Figure 4.

Effect of erastin derivatives on ATPase activity of P-gp. The effect of imidazole ketone erastin, piperazine erastin and erastin or the vanadate-sensitive ATPase activity of P-gp was determined as outlined in Materials and Methods. Basal ATPase activity was compared to that in the presence of 10 µM concentrations of the compounds; verapamil at 10 µM served as a positive control for stimulation of ATPase activity. Significance was determined by a one-way ANOVA followed by a Dunnett test for multiple comparisons. Asterisks denote significant differences from the DMSO control, where ***P < 0.001 or ****P < 0.0001.