RT Journal Article
SR Electronic
T1 Inhibition of LPS-stimulated NO Production in Mouse Macrophage-like Cells by Tropolones
JF Anticancer Research
JO Anticancer Res
FD International Institute of Anticancer Research
SP 3917
OP 3922
VO 24
IS 6
A1 YOKOYAMA, KEIKO
A1 HASHIBA, KANA
A1 WAKABAYASHI, HIDETSUGU
A1 HASHIMOTO, KEN
A1 SATOH, KAZUE
A1 KURIHARA, TERUO
A1 MOTOHASHI, NOBORU
A1 SAKAGAMI, HIROSHI
YR 2004
UL http://ar.iiarjournals.org/content/24/6/3917.abstract
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