Total phenolic content and antibacterial activity of five plants of labiatae against four foodborne and some other bacteria

The aim of this study was to evaluate the antibacterial effects of Thymus vulgaris, Thymus caramanicus Zataria multiflora, Zizphora clinopodioides and Zizphora tenuior against four foodborne and four other bacteria including Staphylococcus aureus, Shigella dysenteriae, Salmonella typhimurium, Escherichia coli Staphylococcus epidermidis, Bacillus subtilis, MRSA and Pseiidomona aeruginosa and measuring the amount of total phenolics of the plants. The extracts were prepared by maceration method. Pre-evaluation of the antimicrobial effect was utilized by cup-plate technique and then Minimum Inhibitory Concentration was determined by agar dilution method according to NCCLS. The total phenolics as a possible cause of antibacterial effect, was measured by Folin-Ciocalteucolorimetry. The results showed that T. caramanicus and Z. multiflora were the most effective ones with MIC values between 0.78-3.125 mg/mL against all of the Bactria and Z. tenuior and Z. clinopodioides had the minimum antimicrobial activity. Total phenolic contents of these five plants were different and followed the general pattern of the antimicrobial effect. The antibacterial effects and the total phenolic content of T. caramanicus and Z. multiflora were remarkable and should be investigated more in future studies