Study of Chemical Composition, Antibacterial and Antioxidant Activity of Thyme Leaves and Stems Essential Oil

Abstract

Given the increase in drug resistance of microorganisms and the tendency in using medicinal plants, the present study was carried out to investigate the chemical compounds of Thymol as a constituent of essential oil and antimicrobial activity against several pathogenic bacteria and its antioxidant activity. In this study, the chemical compounds of Thymol extracted from the two parts of the plant together (the leaves and stems) were performed by making use of gas chromatography and the other gas chromatography linked to the mass spectrograph and its antibacterial activity against Ecoli, Klebsiella, Pseudomonas, Staphylococcus, Salmonella Paratyphi B, Salmonella Typhi typhus and enterococci through Microdilution and the minimum inhibitory concentration (MIC), and the minimum bactericidal concentration (MBC) were investigated. The antioxidant activity of essential oils was measured through the ability of essential oil compounds in decolorizing diphenyl picrilhydrazyl (DPPH) free radicals. Chemical analysis of thyme essential oil resulted in the identification of 23 (83.68%) compounds, which Thymol with 25.30% was considered as the main part of the essential oil compound. The highest inhibitory effect was imposed on Klebsiella, Escherichia coli, and Staphylococcus aureus, and the largest inhibitory zone diameter of essential oil appeared against growth Salmonella paratyphi B. Concerning the results, total phenol was equal to 114.3 mg of gallic acid.g and IC50 of thyme was considered to be 49.94 μM/ml. The achieved results from this study declared that thyme essential oil had a suitable inhibitory effect against pathogenic bacteria and also possessed antioxidant properties. In other words, thyme was considered as an alternative to synthetic drugs and food additives.