Study of the efficacy of the Alcoholic Extract of Lavandula stoechas L. leaves against Some Pathogenic Bacteria

Abstract

This study aimed to evaluate the antibacterial activity of the ethanolic extract of Lavandula stoechas leaves against selected pathogenic bacteria, including Escherichia coli, Staphylococcus aureus, and Proteus vulgaris. The results showed that Staphylococcus aureus exhibited the highest sensitivity to the extract, with an inhibition zone diameter of 19 mm at a concentration of 90%. In contrast, Escherichia coli and Proteus vulgaris showed moderate to low sensitivity. The ethanolic extract demonstrated broad-spectrum antibacterial activity against both Gram-positive and Gram-negative bacteria, with the most pronounced effect observed against Staphylococcus aureus. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values were determined. The MIC value for Staphylococcus aureus was 1%, and its MBC value was 4%, indicating strong bactericidal efficacy. For Escherichia coli and Proteus vulgaris, the MIC and MBC values were 10% and 16%, respectively, suggesting moderate antibacterial potential. The findings highlight the potential of Lavandula stoechas ethanolic extract as a natural antibacterial agent, particularly against Staphylococcus aureus. This study was conducted in the Department of Biology, Faculty of Science, Damascus University, during 2023.