DNA/BSA Binding Affinity and Cytotoxicity of Dinuclear Palladium(II) Complexes with Amino Acids as Ligands

Abstract

This study investigates the synthesis, characterization, and cytotoxicity of dinuclear palladium(II) complexes with glycine (Pd1), alanine (Pd2), and methionine (Pd3) as ligands. UV-Vis and fluorescence spectroscopy were used to investigate the complexes’ interactions with calf thymus DNA (CT-DNA) and bovine serum albumin. The obtained measurements demonstrate that Pd1 and Pd2 have stronger binding affinities for CT-DNA compared to Pd3, with Pd3 exhibiting the most significant cytotoxicity against the MDA-MB-231 cancer cell line. The binding behavior was quantified by calculating intrinsic binding constants (Kb) and Stern–Volmer constants (Ksv), showing that Pd1 and Pd2 interact more effectively with DNA, possibly due to less steric hindrance in their chelation. Cytotoxic activity was evaluated using an MTT assay, and the results confirm that Pd3, with methionine as the ligand, exhibited superior antitumor effects, inducing apoptosis through caspase-3 activation. The complexes also showed a strong affinity for BSA, indicating their potential for biological interaction. These discoveries shed light on the processes of palladium(II) complexes in biological systems, highlighting their DNA and protein-binding capabilities, as well as their anticancer potential. Further research is required to explore their pharmacokinetics and possible clinical applications.