Safflower seed extract reduces matrix metalloproteinases (MMP3 and MMP13) expression in articular chondrocytes induced by IL-1β. Chondrocytes were treated with IL-1β (1 ng/mL) in a time-dependent manner (A) and co-treated with different concentrations (100, 200, and 400 µg/mL) of safflower seed extract (B). The mRNA expression levels of Mmp3 and Mmp13 were measured using RT-PCR (A,B, left) and qRT-PCR (A,B, right). The protein expression of MMP3 and MMP13 was determined by western blotting (C, left) and quantified by densitometry (C, right). Gapdh and β-actin were used as the loading controls. Collagenase activity in safflower seed extract-treated chondrocytes was evaluated using the Enzchek gelatinase/collagenase assay and detected by ELISA at 482/530 nm (D). Data are shown as mean ± SD of each group (n = 5). # p < 0.05 compared with the control; * p < 0.05, ** p < 0.01, and *** p < 0.001 compared with the IL-1β-treated or safflower seed extract-treated groups.