Since ancient times, mankind has been dependent on plants for food, flavours,
medicinal and many other uses. Ancient written records of many civilizations (i.e.
Egyptian, Roman, Chinese) give strong evidence regarding use of medicinal plant
[1],for example ayurveda documents record the use of medicinal plants to cure many
ailments [2-3].
At present there are many well established herbal and plant medicine practices
(Ayurvedic medicine in India) which are popular in many parts of the world. The
World Health Organisation (WHO) reported that 80% of people in the developing
world use medicinal plants for their primary health care [4]. Table 1, shows some
important medicinal plants with their key metabolites and uses.
The use of herbal medicines is growing in developed countries, presently 25% of the
UK population use herbal medicine [4-5]. About 40% of compounds used in
pharmaceutical industry are directly or indirectly derived from plants [6-7] because
the chemical synthesis of such compounds is either not possible and/or economically
not viable [8]. Therefore a large number plant species (especially medicinal) are
under threat of extinction because of their over exploitation [4, 7, 9].