Applying Cu(II) complexes assisted by water-soluble porphyrin to DNA binding and selective anticancer activities

Cancer is one of the killers endangering human health and its treatment has always been a focus of the medical community. For anticancer drugs, water-soluble porphyrin and Schiff bases have always been of interest. We report here three Cu(II)-based complexes functionalized by water-soluble cationic porphyrin and hydrazine Schiff base, which were prepared and evaluated for their biological activity. The three Cu(II) complexes all exhibited potent binding affinity to calf thymus DNA, the strongest interaction being between CuP2 and DNA. We studied the cytotoxicity of the complexes and ligands against different types of cancer cells (A549, H-1975, HepG2 and T47D), results showing the ligands are less cytotoxic; therefore, the anticancer activity of the complexes is improved by complexation. Furthermore, the cytotoxicity of ligands and complexes was also evaluated against the normal cell line Hs 578Bst, complexes showing more negligible cytotoxicity than ligand. Moreover, the cellular uptake of these Cu(II) complexes was investigated using the extraction method and results suggested that CuP2 exhibits the best cellular uptake towards H-1975 cells. Interestingly, fluorescence microscopy experiments and flow cytometric analysis (cell cycle) were used to further investigate the potent anticancer activities.