Fig 10. Analysis of the DNA damage induced by 1, 2 and 5.

(A) Quantification of cellular DNA damage. MCF-7 cells were exposed to 10 μmol/L 1, 2 and 5 for the indicated times and the levels of p-H2A.X were quantified using flow cytometry after immunostaining with anti-pH2A.X specific antibodies. The graph represents the mean fluorescence intensity for each experimental condition, relative to untreated cells. (B) Electrophoretic analysis of DNA cleavage. Supercoiled pUC18 plasmid DNA (18.9 μmol/L) was incubated with ligands 1, 2 and 5 and their respective Fe(II) complexes 1-Fe, 2-Fe and 5-Fe at 25 μM for 1 h (37°C). Lane 1, DNA control; lane 2, DNA control + H₂O₂; lane 3, 5, 7, 9, 11, 13, ligand or Fe(II) complex in the absence of H₂O₂; lane 4, 6, 8, 10, 12, 14, ligand or Fe(II) complex in the presence of H₂O₂. (C) Effect of groove binders and ROS scavengers on the cleavage of supercoiled pUC18 plasmid DNA treated with complexes 1-Fe, 2-Fe and 5-Fe at 15 μmol/L for 1 h (37°C) in the presence of H₂O₂. Lane 1, DNA control; lane 2, DNA control + H₂O₂; lane 3, complex control in the absence of potential inhibitors; lane 4, Hoechst 40 μmol/L; lane 5, methyl green 20 μmol/L; lane 6, Tiron 10 mmol/L; lane 7, sodium azide 0.4 mol/L; lane 8, 3 μL of DMSO.