Biodiversity and Human Health: The Benefits of Studying Medicinal Plants and Ethnobotany, page 1

Ethnobotany is the study of the cultural knowledge of plants, including plants for medicinal uses. Traditional peoples around the world possess unique knowledge of the natural resources on which they depend, including tremendous botanical expertise. Indigenous peoples are the "faculty", keepers of the cumulative knowledge of generations; the plants they utilize are the "stockroom" of potential medicines.

Fewer than 1% of indigenous cultures have been surveyed for their knowledge of medical plants and other natural products.

Many of the plant-derived drugs used today in modern medicine were originally discovered through the study of the folk medical knowledge of indigenous peoples. For example, in the sixteenth century the Spanish invading the Inca empire in Peru discovered that the Indians used the bark of a rain forest tree, Cinchona species, to treat fevers. This bark became the source of quinine used worldwide for the treatment of malaria -- until quinine-resistant malaria developed in recent years in some regions, necesitating the switch to Mefloquine and other derivatives (Balick and Cox 1996).

Historically, in the search for new medicines, the average success rate for identifying useful medicines from plants is one in 125. The success rate for new drugs from randomly synthesized chemicals is only one in 10,000 (Farnsworth, in Chadwick and Marsh 1994). So looking for new medicinal compounds from natural sources, especially plants, makes a great deal of sense -- and leads to savings of both time and money. When native healers from indigenous societies can be recruited to assist in these efforts, the success rates are even higher. But at the current rate of worldwide ecological destruction -- which includes an extinction rate one hundred to a thousand times faster than before the arrival of Homo sapiens -- we may be forever losing potentially lifesaving new medicines.

As a global community, we are now in the midst of a crisis in loss of biological and cultural diversity. The current ongoing loss of biodiversity is the greatest contraction of life since the end of the Mesozoic Era sixty-five million years ago -- a wave of extinctions that extinguished the dinosaurs (Wilson 1992). Although prehistoric extinction spasms tended to claim mostly animals, plants too are now threatened with extinction on a large scale. One-fourth of all tropical plants may be wiped out in the next 30 years. Outside the tropics, the greatest concentration of threatened plants is found in southern Africa, where 13% of endemic plants are threatened. In southwestern Australia, two-thirds of plant species are endangered by a fungal disease carried by humans walking or driving through the bush. In the US nearly 1 in 8 native species is in danger. According to the 1997 IUCN Red List of Threatened Plants compiled by the World Conservation Union, worldwide 13.8% of vascular plants are imperiled. In addition, much of earth's biodiversity is clustered in tropical regions. Many of these "hotspots" of diversity are populated by indigenous peoples. Today most of the world's indigenous peoples are as imperiled as their homelands, threatened by loss of habitat and westernization.

Balick, Michael J and P.A. Cox. 1996. Plants, People, and Culture: The Science of Ethnobotany. New York: Scientific American Library.

Chadwick, Derek J. and J. Marsh, eds. 1994. "Ethnobotany and the Search for New Drugs," Ciba Foundation Symposium 185. John Wiley and Sons.

Wilson, E.O. 1992. The Diversity of Life. Cambridge, Mass.: The Belknap Press of Harvard University Press.

The Benefits of Studying Medicinal Plants and Ethnobotany  by Kimberly Johnson, MD

The Benefits of Studying Medicinal Plants and Ethnobotany
by Kimberly Johnson, MD