In vitro antioxidant and antibacterial properties and total phenolic contents of essential oils from Thymus vulgaris, T. kotschyanus, Ziziphora tenuior and Z. clinopodioides

Objective: The objective of present study was to evaluate the antibacterial and antioxidant activities of essential oils from Thymus vulgaris, Thymus kotschyanus, Ziziphora tenuior and Ziziphora clinopodioides. Methods: The antioxidant potency of essential oils was determined by 2,2-diphenyl-1-picrylhydrazyl and reducing power assays. Total phenolic contents of essential oils were determined using the Folin-Ciocalteu reagent assay. The antibacterial activity of essential oils was evaluated using agar disc diffusion and minimum inhibitory concentration ( MIC) methods. Results: The essential oils of Ziziphora clinopodioides and Thymus vulgaris showed the highest antioxidant activity. The essential oils of Thymus vulgaris showed the strongest antibacterial activity with the widest inhibition zone and the lowest MIC value (2.5 mu l/ml). The essential oils of Thymus vulgaris had the highest concentration of total phenolics (116.5 mg GAE/g). Conclusion: In conclusion, the essential oils of Thymus vulgaris and Ziziphora clinopodioides can be used as potent antibacterial and antioxidant for food preservation.