4′-Bromo-5,6,7-trimethoxyflavone represses lipopolysaccharide-induced iNOS and COX-2 expressions by suppressing the NF-κB signaling pathway in RAW 264.7 macrophages
作者:Dong Han Kim、Chang Hyeon Yun、Min Hwan Kim、Ch. Naveen Kumar、Bo Hee Yun、Ji-Sun Shin、Hyo Jin An、Young Hun Lee、Yong Don Yun、Hong-Kun Rim、Min-Sang Yoo、Kyung-Tae Lee、Yong Sup Lee
DOI:10.1016/j.bmcl.2011.10.067
日期:2012.1
The regulations of the NO and PGE(2) productions are research topics of interest in the field of anti-inflammatory drug development. In the present study, 5,6,7-trimethoxy- and 5,6,7-trihydroxyflavones 3a-3g were synthesized from cinnamic acid derivatives. In particular, 4'-bromo-5,6,7-trimethoxyflavone ( 3b) most potently inhibited the productions of NO and PGE(2) in LPS-treated RAW 264.7 cells ( IC(50) = 14.22 +/- 1.25 and 10.98 +/- 6.25 mu M, respectively), and these inhibitory effects were more potent than those of oroxylin A or baicalein. Consistent with these findings, 3b concentration-dependently reduced the LPS-induced expressions of iNOS and COX-2 at the protein and mRNA levels. In addition, the release of TNF-alpha, IL-6, and IL-1 beta and the mRNA expressions of these cytokines were reduced by 3b in a concentration-dependent manner. Furthermore, 3b attenuated the LPS-induced transcriptional activities of NF-kappa B and this was accompanied by parallel reductions in the degradation and phosphorylation of I kappa B-alpha, and consequently by a decrease in the nuclear translocation of the p65 subunit of NF-kappa B. Taken together, these results suggest that suppressions of the expressions of iNOS, COX-2, TNF-alpha, IL-6, and IL-1 beta via NF-kappa B inactivation are responsible for the anti-inflammatory effects of 3b. (C) 2011 Elsevier Ltd. All rights reserved.