Synthesis, DNA Interaction and Anticancer Activity of Mixed-Ligand Copper(II) Complex of 5-Methyl-2-(2 '-pyridyl)benzimidazole and Glycinate

A new copper(II) complex [Cu (HPBM) (Gly) (H2O)]ClO4 center dot 0.5H(2)O (HPBM=5-methyl-2-(2'-pyridyl)benzimidazole, Gly=Glycinate), was prepared and characterized by elemental analysis, IR spectroscopy, UV-Vis spectroscopy, molar conductivity and ESI-MS spectroscopy. Electronic absorption spectroscopy, EB-DNA fluorescence quenching spectroscopy, viscosity measurement and molecular docking revealed that the complex could interact with CT-DNA through a minor groove binding mode. The cytotoxic activity in vitro of the complex against Eca-109, HeLa and A549 cell lines was evaluated by MTT method. The IC50 values ranged from 6.4 to 8.5 mu mol center dot L-1 AO/EB double staining analysis indicated that the complex could induce apoptosis in Eca-109 cells. The comet assays demonstrated that the complex could damage DNA in Eca-109 cells, which further revealed that the complex could cause apoptosis in the cells. The mitochondrial membrane potential studies showed that the complex could induce decrease in the intracellular mitochondrial membrane potential. Moreover, the cell cycle arrest of Eca-109 cell lines was investigated by flow cytometry. The results demonstrated that the complex can induce apoptosis in Eca-109 cell through DNA interaction and mitochondria dysfunctional pathways.