Ginsenoside Rp1, a ginsenoside derivative, blocks lipopolysaccharide- induced interleukin-1β production via suppression of the NF-κB pathway

Ginsenoside Rp1 (G-Rp1) is a ginseng saponin derivative with chemopreventive and anti-cancer activities. In this study, we examined the regulatory activity of G-Rp1 on the production of interleukin (IL)-1β, a pro-inflammatory cytokine managing acute or chronic inflammatory diseases such as septic shock and rheumatoid arthritis, from lipopolysaccharide (LPS)-treated macrophage-like RAW264.7 cells. G-Rp1 dose-dependently inhibited IL-1β production from LPS-treated RAW264.7 cells without altering cell viability. This compound suppressed both mRNA and protein levels of IL-1β. In particular, this compound was found to down-regulate phosphorylation of the inhibitor of κB (IκB) kinase (IKK)/IκBα, and consequent activation of NF-κB, but not the activation of its upstream signaling enzymes such as mitogen-activated protein kinases (MAPK) and p85, a regulatory subunit of phosphoinositide 3-kinase (PI3K). Therefore, these results suggest that G-Rp1 may act as an inhibitor of IL-1β production by inhibiting the NF-κB pathway.