Antioxidant and antimicrobial activity of thymus vulgaris L. on some pathogenic bacteria in vitro

Thyme (Thymus vulgaris) belongs to the Lamiaceae family, and has been used since antiquity in traditional medicine. It is recognized by its therapeutic virtues. The ancient-Iranians were familiar with many medicinal herbs and were aware of their usefulness in treatment of various diseases. In this study Thymus vulgaris L. to evaluate the antimicrobial activity, Disc Diffusion Test with Kirby-Bauer method was used. The Minimum Inhibitory Concentrations (MIC) and Minimum Bactericidal Concentration (MBC) were determined by using the dilution method. Methanolic extracts of Thymus vulgaris L. were investigated for their antioxidant activity by DPPH and FRAP assay. Data was analyzed by SPSS18 software and one-way ANOVA test analysis and Tukey test. p <0.05 was considered significant. The results show that methanolic extract were quite effective in 2000 μg/ml concentration on Pseudomonas aeruginosa PTCC 1310 and Streptococcus pyogenes PTCC 1447 and were prevented from growth them on medium. In disk agar diffusion method , 10, 20, 30 and 40 % methanolic extract concentrations, was deterrented effect on Pseudomonas aeruginosa PTCC 1310 and Streptococcus pyogenes PTCC 1447. The Thymus vulgaris L. extract presented the more effective impact on the growth of Streptococcus pyogenes PTCC 1447 than Pseudomonas aeruginosa PTCC 1310 (p<0.05). IC50 for antioxidant activity for Thymus vulgaris L. 1426.52 μg/ml (by DPPH) and inhibition percent Thymus vulgaris L. 69 (by FRAP) and total phenolic content Thymus vulgaris L. 44.92 mg gallic acid equivalent/g of extract. Results showed Thymus vulgaris L. extracts can be used as natural antimicrobial in food products.