Chemical composition, bactericidal kinetics, mechanism of action, and anti-inflammatory activity of Isodon melissoides (Benth.) H. Hara essential oil

Present study was aimed to investigate the antibacterial activity, bactericidal mechanism of action, killing kinetics and anti-inflammatory activity of Isodon melissoides (Benth.) H. Hara essential oil. The gas chromatography-flame ionization detector (GC-FID) and gas chromatography-mass spectrometry (GC-MS) analysis revealed the presence of carvacrol (45.4%), p-cymene (11.6%) and thymol (11.3%) as major constituents of the oil. The oil displayed broad spectrum significant antibacterial activity (MIC: 0.13–8.33 ppm; MBC: 0.13–>33.34 ppm) against test strains. The oil exhibited a time and dose-dependent bactericidal effect. The oil disrupted the cell membrane by changing the cell membrane permeability. The essential oil significantly decreased the overproduction of proinflammatory cytokines in LPS-induced inflammation in HaCaT cells without any cytotoxic effect. I. melissoides essential oil can be a promising alternative antimicrobial agent for the control of methicillin resistant staphylococci and other pathogenic bacteria tested, and also useful for the topical anti-inflammatory properties.