Anti-inflammatory effects of essential oils extracted from Chamaecyparis obtusa in inflammatory models of mice and raw 264.7 cells (CAM1P.165)

Abstract

Abstract Although the biological activities of essential oil extracted from Chamaecyparis obtusa (EOCO) are not yet fully understood, antimicrobial, antifungal and anti-inflammatory effects have been reported. In this study, we investigated the anti-inflammatory effects of EOCO in two inflammatory models of mice, carrageenan-induced paw edema and thioglycollate-induced peritonitis, and lipopolysaccharide (LPS)-stimulated Raw 264.7 macrophage cells. Levels of pro-inflammatory cytokines were analyzed by ELISA, expression of nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) were determined by western blotting, and nitrite concentration was measured using Griess reagent. The thicknesses of mice paw edema induced by carrageenan and interleukin-1β (IL-1β) and interleukin-6 (IL-6) levels in paw homogenates were significantly decreased in the EOCO (5 and 10 mg/kg) group as compared with control group. In mice with thioglycollate-induced peritonitis, EOCO (5 and 10 mg/kg) treatment reduced the numbers of total cells and suppressed tumor necrosis factor (TNF)-α, IL-1β, and IL-6 levels in peritoneal fluid. EOCO also decreased nitric oxide (NO), TNF-α and IL-6 production and inhibited iNOS and COX-2 expressions in LPS-stimulated Raw 264.7 cells. These data showed that EOCO has anti-inflammatory effect both in vivo and in vitro, and this effect may be related with inhibition of inflammatory mediators. In conclusion, EOCO could be an effective therapeutic agent in inflammatory diseases.