The Inclusion and Selection of Medicinal Plants in Traditional Pharmacopoeias-Evidence in Support of the Diversification Hypothesis

The Inclusion and Selection of Medicinal Plants in Traditional Pharmacopoeias-Evidence in Support of the Diversification Hypothesis. An ethnobotanical study with phytochemical analyses was undertaken to examine the medicinal plants used by residents of a small rural community in northeastern Brazil. The present work tested two ideas that attempt to explain the inclusion and selection of medicinal plants in a given culture: the diversification hypothesis and the concept of versatility. The study involved 101 people and used semistructured interviews. A total of 61 plants were selected, including 25 exotic and 36 native species. Plants were classified according to their habit and analyzed for their phytochemical components. In addition, the relative importance (RI) of these plants was calculated, and a chemical diversity index (CDI) was created and applied to each of the species. Exotic and native plants were found to have significantly different occurrences of certain classes of compounds; this result supports the diversification hypothesis. It was therefore concluded that exotic plants are included in traditional pharmacopoeias to fill therapeutic vacancies that native plants cannot satisfy.