Fig. (4) IC50 value determination for 2HQ using serum paraoxonase assay. Reaction velocities were measured at the indicated 2HQ concentrations. Final DMSO concentration all 2HQ concentrations was 1%. Data points were performed in triplicate determinations and error bars represent standard deviations. Data are representative of three independent experiments. The average IC50 value of all experiments was 7.9 µM.