편백나무(Chamaecyparis obtusa)는 측백나무과에 속하며 우리나라 남쪽 지역에서 주로 잘 자 생한다. 편백나무의 목재는 재질이 우수하여 가구로서의 활용이 높으며 남은 목재, 가지, 잎은 정유 추출에 사용되고 있다. 편백 정유는 항염, 향균, 탈취, 진정 효능이 탁월한 것으로 알려져 있다. 본 연구는 이러한 편백나무의 잎에서 추출한 오일이 주름 개선, 피부 장벽 및 보습능에 미치는 영향을 평가하고자 하였다. 먼 저, DPPH assay와 ABTS assay를 통해 항산화 활성을 평가한 결과, 편백 오일은 두 가지 라디칼을 농도 의존적으로 유의하게 소거하였다. 그리고 주름 생성 억제 효능 평가를 위해 elastase 활성을 측정한 결과, 편백 오일은 elastase 활성을 직접적으로 억제시킴을 확인하였다. 다음으로는 real-time PCR을 통해 유전 자 발현을 확인한 결과, 편백 오일은 인간섬유아세포에서 MMP-1 유전자 발현을 유의하게 감소시켰다. 또 한, 편백 오일에 의해 각질형성세포에서 filaggrin과 HAS-2 유전자 발현이 유의하게 증가함을 확인하였다. 이러한 결과를 종합해보면, 편백 오일은 주름 개선과 피부 장벽 및 보습능 강화에 도움을 주어 항노화 화장 품의 기능성 원료로서 활용될 수 있을 것으로 기대된다.

Despite the various effects on the health of Chamaecyparis obtusa essential oil (COEO), an adverse effect on the skin has recently been reported. Therefore, in this study, the skin sensitization test of COEO was conducted to confirm the skin safety of the essential oil by the guinea pig maximization test. Guinea pigs were sensitized with intradermal injection of 0.1ml COEO for 24 h. After 1 week, 5% of COEO was treated on the site of injection and 2% of the essential oil was challenged 2 weeks later. The average skin reaction evaluated by erythema and edema on the challenge sites and sensitization rate in the COEO-treatment group at 24 h were 0.0 and 0%, respectively, which are substantially low compared with in the 2,4-dinitrochlorobenzene-treatment group (positive control group) (average skin reaction: 3.0, sensitization rate: 100%) and identical with in the olive oil-treatment group (negative control group), representing a weak sensitizing potential. The average skin reaction and sensitization rate observed at 48 h were 0.0 and 0% in the COEO-treatment group, respectively, and 2.0 and 100% in the positive control group, respectively. It was concluded that 5% of COEO classified to Grade I, induced no sensitization when tested in guinea pigs.

The present study was carried out to investigate the acute oral toxicity of Chamaecyparis obtusa (C. obtusa) essential oil in ICR male and female mice. Acute oral treatment with C. obtusa essential oil did not reveal any sign of toxicity or mortality in treated mice. Mouse body weights were not affected after single oral administration of C. obtusa essential oil during the 14-day observation period. In the hematological and blood biochemical analysis, all parameters of the treated group with 2,000 mg/kg body weight of the essential oil were not significantly different those of the control group. Therefore, the lethal dose 50 of the essential oil was estimated to be greater than 2,000 mg/ kg body weight in mice, which indicated that the essential oil is non-toxic. In conclusion, this study suggests that C. obtusa essential oil orally safe ICR mice.