PT  - JOURNAL ARTICLE
AU  - YOKOYAMA, KEIKO
AU  - HASHIBA, KANA
AU  - WAKABAYASHI, HIDETSUGU
AU  - HASHIMOTO, KEN
AU  - SATOH, KAZUE
AU  - KURIHARA, TERUO
AU  - MOTOHASHI, NOBORU
AU  - SAKAGAMI, HIROSHI
TI  - Inhibition of LPS-stimulated NO Production in Mouse Macrophage-like Cells by Tropolones
DP  - 2004 Nov 01
TA  - Anticancer Research
PG  - 3917--3922
VI  - 24
IP  - 6
4099  - http://ar.iiarjournals.org/content/24/6/3917.short
4100  - http://ar.iiarjournals.org/content/24/6/3917.full
SO  - Anticancer Res2004 Nov 01; 24
AB  - 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