Antioxidant and Anti-Inflammatory Activities of Essential Oils: A Short Review

Miguel, Maria Graça

Incubation of RAW 264.7 cells with Origanum ehrenbergii Boiss. oil, in which thymol and pcymene predominated, induced a significant inhibitory effect on the LPS-induced NO production. Origanum syriacum L. predominatly composed by carvacrol and thymol did not show such ability [139] . However, more examples of NO inhibition can be reported, for example the production of NO was also inhibited by the citrus peel waste essential oil in LPS-activated RAW 264.7 macrophages [140] , or the oil of Distichoselinum tenuifolium (Lag.) Garcia Martin & Silvestre, mainly composed by myrcene, that significantly inhibited NO production stimulated by LPS in macrophages, demonstrating, therefore, in vitro anti-inflammatory properties [141] . PGE 2 was only inhibited by LPS-stimulated macrophages J774.A1 cells when treated with high concentrations of (-)-linalool. The same was observed for the COX-2 expression. The same monoterpene inhibited NO release but did not inhibit the increase of iNOS expression indicating that the inhibitory activity of linalool was mainly attributed to the iNOS enzyme activity [142] .