WHC differentially induced DNA double strand break (DSB) damage (γH2AX) of breast cancer cells. (A,B) γH2AX profiles and statistics for dose effects on WHC. Breast cancer (MCF7 and SKBR3) cells were treated with WHC (control (0.075% DMSO), 0.25, 0.5, and 0.75 μM) for 48 h. Box region of each profile is counted for γH2AX (+) (%). (C,D) NAC pretreatments reversed the WHC induced γH2AX generation. Following pretreatments with NAC (10 mM for 1 h), cells were treated with control (0.075% DMSO) and 0.75 μM of WHC for 0, 24, and 48 h, i.e., NAC/WHC. Data are means ± SDs (n = 3). Results marked without overlapping letters show significant differences (P < 0.005 to 0.0001).