production of high value secondary metabolites owing to the consistency in quality and quantity of the desired product. Plant cells are biosynthetically totipotent which means that each cell in culture retains the complete genetic information to produce the range of chemicals found in the parent plant. Azadirachta indica A. Juss. is a remarkable multipurpose, evergreen tree of the mahogany family, Meliaceae. The history of commercial use of neem tree is shrouded in the mystery and tradition of Vedic period of India. In the last two decades, neem has become the focus of attention due to its medicinal, agrochemical and economic uses. These properties can be attributed to several secondary metabolites present in the genus most of which, chemically, belong to the class of terpenoids. Among the entire range of diverse chemicals, one which remains the most sought after by scientists is azadirachtin, a highly oxidized tetranortriterpenoid, present in the neem seed kernels. This molecule has emerged as the safest, environment friendly and biodegradable biopesticide, unlike the chemical ones that pose problems of bioaccumulation in food chains upon long term usage. Current supply of azadirachtin from neem tree will not meet the increasing demand if the extractions from seeds remain the only source, hence, there is a need for the development of a commercially viable alternative for its enhanced and continuous production. Chemically, azadirachtin is a complex molecule and due to this complexity it is difficult to accomplish its total chemical synthesis in the laboratory. Keeping in consideration all these factors, plant cell culture can be seen as a potential alternative production system. With the cell culture methods, production can be more controlled and the product quality and quantity can be ensured, independent of geographical and climatic barriers. In cell culture, the culture conditions and process variable can be more easily optimized. Cell culture can also offer better selectivity and yield of the desired bioactive compound. In the present study, we made an effort towards systematic selection and screening of elite in vitro cell lines for constant and improved production of azadirachtin. Spilanthes acmella Murr. is an indigenous herb belonging to the family Asteraceae. The genus contains several secondary metabolites which are of therapeutic value and have been widely used in traditional medicine throughout the world, since time immemorial. In spite of being a plant of potential medicinal interest there are only a few scientific reports on the properties of this species. All the biochemical studies carried out, so far, have been done using natural population. As we are aware that environmental fluxes...
Supervisor: Rakhi Chattorvedi
BIOSCIENCES AND BIOENGINEERING