RT Journal Article SR Electronic T1 Inhibition of LPS-stimulated NO Production in Mouse Macrophage-like Cells by Azulenequinones JF Anticancer Research JO Anticancer Res FD International Institute of Anticancer Research SP 4157 OP 4163 VO 25 IS 6B A1 NISHISHIRO, MASAYUKI A1 ARIKAWA, SATOMI A1 WAKABAYASHI, HIDETSUGU A1 HASHIMOTO, KEN A1 SATOH, KAZUE A1 YOKOYAMA, KEIKO A1 UNTEN, SENWA A1 KAKUTA, HANZO A1 KURIHARA, TERUO A1 MOTOHASHI, NOBORU A1 SAKAGAMI, HIROSHI YR 2005 UL http://ar.iiarjournals.org/content/25/6B/4157.abstract AB Azulenequinone derivatives have been reported to display a broad spectrum of biological activities, but study at the cellular level has been limited. The effect of twenty-seven azulenequinone derivatives on nitric oxide (NO) production by mouse macrophage-like cells Raw 264.7 was investigated in this study. All of these compounds failed to stimulate the Raw 264.7 cells to produce detectable amounts of NO, but did inhibit NO production by lipopolysaccharide (LPS)-activated Raw 264.7 cells to varying extents. Compounds [7, 8, 9, 13, 16, 25, 27], which showed lesser cytotoxic activity (CC50=425, 381, 482, 179, 119, 235, 225 μM, respectively), inhibited NO production to the greatest extent [selectivity index (SI)= 15.4, 26.2, 3.9, 21.6, 3.1, 6.0, 8.4, respectively]. Western blot and RT-PCR analyses demonstrated that the most active derivatives, 3-morpholino-1,5-azulenequinone [8] and 3,7-dibromo-1,5-azulenequinone [13], significantly reduced both the intracellular concentration of iNOS protein and the expression of iNOS mRNA. ESR spectroscopy showed that compounds [8, 13] weakly scavenged NO produced by NOC-7, possibly via their general reducing activity. These data suggest that the inhibitory effect of NO production by compounds [8, 13] might be generated mostly via the inhibition of iNOS expression, rather than the radical-mediated mechanism. Copyright© 2005 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved