Anti-Candida and Antibiofilm Activity of Selected Lamiaceae Essential Oils

Candidiasis is a common oral and vaginal infection. Some papers have presented that the essential oils of Lamiaceae plants can have antifungal activity. This study aimed to investigate the activity of 7 essential oils of the Lamiaceae family with known phytochemical compositions against Candida fungi.

Forty-four strains belonging to six species were tested: C. albicans, C. glabrata, C. guilliermondii, C. krusei, C. parapsilosis, and C. tropicalis. During this investigation, the following methods were used: determination of the minimal inhibitory concentrations (MICs), biofilm inhibition studies, and in silicotoxicity tests.

Essential oils of lemon balm (Melissa officinalis) and oregano (Origanum vulgare) showed the best anti-Candida activity, with MIC values below 3.125 mg/mL. Lavender (Lavandula stoechas), mint (Mentha × piperita), rosemary (Rosmarinus officinalis), and thyme (Thymus vulgaris) essential oils were also very active (0.39 to 6.25 or 12.5 mg/mL). Sage (Salvia officinalis) essential oil presented the lowest activity, with MIC values ranging from 3.125 to 100 mg/mL. In an antibiofilm study using MIC values, oregano and thyme essential oils showed the greatest effect, followed by lavender, mint, and rosemary oils. The weakest antibiofilm activity was observed with the lemon balm and sage oils. In silico toxicity research suggests that most of main compounds of Lamiaceae essential oils probably do not exhibit carcinogenicity, mutagenicity, or cytotoxicity.

The obtained results showed that Lamiaceae essential oils have anti-Candida and antibiofilm activity. Further research is required to confirm the safety and efficacy of essential oils in the topical treatment of candidiasis.