Figure 1.

Effect of skullcapflavone II on expression of matrix metalloproteinase-1 (MMP-1) and type I collagen in fibroblasts. (A) Primary human foreskin fibroblasts and primary human buttock skin fibroblasts were incubated for 24 h in serum-free Dulbecco’s Modified Eagle’s Medium (DMEM) with the indicated concentrations of skullcapflavone II. * p < 0.05, ** p < 0.01, and *** p < 0.001 vs. the sample incubated with 0 μM skullcapflavone II; n.s., not significant. (B) Foreskin fibroblasts were incubated for the indicated times in serum-free DMEM or DMEM containing 3% fetal bovine serum (FBS) with (+) or without (−) 3 μM skullcapflavone II. Conditioned medium and cell lysates were analyzed by 9% SDS-PAGE and Western blot with anti-MMP-1, anti-pN-ColIα1, and anti-glyceraldehyde 3-phosphate dehydrogenase (GAPDH) antibodies. * p < 0.05 and ** p < 0.01 vs. the sample incubated without skullcapflavone II.