title: Phase 2 enzyme inducer sulphoraphane blocks prostaglandin and nitric oxide synthesis in human articular chondrocytes and inhibits cartilage matrix degradation.
abstract: OBJECTIVE
  We explored the inhibitory effect of sulphoraphane (SFN), a potent inducer of Phase 2 enzymes, on cytokine-induced prostaglandin E(2) (PGE2) and nitric oxide (NO) production and cartilage degradation in articular chondrocytes. The regulatory mechanism of SFN on nuclear factor (NF)-κB was investigated.
  
  
  METHODS
  Chondrocytes were obtained from patients with knee OA. Chondrocytes were stimulated with IL-1β or TNF-α with or without pre-incubation with SFN. Production of PGE2 and NO was evaluated by the Griess reaction and an ELISA. The expression of microsomal PGE synthase (mPGES), cyclo-oxygenase (COX)-2 and inducible NO synthase (iNOS) was evaluated by real-time RT-PCR and western blot analysis. The regulation of NF-κB activity was explored using luciferase and chromatin immunoprecipitation assays as well as a western blot for phosphorylated IκB kinase (IKK), IκB and the degradation of IκB. Proteoglycan and type II collagen degradation products released from explant cultures were analysed using the dimethylmethylene blue assay and an ELISA for C-terminal telopeptides of type II collagen.
  
  
  RESULTS
  SFN inhibited the production of PGE2 and NO induced by IL-1β and TNF-α. At a concentration as low as 5 μM, SFN completely inhibited mPGES, COX-2 and iNOS at the mRNA and protein levels, and proteoglycan and type II collagen degradation product release in explant culture. Various signalling pathways required for the NF-κB activation were affected by SFN.
  
  
  CONCLUSIONS
  SFN inhibited a broad range of catabolic mechanisms in articular chondrocytes. SFN may be a safe and effective candidate drug for the inhibition of cartilage degradation in arthritic diseases.
authors.affiliation: Division of Rheumatology, Department of Internal Medicine, Hallym University Sacred Heart Hospital, 896, Pyongchondong, Dongan-gu, Anyang, Kyunggi-do 431-070, Korea. kimha@hallym.ac.kr
authors.forename: Hyun-Ah
authors.initials: HA
authors.lastname: Kim
authors.forename: Yunshin
authors.initials: Y
authors.lastname: Yeo
authors.forename: Hyun A
authors.initials: HA
authors.lastname: Jung
authors.forename: Young O
authors.initials: YO
authors.lastname: Jung
authors.forename: Su J
authors.initials: SJ
authors.lastname: Park
authors.forename: Song J
authors.initials: SJ
authors.lastname: Kim
mesh_terms: D000368:Aged; D002358:Cartilage, Articular / Q000166:cytology; D002478:Cells, Cultured; D019902:Chondrocytes / Q000166:cytology / Q000187:drug effects* / Q000201:enzymology*; D024043:Collagen Type II / Q000378:metabolism; D051546:Cyclooxygenase 2 / Q000235:genetics / Q000378:metabolism; D015232:Dinoprostone / Q000096:biosynthesis / Q000276:immunology / Q000378:metabolism*; D005109:Extracellular Matrix / Q000276:immunology / Q000378:metabolism; D005260:Female; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D006801:Humans; D053583:Interleukin-1beta / Q000494:pharmacology; D019746:Intramolecular Oxidoreductases / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D016328:NF-kappa B / Q000378:metabolism; D009569:Nitric Oxide / Q000096:biosynthesis / Q000276:immunology / Q000378:metabolism*; D052247:Nitric Oxide Synthase Type II / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D009570:Nitriles / Q000494:pharmacology*; D020370:Osteoarthritis, Knee / Q000188:drug therapy* / Q000276:immunology / Q000378:metabolism; D000071876:Prostaglandin-E Synthases; D013454:Sulfoxides / Q000494:pharmacology*; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology
chemical_list: D024043:Collagen Type II; D053583:Interleukin-1beta; D016328:NF-kappa B; D009570:Nitriles; D013454:Sulfoxides; D014409:Tumor Necrosis Factor-alpha; C534606:sulphoraphane nitrile; D009569:Nitric Oxide; C496319:NOS2 protein, human; D052247:Nitric Oxide Synthase Type II; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; D019746:Intramolecular Oxidoreductases; D000071876:Prostaglandin-E Synthases; D015232:Dinoprostone