Antioxidant activity and chemical composition of the essential oils of Origanum vulgare subsp. hirtum, from two wild populations and of Salvia officinalis from two wild and one cultivated population, from Albania

The chemical composition of the volatile oils of five populations from two species from Albania, Origanum vulgare subsp. hirtum, from two wild populations and of sage (Salvia officinalis) from two wild and one cultivated population have been investigated. The essential oils were obtained by hydrodistillation and their analyses were performed by GC-MS. The major constituents resulted: carvacrol (81.0, 78.6%) followed by γ-terpinene (5.5, 7.1%) and p-cymene (4.9, 4.1%) for O. vulgare originating from Tepelena and Vlora, respectively; camphor (40.2, 47.8, 45.9%), α-thujone (19.2, 22.2, 13.7%), eucalyptol (5.4, 2.6, 6.0%), camphene (5.8, 6.1, 3.9%), borneol (2.1, 2.9, 5.7%) and bornyl acetate (3.3, 1.4, 5.6%) for S. officinalis originated from Tepelena, Tirana and Vlora, respectively. Moreover, the essential oils were tested for their free radical scavenging activity using the following in vitro assays: i) interaction with the free stable radical of DPPH (1,1-diphenyl-2-picrylhydrazyl), ii) inhibition of linoleic acid peroxidation with the dihydrochloric acid of 2,2'-azobis-2-methyl-propanimidamide, dihydrochloride (AAPH). Finally, their inhibitory activity toward soybean lipoxygenase was evaluated, using linoleic acid as substrate. The essential oil of O. vulgare originated from Vlora (OV-VL) has presented the highest interaction with the stable radical DPPH (76.49%). O. vulgare originated from Tepelena (OV-TP) showed high anti-lipid peroxidation activity (97.55), higher than the reference compound trolox (73.0%). Only the tested sample O. vulgare (OV-VL) significantly inhibits soybean lipoxygenase (54.24%).

Keywords: Essential oils, antioxidant activity, aromatic and medicinal plants, Albania.