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 (H₂O). 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.