Challenges and opportunities in drug discovery from plants.

Drug discovery from plants involves a multidisciplinary approach combining botanical, ethnobotanical, phytochemical and biological techniques. Plants continue to provide us new chemical entitities (lead molecules) for the development of drugs against various pharmacological targets, including cancer, HIV/AIDS, malaria, Alzheimer's disease and pain. Several natural-product drugs of plant origin are in clinical use, including paclitaxel, camptothecin-derived analogues, arteether, galanthamine, tiotropium to name a few, and some are undergoing Phase II and Phase III clinical trials. Although plant-based drug discovery programmes continue to provide an important source of new drug leads, numerous challenges are encountered, including procurement and authentication of plant materials, implementation of high-throughput screening bioassays and scale-up of bioactive lead compounds. At the same time, there are opportunities for India as it is rich in genetic resources and traditional knowledge, which are key components for bioprospecting and value-addition. [ABSTRACT FROM AUTHOR]