Medicinal plants: traditions of yesterday and drugs of tomorrow.

Plants have provided Man with all his needs in terms of shelter, clothing, food, flavours and fragrances as not the least, medicines. Plants have formed the basis of sophisticated traditional medicine systems among which are Ayurvedic, Unani, Chinese amongst others. These systems of medicine have given rise to some important drugs still in use today. Among the lesser-known systems of medicines are the African and Australian, Central and South American amongst others. The search for new molecules, nowadays, has taken a slightly different route where the science of ethnobotany and ethnopharmacognosy are being used as guide to lead the chemist towards different sources and classes of compounds. It is in this context that the flora of the tropics by virtue of its diversity has a significant role to play in being able to provide new leads. Nonetheless the issue of sovereignty and property rights should also be addressed in line with the Convention for Biological Diversity (CBD). This paper highlights the above, provides an overview of the classes of molecules present in plants and gives some examples of the types of molecules and secondary metabolites that have led to the development of these pharmacologically active extracts. The paper also presents some data on the use of plant products in the development of functional foods, addresses the needs for validation of plant extracts and always stressing on safety, efficacy and quality of phyto-medications.