Pol J Microbiol. 2009; 58(1): 61-8Yoon WJ, Kim SS, Oh TH, Lee NH, Hyun CGIn this study, the chemical composition of Cryptomeria japonica essential oil (CJE) was analyzed and its biological activities were tested. CJE was obtained by steam distillation from leaves collected from Jeju Island and analyzed by gas chromatography (GC)-flame ionization detection (FID) and GC-MS. Kaurene (17.20%), elemol (10.88%), gamma-eudesmol (9.41%), and sabinene (8.86%) were the major components in CJE. The antibacterial and anti-inflammatory activities of CJE against drug-susceptible and -resistant skin pathogens have been not reported previously. Thus, we determined the anti-bacterial activities of CJE using the disk diffusion method and minimum inhibitory concentration (MIC) values. CJE showed excellent antibacterial activities against Propionibacterium acnes and Staphylococcus epidermidis, which are acne-causing bacteria. The MIC of CJE against drug-susceptible and -resistant P. acens and S. epidermidis ranged from 0.16 to 10.0 microl/ml. In addition, the effects of CJE on nitric oxide (NO), prostaglandin E2 (PGE2), tumor necrosis factor (TNF)-alpha, interleukin (IL)-1beta, and IL-6 production in lipopolysaccharide (LPS)-activated RAW 264.7 macrophages were also examined. Pro-inflammatory cytokine and mediator tests indicated that CJE has excellent dose-dependent inhibitory activities. Therefore, based on these results, we propose that CJE is an attractive acne-mitigating candidate for skin health.