title: Inhibitory effect of sulphated polysaccharide porphyran on nitric oxide production in lipopolysaccharide-stimulated RAW264.7 macrophages.
abstract: Porphyran, extracted from an edible red alga (Porphyra yezoensis), is a sulphated polysaccharide with a wide variety of biological activities including anti-tumour, antioxidant and immuno-modulating activities. In this study, we examined the effect of porphyran on nitric oxide (NO) production in mouse macrophage cell line RAW264.7 cells. Although no significant activity of porphyran to induce NO or tumour necrosis factor-α (TNF-α) production in RAW264.7 cells was observed at the concentration range tested (10-500 µg/ml), it was found for the first time that porphyran inhibited NO production and expression of inducible nitric oxide synthase (iNOS) in RAW264.7 cells stimulated with lipopolysaccharide (LPS). In the presence of 500 µg/ml porphyran, NO production and expression of iNOS in LPS-treated RAW264.7 cells were completely suppressed. On the other hand, porphyran showed only a marginal effect on the secretion of TNF-α from LPS-stimulated RAW264.7 cells. Electrophoretic mobility shift assay (EMSA) using infrared dye labelled oligonucleotide with nuclear factor-κB (NF-κB) consensus sequence suggested that porphyran inhibited the LPS-induced NF-κB activation. The LPS-inducible nuclear translocation of p65, and the phosphorylation and degradation of IκB-α were also inhibited by the pre-treatment with porphyran. Our results obtained in in vitro analysis suggest that porphyran suppresses NO production in LPS-stimulated macrophages by the blocking of NF-κB activation.
authors: Graduate School of Science and Technology, Nagasaki University, 1-14 Bunkyo-machi, Nagasaki 852-8521, Japan.
authors: Zedong
authors: Z
authors: Jiang
authors: Yoichiro
authors: Y
authors: Hama
authors: Kenichi
authors: K
authors: Yamaguchi
authors: Tatsuya
authors: T
authors: Oda
mesh_terms: D021581:Active Transport, Cell Nucleus / Q000187:drug effects; D000818:Animals; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism; D002470:Cell Survival / Q000187:drug effects; D053938:DNA Fragmentation / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D020672:I-kappa B Proteins / Q000378:metabolism; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008264:Macrophages / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D051379:Mice; D000072000:NF-KappaB Inhibitor alpha; D016328:NF-kappa B / Q000378:metabolism; D009569:Nitric Oxide / Q000096:biosynthesis*; D052247:Nitric Oxide Synthase Type II / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D010766:Phosphorylation / Q000187:drug effects; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012685:Sepharose / Q000031:analogs & derivatives* / Q000494:pharmacology; D013481:Superoxides / Q000378:metabolism; D051996:Transcription Factor RelA / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis
chemical_list: D020672:I-kappa B Proteins; D008070:Lipopolysaccharides; D016328:NF-kappa B; C000606205:Nfkbia protein, mouse; D051996:Transcription Factor RelA; D014409:Tumor Necrosis Factor-alpha; C038549:porphyran; D013481:Superoxides; D000072000:NF-KappaB Inhibitor alpha; D009569:Nitric Oxide; D012685:Sepharose; D052247:Nitric Oxide Synthase Type II