The use of plants to heal or combat illness is as old as mankind. Since age long, plants have remained the basis for the development of modem drugs for human health. Medicinal plants are considerably useful and economically essential. They contain active constituents which are used in the treatment of many human diseases. Besides being used as direct remedies, they are also used in the pharmaceuticals, agriculture, cosmetics, perfumery and food industries.
Pharmaceuticals mainly use plants containing known medically effective chemical substances which are first isolated from the plants and then used in the manufacture of drugs. Among these active substances include ephedrine which is extracted from the Chinese herb, Ma Huang, is used to ease the difficult breathing of Asthma sufferers. Ginseng from the root of panax ginseng, a perennial herb has been widely used as a toxic and precious medicine since ancient times. This substance is effective for gastroenteric disorders, diabetes and weak circulation and has equally been used as adjuvant to prevent various disorder. Ginseng has been shown to contain various saponins and sapogenins.