Synthesis, DNA-binding abilities, and in vitro antitumor activity of water-soluble copper porphyrin and its Schiff-base complexes

Herein, three new water-soluble porphyrin Cu(II)-complexes (denoted as CuP-1, CuP-2, and CuP-3, respectively) have been successfully prepared and well characterized. A variety of spectral analysis techniques showed that the three complexes bind with calf thymus DNA (ct-DNA) via an intercalation mode, and CuP-1 showed the strongest binding affinity with ct-DNA. In addition, the effects of the water-soluble porphyrin Cu(II)-complexes (CuP-1, CuP-2, and CuP-3) on the survival rates of different tumor cells were tested via MTT assays. The results showed that all the complexes exhibit high cytotoxicity towards three tumor cell types, especially CuP-1, which showed strong cytotoxicity towards TCA8113 tumor cells. In addition, the cell cycle distribution and induction of apoptosis were studied via flow cytometric analysis based on three tumor cell lines, and the results demonstrated that the tested complexes may induce cell death through early apoptosis and inducing a block on the G(1)/S phase of the cell cycle.