ANTIMICROBIAL ACTIVITY OF VAPOR PHASE OF SALVIA SPECIES ESSENTIAL OILS

Objective: The rise of multidrug-resistant microorganisms and increasing antibiotic resistance have heightened the need to explore alternative strategies for the treatment and prevention of respiratory tract infections. The use of plants in disease treatment dates back thousands of years, and plant-derived compounds are known to form the basis of the pharmaceutical industry. Among significant plant-derived resources, essential oils are defined as aromatic secondary metabolites that can evaporate at room temperature. Because of their volatile properties, essential oils can penetrate the respiratory tract faster than systemic therapies. In this study, the antimicrobial activities of the vapor phases of essential oils obtained from three different Salvia species were evaluated against microorganisms responsible for respiratory tract infections. Material and Method: The antimicrobial activity of the vapor phase of essential oils was determined using vapor diffusion method. The Minimum Inhibitory Concentration (MIC) test for the vapor phase was conducted in microtubes designed to ensure direct contact between microorganisms and essential oil’s vapors at different concentrations. During the evaluation of vapor diffusion, Petri dishes were not hermetically sealed, allowing the vapor phase to disperse into the external environment. However, in MIC experiments, microtube caps were closed to ensure that microorganisms were exposed solely to essential oil vapor. Result and Discussion: The essential oil of Salvia aucheri subsp. canascens exhibited the highest activity. In vapor diffusion tests, inhibition zone diameters of 8±1 mm was recorded against Staphylococcus aureus ATCC 29213. In the vapor phase MIC test, the essential oil exhibited activity against Klebsiella pneumoniae ATCC 13883 at a concentration of 3.15 mg/ml. The high efficacy of the same essential oil against different bacteria may be explained by the variability of the vapor phase in environmental conditions and differences in oxygen levels during the experiments.