However, the black tea-derived polyphenol theaflavin-3,3′-digallate (TFDG) demonstrated some protective activity against osteoclast formation and osteoporosis via the inhibition of MMP-2 and MMP-9, both of which are responsible for the degradation of collagens and joint destruction in RA patients [203, 204]. The gene discussed is MMP9; the disease is rheumatoid arthritis.