Antioxidant properties of thyme (Thymus vulgaris L.) and wild thyme (Thymus serpyllum L.) essential oils

Abstract

In this study, the composition of the volatile compounds and the antioxidant activity of thyme (Thymus vulgaris L.) and wild thyme (Thymus serpyllum L.) essential oils were investigated using three different methods: the DPPH radical scavenging method, the thiobarbituric acid reactive species (TBARS) assay and the β-carotene bleaching method. The results obtained for the total essential oils in both plants and their two fractions (hydrocarbon- and oxygen- containing fractions) were compared with those of α-tocopherol, ascorbic acid and the synthetic antioxidants - butylated hydroxytoluene (BHT) and butylated hydroxyanisole (BHA). Thyme and wild thyme essential oils exhibit significant in vitro antioxidant activity, while fractions of the essential oils that contain hydrocarbon compounds (CH fractions) only show antioxidant activity in the TBARS assay.