Anti-inflammatory Effects of Schisandra chinensis (Turcz.) Baill Fruit Through the Inactivation of Nuclear Factor-κB and Mitogen-activated Protein Kinases Signaling Pathways in Lipopolysaccharide-stimulated Murine Macrophages

BACKGROUND Schisandrae Fructus, the dried fruit of Schisandra chinensis (Turcz.) Baill. (Magnoliaceae), is widely used in traditional medicine for the treatment of a number of chronic inflammatory diseases. This study examined the anti-inflammatory effects of Schisandrae Fructus ethanol extract (SF) on the production of pro-inflammatory substances in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. METHODS To measure the effects of SF on pro-inflammatory mediator and inflammatory cytokine's expression and production in RAW 264.7 cells, we used the following methods: cell viability assay, Griess reagent assay, enzyme-linked immunosorbent assay, reverse transcriptase-polymerase chain reaction, Western blotting analysis and immunofluorescence staining. RESULTS Stimulation of the RAW 264.7 cells with LPS caused an elevated production of nitric oxide (NO), tumor necrosis factor α (TNF-α) and interleukin (IL)-1β, which was markedly inhibited by the pretreatment with SF without causing any cytotoxic effects. SF also inhibited the expression of inducible NO synthase, TNF-α, and IL-1β protein and their mRNAs in LPS-stimulated RAW 264.7 cells. Furthermore, SF attenuated LPS-induced nuclear translocation of nuclear factor-κB (NF-κB) by reducing inhibitory-κB degradation, and reduced the phosphorylation of mitogen-activated protein kinases (MAPKs), implying that SF regulated LPS-induced NF-κB-dependent inflammatory pathways through suppression of MAPKs activation. CONCLUSIONS SF may be useful for the treatment of various inflammatory diseases.