ANTIMICROBIAL ACTIVITIES OF TWELVE MEDICINAL PLANTS USED FOR THE TREATMENT OF GASTROENTERITIS IN SOUTH AFRICA

This study focused on the in vitro antimicrobial evaluation of South African traditional medicinal plants that are used for the treatment of gastroenteritis. Different parts of twelve plant species were extracted using petroleum ether, dichloromethane, ethanol (70%) and water. Crude extracts were tested using microdilution assays against Gram–positive (Bacillus subtilis, Staphylococcus aureus) and Gram-negative (Escherichia coli, Klebsiella pneumoniae) bacteria as well as Candida albicans. Water extracts showed poor antimicrobial activity. Most solvent extracts exhibited some antimicrobial activity. The ethanol extracts of Becium obovatum leaves showed the best antibacterial activity with a MIC value of 0.074 mg/ml against B. subtilis. The petroleum ether extracts of leaves of Cucumis hirsutus, Haworthia limifolia, and Protea simplex showed good antibacterial activity with MIC values ranging between 0.910 to 0.098 mg/ml against all the test bacteria. Agapanthus campanulatus, Dissotis princeps, Gladiolus dalenii and P. simplex showed activity against C. albicans with MIC values ranging between 0.014 to 0.39 mg/ml. The results obtained in this study show that these plants are indeed effective for the traditional treatment of gastroenteritis problems of bacterial and fungal origins. Acknowledgement: National Research Foundation and University of KwaZulu-Natal.