Medicinal plants of the Washambaa (Tanzania): documentation and ethnopharmacological evaluation

Medicinal plants are an important local resource for the Washambaa of the Western Usambara Mountains in Tanzania. In this study the Washambaa medicinal plants are inventoried. It is based on ethnobotanical fieldwork carried out over 15 months. This study presents for the first time an analysis of medicinal plants used in Africa with a ranking of these taxa by the frequency of their reported use. A total of 328 taxa were collected and yielded 2260 individual use reports. The most popular species are Myrica salicifolia and Toddalia asiatica. Subsequently, the use reports were arranged into 9 groups of medicinal uses based on the types of illness treated. The Factor of Informant Consensus (F(IC)) is used in order to evaluate the ethnobotanical importance of the plants. The largest number of plants and of use reports are in the group of gastrointestinal disorders. For the most commonly used taxa, an ethnopharmacological evaluation was performed. Studies to evaluate the Washambaa therapeutic claims as well as toxicological data are still lacking for many of the species. This study will form the basis for pharmacological and phytochemical research on selected Washambaa medicinal plants.