Anti-inflammatory Effects of Epimedii Herba Water Extract through Inhibition of Nuclear Factor-κB in RAW 264.7 Cells

Objectives : Epimedii Herba has been frequently used in Korean Traditional Medicine to treat impotence, spermatorrhoea, exophthalmos, and forgetfulness. Present study investigated anti-inflammatory effects of Epimedii Herba water extract (EWE) and attempted to elucidate molecular mechanisms involved. Methods : To explore anti-inflammatory effects of EWE, RAW 264.7 cells, a murine macrophage cell line, were pretreated with $10-100{\mu}g/m{\ell}$ of EWE, and then subsequently exposed to $1{\mu}g/m{\ell}$ of lipopolysaccharide (LPS). Levels of nitric oxide (NO), interleukin-6, $interleukin-1{\beta}$, and tumor necrosis $factor-{\alpha}$ were monitored in the medium. Expression levels of inducible nitric oxide synthase and cyclooxygenase-2 were determined by immunoblot and real-time PCR analyses. Signaling pathways related with nuclear $factor-{\kappa}B$ ($NF-{\kappa}B$) and mitogen-activated protein kinases were monitored to elucidate molecular mechanisms involved. Finally, the role of three flavonoid compounds in EWE on LPS-mediated NO production were investigated. Results : In conditioned medium, pretreatment of EWE ($100{\mu}g/m{\ell}$) significantly inhibited LPS-stimulated NO and pro-inflammatory cytokine production. In addition, EWE attenuated the expressions of inducible nitric oxide synthase and cyclooxygenase-2 by LPS. EWE prevented the phosphorylation and degradation of inhibitory ${\kappa}B{\alpha}$, nuclear translocation of $NF-{\kappa}B$, and DNA binding of $NF-{\kappa}B$, while EWE did not change the phosphorylation of mitogen-activated protein kinases by LPS. Moreover, icariin, icaritin, and quercetin partly, but significantly, inhibited the LPS-stimulated NO production. Conclusions : These results suggest that EWE has an ability to prevent inflammation in macrophages through inhibition of $NF-{\kappa}B$ signaling pathway.

RAW 264.7 세포에서 음양곽(淫羊藿) 물 추출물의 nuclear factor-κB 억제를 통한 항염증 효과