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Saving What Remains
MEDICINAL DRUGS / RAINFOREST CURES
July 22, 2007
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The rainforest may someday provide the cure for AIDS, pancreatic cancer, antibiotic-resistant staph infections, lassa fever, or Alzheimer's disease, if given the chance to do so. Unfortunately, as primary forest cover is diminished by
1-2 percent every year, it is projected that 20-25 percent of the world's plant species will be extinct by the year 2015. Perhaps
in some remote Andean valley, slated for destruction today, lives a rare orchid which has developed an anti-viral
chemical that kills HIV, halts cancer, or slows aging. In addition, the shamans who provide much of the insight
into identifying these plants and their uses, are disappearing at an even faster rate as their villages seek a
more Western lifestyle. These shamans are generally elders and when they die, their unique knowledge of traditional
uses of rainforest plants will die with them.
Some organizations are trying to prevent the loss of medicinal knowledge when indigenous elders die. The Terra
Nova Rainforest Reserve is the first ethnomedicinal forest reserve designed to ensure that medicinal plants will be
available for local use. The reserve encourages the use of such plants and has also implemented a program teaching
youths about uses of medicinal plants so this knowledge will not die, but be passed on to future generations and
researchers.
National botanical gardens, like those of Missouri and New York, are playing an important role in propagating medicinal
plants that are either threatened in the wild or so rare that collection cannot satisfy demand. Several gardens
have propagated such medicinal plants and freely distributed seedlings to peasants who can integrate them into
their traditional food crops. The plants can provide substantially more cash than many traditional crops like bananas,
coffee, and cocoa.
Animals as an inspiration for drugs
Animals also provide compounds useful to humans as medicinal drugs. Both leeches and vampire bats have powerful
anticoagulants they use in feeding on their prey. From the saliva of the leech comes hirudin, which is now used
to dissolve blood clots in humans. The vampire bat has a salival substance that can be used to prevent heart attacks.
The slimy secretions of frogs are used to treat infections, mental disorders, and even HIV, while scientists hope that
one day blood from the ubiquitous (in the western U.S.) western fence lizard (more popularly known as the "blue-belly")
will help prevent or cure Lyme disease. ABT-594 is an experimental painkiller derived from the skin secretions of Epipedobates tricolor, a colorful poison arrow frog, and crocodile blood is being examined for its anti-HIV properties.
Plant-derived medications. (Photo by R. Butler)
Review questions:
Why are plants a good potential source for natural pesticides?