TY - JOUR T1 - Inhibition of LPS-stimulated NO Production in Mouse Macrophage-like Cells by Tropolones JF - Anticancer Research JO - Anticancer Res SP - 3917 LP - 3922 VL - 24 IS - 6 AU - KEIKO YOKOYAMA AU - KANA HASHIBA AU - HIDETSUGU WAKABAYASHI AU - KEN HASHIMOTO AU - KAZUE SATOH AU - TERUO KURIHARA AU - NOBORU MOTOHASHI AU - HIROSHI SAKAGAMI Y1 - 2004/11/01 UR - http://ar.iiarjournals.org/content/24/6/3917.abstract N2 - We investigated the effect of 27 tropolones on nitric oxide (NO) production by mouse macrophage-like Raw 264.7 cells. All of these compounds failed to stimulate the Raw 264.7 cells to produce detectable amounts of NO, but inhibited NO production by lipopolysaccharide (LPS)-activated Raw 264.7 cells to various extents. Generally, the ability of tropolones to inhibit LPS-stimulated NO production was inversely related to their cytotoxic activity. Western blot and RT-PCR analyses demonstrated that the most active compound, 2,4-dibromo-7-methoxytropone [21], significantly reduced both the intracellular concentration of iNOS protein and the expression of iNOS mRNA. ESR spectroscopy showed that [21] did not produce radicals under alkaline condition, nor scavenged NO, produced by NOC-7. These data suggested that the inhibitory effect of [21] on NO production might be generated via the inhibition of iNOS expression, rather than a radical-mediated mechanism. Copyright© 2004 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved ER -