ACTIVE COMPOUND OF ZINGIBER CASSUMUNAR ROXB. DOWN-REGULATES THE EXPRESSION OF GENES INVOLVED IN JOINT EROSION IN A HUMAN SYNOVIAL FIBROBLAST CELL LINE
Rujirek Chaiwongsa1, Siriwan Ongchai1*, Phorani Boonsing1, Prachya Kongtawelert1, Ampai Panthong2 and Vichai Reutrakul3 1Thailand Excellence Center for Tissue Engineering and Stem Cells, Department of Biochemistry and Center of Excellence for Innovation in Chemistry, Faculty of Medicine, Chiang Mai University, Chiang Mai 50200, Thailand 2Department of Pharmacology and Center of Excellence for Innovation in Chemistry, Faculty of Medicine, Chiang Mai University, Chiang Mai 50200, Thailand 3Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Mahidol University, Bangkok 10400, Ongchai Department of Biochemistry, Faculty of Medicine, Chiang Mai University, Chiang Mai, 50200 Thailand. *E-mail: email@example.com Abstract Rheumatoid arthritis (RA) is a chronic inflammatory disease of the synovium. It is involved in up-regulation of pro-inflammatory cytokines and matrix metalloproteinases (MMPs), resulting in joint inflammation and erosion. Zingiber cassumunar Roxb. has long been used to reduce joint pain and inflammation. This study aimed to investigate the inhibitory activities of an active compound of Z. cassumunar, (E)-4-(3′,4′-dimethoxyphenyl)but-3-en-1-ol (compound D), against cytokine-induced up-regulation of catabolic genes involved in cartilage degradation in RA. Synovial fibroblast cell line, SW982, was cultured in media containing interleukin-1ß (IL-1ß), in the presence or absence of compound D at the concentration range of 1 to 100 μM. After 24 hours, the cells were analyzed for the expressions of MMPs, IL-1ß and interleukin-1ß-converting enzyme (ICE) by RT-PCR. MMPs activities in the culture media were analyzed by zymographic techniques. Dexamethasone was used as the positive control. It was found that compound D at the concentration of 10 – 100 M significantly decreased the mRNA expressions of MMP-1, -2, -3, and -13 which was induced by IL-1ß (P<0.05) concomitantly with a decrease in activities of these MMPs in the culture media. An increase in the mRNA expression of IL-1ß and ICE was also suppressed by compound D. The results suggest that the potent activities of this compound may be involved in the reduction of IL-1ß protein synthesis in both pro-form and active form which played an important role in up-regulation of MMPs. This study first revealed the chondroprotective activity of Z. cassumunar in the transcriptional level by suppressing cytokine-induced catabolic genes which caused cartilage erosion in RA. Key words: (E)-4-(3′,4′-dimethoxyphenyl)but-3-en-1-ol, compound D, matrix metalloproteinases, interleukin-1ß, interleukin-1-converting enzyme, Zingiber cassumunar. Introduction Rheumatoid arthritis (RA) is an autoimmune disease which causes chronic inflammation of the joints and the surrounding tissues, leading to joint pain and deformity (Scher and Abramson, 2011). The inflammatory process of the synovial membrane causes the progressive destruction of cartilage and bone (Feldmann et al., 1996). The mechanism of action is involved in an elevation of the pro-inflammatory cytokines, especially interleukin-1beta (IL-1ß) and thereby results in the up-regulation of matrix metalloproteinases (MMPs) which are responsible for joint erosion (Mohammed et al., 2003). The current treatment of RA includes three categories; non-steroidal anti-inflammatory drugs (NSAIDs), glucocorticoids such as dexamethasone, and disease-modifying anti-rheumatic drugs (DMARDs) (Peng-Thim and Keng- Hong, 2007). However, long-term use of these pharmacological agents causes deleterious side effects (Weisman, 2005). Thus, alternatively some medicinal plants have been used for pain relief, which is a regular symptom of this disease. Zingiber cassumunar Roxb. is one of the most widely used medicinal plants of Asian folk remedies for joint and muscular pain. (E)-4-(3′,4′-dimethoxyphenyl)but-3-en-1-ol, compound D, is an active ingredient of the essential oil isolated from the hexane extract of Z. cassumunar (Amatayakul, 1979). There have been reports that compound D exhibited a strong anti-inflammatory response in vivo (Masuda and Jitoe, 1994) and protected cartilage degradation in the cartilage explant model (Chaiwongsa, 2012). We therefore attempted to verify the chondroprotective activities of compound D at the molecular level against the IL-1ß-induced expression of catabolic genes which caused joint destruction. Results of this study may provide alternative medical treatment for RA. Conclusion :
The present study clearly demonstrated the inhibitory activities of compound D, an anti-inflammatory compound of Z. cassumunar against the IL-1ß-induced catabolic gene expression that involves in cartilage degeneration. The results indicated that compound D can serve as an upstream inhibitor of the catabolic cascade in chronic inflammatory joint erosion.
These data provided the additional scientific-based information that Z. cassumunar may not only be effective on the reduction of joint pain and inflammation, but also delay joint destruction. Our study supports complementary and alternative medicines’ utilization of Z. cassumunar for the treatment of chronic inflammatory joint diseases. Acknowledgments This study was supported by a grant from Center of Excellence for Innovation in Chemistry (PERCH-CIC) and Thailand Excellence Center for Tissue Engineering and Stem Cells, Faculty of Medicine, Chiang Mai University, Thailand. Commission on Higher Education and The Graduate School Chiang Mai University are gratefully acknowledged.