title: Suppression of NF-κB by dieckol extracted from Ecklonia cava negatively regulates LPS induction of inducible nitric oxide synthase gene.
abstract: Dieckol, extracted from brown algae, Ecklonia cava, is suggested to elicit anti-inflammatory or anti-tumorigenic activities. However, dieckol-mediated regulatory mechanism for inflammatory response still remains elusive. Here, we show that dieckol suppressed lipopolysaccharide (LPS)-induced inducible nitric oxide synthase (iNOS) expression in mouse leukemic macrophage Raw264.7 cells. Also, dieckol decreased LPS-induced both nitric oxide (NO) production and iNOS promoter-driven transcriptional activity in a dose-dependent manner. On the other hand, LPS-mediated NF-κB activity was inhibited by dieckol treatment. Moreover, results revealed that dieckol diminished LPS-mediated p65 nuclear translocation or IκBα phosphorylation dose-dependently, and reduced LPS-induced phosphorylation of mitogen-activated protein kinases (MAPKs), significantly p38MAPK. Collectively, these findings suggest that dieckol acts as a negative regulator of LPS-mediated iNOS induction through suppression of NF-κB activity, implying a mechanistic role of dieckol in regulation of inflammatory response.
authors.affiliation: Department of Biochemistry, College of Medicine, Konyang University, 685 Gasuwon-dong, Seo-gu, Daejeon, 302-832, South Korea.
authors.forename: Hye-Jin
authors.initials: HJ
authors.lastname: Choi
authors.forename: Jung-Hwan
authors.initials: JH
authors.lastname: Park
authors.forename: Bong Ho
authors.initials: BH
authors.lastname: Lee
authors.forename: Hee Youn
authors.initials: HY
authors.lastname: Chee
authors.forename: Kyung Bok
authors.initials: KB
authors.lastname: Lee
authors.forename: Sang-Muk
authors.initials: SM
authors.lastname: Oh
mesh_terms: D021581:Active Transport, Cell Nucleus / Q000187:drug effects; D000818:Animals; D001572:Benzofurans / Q000737:chemistry / Q000494:pharmacology; D045744:Cell Line, Tumor; D002467:Cell Nucleus / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D004790:Enzyme Induction / Q000187:drug effects; D008070:Lipopolysaccharides / Q000633:toxicity*; D020935:MAP Kinase Signaling System / Q000187:drug effects; D008264:Macrophages / Q000378:metabolism*; D051379:Mice; D052247:Nitric Oxide Synthase Type II / Q000096:biosynthesis*; D000459:Phaeophyceae / Q000737:chemistry*; D051996:Transcription Factor RelA / Q000378:metabolism*
chemical_list: D001572:Benzofurans; D008070:Lipopolysaccharides; C498144:Rela protein, mouse; D051996:Transcription Factor RelA; C503840:dieckol; D052247:Nitric Oxide Synthase Type II; C496317:Nos2 protein, mouse