Purification, chemical characterization and evaluation of the antioxidant potential of carvacrol from <i>Thymus vulgaris</i>

This work focuses on the purification, chemical characterization and evaluation of the antioxidant activity of carvacrol in order to determine its contribution in the high antioxidant potential of Thymus vulgaris essential oil (TEO). Firstly, 68% of carvacrol was purified from TEO using chromatography on silica gel column and then chemically characterized using spectroscopic techniques (IR, MS and 1H and 13C NMR). In vitro, the antioxidant activity has been determined using DPPH, ABTS•+ and iron chelating assays. All assays proved the strong radical scavenging and reducing power of carvacrol. In vivo, antioxidant capacity towards stressed Saccharomyces cerevisiae cells was investigated by evaluating cell viability, antioxidant enzymes’ activity, the level of lipid peroxidation (LPO) as well as the activity of succinate dehydrogenase (SDH). Using carvacrol in a dose dependent manner (6.25-25 μg/mL), cell viability was outstandingly improved by 34.5-55% compared to stressed cells. Antioxidant enzymes (CAT, SOD, GR) activities were also brought back to values comparable to control cells along with lower LPO (0.81±0.07 nmol/mg) and SDH (1.15± 0.07 μmol/min/mg of protein) at 25 μg/mL. These findings suggest that the powerful antioxidant properties of TEO found in our previous study were mainly associated to its main component (carvacrol) that showed higher antioxidant activity compared to the other components. Therefore, carvacrol can be of a great use as a pharmacological agent against damages related to oxidative stress.</p