Chemical Composition, Olfactory Evaluation and Antioxidant Effects of an Essential Oil of Origanum Vulgare L. from Bosnia

The chemical composition of an essential oil of oregano (Origanum vulgare L.) from Bosnia was analyzed by GC/FID and GC-MS. In total, 33 constituents were identified and carvacrol (66.2%), p-cymene (9.1%), γ-terpinene (7.3%) and β-caryophyllene (4.1%) were found to be the main compounds. In addition, olfactory evaluation data of the sample and correlations with the odor attributes of the single components are presented to explain the complex aroma impression of this essential oil. The oil possessed antiradical activity with respect to DPPH radicals, exceeding that of its major phenolic component, carvacrol. The oil also revealed scavenging potential with respect to hydroxyl radicals (OH•), which was superior to that towards the DPPH radical; the respective concentrations needed for 50% inhibition (IC50) were 53.8 μg/mL for DPPH and 0.31 μg/mL for OH•. The superoxide scavenging activity of oregano oil was 82.7% at 50 μg/mL. The oil also demonstrated antioxidant activity in a linoleic acid emulsion model system; at 0.05% concentration it inhibited conjugated dienes formation by 69.0% and the generation of secondary oxidized products from linoleic acid by 73.1 %.