Figure 5.

Protection of human ARPE-19 cells against the toxicity of menadione, tert-butyl hydroperoxide (0.5, 0.75, 1 mM for 16 h), 4-hydroxynonenal (6.25, 12.5, 25 μM for 4 h), and peroxynitrite (1, 2, 4 mM for 2 h) as a function of prior exposure for 24 h to 0–2.5 μM sulforaphane. The bar graphs show that cell viability is a function of both the concentrations of the oxidant and of the sulforaphane inducer. The front, center, and rear series of bars refer to the highest, middle, and lowest concentration of oxidants, respectively.