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TROPICAL FORESTS AND MEDICAL RESOURCES

Tropical forests are biological cornucopias, possessing a stunning array of plant and animal life. Costa Rica, about size of South Carolina, contains as many bird species as all of North America, more species of insects, and nearly half the number of plant species. One stand of rain forest in Kalimantan contains more than 700 species of tree, as many as exist in North America, and half a square kilometre of Malaysia’s forest can feature as many tree and shrub species as the whole of United States and Canada. Forty-three species of ant inhabit in a single tree variety in Peru, dependent on it for food and shelter and providing in return protection from other insects. The tropical forests yield an abundance of chemical products used to manufacture alkaloids, steroids, anaesthetics,  and other medicinal agents. Indeed, one quarter to one half of all modern drugs, including strychnine, quinine, curare, and ipecac, come from the tropical forests. A single flower, the Madagascar periwinkle, produces two drugs used to treat leukemia and Hodgkin’s disease. As significant as these and other modern drugs derived from tropical plants are, scientists believe that the medical potential of the tropical forests remains virtually untapped. They fear that deforestation will eradicate medicinal plants and traditional formulas before their uses become unknown, depriving humans of untold potential benefits that may never be realised. Indigenous peoples make free use of plants of the rain forest for such purposes as treating stings and snakebites, relieving burns and skin fungi, reducing fevers, and curing earaches. Yet botanists have only recently begun to identify tropical plants and study traditional herbal medicines to discover which plants might contain pharmaceutically important compounds. A second concern is that forest destruction will create shortage of drugs already derived from those plants. Reportedly, as many as 60.000 plants with valuable medical properties are likely to become extinct by 2050. Already endangered is reserpine, an ingredient in certain tranquilliser that is derived from the Rauwolfia serpentina plant found in India. Also threatened are cinchona, whose bark produces quinine, and foxglove varieties that are used to make the heart medications digitoxin and acetyldigitoxin.