Ethnomedicinal study of plants used for human ailments in Ankober District, North Shewa Zone, Amhara Region, Ethiopia

BACKGROUND Ankober District has long been inhabited by people who have a long tradition of using medicinal plants to treat human ailments. Overexploitation of medicinal plants coupled with an ever-increasing population growth, deforestation and agricultural land expansion threatens plants in the area. Hence, this study aimed at documenting and analyzing the plant-based ethnomedicinal knowledge of the people in order to preserve the dwindling indigenous knowledge. METHODS Ethnobotanical data were collected using semi-structured interviews, focus group discussions, participant observation and walk-in-the-woods. Quantitative approaches were used to determine Informant Consensus Factor (ICF) and Fidelity level (FL) values. Statistical tests were used to compare the indigenous knowledge on medicinal plants among different informant categories. RESULTS A total of 135 medicinal plant species belonging to 128 genera and 71 botanical families were reported to treat human diseases in the District. Families Asteraceae (12 species, 9%) and Fabaceae (10, 7.4%) were found to be best represented in the area. About 44% of preparations were reported to be obtained from roots. Significant difference (P < 0.05) was observed on the mean number of medicinal plants reported by groups of respondents compared within age, literacy level and experience parameters. Highest ICF values were recorded for gastro-intestinal & parasitic and dermatological disease categories (0.70 each) indicating best agreement among informants knowledge on medicinal plants used to treat aliments in these categories. Highest fidelity level values were recorded for Zehneria scabra (95%) and Hagenia abyssinica (93.75%) showing conformity of knowledge on species of best healing potential. Podocarpus falcatus was ranked first in a direct matrix ranking exercise of multipurpose medicinal plants. The output of preference ranking exercise indicated that Olea europaea subsp. cuspidata was the most preferred species to treat atopic eczema. CONCLUSION The study revealed that Ankober District is rich in medicinal plant diversity and associated indigenous knowledge. However, anthropogenic factors coupled with acculturation and very poor conservation efforts threaten medicinal plant survival in the area. Promoting a complementary in situ and ex situ conservation strategy for medicinal plants of the District is highly recommended.