Analysis of the antibacterial potentials of the leaf extracts of selected medicinal plants against pathogenic bacterial strains

Abstract

Medicinal plants render herbal remedies for human ailments and hence prevail over traditional healthcare practices. This study has analysed the antibacterial potential of the leaf extracts of four selected medicinal plants namely, Azadirachta indica, Ocimum tenuiflorum, Biophytum sensitivum, and Mimosa pudica, using Kirby-Bauer’s disc diffusion method. Six bacterial species, namely Escherichia coli, Pseudomonas aeruginosa, Acinetobacter baumannii, Bacillus megaterium, Bacillus subtilis, and Brevibacillus choshinensis were used to assess the growth inhibitory potentials of the aqueous and ethanolic extracts of the selected plant leaves. The study revealed that the leaf extract of B. sensitivum had the most pronounced antibacterial potential, followed by A. indica and O. tenuiflorum. The least inhibitory potential was showed by the extracts of M. pudica. The findings of the investigation state that the aqueous extract had more consistent antibacterial activity than the ethanolic extracts, confirming that the antibacterial agents present in these leaf extracts are hydrophilic in nature. In terms of growth inhibition, the susceptibility of the pathogenic, virulent strains of bacteria toward these extracts was found comparatively lower than that of the non-virulent, environmental bacteria. With the aqueous extracts, A. baumannii was found to be the most susceptible bacterial species while E. coli was the most resistant. With the ethanolic extracts, E. coli was found to be the most susceptible and B. subtilis the least. The current study supports the usage of the screened medicinal plants in alternative medical practices, as a measure to avoid opportunistic infections by environmental bacteria.