Exploring the Antibacterial Potential of Laurus nobilis Essential Oil and the Synergistic Interaction with 1,8-Cineole and Gentamicin Against Methicillin-Resistant Staphylococcus aureus

Authors : Demet Hançer Aydemir
Pages : 2111-2132
Doi:10.47495/okufbed.1608467
View : 52 | Download : 184
Publication Date : 2025-12-15
Article Type : Research Paper
Abstract :This study aims to determine the in vitro antibacterial activity of the commercially purchased Laurus nobilis essential oil (LnEO) and the synergistic interaction of the 1,8-cineole with gentamicin against methicillin-resistant S. aureus. The chemical profile of the LnEO was evaluated by GC-MS. In vitro antibacterial activity of the LnEO was tested by the disk diffusion method. MIC and MBC values were assessed using the broth macro-dilution method. The killing kinetics of the LnEO against S. aureus were investigated. The interaction of the 1,8-cineole with gentamicin was assessed by the checkerboard method. 45 volatile compounds constituting 100% of the total essential oil were determined. 1,8-cineol (51.43%) was shown as the main component. The LnEO does not affect the growth of S. aureus at 1:40 and 1:20 dilution ratios. The LnEO formed an inhibition zone of 14.2 mm at a 1:1 dilution ratio, 11.8 mm at 1:5, and 8.7 mm at 1:10. It was concluded that S. aureus is sensitive to the LnEO at dilution ratios of 1:1, 1:5, and 1:10. The MIC and the MBC values were determined as 1:4, and 1:2, respectively. Time-kill assay has shown that the LnEO has a bactericidal activity. It was determined that 95% of S. aureus died after 10 minutes of contact with the LnEO, and after 90 minutes of contact, the entire bacterial strain was killed. The combination of gentamicin and 1,8-cineole showed a synergistic effect on S. aureus (FICI≤ 0.5). Obtained data show that LnEO and the 1,8-cineole contained in its composition may help develop effective strategies to combat MRSA infections. It is thought that it may be possible to reduce possible toxic effects and resistance development when drug-active ingredients are used in combination with natural bioactive components at lower doses instead of being used alone at high doses.
Keywords : Metisilin dirençli Staphylococcus aureus, Laurus nobilis, 1, 8 sineol, Antibakteriyal aktivite, Gentamisin

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