Anti-inflammatory effects of dichloromethane fraction from Orostachys japonicus in RAW 264.7 cells: Suppression of NF-κB activation and MAPK signaling

摘要

Ethnopharmacological relevance: Orostachys japonicus A. Berger (O. japonicus) is known to reduce the risk of many diseases. Aim of the study: We investigated the anti-inflammatory effects of the dichloromethane (DCM) fraction from O. japonicus (OJD) in LPS-stimulated RAW 264.7 cells. Materials and methods: NO was measured using the Griess method. Key pro-inflammatory cytokines and mediators including IL-1β, TLR4, iNOS, and COX-2; 2 important pro-inflammatory transcription factors, NF-κB p65 and IκBα; and MAPKs such as ERK1/2, JNK, and p38 were analyzed by Western blotting. Results: OJD significantly inhibited NO production, IL-1β, TLR4, iNOS, and COX-2 expression in LPS-stimulated cells. Additionally, it inhibited LPS-induced NF-κB p65 activation via inhibition of IκBα phosphorylation. Furthermore, phosphorylation of p38 and JNK was suppressed by OJD in a dose-dependent manner in the LPS-stimulated RAW 264.7 cells. Conclusions: Our data suggest that OJD inhibits the inflammatory response via suppression of NF-κB activation and MAPK signaling.