Antifungal activity of Lavandula angustifolia essential oil against Candida albicans yeast and mycelial form

The antifungal activity of the essential oil of Lavandula angustifolia Mill. ( lavender oil) and its main components, linalool and linalyl acetate, was investigated against 50 clinical isolates of Candida albicans ( 28 oropharyngeal strains, 22 vaginal strains) and C. albicans ATCC 3153. Growth inhibition, killing time and inhibition of germ tube formation were evaluated. The chemical composition of the essential oil was determined by gas chromatography and mass spectrometry. Lavender oil inhibited C. albicans growth: mean minimum inhibitory concentration ( MIC) of 0.69% (vol./ vol.) ( vaginal strains) and 1.04% ( oropharyngeal strains); mean MFC of 1.1% ( vaginal strains) and 1.8% ( oropharyngeal strains). Linalool was more effective than essential oil: mean MIC of 0.09% ( vaginal strains) and 0.29% ( oropharyngeal strains); mean MFC of 0.1% ( vaginal strains) and 0.3% ( oropharyngeal strains). Linalyl acetate was almost ineffective. Lavender oil (2%) killed 100% of the C. albicans ATCC 3153 cells within 15 min; linalool (0.5%) killed 100% of the cells within 30 s. The essential oil inhibited germ tube formation ( mean MIC of 0.09%), as did the main components ( MIC of 0.11% for linalool and 0.08% for linalyl acetate). Both the essential oil and its main components inhibited hyphal elongation of C. albicans ATCC 3153 ( about 50% inhibition at 0.016% with each substance). Lavender oil shows both fungistatic and fungicidal activity against C. albicans strains. At lower concentrations, it inhibits germ tube formation and hyphal elongation, indicating that it is effective against C. albicans dimorphism and may thus reduce fungal progression and the spread of infection in host tissues