Orostachys japonicus extract inhibits the lipopolysaccharide‐induced pro‐inflammatory factors by suppression of transcription factors

Orostachys japonicus (O. japonicus) was extracted with ethanol (EtOH) and sequentially separated with organic solvents, including n‐hexane (Hex), dichloromethane (DCM), ethyl acetate (EtOAc), n‐butanol (BuOH), and water (H(2)O). All the fractions were confirmed for anti‐inflammatory activity in an inflammatory condition. The DCM fraction showed the highest anti‐inflammatory ability. Here, we examined the effect of DCM fraction and investigated the intracellular signaling pathways in LPS‐stimulated RAW 264.7 macrophage cells. The DCM fraction significantly inhibited the mRNA levels of pro‐inflammatory mediators and cytokines including iNOS, COX‐2, IL‐1β, IL‐2, IL‐6, and IP‐10 in LPS‐stimulated cells. Also, the treatment of DCM fraction excellently reduced the expression of the proteins of AP‐1 (phospho‐c‐Jun and phospho‐c‐Fos) and phospho‐IRF3 as transcription factors. As a result, it suppressed LPS‐induced inflammatory mediator and cytokines via inhibition of transcription factors. In conclusion, our data demonstrated that DCM fraction has a strong anti‐inflammatory activity that improves the inflammatory state.