In Vitro Antimicrobial Activity of Some Medicinal Plants against Human Pathogenic Bacteria

The emergence and spread of antibiotic resistance, as well as the evolution of new strains of disease causing agents, are of great concern to the global health community. Effective treatment of a disease entails the development of new pharmaceuticals or some potential source of novel drugs. Commonly used medicinal plants of our community could be an excellent source of drugs to fight off this problem. This study is focused on exploring the antimicrobial properties of the plants that are commonly being used as traditional medicines. The antimicrobial potential of four different plant extracts was screened against twelve pathogenic microorganisms and two reference bacterial strains. Methanolic extracts of Oxalis corniculata, Artemisia vulgaris, Cinnamomum tamala, and Ageratina adenophora were subjected to a test of their antimicrobial properties by agar well diffusion method. The result indicated that most of the extracts exhibited antimicrobial properties. The highest potential was observed in the extract of O. corniculata against Escherichia coli, Salmonella Typhi, MDR Salmonella Typhi, Klebsiella pneumoniae, and Citrobacter koseri with zone of inhibition (ZOI) of 17 mm, 13 mm, 16 mm, 11 mm, and 12 mm, respectively. Oxalis corniculata also showed the highest MIC against test organisms. The methanolic extract of Artemisia vulgaris, Cinnamomum tamala, and Ageratina adenophora showed efficacy against Staphylococcus aureus. Ageratina adenophora also showed antifungal activity against Rhizopus spp. The experiment confirmed the efficacy of some selected plant extracts as natural antimicrobials and suggested the possibility of employing them in drugs for the treatment of infectious diseases caused by the test organisms.