Medicinal Treasures of the Rainforest
A look at the botanical treasures, both known and undiscovered, that exist within tropical rainforests.
The widespread destruction of tropical rainforest ecosystems and the consequent extinction of numerous plant and animal species is happening before we know even the most basic facts about what we are losing.
Covering only 6 percent of the Earth's surface, tropical moist forests contain at least half of all species. The abundant botanical resources of tropical forests have already provided tangible medical advances; yet only 1 percent of the known plant and animal species have been thoroughly examined for their medicinal potentials. Meanwhile, 2 percent of the world's rainforests are irreparably damaged each year. Scientists estimate that, at the accelerating rate at which rainforests are now being destroyed, as much as 20 or 25 percent of the world's plant species will be extinct by the year 2000.
Approximately 7,000 medical compounds prescribed by Western doctors are derived from plants. These drugs had an estimated retail value of US$43 billion in 1985. Seventy percent of the 3000 plants identified by the United States National Cancer Institute as having potential anti-cancer properties are endemic to the rainforest. Tropical forest species serve Western surgery and internal medicine in three ways. First, extracts from organisms can be used directly as drugs. For maladies ranging from nagging headaches to lethal contagions such as malaria, rainforest medicines have provided modern society with a variety of cures and pain relievers.
• Quinine, an aid in the cure of malaria, is an alkaloid extracted from the bark of the cinchona tree found in Latin America and Africa.
• From the deadly poisonous bark of various curare lianas, used by generations of indigenous peoples in Latin America, has been isolated the alkaloid d-turbocuarine, which is used to treat such diseases as multiple sclerosis, Parkinson's disease and other muscular disorders. It also permits tonsillectomies, eye, abdominal and other kinds of surgery due to its anesthetic qualities.
• From Africa, Madagascar's rosy periwinkle provides two important anti-tumor agents. One provides for a 99 percent chance of remission in cases of lymphocytic leukemia. The other offers a life in remission to 58 percent of Hodgkin's Disease sufferers. In 1960, only 19 percent had a chance for survival. Commercial sales of drugs derived from this one plant are about US$160 million a year.
• Without wild yams from Mexico and Guatemala, society would be without diosgenin and cortisone, the active ingredients in birth control pills. Until recently this plant provided the world with its entire supply of diosgenin.
Secondly, chemical structures of forest organisms sometimes serve as templates from which scientists and researchers can chemically synthesize drug compounds. For example, the blueprint for aspirin is derived from extracts of willow trees found in the rainforest. Neostigmine, a chemical derived from the Calabar bean and used to treat glaucoma in West Africa, also provides the blueprint for synthetic insecticides. However, the chemical structures of most natural drugs are very complex, and simple extraction is usually less expensive than synthesis. Ninety percent of the prescription drugs that are based on higher plants include direct extractions from plants.
Finally, rainforest plants provide aids for research. Certain plant compounds enable scientists to understand how cancer cells grow, while others serve as testing agents for potentially harmful food and drug products. Tropical forests offer hope for safer contraceptives for both women and men. The exponential growth of world population clearly demonstrates the need for more reliable and effective birth control methods. Worldwide, approximately 4,000 plant species have been shown to offer contraceptive possibilities. The rainforest also holds secrets for safer pesticides for farmers. Two species of potatoes have leaves that produce a sticky substance that traps and kills predatory insects. This natural self-defense mechanism could potentially reduce the need for using pesticides on potatoes. Who knows what other tricks the rainforest might have up its leaves?
Shamans and Indigenous Peoples
The chemical components of plants that medicine men use in healing rites could conceivably be building blocks for new drugs or even cures for such scourges as cancer or AIDS.
For thousands of years, indigenous groups have made extensive use of the materials contained in the rainforest to meet their health needs. Forest dwellers in Southeast Asia, for example, use around 6,500 different plants to treat their ills. Shamans were the first medical specialists in indigenous communities, and their traditional methods are known to be effective in treating both physical and psychological ailments. The World Health Organization estimates that 80 percent of the people in developing countries still rely on traditional medicine for their primary health care needs. Without money, access to, or faith in modern facilities, indigenous people depend on shamans, herbal healers, and rainforest plants for their survival. Shamans also play a crucial role in helping scientists to discover the potentials of plants. As one scientist has said, "Each time a medicine man dies, it is as if a library has been burned down. There is much yet to be learned from local shamans, yet their individual and cultural survival is seriously threatened as modern loggers, miners, multinational corporations, and landless farmers invade and decimate the forest.
What You Can Do
Tropical forest plants serve as vital resources for the eradication of disease, but we could easily lose these plants as well as the traditional knowledge that can unlock their potential if tropical ecosystems and indigenous cultures are not preserved intact. The future health and welfare of humanity will be determined, to a great extent, by the fate of the rainforests. There are no easy answers to the social and environmental crises facing the rainforest today. But one important step towards saving the rainforest is to increase public recognition of the importance of rainforest medicines in our modern pharmacopoeia and the importance of preserving the primary habitats of these flora. You can do your part by educating yourself and others about the rainforests and the forces that are destroying them. Countless books and environmentally friendly travel opportunities exist, such as research documentation and in-depth Amazon tours.
Notes and other sources:
The Unseen Garden: Research at the Missouri Botanical Garden. St. Louis: Missouri Botanical Garden, 1987.
Jackson, D. "Searching for Medicinal Wealth in Amazonia." Smithsonian. February 1989.
Plotkin, M. "The Outlook for New Agricultural and Industrial Products from the Tropics." In E.O. Wilson, ed. Biodiversity. Washington D.C.: National Academy Press, 1988.
Caufield, C. In the Rainforest. Chicago: University of Chicago Press, 1984.
Farnsworth, N. "Screening Plants for New Medicines." In E.O. Wilson, ed. Biodiversity. Washington D.C.: National Academy Press, 1988.
Peterson, D. The Deluge and the Ark. Boston: Houghton Mifflin, 1989.
Information aquired from Rainforest Action Network