Essential oil chemical composition, antimicrobial, anticancer, and antioxidant effects of Thymus convolutus Klokov in Turkey

Abstract

Abstract In this study, the chemical composition, antimicrobial, antioxidant, and anticancer effects of Thymus convolutus Klokov oil and its main compound camphor were investigated. The oil was isolated from T. convolutus using hydrodistillation method, analyzed by gas chromatography/mass spectrometry (GC–MS), and 66 compounds were identified. The main component was determined as camphor at 16.6%. The antioxidant properties were identified with the DPPH (2,2′-diphenyl-1-picrylhydrazyl) radical-scavenging method and, 33.39 ± 0.25% DPPH was scavenging in 1000 μg/mL of essential oil. The strong antimicrobial activity was observed against Escherichia coli, Enterobacter aerogenes, Proteus vulgaris, and Pseudomonas aeruginosa with MIC values of 125 μg/mL. Aspergillus flavus was more sensitive (28%) against T. convolutus essential oil than other fungi. The cytotoxic effect of oil was analyzed by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) method. Camphor was effective on human hepatoma cells (Hep3B) at concentrations of 1 mg/mL, 500, 250, and 125 μg/mL, while essential oil of T. convolutus was found to be effective at concentrations of 250 and 125 μg/mL. A reduction in cell proliferation was observed in colon carcinoma cells (HT-29) treated with 500 μg/mL camphor for 48 h. No statistically significant effect was found in Umbilical Vein Endothelial Cells (HUVEC) treated with essential oil and camphor.