TLR4 and rheumatoid arthritis: Studies (62, 63) have shown that sinomenine can inhibit the levels of inflammatory factors (TNF-α, IL-6, NO, PGE2, iNOS and COX-2) in IL-1β-induced RA-FLS, and inhibit the expression of TLR4, MyD88, p-NF-κB p65 and TRAF-6 in RA-FLS, suggesting that sinomenine prevents IL-1β-induced inflammation in human RA-FLS by inhibiting the TLR4/MyD88/NF-κB signaling pathway.