The Effect of YQFS on the expression of MMP-2/9 in vivo . Gelatin Zymography analysis of MMP-2/9 in vivo, as described in the materials and methods section. The relative fold change in expression of MMP-2/9 is plotted as a graph. Each value is presented as the mean ± SD as determined from three independent experiments. *P < 0.05 vs. the control; **P < 0.01 vs. the control.