Abstract
Chamaecyparis obtusa Siebold & Zucc. f. formosana Hayata (Cupressaceae) is one of the treasured conifers in Taiwan. In this study, the wood essential oil of the species was extracted and its anti-inflammatory bioactivities analyzed. The composition analysis of the essential oil yielded a total of 57 compounds with α-terpineol (19.4%), τ-muurolol (16.9%), borneol (16%), and α-cadinol (10.9%) predominating. The anti-inflammatory assays of the essential oil suggest that C. obtusa f. formosana wood oil has no cytotoxicity, and was capable of inhibiting the expressions of tumor necrosis factor (TNF-α), IL-6, IL-1, pro IL-1β, NO, iNOS, and NLRP3 in murine macrophage cells. It was unable, however, to inhibit the expression of COX-2. Further investigation of the effect of the essential oil on the cellular signal transduction indicated that it was capable of inhibiting ERK1/2, JNK1/2 and p38; it also showed excellent inhibition against ROS. Thus, the overall results indicated that C. obtusa f. formosana wood oil had very good anti-inflammatory efficacies.