Quantitative assessments of the anti-proliferative activity of (A) combinations of metal-chelating agents and (B) their iron (Fe) and copper (Cu) complexes that were formed at an metal binding equivalent of 1 in MCF-7 cells.

All of the studied compounds and their combinations were incubated with MCF-7 cells for 72 h at 37°C at a concentration corresponding to their IC50 value. The combination index (CI) values were calculated using the Chou and Talalay method from n≥4 experiments using CalcuSyn 2.0 software; CI <1, ≈1, or >1 indicate synergism, an additive effect, or antagonism, respectively. Statistical significance (ANOVA): *p<0.05, **p<0.01, ***p<0.001 as compared to the same combination with uncomplexed parent chelator.