Contents lists available at ScienceDirect Journal of Herbal Medicine journal homepage: www.elsevier.com/locate/hermed Research paper Antibacterial activity of selected medicinal plants used by traditional healers in Genta Meyche (Southern Ethiopia) for the treatment of gastrointestinal disorders Awoke Guadie a,c,d , Demisse Dakone a , Dikaso Unbushe b , Aijie Wang c , Siqing Xia d, * a Department of Biology, College of Natural Sciences, Arba Minch University, P.O.Box. 21, Arba Minch, Ethiopia b Department of Biology, College of Natural and Computational Sciences, Jinka University, P.O.Box. 165, Jinka, Ethiopia c Key Laboratory of Environmental Biotechnology, Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China d State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China ARTICLE INFO Keywords: Antibacterial activity Genta Meyche Gastrointestinal disorder Medicinal plant ABSTRACT 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 semi- structured 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 con- centration (MIC) values ranging from 7.40 ± 0.60 − 16.81 ± 2.03 mm and 156 − 2500 μg/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. 1. Introduction Gastrointestinal disorders (GIDs) are a common human health problem in both developing and developed countries (Johns et al., 1995). Among GIDs, functional digestive disorders are the most pro- minent with about 50 % of patients who refer to gastroenterology care centers suffering from them (Bahmani et al., 2014). These disorders often lead to diarrhea, nausea, vomiting, fever, abdominal pain, in- testinal inflammation, bloating and flatulence, or systemic diseases (Ahmed et al., 2013). Diarrhea is a major GID caused by a host of bacterial, viral and parasitic organisms, most of which are spread by contaminated water and food (Bahmani et al., 2014; Kadir et al., 2013; Singh et al., 2016). Rotavirus and Escherichia coli are the two most etiological agents of diarrhea in developing countries (WHO, 2013). Some of the other pa- thogenic bacteria which cause GIDs (diarrhea) include Escherichia coli, Salmonella typhi, Bacillus cereus, Staphylococcus aureus, Enterococcus feacalis, Campylobacter jejuni, Aeromonas hydrophila, Shigella spp., Yer- sinia spp. and Vibrio cholera (Fabry et al., 1998; Pendota et al., 2013; Singh et al., 2016). Giardia intestinalis and Cryptosporidium parvum are also major parasitic organisms that cause diarrheal disease (Johns et al., 1995). The World Health Organization (WHO) estimated approximately 1.7 billion cases of diarrhea worldwide per year in 2013, with these causing 6.9 % of deaths overall (WHO, 2013). In 2004, diarrheal https://doi.org/10.1016/j.hermed.2020.100338 Received 19 December 2016; Received in revised form 20 January 2020; Accepted 27 January 2020 ⁎ Corresponding author. E-mail address: siqingxia@gmail.com (S. Xia). Journal of Herbal Medicine xxx (xxxx) xxxx 2210-8033/ © 2020 Elsevier GmbH. All rights reserved. Please cite this article as: Awoke Guadie, et al., Journal of Herbal Medicine, https://doi.org/10.1016/j.hermed.2020.100338