Inhibitory activity of nine essential oils on nitric oxide production by human leukocytes

• Published in: Planta Medica
• Main Authors: Pérez-Rosés, R, Risco, E, Vila, R, Peñalver, P, Cañigueral, S
• Format: Conference Proceeding
• Language: English
• Published: 21.07.2009
• ISSN: 0032-0943; 1439-0221
• DOI: 10.1055/s-0029-1234771

Nitric oxide (NO) plays a key role in the production of reactive nitrogen species (RNS), which have cytotoxic properties against pathogenic microbes and, at the same time, can damage host tissues [1]. Some essential oils have antioxidant properties and their consumption can influence immune cell functions [2,3]. In order to widen our knowledge of the antioxidant properties of essential oils we studied their effect on NO production induced by LPS in human blood leukocytes. NO was determined in 96-well microtiter plates by the Griess reaction [4]. N G -methyl-L-arginine acetate (L-NMMA, IC 50 =38.2±1.4µg/ml) was used as positive control. The essential oils investigated were obtained from commercial sources: nutmeg (NM) ( Myristica fragans Houtt), clove leaves (CL) ( Syzygium aromaticum (L) Merr. et L.M. Perry), tarragon (TR) ( Artemisia dracunculus L.), juniper berries (JB) ( Juniperus communis L.), rosemary (RO) ( Rosmarinus officinalis L.), lemon grass (LG) ( Cymbopogon martinii Roxb. Wats.), lemon (LE) ( Citrus limon (L.) Burman fil.), thyme (TH) ( Thymus zygis (Loefl) L.) and Spanish oregano (SO) ( Thymbra capitata Griseb.). In addition, nutmeg terpenes (NT, a fraction of nutmeg oil) and the pure compounds eugenol (EU), thymol (TM) and carvacrol (CR) were also tested. All the essential oils were chemically characterised by GC-FID and GC-MS. Results showed that CL (IC 50 =39.8±6.3µg/ml) and its major constituent, EU (IC 50 =19.0±1.8µg/ml), were the most active. JB, NM, NT, TR and SO had an IC 50 >50µg/ml, and CR, the main component of SO had an IC 50 =39.3±6.8µg/ml. LE, LG, RO, TH and TM showed no measurable activity. The results confirmed the good antioxidant profile of CL [3]. Acknowledgements: Thanks are due to Lidervet S.L. (Tarragona, Spain) for the financial support. The work of R. Perez-Roses was supported by the Department of Education and Universities of the Generalitat de Catalunya and the European Social Fund. References: [1] Martínez, M.C. et al. (2009) Antioxid. Redox Sign. 11:669–702. [2] Pérez-Roses, R. et al. (2007) Planta Med. 73:976. [3] Pérez-Roses, R. et al. (2008) 39th ISEO, Quedlingburg (Germany). [4] Green, L.C. et al. (1982) Anal. Biochem. 124:131–138.