Antibacterial activity of selected medicinal plants used by traditional healers in Genta Meyche (Southern Ethiopia) for the treatment of gastrointestinal disorders

This study was designed to investigate the antibacterial activity of selected medicinal plants used by the Genta Meyche community in Southern Ethiopia. Ethnomedicinal data was collected from 25 herbalists through semistructured interviews and observations. Based on the highest use value (UV), plants were selected to be tested on pathogenic bacteria. A total of 26 ethnomedicinal plant species belonging to 17 families were collected and identified. The extraction of active compounds from the selected plants was carried out using five solvents. Roots (30.8 %) and leaves (26.9 %) were the plant parts most frequently used for the treatment of gastrointestinal disorders (GIDs). Herbalists mostly prepared medicinal plants as juice (57.7 %) and administered the juice through oral routes (92.3 %). Solanum incanum L. (UV = 0.44), Harrisonia abyssinica Oliv. (UV = 0.36), Hydnora abyssinia A.Br. (UV = 0.36) and Leucas aspera (Willd.) Link. (UV = 0.32) were found to be the most frequently used medicinal plants in the study area. These plants showed a promising broad spectrum of activity against Gram-positive and Gram-negative test bacteria with growth inhibition zone and minimum inhibition concentration (MIC) values ranging from 7.40 +/- 0.60 (-) 16.81 +/- 2.03 mm and 156 (-) 2500 mu g/mL, respectively. Among solvents, ethanol and ethyl acetate extracts showed significantly greater antibacterial activity than aqueous, acetone and chloroform extracts. Steroids, tannins, saponin, flavonoids, alkaloids and terpenoids were identified as bioactive compounds in most of the tested plants. Unused parts of Solanum incanum L. and Harrisonia abyssinica Oliv. were investigated and results exhibited potential candidacy with inhibition zones of 7.1 (-) 13.7 and 10.2 (-) 15.3 mm, respectively. Overall, the results of this study provide evidence for the treatment of GIDs by using traditional medicinal plants used by the Genta Meyche community to act against pathogenic bacteria.