Our results clearly showed that treatment of RA-FLSs with COE suppressed IL-1β and TNF-α-induced cell migration and invasion, and revealed that COE inhibited the transcriptional activity of MMP-9 by suppressing the binding activity of NF-κB in the MMP-9 promoter, and inhibited IκBα phosphorylation and NF-κB nuclear translocation. Here, MMP9 is linked to rheumatoid arthritis.