ABSTRACT
Plant medicine is a broad category of medicaments which include drugs used in traditional systems of medicine, folklore and ethnomedical products, as well as drugs discovered from plants having no documented therapeutic use. There has been a resurgence of interest in the development of new drugs from plant sources. A broad-based programme of biological screening of medicinal plants was initiated at the Central Drag Research Institute, Lucknow, in 1963 and the first results were reported in 1968. Once activity is detected it has to be reconfirmed in one of the primary fractions before selecting the plant for detailed study. In addition to identifying the type of central nervous system (CNS) effects it also provides some indication of therapeutic index or safety margin. Moreover, data on standard compounds having various type of CNS activity have been generated and a quantitative assessment of activity of a new test material is therefore possible even during the initial screening tests.
