The effect of ozagrel on cell viability reduced by NAPQI in RLC-16 cells. Cells were exposed to 250 μM NAPQI in either the presence or absence of ozagrel (1–100 μM) or NAC (1 mM). Cell viability was measured 24 h after the NAPQI exposure using the WST-1 assay. NAPQI (black bar) induced a decrease in cell viability. This reduction was significantly inhibited by ozagrel (gray bar) and NAC (hatched bar). Each bar represents the mean ± S.E.M. (n = 4). *p < 0.01 compared with the APAP group.