POTENTIAL EFFECT OF THYME AND OREGANO ESSENTIAL OILS TO ANTIMICROBIAL ACTIVITY AND YEAST ENZYMATIC ANTIOXIDATIVE SYSTEM

Abstract

This in vitro study was aimed to assess the effects of Thymus vulgaris L. and Origanum vulgare L. essential oils (EOs) on cell viability and enzymatic antioxidative system in yeast Saccharomyces cerevisiae. Yeasts were cultivated with different concentrations of thyme (Thymus vulgaris L.) (0.05 – 1.00 µl/ml) and oregano (Origanum vulgare L.) (0.05 – 0.70 µl/ml) EOs for 24 hours. For the present study, gas chromatography-mass spectrometry (GC-MS) analysis was used to quantify chemical composition of EOs. The main components of thyme essential oil were caryophyllene (7.94%), p-cymene (18.55%), and thymol (46.55%). In essential oil of oregano, there was found p-cymene (8.43%) and carvacrol (69.99%) mainly. The antimicrobial activity of selected EOs was investigated by the microbroth dilution method using 96 well microtiter plates. The most potent essential oil able to inhibit growth of Saccharomyces cerevisiae was oregano EO with the values of MIC50 0.468845 µl/ml and MIC90 0.501845 µl/ml. Also, the activity of superoxide dismutase (SOD) and glutathione peroxidase (GPx) were assessed. According to our results, Thymus vulgaris L. significantly increased the SOD levels at 0.2, 0.4, 0.5 to 0.9 µl/ml and GPx production at 0.05 to 0.7 µl/ml (P<0.001). In case of Origanum vulgare L., significant increase of SOD production at 0.05 - 0.2 µl/ml (P<0.001) was observed. This essential oil also elevated GPx concentration in all experimental groups (P<0.001) significantly. Data from this study suggest that selected EOs have significant effects on enzymatic antioxidants that may affect the first-line cell defense system against oxidative stress.