Commercialization of Andean Wild Yam Species (Dioscorea L.) for Medicinal Use in Bogotá, D.C., Colombia

Abstract

Commercial exploitation of wild yams (Dioscorea spp.) was once a pillar of the Mexican economy and is currently practiced in the USA and Asia. However, no such activity has yet been reported in South America, the continent richest in Dioscorea species. Upon discovery of wild Dioscorea tubers in marketplaces in Bogota, Colombia, we sought to (1) identify the species being sold, (2) document the medicinal properties attributed to them, and (3) conduct a preliminary characterization of the market for this product in the capital. During the years 2010, 2012, and 2013, 226 semi-structured interviews were conducted with vendors in 82 medicinal plant stalls distributed in marketplaces throughout Bogota. Tubers of four native species were identified, all wild-harvested: Dioscorea coriacea, Dioscorea lehmannii, Dioscorea meridensis, and Dioscorea polygonoides; all were sold under the generic name zarzaparrilla, with D. coriacea being the most prevalent species. All vendors interviewed recommended Dioscorea spp. for treating “ailments of the blood,” with “blood cleanser,” and lowering triglycerides and cholesterol as the most often-cited specific uses. Total estimates of sales of wild yams over the study period averaged 488 kg/week, extrapolated to over 25,000 kg/year, with yearly sales varying between 5% and 6% around the mean. This is the first report of raw tubers of any Dioscorea species being commercialized for the treatment of blood or metabolic disorders in Latin America, and the data suggest there is a robust market established in Bogota. In the interest of public health, pharmacological studies should be undertaken to test the biological activity of these species and to rule out toxicity. We especially recommend population studies of D. coriacea to provide baseline data for sustainable management of this non-timber forest product.