Figure 5.

Apoptosis induction by PARP cleavage with Vitamin E treatment. The (a) MDA‐MB‐231 and (b) MCF‐7 human breast cancer cells were co‐cultured for 24 h with 10 μg/ml of various isomers of vitamin E. These cells were briefly exposed to 1 nm TNF‐α for 30 min. The PARP cleavage activity was determined using the western blotting method.