Antifungal effect of various essential oils against Candida albicans.: Potentiation of antifungal action of amphotericin B by essential oil from Thymus vulgaris

The antifungal effect of the essential oil from Satureja montana L., Lavandula angustifolia Mill., Lavandula hybrida Reverchon, Syzygium aromaticum (L.) Merril and Perry, Origanum vulgare L., Rosmarinus officinalis L. and six chemotypes of Thymus vulgaris L. on Candida albicans growth were studied. The most efficiency was obtained with the essential oil from Thymus vulgaris thymol chemotype (MIC 80% = 0.016 muL/mL and K-aff = 296 muL/mL). The presence in the culture medium of essential oil from Thymus vulgaris thymol chemotype (0.01, 0.1, 0.2, 0.3 mug/mL) and amphotericin B involved a decrease of the MIC 80% of amphotericin B. In contrast, the combination of amphotericin B and low concentrations (0.00031-0.0025 mug/mL) of essential oil was antagonistic. The strongest decrease (48%) of the MIC 80% was obtained with medium containing 0.2 muL/ mL of essential oil. These results signify that the essential oil of Thymus vulgaris thymol chemotype potentiates the antifungal action of amphotericin B suggesting a possible utilization of this essential oil in addition to antifungal drugs for the treatment of mycoses. Copyright (C) 2004 John Wiley Sons, Ltd.