Fig. 5.

Activation of Nrf2 reporter cells by NSOA is supplemented by cysteine preincubation. (A) Induction of Nrf2 responses by NSOA in Nrf2 Luciferase reporter MCF7 stable cell line. Results are presented as fold relative to vehicle control group (n = 12). P values are <0.001 for all treatments. (B) The induction of Nrf2 responses by NSOA were supplemented by preincubation with free cysteine. Results are presented as fold relative to vehicle control group (n = 6). ***P < 0.001. (C) The schematic figure demonstrates that electrophilic NSOA chemicals (e.g., 1,2-naphthoquinone) are sequestered by free cysteine during preincubation, and hence reduce the activation of Nrf2 pathways inside the Nrf2 reporter cells.