In Vitro Evaluation of Antibacterial Activities of Selected Ethno-Medicinal Plants from West Shewa Zone

Abstract

An in vitro experimental study was conducted in Ambo University, Mamo Mezemir Campus from November, 2020 to August, 2021 to evaluate antibacterial effect of Leaves of Withania sominifera, steam of Clausena anisata, leaves of Carica papaya L, fruit of Solanum incanum, roots of R. nepalensis and leaves of Nicotiana tabacum against Bacterial species (Escherichia coli/ATCC 25322, Staphylococcus aureus/ATCC 13076, Entrococcus feacalis/ATCC 29212 and Pseudomonas aeruginousa/ATCC 27853). The antimicrobial activities of the extract against test organisms were tested by using agar well diffusion assay, and the MIC and MBC values were determined by agar dilution assay. The results revealed that the methanol extracts of Nicotiana tabacum, Carica papaya, Rumex nepalensis, Solinum incanum and Withania somnifera had the most antibacterial activity against Staphylococcus aereus, Escherichia coli, Enterococcus faecalis, and Pseudomonus aeruginousa. Still, the Methanol extract of Clausena anisata, had no activity against E. coli, E. faecalis and Staphylococcus aeruginousa. The methanol extract of Rumex nepalensis had more activity than other extracts against Staphylococcus aereus, Escherichia coli, Enterococcus faecalis, and Staphylococcus aeruginousa, with MIC ranging from 6.25mg/ml to 25mg/ml and MBCs ranging from 12.5mg/ml to 50mg/ml. Moderate antibacterial activity results have also been recorded from leaves of Withania somnifera and stem of Clausena ansita extract against Staphylococcus aureus (18.83±0.76mm) and (13±0), respectively. The methanolic extract of Carica papaya exhibited maximum activity against Staphylococcus aureus (25.67±0.58 mm) and least towards Escherichia coli (7.67±0.58mm). The main components of plant-derived phytochemicals revealed from present studies are flavonoids, glycosides, tannins, saponins, phenolics, and Phlobatanins. However, Phytosterols were found only in Solinum incanum extracts. Generally, the current experimental study showed that all extracts have antibacterial activities against all tested standard organisms, which play a vital role in substituting resistant drugs, as evidenced by a high zone of inhibition. However, further antibacterial activity tests need to be performed using other methods for those plants that did not show any antibacterial activity in this study.