Inhibitory Effects of an Ethyl Acetate Fraction from Cephalonoplos segetum on Inflammatory Mediators from Lipopolysaccharide-induced RAW 264.7 Macrophages

Cephalonoplos segetum has been used as an herbal remedy, and is considered to have anti-inflammatory potential. However, its biological mechanism in this treatment process remains unknown. Therefore, the anti-inflammatory activity of the ethyl acetate fraction of C. segetum extracts (CSE-EA), more active than C. segetum extracts (CSE) in murine macrophages, was investigated. Production levels of nitric oxide (NO), prostaglandin E-2 (PGE(2)), tumor necrosis factor-alpha (TNF-alpha), and interleukin-1 beta (IL-1 beta) by lipopolysaccharide (LPS)-induced RAW 264.7 macrophages were measured by ELISA. In addition, protein expression levels of inducible NO synthase (iNOS) and cyclooxygenase (COX)-2, and the phosphorylation of mitogen-activated protein kinases (MAPKs) in the LPS-induced macrophages were investigated by Western blotting. The CSE-EA (50, 100 or 200 mu g/mL) significantly inhibited NO, PGE(2), INF-alpha, and IL-1 beta production in LPS-induced macrophages in a dose-dependent manner with 50% inhibitory concentration values of 80.4, 104.7, 91.3, and 46.7 mu g/mL, respectively. Similarly, CSE-EA reduced protein expression of iNOS and COX-2 and led to the attenuated activation of kinases ERK1/2 and JNK in the macrophages. Results of the present study suggest that the anti-inflammatory effects of CSE-EA are likely due to the down-regulation of NO, PGE(2), INF-alpha, and IL-1 beta and the reduced expression of iNOS and COX-2 via suppression of MAPK signaling pathways in LPS-induced murine macrophages.