Global resurgence of interest in medicinal plants has resulted in explosive growth of the herbal drug industry. Today modern medicine uses 7,000 compounds that may be sourced to plants. Natural products have until recently been the primary source of commercial medicines and drug leads. A recent survey revealed that 61% of the 877 drugs introduced worldwide can be traced to or were inspired by natural products. Lukewarm results for the search for new compounds from synthetic chemistry and/or combinatorial chemistry has led only recently to a newfound respect for the privileged structures inherent within natural products. The World Health Organization (WHO) estimates that 80% of the population of developing countries relies on traditional medicines, mostly plant drugs for its primary heath care needs. Even the modern pharmacopoeia contains at least 25% drugs derived from plants and many others, which are semi-synthetic, are built on prototype compounds isolated from plants. Medicinal plants are the major components of all indigenous or alternative systems of medicine. Use of indigenous drugs from plant origin forms a major part of complementary and alternative medicine.