Figure 7. The increase in β-lapachone-induced cell death caused by sulindac and its metabolites is blocked by the NQO1 inhibitor, dicoumarol.

CL1-1 cells (left) or CL1-5 cells (right) were left untreated or were pretreated for 6 h with 100 or 250 µM sulindac (A), sulindac sulfone (B), or sulindac sulfide (C) with or without 10 µM dicoumarol, then were incubated for a further 12 h with or without addition of 2 µM β-lapachone, then cell survival was measured by crystal violet staining and expressed as percentage survival compared to the untreated cells. * : p<0.05.