LPS로 유도된 RAW 264.7 대식세포에 대한 대황(Eisenia bicyclis) 헥산 분획물의 항염증 효과

Eisenia bicyclis is known to have secondary metabolites exhibiting various biological activities. In a preliminary study, the n-hexane fraction obtained from the ethanolic extract of E. bicyclis showed higher anti-inflammatory activity than the ethyl acetate and butyl alcohol fractions based on the inhibition of lipopolysaccharide (LPS)-stimulated nitric oxide (NO) production in RAW 264.7 cells. Using this fraction (E. bicyclis hexane fraction, EHF), we investigated the molecular mechanisms underlying its anti-inflammatory effect in LPS-stimulated RAW 264.7 cells. Pretreatment of the cells with up to 50 μg/mL EHF significantly inhibited NO and prostaglandin E2 production as well as their responsible enzyme proteins and mRNAs, in a dose-dependent manner (P<0.05). Similarly, EHF markedly reduced the production of pro-inflammatory cytokines, such as interleukin (IL)-1β, IL-6 and tumor necrosis factor (TNF)-α as well as their mRNA levels. Nuclear translocation of nuclear factor-kappa B (NF-κB) was strongly suppressed by EHF treatment. EHF significantly reduced the phosphorylation of mitogen-activated protein kinases and phosphatidylinositol 3-kinase/Akt in LPS-stimulated cells. Moreover, EHF reduced ear edema in phorbol myristate acetate (PMA)-induced mice. These results indicate that EHF contains potent anti-inflammatory compounds, which may be used as a dietary supplement for the prevention of inflammatory diseases.