Chemical composition and biological (antioxidant, antimicrobial and haemolyitc) activities of essential oils of an endemic plant (Thymus linearis subsp hedgei Jalas)

In the current study, we investigated for the first time, the chemical composition, as well as biological (antioxidant, antimicrobial and hemolytic) activities of conventionally hydrodistilled (CHD) and microwave, assisted hydrodistilled (MAHD) essential oils of Thymus linearis subsp. hedgei Jalas. For this purpose, chemical components of CHD and MAHD essential oils were characterized using GC-MS. Antioxidant potential of two fundamental oils was determined using 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging and linoleic acid inhibition assays. Antimicrobial activity was estimated by disc diffusion and MIC assays. Haemolytyic assay was used to assess the effect of each essential oil on human erythrocyte membrane. The results of GC-MS study showed that CHD and MAHD essential oils of were rich in carvacrol with the chemical contribution of 52.88% and 38.03%, respectively. Meanwhile, MAHD essential oil consistently exhibited the higher 1,1-diphenyl-2-picrylhydrazyl(DPPH) radical scavenging activity, linoleic acid inhibition (65.9 +/- 1.01%) and antimicrobial activity than CHD essential oil. The outcome of haemolyitc assay revealed that both the oils were safe to erythrocyte membrane. The current study demonstrates that T. linearis subsp. hedgei Jalas essential oils particularly that extracted by microwave assisted hydrodistillation could be used as novel natural source of antioxidant and antimicrobial agents.