Fructus sophorae attenuates secretion of proinflammatory mediators and cytokines through the modulation of NF-κB and MAPK signaling pathways in LPS-stimulated RAW 264.7 macrophages

Abstract

This study investigated the inhibitory effects and underlying mechanisms of fructus sophorae, the dried ripe fruit of Styphnolobium japonicum (L.) Schott, on the production of proinflammatory molecules in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. The results indicated that pretreatment with noncytotoxic concentrations of fructus sophorae extract (FSE) significantly inhibited the release of the proinflammatory mediators nitric oxide (NO) and prostaglandin E(2), which were associated with the downregulation of both mRNA and protein for inducible NO synthase and cyclooxygenase-2, respectively, in LPS-challenged RAW 264.7 cells. FSE also blocked the LPS-induced expression of the proinflammatory cytokines interleukin (IL)-6 and IL-1β. Furthermore, the results showed that FSE efficiently attenuated the LPS-induced nuclear translocation of nuclear factor-kappa B (NF-κB) and phosphorylation of the mitogen-activated protein kinases (MAPKs) extracellular signal-regulated kinase (ERK) and c-Jun N-terminal kinase (JNK) but not p38 MAPK. These results suggest that FSE exhibits anti-inflammatory activity by inhibiting proinflammatory mediators and cytokines through the inactivation of NF-κB, ERK and JNK, and it may offer therapeutic potential for treating inflammatory diseases accompanied with macrophage activation.