Synthesis,biological activities studies of ruthenium(II) polypyridyl complexes

Four ruthenium(II) polypyridyl complexes were synthesized and characterized by elemental analysis, IR, ESI-MS and ¹H NMR. The in vitro cytotoxicities of the complexes against BEL-7402, HeLa, A549, HepG2 and MG-63 cancer cells were investigated by MTT methods, giving IC₅₀ values ranging from 6.9 to 43.5 μM. The complexes show their highest inhibitory effect on MG-63 cells, but no cytotoxic activities against HeLa cells. Cellular uptake experiments indicate that the complexes can enter the cytoplasm and accumulate in the cell nuclei. The complexes can induce apoptosis in MG-63 cells, enhance the levels of reactive oxygen species, and induce a decrease in mitochondrial membrane potential. The cell cycle distribution shows that the complexes induce cell cycle arrest at S phase in MG-63 cells. Additionally, these complexes can up-regulate the levels of Bad and Bid expression and down-regulate the expression of Bcl-2 and Bcl-x.