Ethnobotany and its role in drug development.

The botanical collections of early explorers and the later ethnobotany have played important roles in the development of new drugs for many centuries. In the middle of the last century interest in this approach had declined dramatically, but has risen again during its last decade, and new foci have developed. The systematic evaluation of indigenous pharmacopoeias in order to contribute to improved health care in marginalized regions has been placed on the agenda of international and national organizations and of NGOs. In this paper the results of various projects on Mexican Indian ethnobotany and some of the subsequent pharmacological and phytochemical studies are summarized. Medicinal plants are an important element of indigenous medical systems in Mexico. This study uses the medicinal plants in four indigenous groups of Mexican Indians-Maya, Nahua, Zapotec and Mixe-as an example. The relative importance of a medicinal plant within a culture is documented using a quantitative method and the data are compared intra- and interculturally. While the species used by the indigenous groups vary, the data indicate that there exist well-defined criteria specific for each culture, which lead to the selection of a plant as a medicine. For example, a large number of species are used for gastrointestinal illnesses by two or more of the indigenous groups. At least in this case, the multiple transfers of species and their uses within -Mexico seems to be an important reason for the widespread use of a species. Some of the data we gathered in order to evaluate the indigenous claims are also discussed, focusing on the transcription factor NF-kappaB as a molecular target. This led to the identification of sesquiterpene lactones such as parthenolide as potent and relatively specific inhibitors of this transcription factor.