Screening of natural products for drug discovery.

The discovery of new biologically active compounds derived from natural products seems to be the main objective of many scientific researchers and pharmaceutical companies. Screening of natural products for this objective with the greatest possibility of success is always needed. Using plants in this area, especially, has a huge advantage owing to their long-term use in health care. In this review, the place of natural products in the therapeutic arsenal is rigorously analysed. The authors also describe and discuss several approaches (essentially biological approaches, including pharmacological and clinical) in selecting and screening natural products as candidates for drug discovery and for drug development. Furthermore, the steps leading from plants to drug discovery are given. In addition, approaches to select plants for biological and/or phytochemical investigation in the laboratory are discussed. Finally, the authors list some of the known drugs and their plant sources.