The use of natural products with therapeutic properties is as ancient as human civilization and, for a long time, mineral, plant and animal products were the main sources of drugs1. Primitive peoples throughout the world made use of their indigenous flora as a source of medicines. Through the process of trial and error, these cultures examined and discovered many plants that produce unique molecular entities with valuable biological properties. Various traditional systems of medicines like Traditional Chinese Medicine, Ayurvedic System of Medicine, Unani System of Medicine, Siddha system of Medicine, Homeopathic system of Medicine, Tibetan Traditional System of Medicine etc. have been exploiting the use of plants for curing various disorders in different parts of the world for thousands of years. Natural products have made an immense contribution to the development of drugs used in modern medicine.