title: [Inhibitory effect of triptolide on interleukin-18 and its receptor in rheumatoid arthritis synovial fibroblasts].
abstract: OBJECTIVE
  To determine the effects of triptolide (TP) on the expression of interleukin-18 (IL-18) and its receptor in phorbol 12-myristate 13-acetate (PMA)-stimulated rheumatoid arthritis synovial fibroblasts (RASF).
  
  
  METHODS
  RASF were pretreated with TP (0-100 microg/L) for 2 h before stimulation with PMA (50 microg/L). The bioactivity of IL-18 in the supernatant was detected based on IFN-gamma secretion from IL-18-responding human myelomonocytic KG-1 cells. IL-18 level was analyzed by ELISA. To estimate the protein and mRNA expression of IL-18 and IL-18Ralpha in RASF, Western blot and quantitative RT-PCR were performed. Nuclear factor-kappaB (NF-kappaB) activity in the whole-cell extract of treated RASF was also measured using an ELISA-based method.
  
  
  RESULTS
  TP effectively inhibited the bioactivity of IL-18 in PMA-stimulated RASF. The expression of IL-18 and IL-18R at protein and gene levels was reduced by TP. NF-kappaB activity in PMA-stimulated RASF was profoundly suppressed by TP. These effects showed a high correlation with TP concentration (0-100 microg/L).
  
  
  CONCLUSIONS
  TP effectively inhibited the expression of IL-18 and its receptor in PMA-stimulated RASF. These results suggest a mechanism of TP in RA therapy.
authors.affiliation: The Obstetrics and Gynecology Hospital, College of Medicine, Zhejiang University, Hangzhou 310006, China. aimaoxiaodan@hotmail.com
authors.forename: Xiao-dan
authors.initials: XD
authors.lastname: Mao
authors.forename: Sai-jun
authors.initials: SJ
authors.lastname: Sun
authors.forename: Zi-yan
authors.initials: ZY
authors.lastname: Pei
authors.forename: Li-huang
authors.initials: LH
authors.lastname: Zhang
mesh_terms: D001172:Arthritis, Rheumatoid / Q000188:drug therapy* / Q000276:immunology; D004224:Diterpenes / Q000494:pharmacology*; D004852:Epoxy Compounds / Q000494:pharmacology; D005347:Fibroblasts / Q000187:drug effects / Q000276:immunology; D006801:Humans; D007166:Immunosuppressive Agents / Q000494:pharmacology*; D020382:Interleukin-18 / Q000037:antagonists & inhibitors*; D016328:NF-kappa B / Q000037:antagonists & inhibitors; D010616:Phenanthrenes / Q000494:pharmacology*; D053724:Receptors, Interleukin-18 / Q000037:antagonists & inhibitors*; D013583:Synovial Membrane / Q000187:drug effects* / Q000276:immunology
chemical_list: D004224:Diterpenes; D004852:Epoxy Compounds; D007166:Immunosuppressive Agents; D020382:Interleukin-18; D016328:NF-kappa B; D010616:Phenanthrenes; D053724:Receptors, Interleukin-18; C001899:triptolide