BIOLOGICA NYSSANA 7 (2)  December 2016: 131-139 Stanojević, Lj.P. et al.  Antioxidant activity of oregano essential oil… 131 Original Article Received: 30 June 2016 Revised: 31 October 2016 Accepted: 24 November 2016 Antioxidant activity of oregano essential oil (Origanum vulgare L.) Ljiljana P. Stanojević*, Jelena S. Stanojević, Dragan J. Cvetković, Dušica P. Ilić Faculty of Technology, University of Niš, Bulevar Oslobodenja 124, 16000 Leskovac, Serbia * E-mail: stanojevic@tf.ni.ac.rs Abstract: Stanojević, Lj.P., Stanojević, J.S., Cvetković, D.J., Ilić, D.P. : Antioxidant activity of oregano essential oil (Origanum vulgare L.). Biologica Nyssana, 7 (2), December 2016: 131-139. Essential oil obtained from oregano (Origanum vulgare L.) by Clevenger-type hydrodistillation and hydromodulus 1:10 m/v during 180 minutes, has been investigated in this work. Qualitative and quantitative composition of the oil was determined by GC-MS and GC-FID spectrometry. Antioxidant activity of the obtained oil was examined spectrophotometrically by DPPH test (after 20, 30, 45 and 60 minutes of incubation) and TBA-MDA assay. The yield of essential oil was 4.1 mL/100 g of plant material. Seven components were identified: -thujene, myrcene, -terpinene, o-cymene, γ-terpinene, thymol and carvacrol. The major components were thymol (45%) and carvacrol (37.4%). Oil incubated for 60 minutes has shown the best antioxidant activity according to DPPH test. The concentrations of essential oil, required for neutralization of 50% of initial DPPH radical concentration (EC50), were 0.761, 0.590, 0.360 and 0.326 mg/mL, after 20, 30, 45 and 60 minutes of incubation, respectively. Lipid peroxidation inhibition of 92.3% was achieved by 1.35 mg/mL essential oil concentration. The results obtained indicate that oregano essential oil is a good source of natural antioxidants with potential application in food and pharmaceutical industries, as a safer alternative to the synthetic antioxidants. Key words: Origanum vulgare L., essential oil, antioxidant activity, GC-MS analysis Apstrakt: Stanojević, Lj.P., Stanojević, J.S., Cvetković, D.J., Ilić, D.P.: Antioksidativna aktivnost etarskog ulja vranilove trave (Origanum vulgare L.). Biologica Nyssana, 7 (2), December 2016: 131-139. U ovom radu je ispitivano etarsko ulje vranilove trave (Origanum vulgare L.) dobijeno Clevenger hidrodestilacijom pri hidromodulu 1:10 m/v, u toku 180 minuta. Kvalitativni i kvantitativni sastav dobijenog etarskog ulja određen je GC-MS i GC-FID spektrometrijom. Antioksidativna aktivnost ulja je određena spektrofotometrijski, DPPH testom (posle 20,30, 45 i 60 minuta inkubacije) i TBA-MDA testom. Prinos etarskog ulja bio je 4.1 mL/100 g biljnog materijala. Identifikovano je sedam komponenti: -tujen, mircen, - terpinen, o-cimen, γ-terpinen, timol i karvakrol. Kao glavne komponente identifikovane su timol (45%) i karvakrol (37,4%). Najbolju DPPH-antioksidativnu aktivnost pokazalo je ulje nakon 60 min inkubacije. Koncentracije etarskog ulja neophodne za neutralizaciju 50% od početne koncentracije DPPH radikala (EC50 vrednosti) bile su 0,761; 0,590; 0,360 i 0,326 mg/mL, nakon 20, 30, 45 i 60 min inkubacije, respektivno. Inhibicija lipidne peroksidacije od 92,3% je postignuta sa 1,35 mg/mL eterskog ulja. Dobijeni rezultati sugerišu da dobijeno etarsko ulje vranilove trave predstavlja dobar izvor prirodnih antioksidanasa sa potencijalnom primenom u prehrambenoj i farmaceutskoj industriji kao bezbednija alternartiva sintetskim antioksidansima. Ključne reči: Origanum vulgare L., etarsko ulje, antioksidativna aktivnost, GC-MS analiza 7 (2) • December 2016: 131-139 12 th SFSES • 16-19 June 2016, Kopaonik Mt DOI: 10.5281/zenodo.200410