Curcumin induces apoptosis and inhibits prostaglandin E(2) production in synovial fibroblasts of patients with rheumatoid arthritis.
Rheumatoid arthritis (RA) is a chronic inflammatory disease that is characterized by hyperplasia of the synovial fibroblasts, which is partly the result of decreased apoptosis. This study investigated the mechanisms through which curcumin, a polyphenolic compound from the rhizome of Curcuma longa, exerts its anti-proliferative action in the synovial fibroblasts obtained from patients with RA. Exposure of the synovial fibroblasts to curcumin resulted in growth inhibition and the induction of apoptosis, as measured by MTT assay, fluorescent microscopy and Annexin-V-based assay. RT-PCR and immunoblotting showed that treating the cells with curcumin resulted in the down-regulation of anti-apoptotic Bcl-2 and the X-linked inhibitor of the apoptosis protein as well as the up-regulation of pro-apoptotic Bax expression in a concentration-dependent manner. Curcumin-induced apoptosis was also associated with the proteolytic activation of caspase-3 and caspase-9, and the concomitant degradation of poly(ADP-ribose) polymerase protein. Furthermore, curcumin decreased the expression levels of the cyclooxygenase (COX)-2 mRNA and protein without causing significant changes in the COX-1 levels, which was correlated with the inhibition of prostaglandin E(2) synthesis. These results show that curcumin might help identify a new therapeutic pathway against hyperplasia of the synovial fibroblasts in RA.
Department of Biochemistry, Dongeui University College of Oriental Medicine, Busan 614-052, Korea.
Cheol
C
Park
Dong-Oh
DO
Moon
Il-Whan
IW
Choi
Byung Tae
BT
Choi
Taek-Jeong
TJ
Nam
Chung-Ho
CH
Rhu
Taeg Kyu
TK
Kwon
Won Ho
WH
Lee
Gi-Young
GY
Kim
Yung Hyun
YH
Choi
D017209:Apoptosis / Q000187:drug effects*; D001172:Arthritis, Rheumatoid / Q000188:drug therapy* / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D001483:Base Sequence; D053148:Caspase 3 / Q000378:metabolism; D053453:Caspase 9 / Q000378:metabolism; D049108:Cell Enlargement / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D003474:Curcumin / Q000494:pharmacology*; D051546:Cyclooxygenase 2 / Q000378:metabolism; D017931:DNA Primers / Q000235:genetics; D015232:Dinoprostone / Q000096:biosynthesis*; D004789:Enzyme Activation / Q000187:drug effects; D005347:Fibroblasts / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D015870:Gene Expression / Q000187:drug effects; D019254:Genes, bcl-2 / Q000187:drug effects; D006801:Humans; D066298:In Vitro Techniques; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D013583:Synovial Membrane / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D051636:X-Linked Inhibitor of Apoptosis Protein / Q000235:genetics
D017931:DNA Primers; D012333:RNA, Messenger; D051636:X-Linked Inhibitor of Apoptosis Protein; C496866:XIAP protein, human; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; C505407:CASP3 protein, human; C506433:CASP9 protein, human; D053148:Caspase 3; D053453:Caspase 9; D003474:Curcumin; D015232:Dinoprostone