IL1B and osteoarthritis: For example, isofraxidin (1, 10, and 50 μmol/L) blocked IL-1β-stimulated production of NO and PGE2, inhibited the expression of COX-2, iNOS, MMP-1, MMP-3, MMP-13, ADAMTS-4 and -5, and suppressed IL-1β-induced IκB-α degradation and NF-κB activation in human osteoarthritis chondrocytes (Lin et al., 2018); it should be noted that there was no positive control group in this study.