Fig. 1.

Effect of estrogen-receptor antagonist ICI, 182, 780 on the genotoxicity of PhIP in breast cells: Cells were harvested 48 h post treatment (24 h). Cytotoxicity is expressed as % cell survival as measured by cell counting using haemocytometer (a, b). Genotoxicity of PhIP measured by micronucleus (MN) frequency in presence/absence of ICI 182,780 in MCF-7 (c) and MDA-MB-231 (d) cells. Etoposide was used as a positive control. MN frequency per 1000 cells was measured following treatment (1000/slide and two slides per culture). Statistically significant differences between PhIP vs. PhIP & ICI 182, 780 co-treated samples were assessed by Student’s t test in GraphPad Prism 6. Significance is shown in p values; ***p < 0.001, **p < 0.01, *p < 0.05, NS no significant difference. Error bars represent the standard error of the mean (SEM) for independent cultures (n = 3)