Ethnobotany and human health.
From ancient times, plants and herbs have been used in almost all cultures as a major resource of herbal remedies. The widespread use of herbal remedies and healthcare preparations, as described in ancient texts, and obtained from traditional/folklore practices, has been traced to the incidence of natural products with medicinal properties (Anonymous, 2006). <?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" />
Medicinal Plants have served as a major source of new pharmaceutical products and inexpensive preparatory materials for the production of some known drugs. Many components with medicinal properties from plants play an important role in conventional Western medicine (Ya et al., 1998).
About 25% of the Western medicines, issued in the <?xml:namespace prefix = st1 ns = "urn:schemas-microsoft-com:office:smarttags" />USA and Canada are derived from plant based natural products and a large number of secondary metabolites are used globally as drugs (Lev., 2006). Only 15% of all angiosperms have been investigated chemically and 74% of pharmaceutically active plant derived components were discovered after following up on ethnomedicinal use of the plant (Rao, 1996, 2004; Ahmad et al., 2007).
Different parts of medicinal plants are used as medicine by the local traditional healers. Among the different plant parts, the leaves are most frequently used parts for the treatment of diseases, followed by whole plant, fruit, stem, root, stem and root bark, seed, flower and latex. The methods of preparation fall into many categories, viz.: plant parts applied as a paste, juice extracted from the fresh plant parts, and powder made from fresh or dried plant parts, some fresh plant parts, and decoction. External applications (mostly for skin diseases, snakebites, and wounds) and internal consumption of the preparations were involved in the treatment of diseases.
The traditions of collecting, processing, and applying plant and plant-based medications have been handed down from generation to generation. In many countries, traditional medicines are sold in marketplaces or prescribed by traditional healers in their homes. Because of this strong dependence on plants as medicines, it is important to study their safety and efficacy (Pushpangadan, 1995).
The value of ethnomedicine and traditional pharmacology is nowadays achieving great appreciation in modern medicine, because the search for new potential medicinal plants is frequently based on an ethnomedicinal basis (Muthu et al., 2006). In the ethnopharmacological approach, local knowledge about the potential uses of the plants is very useful as compared to the random approach where indigenous knowledge is not taken into consideration. Compounds inhibiting microorganisms, such as benzoin and emetine have been isolated from plants (Dhar et al., 2002; Rao et al., 2004).
In term of the number of species individually targeted, the use of plants as medicine represents the biggest human use of the natural world. Plants provide the predominant ingredients of medicines in most medical traditions (Schippmann et al., 2002). India and China are the world’s leading producing nations of medicinal and aromatic plants (Rao et al., 2004). Estimates for the number of species used medicinally include 35000-70000 plants worldwide, 4900 plants in China, and about 3000 plants in India, (Katewa et al., 2004; Mendonca 2006) (Table 3.1 and Fig: 3.1).
Plants face many stresses in their life cycle and in the process produce secondary metabolites. These secondary metabolites are not important for the metabolic functions of the plant but help to face many stressful conditions like diseases, pests, etc. Some of these secondary metabolites have capacity to fight microorganisms and can be used for medicinal purposes (Anon, 1994; Muthu et al., 2006).
Some estimates suggest that there are more than 250,000 species of higher plants existing on this planet, and only a very small percentage of plants have been exhaustively studied for their potential value as a source of drugs. This behooves us to study these practices of indigenous populations before they are lost, through either human indifference or our relentless ability to change and destroy the vegetation around us (Anon, 1994).
Information on folk medicinal uses of the plants has become of improved interest in search for new therapeutic agent. Huge information on medicinal plants exists as oral among the folklore and primitive societies of India, where a large number of potent medicinal herbs are found growing wild. Although, a huge quantity of ethnobotanical explorations has been done in various pockets of tribal and rural population, scattered throughout the country, but there is still a lot to be explored. Ethnobotanical investigations play crucial role in revealing the information about such plant species that can be source of safer, cheaper, and effective drugs for the benefit of humankind.
According to an estimate 70 percent, inhabitants still rely on herbs in India. Traditional healers are currently using about 2,500 species of plants from about 1000 genera (Jain et al., 2005). Ethnobotanical studies of different areas of Rajasthan state has been carried out by many workers in this field (Singh and Pandey, 1998; Mishra and Kumar, 2000, 2001; Trivedi, 2002; Katewa et al., 2004). Information on the uses of indigenous plants in traditional medicines in rural areas of Churu district has been recently documented by us (Parveen et al., 2007).
The plants of family Euphorbiaceae are mostly monoecious herbs, shrubs, and trees, sometimes succulent and cactus-like. With about 300 genera and 7,500 species, Euphorbiaceae is one of the largest families of plant world, which are further characterized by the frequent occurrence of milky sap. This family occurs mainly in the tropics, with the majority of the species in the Indo-Malayan region and tropical America. However, genus Euphorbia also has many species in non-tropical areas such as the Mediterranean, the Middle East, South Africa, and southern USA (Radcliffe, 1986; Chellaiah et al., 2006). A number of plants of the Spurge family are of considerable economic importance and many are grown as ornamental plants.
In order to document the ethnobotanical uses of some medicinal plants of genus Euphorbia, survey was carried out during the year 2005, in many districts in Thar Desert. The survey was spread across the seasons to get maximum information. The information on medicinal uses of the indigenous plants have been described after gathering information from general local people, experienced aged rural folk, traditional herbal medicine practitioners and local herbal drug sellers and concluded them by consulting literature.