(A, B) Effect on promoter activity. HepG2-AD1 (A) and HepG2-AD13 (B) cells (3 × 105 cells) were cultured in a 24-well plate for 24 h, incubated for 6 h with indicated initial concentrations of MMA or HEMA, and subjected to the assay for the luciferase activities, respectively. Data are presented as the mean ± SD (n = 7–12). (C) Effect on intracellular GSH level. HepG2-AD13 cells were incubated for 6 h with indicated initial concentrations of MMA or HEMA, and subjected to the assay for intracellular levels of GSH. Data are presented as the mean ± SD (n = 3). (D) Effect on cell viability. Cells were incubated for 24 h with indicated initial concentrations of MMA or HEMA, and subjected to the assay to determine cell viability using WST-8. Cell viability is expressed with the control value, obtained after incubation without exposure to MMA or HEMA, taken as 100%. Data are presented as the mean ± SD (n = 3). *p < 0.05, **p < 0.01.