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Inflammation Research

, Volume 48, Issue 11, pp 575–581 | Cite as

The molecular mechanism of inhibition of interleukin-1β-induced cyclooxygenase-2 expression in human synovial cells by Tripterygium wilfordii Hook F extract

  • K. Maekawa
  • N. Yoshikawa
  • J. Du
  • S. Nishida
  • H. Kitasato
  • K. Okamoto
  • H. Tanaka
  • Y. Mizushima
  • S. Kawai

Abstract.

Objective: Several extracts of Tripterygium wilfordii Hook F (TWHF) have been reported to be effective in patients with rheumatoid arthritis. We investigated the effect of multi-glycosides of TWHF (GTW), a TWHF extract, on interleukin (IL)-1β-stimulated human rheumatoid synovial cells. ¶Materials and Methods: IL-1β-stimulated synovial cells were used to detect the effects of GTW on cyclooxygenase (COX)-1 and COX-2 activities, expression of COX protein and mRNA, and nuclear transcription factors in experiments using respective reporter plasmids. ¶Results: GTW inhibited prostaglandin E2 production by IL-1β-stimulated synovial cells in a concentration-dependent manner, and also inhibited COX-2 protein and mRNA expression in a similar fashion to dexamethasone. However, GTW did not act as a glucocorticoid agonist. GTW repressed IL-1β-induced nuclear factor-κB activity, but did not have a significant influence on activating protein-1 activity. ¶Conclusion: The anti-rheumatic effect of GTW or TWHF may be partly mediated through the inhibition of prostaglandin E2 production in human synovial cells due to suppression of COX-2 mRNA, possibly via inhibition of nuclear factor-κB activity.

Key words: Tripterygium wilfordii Hook F — Cyclooxygenase-2 — Glucocorticoid receptor — Nuclear factor-κB — Synovial cells 

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Copyright information

© Birkhäuser Verlag, Basel, 1999

Authors and Affiliations

  • K. Maekawa
    • 1
  • N. Yoshikawa
    • 2
  • J. Du
    • 1
  • S. Nishida
    • 1
  • H. Kitasato
    • 1
  • K. Okamoto
    • 2
  • H. Tanaka
    • 2
  • Y. Mizushima
    • 1
  • S. Kawai
    • 1
  1. 1.Institute of Medical Science, St. Marianna University School of Medicine, 2-16-1 Sugao, Miyamae, Kawasaki 216-8512, Japan, Fax +81449774061, e-mail: s2kawai@marianna-u.ac.jp JP
  2. 2.Second Department of Internal Medicine, Asahikawa Medical College, 4-5-3 Nishikagura, Asahikawa 078-8510, Japan JP

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