Down-regulatory effect of quercitrin gallate on nuclear factor-kappa B-dependent inducible nitric oxide synthase expression in lipopolysaccharide-stimulated macrophages RAW 264.7.
Quercetin 3-O-beta-(2''-galloyl)-rhamnopyranoside (QGR) is a naturally occurring quercitrin gallate, a polyphenolic compound isolated from Persicaria lapathifolia (Polygonaceae). In the present study, QGR compound was discovered to have inhibitory effect on nitric oxide (NO) production in lipopolysaccharide (LPS)-stimulated macrophages RAW 264.7. QGR compound attenuated LPS-induced synthesis of both mRNA and protein of inducible nitric oxide synthase (iNOS), in parallel, and inhibited LPS-induced luciferase expression as a reporter of iNOS promoter activity in the macrophages. As a mechanism of the anti-inflammatory action shown by QGR compound, suppression of nuclear factor (NF)-kappaB activation has been documented. QGR compound exhibited inhibitory effect on LPS-mediated NF-kappaB transcriptional activity in macrophages RAW 264.7. Furthermore, the compound inhibited LPS-mediated nuclear translocation of NF-kappaB p65 and DNA binding activity of NF-kappaB complex, in parallel, but did not influence LPS-mediated IkappaBalpha degradation. Taken together, QGR compound suppressed LPS-mediated NF-kappaB activation, specifically to nuclear localization step of NF-kappaB p65, which was attributable to its down-regulatory action on LPS-induced NO production and iNOS expression.
Kim
Byung Hak
BH
College of Pharmacy and Research Center for Bioresource and Health, Chungbuk National University, Cheongju 361-763, Republic of Korea.
Cho
Sung Min
SM
Reddy
Alavala Matta
AM
Kim
Yeong Shik
YS
Min
Kyung Rak
KR
Kim
Youngsoo
Y
D000818:Animals; D002460:Cell Line; D004305:Dose-Response Relationship, Drug; D015536:Down-Regulation / Q000187:drug effects / Q000502:physiology; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects* / Q000502:physiology; D008070:Lipopolysaccharides / Q000494:pharmacology; D008262:Macrophage Activation / Q000187:drug effects / Q000502:physiology*; D051379:Mice; D016328:NF-kappa B / Q000502:physiology*; D019001:Nitric Oxide Synthase / Q000096:biosynthesis* / Q000235:genetics; D052247:Nitric Oxide Synthase Type II; D011794:Quercetin / Q000031:analogs & derivatives* / Q000737:chemistry / Q000494:pharmacology*
D008070:Lipopolysaccharides; D016328:NF-kappa B; C012526:quercitrin; D011794:Quercetin; D019001:Nitric Oxide Synthase; D052247:Nitric Oxide Synthase Type II; C496317:Nos2 protein, mouse