Production of Medicinal Plants in Asia

Medicinal plants have played a significant role in many ancient traditional systems of medication in Asia such as the Ayurvedic and Unanic systems of India, the Chinese traditional medicine, as well as their derivatives in most Asian countries. At present, medicinal plants still play an important role in both developed and developing countries in Asia. In addition, they also generate income to the people of many Asian countries who earn a living from selling collected materials from the wild or through their own cultivation. Asia is unique among geographical regions of the world since it possesses (I) high biological diversity, (ii) high cultural diversity, (iii) diverse ancient civilizations, and (iv) abundant raw material for modern drug manufacturing. Collecting naturally-occurring medicinal plants has taken place in Asia since prehistoric time. At present, such activity, although limited in amount in most countries, is still carried on with the objectives of using them in traditional medicine or for processing into pharmaceutical products. Such activity generates income to the native people, provides raw material at a low cost, and access to material not available through cultivation. However, collection also creates problems in genetic erosion, especially with uncontrolled collection, and thus unsustainability. Cultivation of medicinal plants in Asia is characterized by the following criteria: (i) subsistence cropping systems, (ii) scattered farming areas, (iii) poor quality, and (iv) lack of integration. The advantages of commercial cultivation of medicinal plants include: (i) helping to conserve endangered species in their natural habitat, (ii) permitting production of uniform materials, (iii) providing good income to the farmers, (iv) providing opportunities for value-addition through processing, (v) providing a better environment through utilizing waste and unproductive lands, and (vi) providing continuity of supply. As compared to other economic crops, medicinal plants have received much less attention in genetic and cultural improvements. Only a few countries in the Region are now cultivating improved cultivars, while the rest still depend on wild material collected for cultivation. Their cultivation techniques are quite primitive, resulting in poor yield and quality of the materials. Several constraints are envisaged, e.g. biotic (unimproved cultivars, long life cycle, susceptability to pests and diseases), abiotic (low soil fertility, flood and drought, improper light intensity and duration, extremes of temperatures, and physical injuries or damage), technological (lack of good agronomic practices, lack of technology and technology transfer, and lack of facilities) and socio-economic (competition with other economic crops and modern drugs; lack of market channels, a domestic pharmaceutical industry, and organized cultivation; and no price support/incentive provided). In spite of the above constraints, medicinal plants continue to play a significant role in the welfare of people in Asia. Due to higher demand of raw material for industrial processing, coupled with the loss of natural habitats of most medicinal plants, large-scale cultivation of promising species has recently been attempted in several countries. Proc. WOCMAP III, Vol. 5: Quality, Efficacy, Safety, Processing & Trade in MAPs Eds. E. Brovelli, S. Chansakaow, D. Farias, T. Hongratanaworakit, M. Botero Omary, S. Vejabhikul, L.E. Craker and Z.E. Gardner Acta Hort. 679, ISHS 2005 46 INTRODUCTION Medicinal plants are those that possess certain chemicals that are active in treating and preventing specific ailments and diseases. Such chemicals can be extracted for the manufacture of pharmaceutical products. Medicinal plants have played a significant role in various ancient traditional systems of medication such as the Ayurvedic and Unanic systems of India, the Chinese traditional medicine, and their derivatives in many Asian countries. At present, medicinal plants still play an important role in developing countries in Asia, both in preventive and curative treatments, despite advances in modern western medicine. They also generate income to the people of many Asian countries who earn a living from selling collected materials from the forest, or who cultivate them on their lands. The development of modern medicine since the turn of the century, supplemented with the introduction of modern drugs produced by pharmaceutical companies, have dealt a strong blow to traditional medicine which was accused as being inefficient, laborious in preparation and, most important of all, unavailable due to scarcity of raw material. This is exacerbated by the lack of traditional doctors who cannot earn a living without basic materials (i.e. medicinal plants) and demand (i.e. customers). The high cost of modern drugs (most of which have to be imported from the West), their unavailability in remote areas, and, most important of all, the serious side effects of certain drugs, have all made the pendulum of medical treatment swing back to the side of traditional medicine in recent years. The importance and value of traditional and indigenous herbal medicine were the subject of WHO’s campaign during the 70’s which led to an appeal to all member countries to do their utmost to preserve their national heritage in the form of ethno-medicine and ethno-pharmacology and to reinclude the use of known and tested medicinal plants and derivatives into their primary health care in rural areas, as well as an alternative when modern medicine was not available. Moreover, since a large portion of drugs produced by pharmaceutical industry are derived from medicinal plants, the demand for these raw materials is steadily rising. Such demand is met by obtaining naturally-occurring plants through indiscriminate collecting, or by cultivating them. ASIA: THE LAND OF MEDICINAL PLANTS Asia is unique among geographical regions of the world since it possesses the following tropical ranging from tundra to deserts and rainforests characters: High Biological Diversity Due to its widely diversified ecological conditions, particularly in the tropical rain forests, it has a biological diversity that is the greatest of all regions of the world. This high diversity of the Region is reflected by the number of species of plants and animals, including medicinal plants. High Cultural Diversity Not only is Asia rich in biological diversity, it is also quite rich in cultural diversity. Since the dawn of human history, biodiversity and humanity have become inextricably linked. Areas of high biological diversity are among the most culturally disparate, with large numbers of distinct communities inhabiting adjacent areas, each with their own language, culture, and system of traditional medicine. The last category depends on the availability of medicinal plants easily found within the community. A wealth of traditional knowledge about medicinal plants to cure illness has been accumulated over a long period and has been handed down from generation to generation until the present time. Ancient Civilizations Parallel with cultural diversity that took place in isolated areas in the jungles of tropical Asia was the existence of ancient civilizations in East and South Asia. Unlike the