Invitro Antibacterial Screening of Extracts from Selected Ethiopian Medicinal Plants

Abstract

Indigenous knowledge, literature reports and ethnobotanical records suggest that plants are the basis for medicines. They constitute natural source of antimicrobial drugs that will provide novel or lead compounds for the fight against disease. In this study, the antimicrobial activity of three selected Ethiopian medicinal plants was studied with the objective of screening their antibacterial activity. The fruits of Measalanceolata, aerial part of Cissus quadrangularis and leaf of Dodonae angustifolia were collected, air dried under shed, powdered and soaked in 80% methanol and extracted. In vitro antibacterial activity of the extracts was tested at different concentrations by using agar disc diffusion method and measuring the zone of inhibition. The plant extracts showed broad spectrum activity against gram positive (S. aureus) as well as gram negative (E. coli) bacteria, except Cissus quadrangularis which did not show any activity against E. coli. Furthermore, the plant extracts had also concentration dependant zone of inhibition against the tested bacteria. In fact, the highest activity was obtained for Dodonae angustifolia at 1000mg/ml against S. aureus. The activities are attributed to the presence of some secondary metabolites present in the tested plants which have been associated with antibacterial activities. This finding suggests that these medicinal plants can be potential source to isolate antibacterial drugs.