Ethnopharmacology

Ethnopharmacology is the cross-cultural study of how people use plants, animals, fungi, or other naturally occurring resources for medicinal purposes. Such knowledge provides the basis for the herbal remedy industry and has led to the development of at least 121 pharmaceuticals. Often, this involves observation of how a traditional remedy is used; then, the effective chemical compound is isolated in a laboratory for commercial production. In an early example, the French naturalist Jean B. C. T. Leschenault de la Tour brought a plant of the genus Strychnos to France in 1805, based on its indigenous use in poison arrows in the South Pacific. French chemists isolated strychnine, an alkaloid still widely used in medicine. Pharmacologists have investigated thousands of different plants to derive drugs used for birth control, surgery, malaria, asthma, heart disease, and many other medical applications.

Ethnopharmacology is used as an argument for conserving cultural and biological diversity. “Bio-prospecting” refers to collaboration among drug companies, anthropologists, or biologists searching for new drugs. Some human rights organizations call this “biopiracy,” because indigenous knowledge is exploited for profit, and they have succeeded in stopping research projects. The search for new drugs using indigenous knowledge may become obsolete due to new technologies that allow pharmacologists to rapidly isolate chemical compounds from natural sources and screen them for medicinal potential regardless of their use as folk remedies. Also, traditional medicinal knowledge may be disappearing as indigenous populations integrate with the global economy.

Not all anthropologists or pharmacologists believe that indigenous knowledge is useful for finding medical cures. Some argue that there are too many symbolic treatments targeted at satisfying emotional needs that have no biochemical basis—known as the “placebo effect.” Alternatively, Makoto Taniguchi and Isao Kubo showed that knowledge of traditional African healers was at least four times more likely to produce useful compounds than a random selection of plants from the same environment. Anthropologist Nina L. Etkin argued that a fundamental cross-cultural problem is that indigenous peoples often have different symbolic interpretations of an illness that may be biologically identical to a medically defined illness. She suggested that ethnopharmacologists analyze the complete cultural process of curing, rather than focusing only on which plants are used.

Ethnopharmacology has important implications for evolutionary theory. Plants evolve toxic chemicals as defenses against herbivores. Kenneth E. Glander, [Page 862]Barry A. Bogin, and Timothy A. Johns have argued that higher primates evolved in biologically diverse environments and used taste to optimize nutritional intake, while minimizing toxins. Knowledge of beneficial toxins that reduce parasites is transmitted through primate troops. Higher cognitive abilities of humans allow for symbolic interpretation of taste and illness symptoms and more complex cultural transmission. Johns argues that agriculture reduced dietary diversity, increasing the need to culturally identify beneficial toxins. Contrary to the popular notion that rain forests harbor the greatest medicinal potential, John R. Stepp and Daniel E. Moerman have shown that indigenous people rely heavily on weeds growing in agricultural areas or near houses for medicines.