Figure 1.

Antioxidants decrease the amount of 5-Fu-induced apoptosis in colon cancer cells. (a) HT29 and SW480 colon cancer cells were pretreated with NAC (10 mM, upper panel) or catalase (200 mU, lower panel) for 2 h and then 5-Fu (50 μM) was added to the mixture and cells incubated for an additional 48 h. Apoptosis was determined by flow cytometry. Data are shown as means±S.D. of triplicate measurements. The asterisks indicate a significant decrease in apoptosis in cells treated with NAC or catalase (***P<0.001). (b) HT29 and SW480 cells were treated as in a and harvested. Total and cleaved PARP, caspase-7 and caspase-3 were detected by western blot analysis using specific antibodies. Data shown are representative of results from triplicate independent experiments. (c) HT29 cells were pretreated with VC (50 μg/ml) or GSH (40 μM) for 2 h and then 5-Fu (50 μM) was added to the mixture and cells were incubated for an additional 48 h. Apoptosis was measured by flow cytometry and data are shown as means±S.D. of triplicate measurements. The asterisks indicate a significant decrease in apoptosis in cells treated with VC or GSH (***P<0.001)