Fig. 4. Effects of Korean red ginseng extract on PMA-induced matrix metalloproteinase (MMP)-9 and MMP-2 activity in SW 480 cells. SW 480 cells were plated in 6 well plates at a density 1×10⁶ cell/mL in Dulbecco’s modified Eagle’s medium/Ham’s F12 nutrient mixture supplemented with 10% fetal bovine serum. After 48 h incubation, the monolayers were incubated in serum-free medium with or without 100 μg/L PMA in the absence or presence of various concentrations (100, 200, or 300 μg/mL) of red ginseng extract for 16 h. Medium was collected and concentrated for zymography. (A-a) Photographs of MMP-2, (A-b) Quantitative analysis of the bands. (B-a) Photographs of MMP-9 bands. (B-b) Quantitative analysis of the bands. The enzyme activity was expressed as a percentage of control (without PMA and red ginseng extract). Each bar represents the mean±SD of three independent experiments. Significant differences (p<0.05) among groups are indicated by different letters above each bar.