Anti-inflammatory effects of 4-arylcoumarins in LPS-induced murine macrophage RAW 264.7 cells

This research was undertaken to find the in vitro inflammatory action of 5,7-dimethyloxy-4-p-methoxyl-phenylcoumarin and 5,7-dimethoxy-4-phenylcoumarin produced by Streptomyces aureofaciens CMUAc130. We investigated the effects of 5,7-dimethyloxy-4-p-methoxyl-phenylcoumarin and 5,7-dimethoxy-4-phenylcoumarin not only on the formation of NO, prostaglandin E-2 (PGE(2)), and tumor necrosis factor-alpha (TNF-alpha) but also on inducible nitric oxide synthase and cyclooxygenase-2 (COX-2) in lipopolysaccharide (LPS)-induced murine macrophage RAW 264.7 cells. The data obtained were consistent with the modulation of iNOS enzyme expression. A similar fashion was also observed when LPS-induced PGE(2) release and COX-2 expression were tested. The significant inhibitory effects were shown in concentration-dependent manners. In addition, 5,7dimethyloxy-4-p-methoxylphenylcoumarin and 5,7dimethoxy-4-phenylcoumarin also mildly but significantly reduced the formation of TNF-alpha. These findings support the application of 5,7-dimethyloxy-4-p-methoxylphenylcoumarin and 5,7-dimethoxy-4-phenylcoumarin as anti-inflammatory agents.