Medicinal plants potential and use by pastoral and agro-pastoral communities in Erer Valley of Babile Wereda, Eastern Ethiopia

BACKGROUND Ethiopian plants have shown remarkably effective medicinal values for many human and livestock ailments. Some research results are found on medicinal plants of the south, south west, central, north and north western parts of Ethiopia. However, there is lack of data that quantitatively assesses the resource potential and the indigenous knowledge on use and management of medicinal plants in eastern Ethiopia. The main thrust of the present ethnobotanical study centres around the potential and use of traditional medicinal plants by pastoral and agro-pastoral communities in Babile Wereda (district) of eastern Ethiopia. The results can be used for setting up of conservation priorities, preservation of local biocultural knowledge with sustainable use and development of the resource. MATERIALS AND METHODS Fifty systematically selected informants including fifteen traditional herbalists (as key informants) participated in the study. Semi-structured interviews, discussions and guided field walk constituted the main data collection methods. Techniques of preference ranking, factor of informant consensus and Spearman rank correlation test were employed in data analysis. Medicinal plant specimens were collected, identified and kept at the National Herbarium (ETH) of Addis Ababa University and Haramaya University Herbarium. RESULTS Fifty-one traditional medicinal plant species in 39 genera and 28 families were recorded, constituting 37% shrubs, 29% trees, 26% herbs, 6% climbers and 2% root parasites. Leaves contributed to 35.3% of the preparations, roots (18.8%) and lower proportions for other parts. Formulations recorded added to 133 remedies for 54 human ailments, in addition to some used in vector control. The majority of remedies were the juice of single species, mixtures being generally infrequent. Aloe pirottae, Azadirachta indica and Hydnora johannis were the most cited and preferred species. Aloe pirottae, a species endemic to Ethiopia, is valued as a remedy for malaria, tropical ulcer, gastro-intestinal parasites, gallstone, eye diseases and snake bite. The jel extracted from dried and ground plant material, called SIBRI (Oromo language), was acclaimed as a cleaner of the human colon. Concoction made from leaf, seed and flower of Azadirachta indica was given for treatment of malaria, fungal infections and intestinal worms. Root preparations from Hydnora johannis were prescribed as remedy for diarrhoea, haemorrhage, wound and painful body swelling, locally called GOFLA (Oromo language). CONCLUSIONS The study documented many well known and effective medicinal species of relevance for human healthcare, including for the treatment of malaria which is rampant in the area as it is in many parts of Ethiopia. This underscores the importance of the traditional medicinal plants for the people living in the area and the potential of the resource for development. Consequently, the study area deserves urgent conservation priority coupled with mechanisms for the protection of the associated indigenous medical lore as well as development and effective use of the medicinal plant resource.