Anti-inflammatory effect of the hexane fraction from Orostachys japonicus in RAW 264.7 cells by suppression of NF-κB and PI3K-Akt signaling

• OJH inhibits LPS-induced pro-inflammatory molecules.
• OJH inhibits LPS-induced activation of NF-κB and PI3K signaling.
• OJH is an interesting target for the treatment of inflammatory disease.

We investigated the anti-inflammatory effect of the hexane fraction from Orostachys japonicus (OJH) in LPS (lipopolysaccharide)-stimulated RAW 264.7 cells. Pretreatment with OJH dose-dependently reduced the cellular NO (nitric oxide) concentration and also inhibited expression of iNOS (inducible nitric oxide synthase) protein and mRNA. By the prevention of IκBα (inhibitory factor kappa B alpha) phosphorylation and degradation, OJH inhibited LPS-induced NF-κB (nuclear factor-kappa B) activation. OJH had no effect on the LPS-induced phosphorylation of ERK (extracellular signal-regulated kinase), JNK (c-Jun N-terminal kinase), or p38, whereas it attenuated the phosphorylation of Akt in a dose-dependent manner. In addition, OJH suppressed the LPS-induced expression of LPS receptors CD14 and TLR4 (toll like receptor 4). These results suggest that OJH may interrupt LPS-induced pro-inflammatory cascades through inhibition of NF-κB and Akt activation.