Cell Cycle Arrest, Cytotoxicity, Apoptosis, DNA-Binding, Photocleavage, and Antioxidant Activity of Octahedral Ruthenium(II) Complexes

Three ruthenium(II) complexes [Ru(dmp)2(dcdppz)]2+ 1, [Ru(phen)2(dcdppz)]2+ 2, and [Ru(dip)2(dcdppz)]2+ 3 were synthesized and characterized. The crystal structure of complex 1 was solved by single-crystal X-ray diffraction. This complex crystallizes in the monoclinic system, space group C2/c with a = 18.454(3) angstrom, b = 44.648(7) angstrom, c = 13.082(2) angstrom, beta = 99.911(3)degrees, R = 0.0571, and R = 0.1501. The DNA-binding constants were determined to be 1.78 (+/- 0.24) x 105, 2.73 (+/- 0.16) x 105, and 7.55 (+/- 0.16) x 105 M1 for 1, 2, and 3, respectively. The photocleavage of pBR322 DNA by RuII complexes was studied. The retardation assay of pGL 3 plasmid DNA was investigated. The cytotoxicity of complexes 1, 2, and 3 against BEL-7402, Hela, HepG-2, and MG-63 cells was evaluated by the MTT method. Complexes 1 and 3 show higher cytotoxicity than Cisplatin on Hela cells. The apoptosis and cell cycle arrest were investigated, and the antioxidant activities of these complexes were also explored.