Chemical composition and anti-inflammatory activities of essential oil from Trachydium roylei

Chemical composition, anti-inflammatory activity, and cytotoxicity of essential oils obtained from the aerial parts of Trachydium roylei were investigated in this study. The chemical composition of T. roylei essential oil was analyzed using gas chromatography mass spectrometry. Fifty-nine components, representing 98.87% of the oils, were characterized. The oils were predominated by aromatic compounds and monoterpene hydrocarbons, and the main components were myristicin (25.35%), β-phellandrene (22.95%), elemicine (7.69%), isoelemicin (5.48%), and cedrol (5.26%). The anti-inflammatory activity of the oil in lipopolysaccharide-stimulated murine RAW 264.7 cells was evaluated. The oils downregulated the production of proinflammatory cytokines, including tumor necrosis factor-α, interleukin (IL)-1β, and IL-6, and significantly increased the anti-inflammatory cytokine IL-10 levels. Results indicated that the oils effectively inhibited the secretion of nitric oxide and prostaglandin E2 in lipopolysaccharide-stimulated macrophages. Western blot analyses were performed to determine whether the inhibitory effects of the oils on proinflammatory mediators (nitric oxide and prostaglandin E2) were related to the modulation of inducible nitric oxide synthase and cyclooxygenase-2 expression. These findings suggest that T. roylei essential oils exert an anti-inflammatory effect by regulating the expression of inflammatory cytokines.