Neobavaisoflavone ameliorates LPS-induced RAW264.7 cell inflammations by suppressing the activation of NF-κB and MAPKs signaling pathways

Neobavaisoflavone (NBIF) is an isoflavone isolated from Psoralea corylifolia L. It can effectively regulate the redox state as a natural anti-oxidant and show some anti-inflammatory activity. However, its molecular mechanism is poorly studied. In this study, RAW264.7 cells were treated with lipopolysaccharide (LPS) to investigate the anti-inflammatory activity and potential NBIF mechanism. RAW264.7 cells were treated with LPS (62.5 ng/ml) and exposed to different concentrations of NBIF (0.01, 0.1, and 1 μM) for 24 hr. Inflammatory cytokines of RAW264.7 cells were measured by the Griess method, ELISA, and western blot. Phagocytosis of RAW264.7 macrophages was measured by FITC-dextran uptake assay. The phosphorylation protein expression levels of MAPKs (JNK, p38, and ERK), NF-κB p65, IκBα, and IκB kinase were analyzed by western blot. The results were analyzed using one-way ANOVA with Tukey’s multiple comparison test. NBIF significantly inhibited NO and ROS production by down-regulation of iNOS and COX-2 protein expression. Additionally, the amount of release and protein levels of inflammation cytokines IL-6, IL-1β, and TNF-α were significantly decreased by NBIF. Moreover, FITC–dextran uptake assay by flow cytometry presented that NBIF significantly enhanced the phagocytic capacity of RAW264.7. Mechanistically, NBIF significantly down-regulated MAPK activation and inhibited the nuclear translocation of NF-κB p65.  The present study demonstrates that NBIF inhibited inflammation and enhanced the phagocytic capacity of RAW264.7 cell-related MAPKs and NF-κB signaling pathways induced by LPS. These findings suggest that NBIF may have clinical utility as an anti-inflammatory agent.