Characterization of the Essential Oil and Anticandidal Evaluation of Thymus pallasicus Hayek & Velen. from Turkey

Abstract

Thymus L. of the Lamiaceae with 220 ssp. is concentrated in the Mediterranean region. Thymus species are well known as “Kekik” in Turkish and are used as herbal tea and spices, according to recent records, the genus is represented with 40 ssp. where 17 species are endemic to Turkey.  The study material Thymus pallasicus is one of the endemic species for Turkey, where the essential oil was obtained from the air dried aerial parts by hydrodistillation subsequently analyzed by GC-FID and GC-MS, respectively. The main component was identified as thymol (55.5 %) along with the monoterpenes p-cymene (19.9 %), γ-terpinene (7.2%), carvacrol (5 %), and 1,8-cineole (%1.4). The essential oil was also evaluated for its anticandidal activity against five different standard human pathogenic strains, according to a modified in vitro CSLI micro dilution method. The minimum inhibitory activity of the essential oil was 250-500 microgram/mL against the tested Candida sp. suggesting rather weak inhibitory activity when compared to the standard antifungal fluconazole (0.5-16 microgram/mL). As Thymus species are known for their antimicrobial activities it is suggested that other clinical and pathogenic strains should be further evaluated.