DNA-binding, photocleavage, cytotoxicity in vitro, apoptosis and cell cycle arrest studies of symmetric ruthenium(II) complexes.

Two novel ruthenium(II) complexes [Ru(dmb)2(addppn)](ClO4)2 (1) and [Ru(bpy)2(addppn)](ClO4)2 (2) were synthesized. The DNA-binding constants of complexes 1 and 2 were determined to be 4.78 (±0.49) × 10(5) and 7.42 (±0.53) × 10(5) M(-1). The results indicate that complexes 1 and 2 interact with CT DNA through intercalative mode. The cytotoxicity in vitro of the complexes toward BEL-7402, HeLa, MG-63 and SKBR-3 cells was assessed by MTT assay. The apoptosis was carried out with Hoechst 33258 staining method and flow cytometry. The cellular uptake was observed under fluorescence microscope. The cell cycle arrest shows that the antiproliferative mechanism induced by complexes 1 and 2 on BEL-7402 cells is G0/G1 phase arrest.