Synthesis, structure and in vitro anticancer activity of copper(II) and platinum(II) complexes with pyrrol-appended dipicolylamine ligand

Abstract

Copper complexes exhibit important potential applications as non-platinum based metallodrugs particularly in the field of anticancer research. In this paper, mononuclear copper(II) and platinum(II) complexes containing pyrrole-linked dipicolylamine, namely PPMdpa-Cu and PPMdpa-Pt, were synthesized and characterized. Among these complexes, PPMdpa-Cu exhibited a stronger ability to bind to CT-DNA (calf-thymus DNA) compared to PPMdpa-Pt. In addition, an MTT assay performed throughout our studies demonstrated that PPMdpa-Cu featured significant antitumor activity against the three cancer cell lines U87, AsPC-1 and HepG2, superior to that of PPMdpa-Pt as well as the ligand, PPMdpa. Particularly, the IC50 of PPMdpa-Cu against HepG2 was found to be as low as 27.3 μM. Finally, anticancer mechanism studies showed that PPMdpa-Cu could induce apoptosis in HepG2 cells associated with mitochondrial damage and oxidative stress caused by the generation of reactive oxygen species (ROS).