Comparative Study of Litsea japonica Leaf and Fruit Extract on the Anti-inflammatory Effects

Abstract

본 연구에서는 까마귀쪽나무 잎과 열매 추출물의 항염증 활성을 비교하고자 마우스 대식세포주인 RAW 264.7 cell에서 LPS에 의해 유도된 COX-2/PGE2와 iNOS/NO 및 염증성 cytokine 인 TNF-<TEX>${\alpha}$</TEX>, IL-<TEX>$1{\beta}$</TEX>, IL-6의 생성 억제 정도를 확인하였다. 그 결과, 동일한 농도 조건(<TEX>$10{\mu}g/ml$</TEX>)에서 까마귀쪽나무의 열매 추출물이 잎 추출물에 비해 NO, <TEX>$PGE_2$</TEX>, iNOS, 염증성 cytokine인 TNF-<TEX>${\alpha}$</TEX>, IL-<TEX>$1{\beta}$</TEX>, IL-6의 생성량 모두에서 억제 효능이 우수하게 나타났다. 따라서 까마귀쪽나무가 보여주는 항염증 효과적 측면과 안전성의 두가지 측면을 고려할 때, 까마귀쪽나무의 열매 추출물이 저농도에서 잎 추출물보다 항염증 효과가 우수하거나 동등하며, 그 안전성이 크다고 판단됨으로 까마귀쪽나무의 열매추출물이 항염증 효능을 가진 기능성 식품 소재로써 개발 가능성이 있음을 제시한다. The present study aimed to investigate comparative anti-inflammatory effects of Litsea japonica fruit and leaf extract considering the balance of safety and efficacy. Dose response studies were performed to determine the inhibitory effects of 70% EtOH extract of leaf (L70%) on the pro-inflammatory enzymes expression, COX-2/PGE2 and NO/iNOS, and pro-inflammatory cytokines production, IL-<TEX>$1{\beta}$</TEX>, IL-6, and TNF-<TEX>$\alpha$</TEX> in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. We also examined comparative effects of 30 and 70% EtOH extract of fruits (F30% and F70%) at low concentration (<TEX>$10{\mu}g/ml$</TEX> ) in the same conditions. L70% at 50 and <TEX>$100{\mu}g/ml$</TEX> showed inhibitory effects on almost all the inflammatory mediators we examined except for COX-2 regulation, but there were no effects at <TEX>$10{\mu}g/ml$</TEX>. Since <TEX>$100{\mu}g/ml$</TEX> of L70% have 18.2% cytotoxicity, we compared the effects of fruit extract, F30% and F70% at <TEX>$10{\mu}g/ml$</TEX> on the regulation of NO/iNOS, PGE2, IL-<TEX>$1{\beta}$</TEX>, IL-6, and TNF-<TEX>$\alpha$</TEX> and obtained that fruit extacts are more efficacious and safe than leaf. This study suggests that the 30% EtOH fraction of L. japonica fruit could be a good candidate for development as a functional food supplement in the prevention of inflammatory disorders.