MMP9 and rheumatoid arthritis: These polyphenols target central RA inflammatory network by attenuating TNF, IL1B, IL6, IL17A and their receptors, inhibiting JAK1/JAK2 and IKBKB signalling, suppressing NF-κB and JAK–STAT transcription, and directly targeting MMP3/MMP9, COX-2 and iNOS to limit cartilage degradation and inflammatory mediator generation.