Rheumatoid Arthritis: Lin N

Liu CF, Lin N. · (Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing 100700, China. · Zhongguo Zhong Yao Za Zhi. · Pubmed #17165577 No free full text.

Abstract: Extracts of Tripterygium wilfordii are effective in traditional Chinese medicine for treatment of rheumatoid arthritis (RA). Triptolide, a diterpenoid triepoxide purified from TWHF, has been identified as the major component of TWHF and might account for its therapeutic effects. To make for the clinical reasonable application and further development of triptolide, in this review was introduced the recent ten-years progress in mechanisms of anti-RA of it, including immunosuppression, anti-inflammation, inducing cell apoptosis, inhibiting vascular proliferation, protecting article cartilage and gene regulation. Triptolide is a potent immunosuppressant.

Imada K, Lin N, Liu C, Lu A, Chen W, Yano M, Sato T, Ito A. · Department of Biochemistry and Molecular Biology, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji-shi, Tokyo 192-0392, Japan. <> · Biochem Biophys Res Commun. · Pubmed #18541144 No free full text.

Abstract: Aggrecanase-1/a disintegrin and metalloproteinase with thrombospondin-like motifs (ADAMTS)-4 and aggrecanase-2/ADAMTS-5 have been shown to play crucial roles in cartilage destruction in arthritic diseases, including rheumatoid arthritis and osteoarthritis. In this study, we examined the effects of nobiletin, a citrus polymethoxy flavone, on the expression and production of ADAMTS-4 and -5 in vitro and in vivo. Nobiletin (16-64muM) interfered with the interleukin (IL)-1beta-mediated ADAMTS-4 and -5 mRNA expression in cultured human synovial fibroblasts. Furthermore, intraperitoneal administration of nobiletin (15, 30, and 60mg/kg) also suppressed ADAMTS-4 and -5 mRNA expression in the joint tissues of collagen-induced arthritic (CIA) mice. Immunohistochemical analysis using an antibody against aggrecan neoepitope (NVTEGE(373)) revealed that aggrecanase-mediated degradation of aggrecan in cartilage was effectively inhibited by nobiletin. These results provide novel evidence that nobiletin effectively interferes with gene expression of ADAMTS-4 and -5, and thereby prevents cartilage destruction in CIA mice.

Lin N, Liu C, Xiao C, Jia H, Imada K, Wu H, Ito A. · Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, No. 16, Nanxiaojie, Dongzhimennei, Beijing 100700, China. · Biochem Pharmacol. · Pubmed #17097618 No free full text.

Abstract: Chinese herbal remedy Tripterygium wilfordii Hook. f. (TWHF) has been reported to be therapeutically efficacious in the treatment of rheumatoid arthritis (RA), but its in vivo actions have not been clarified. The purpose of this study was to investigate the effects of triptolide, a diterpenoid triepoxide extracted from TWHF, on inflammation and cartilage destruction in collagen-induced arthritis (CIA) model mice. Histological examination demonstrated that triptolide significantly reduced the inflammatory responses and cartilage damage in the joint tissues. Interestingly, triptolide interfered with CIA-augmented expression of matrix metalloproteinases-13 and -3, which are considered to be key enzymes in the pathological destruction of cartilage, and simultaneously augmented CIA-reduced tissue inhibitors of metalloproteinases-1 and -2 expression in the joints. Moreover, triptolide inhibited prostaglandin E(2) production via selective suppression of the production and gene expression of cyclooxygenase (COX)-2, but not COX-1. The levels of interleukin (IL)-1beta, tumor necrosis factor alpha and IL-6 were also decreased by triptolide in the joint tissues and sera as well as the suppression of CIA-mediated expression of their mRNAs in the joints. In addition, triptolide treatment in vivo was able to reduce an abundance of nuclear factor-kappaB, the transcriptional factor closely related to the inflammatory process, in articular cartilage and synovium in CIA mice. These results suggest that triptolide exerts novel chondroprotective and anti-inflammatory effects on RA, and the therapeutic action of TWHF on RA is, in part, due to the triptolide activities.

Lin N, Sato T, Ito A. · Institute of Chinese Materia Medica, China Academy of Traditional Chinese Medicine, Beijing. · Arthritis Rheum. · Pubmed #11592385 No free full text.

Abstract: OBJECTIVE: Various extracts of the Chinese herbal remedy Tripterygium wilfordii Hook. f. (TWHF) have been reported to be therapeutically efficacious in rheumatoid arthritis (RA) in China, but their mechanism of action remains unclear. We investigated the effect of triptolide, a diterpenoid triepoxide from TWHF, on the production of pro-matrix metalloproteinase 1 (proMMP-1; or procollagenase 1 or pro-interstitial collagenase 1), proMMP-3 (or prostromelysin 1), tissue inhibitors of metalloproteinases (TIMPs), and proinflammatory cytokines in human synovial fibroblasts and J774A.1 mouse macrophages. METHODS: Human synovial fibroblasts and mouse macrophages were cultured with interleukin-1alpha (IL-1alpha) or lipopolysaccharide (LPS) in the presence or absence of triptolide. The production of proMMPs 1 and 3, TIMPs 1 and 2, cyclooxygenase 1 (COX-1) and COX-2, prostaglandin E2 (PGE2), IL-1beta, and IL-6 was assayed by Western blot analysis and enzyme-linked immunosorbent assay. Gene expression of proMMPs 1 and 3, TIMPs 1 and 2, COX-1 and COX-2, IL-1alpha, IL-1beta, tumor necrosis factor alpha (TNFalpha), and IL-6 was also monitored by Northern blot analysis and reverse transcriptase-polymerase chain reaction. RESULTS: Triptolide suppressed the IL-1alpha-induced production of proMMPs 1 and 3 and decreased their messenger RNA levels in human synovial fibroblasts. In contrast, the IL-1alpha-induced gene expression and production of TIMPs 1 and 2 were further augmented by triptolide in the synovial cells. Triptolide also inhibited the IL-1alpha-induced production of PGE2 by selectively suppressing the gene expression and production of COX-2, but not those of COX-1. In addition, triptolide suppressed the LPS-induced production of PGE2 in mouse macrophages. Furthermore, the gene expression of IL-1alpha, IL-1beta, TNFalpha, and IL-6, as well as the production of IL-1beta and IL-6, were inhibited by triptolide in the LPS-treated mouse macrophages. CONCLUSION: We have demonstrated for the first time that the therapeutic effects of TWHF in RA are due in part to the novel chondroprotective effect of triptolide via the direct suppression of the production of proMMPs 1 and 3 and the simultaneous up-regulation of TIMPs in IL-1-treated synovial fibroblasts. Triptolide's interference with gene expression of proinflammatory cytokines and its known inhibitory effects on PGE2 production are also probably very effective.