The inhibitory effect of pinocembrin on TGF-β1-induced activities and expressions of MMP-2/-9 in Y-79 cells. The cultured cells in serum-free medium were pretreated with TGF-β1 (10 ng/ml) and then incubated in the different concentrations of pinocembrin (0, 1, 2.5, and 5 μM). (A) The conditioned media were collected and MMP-2/-9 activities were determined by gelatin zymography. (B) The MMP-2/-9 protein expressions were analyzed by Western blotting. (C) The MMP-2/-9 mRNA expressions were analyzed by RT-PCR. β-Actin and GADPH was used as internal controls.