In Vitro Antibacterial Activity of Selected Medicinal Plants in the Traditional Treatment of Skin and Wound Infections in Eastern Ethiopia

Background. External infections involving the skin and wound are the most frequent complications affecting humans and animals. Medicinal plants play great roles in the treatment of skin and wound infections. This study was aimed to evaluate the in vitro antibacterial activity of crude methanolic extracts of nine medicinal plants. Methods. Agar well diffusion and broth dilution methods were used to determine the antibacterial activity of nine Ethiopian plants against four bacterial species including Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, and Klebsiella pneumoniae. Results. Among the tested plants, seven (Cissus quadrangularis, Commelina benghalensis, Euphorbia heterophylla, Euphorbia prostrate, Momordica schimperiana, Trianthema spp., and Solanum incanum) were found to exhibit considerable antibacterial activity against at least one of the test bacteria. The extracts of C. quadrangularis, E. heterophylla, and E. prostrata had a wide spectrum of antibacterial activities against test bacterial strains while the extracts of Grewia villosa and Schinus molle did not show any inhibitory activity. Clinical isolate and laboratory strain of S. aureus showed the highest susceptibility to highest concentration (780 mg/mL) of E. prostrata with a zone of inhibition of 21.0mm and 22.3mm, respectively. Conclusion. This study indicates clear evidence supporting the traditional use of seven plants in treating skin and wound infections related to bacteria.