Anti-Inflammatory Effect of the Root extracts from Hibiscus syriacus in LPS-Stimulated RAW264.7 Cells

Hibiscus syriacus (H. syriacus) as the national flower of Korea has been used as the herbal medicine in Asia. In this study, we evaluated the anti-inflammatory effect of 70% ethanol extracts from the root of Hibiscus syriacus (RHS-E70) and elucidated the potential signaling pathway in LPS-stimulated RAW264.7 cells. RHS-E70 dose-dependently suppressed NO production by inhibiting iNOS and IL-β expression in LPS-stimulated RAW264.7 cells. RHS-E70 inhibited the phosphorylation and degradation of IκB-α, which contributed to the inhibition of p65 nuclear accumulation and NF-κB activation. Furthermore, RHS-E70 suppressed the phosphorylation of ERK1/2 and p38, which results in the inhibition of ATF2 phosphorylation and subsequent nuclear accumulation. These results indicate that RHS-E70 may exert antiinflammatory activity by inhibiting NF-κB and MAPK/ATF2 signaling. From these findings, RHS-E70 has potential to be a candidate for the development of chemopreventive or therapeutic agents for the inflammatory diseases.