FIGURE 4.

Caspase 3 activity in mock- and GSTP1-transfected HepG2 cells following a 2.5 h exposure to 50 μM AQ-QI (A) or 30 μM DEAQ-QI (B) with or without a 24 h pretreatment with 500 μM BSO. Caspase 3 activity was used as measure for cell death by apoptosis and is presented as percentage relative to respective vehicle controls in mock-transfected cells. Each bar represents the mean ± SD from three independent experiments. Statistical significant differences with corresponding vehicle control are denoted with ‘a’ and with corresponding mock-transfected control are denoted with ‘b’ using the following p-values: ^∗p < 0.05; ^#p < 0.01; ¶p < 0.001 (Student’s t-test).