Comparison of anti-Candida activity of thyme, pennyroyal, and lemon essential oils versus antifungal drugs against Candida species

Because of resistance and side effects to common antifungal drugs, there have been many studies on the use of herbal antifungal essential oils. In this study, the anti-Candida activities of thyme, pennyroyal and lemon essential oils in comparison to antifungal drugs were assessed. The paper disc diffusion method was used to study the inhibitory effects of the essential oils of thyme, pennyroyal and lemon and amphotericin B and fluconazole on different species of Candida including Candida albicans, C. krusei and C. glabrata, which are isolated from patients who suffered from vulvovaginal candidiasis, at 25°C and 37°C. The transparent zone around the paper discs showed that thyme essential oil has the greatest effect against different Candida species, followed by pennyroyal and lemon. The inhibitory effects of essential oils on the growth of Candida at 37°C were better than 25°C. The inhibitory effect of amphotericin B was better than fluconazole. The results of the present study showed that amphotericin B and thyme essential oil had inhibitory effects on the growth of different Candida species. Therefore, after performing controlled studies and experimenting with different types of honey formulation, thyme essential oil may be used in treating empirical candidiasis. In conclusion, these essential oils have anti-Candida activity, in vitro and related to their concentration on paper disc.