Figure 4.

Effects of DMF, TMF, PMF, and QC (positive control) on MMP-1 mRNA expression (A) and secretion (B). HDFs were plated at a density of 2 × 10⁴ cells/well in a 48-well plate and starved with serum-free media for 24 h. Next, the cells were treated with specific concentrations of the samples for 1 h before exposure to 20 ng/mL TNF-α for 24 h. The MMP-1 mRNA level was assessed using qRT-PCR analysis. MMP-1 secretion in the cell supernatants was determined using an ELISA kit. The data were expressed as mean ± standard error of mean (SEM) (n = 2). # p < 0.05 compared to non-treated group and * p < 0.05 compared to TNF-α-treated group. Abbreviations: DMF, 5,7-dimethoxyflavone; TMF, 5,7,4′-trimethoxyflavone; PMF, 3,5,7,3′,4′-pentamethoxyflavone; and QC, Quercetin.