Chemopreventive effects of a curcumin-like diarylpentanoid [2,6-bis(2,5-dimethoxybenzylidene)cyclohexanone] in cellular targets of rheumatoid arthritis in vitro

Aim Synovial fibroblast has emerged as a potential cellular target in progressive joint destruction in rheumatoid arthritis development. In this study, BDMC33 (2,6‐bis[2,5‐dimethoxybenzylidene]cyclohexanone), a curcumin analogue with enhanced anti‐inflammatory activity has been synthesized and the potency of BDMC33 on molecular and cellular basis of synovial fibroblasts (SF) were evaluated in vitro. Methods Synovial fibroblast cells (HIG‐82) were cultured in vitro and induced by phorbol‐12‐myristate acetate (PMA) to stimulate the expression of matrix metalloproteinase (MMPs) and pro‐inflammatory cytokines. The protective effects of BDMC33 were evaluated toward MMP activities, pro‐inflammatory cytokine expression and nuclear factor kappa‐B (NF‐κB) activation by using various bioassay methods, including zymography, Western blotting, reverse transcription polymerase chain reaction, immunofluorescense microscopy and electrophoretic mobility shift assay. Results The results showed that BDMC33 significantly inhibited the pro‐gelatinase B (pro‐MMP‐9) and collagenase activities via suppression of MMP‐1 in activated SF. In addition, BDMC33 strongly suppressed MMP‐3 gene expression as well as inhibited COX‐2 and IL‐6 pro‐inflammatory gene expression. We also demonstrated that BDMC33 abolished the p65 NF‐κB nuclear translocation and NF‐κB DNA binding activity in PMA‐stimulated SF. Conclusions BDMC33 represents an effective chemopreventive agent and could be used as a promising lead compound for further development of rheumatoid arthritis therapeutic intervention.