Antimicrobial potency of methanolic leaf extracts from selected medicinal plants against Staphylococcus aureus

Abstract

The main aim of the study was to test for the antimicrobial potency of Aloe secundiflora, Bulbine frutescens, Tagetes minuta and Vernonia lasiopus against Staphylococcus aureus. All the plants showed a pronounced antimicrobial activity against Staphylococcus aureus with Tagetes minuta being the most active at low concentrations (MIC 8.9 mg/ml; MBC 10.0 mg/ml) whereas Vernonia lasiopus showing less activity (MIC 12.2 mg/ml; MBC 14.2 mg/ml). The efficacy test was carried out using the disc diffusion method. The standard antibiotics used were ciprofloxacin (5 µg/ml) and vancomycin (3 µg/ml) showed significant antimicrobial activity by producing zones of inhibition of 22 mm and 25 mm respectively. Dimethyl sulphoxide and distilled water were used as negative control. The extracts from the plants were also screened for the presence of phytochemicals with the results showing the presence of flavonoids, alkaloids, tannins and saponins in all the extracts. The study suggested that the selected medicinal plants can be used effectively in the treatment of bacterial infection caused by Staphylococcus aureus.