In vitro anticancer activity of Pd(II) complexes with pyridine scaffold: Their bioactivity, role in cell cycle arrest, and computational study

Abstract

A series of Pd(II) based complexes [Pd(PEA)Cl2]; Pd1, [Pd(PEA)(H2O)2]2+; Pd2, [Pd(PEA)(DL-meth)]2+; Pd3, [Pd(PEA)(DL-pen)]+; Pd4, [Pd(PEA)(OX)]; Pd5 and [Pd(PEA)(CBDCA)]; Pd6 (where PEA = 2- pyridylethylamine, DL-meth = DL-methionine, DL-pen = DL-penicillamine, OX2− = oxalate and CBDCA2− = cyclobutanedicarboxylate) were investigated for their biological importance as anticancer drug candidates and bio-molecular interactions. Their interactions with CT-DNA were monitored with absorption and fluorescence spectrometric methods and viscometric titration. Their binding affinity with BSA and binding modes were elaborately investigated spectrophotometrically, including their thermodynamic parameters. Geometrical optimization and electronic transitions of the Pd(II) complexes are being performed by a DFT-based theoretical study. The molecular docking simulation with DNA and BSA was performed to find out a coherent relation with experimental observations. The antiproliferative property and selectivity of the complexes were screened against human breast carcinomas (MCF-7 and MDA-MB-231) and normal HEK293 cell lines. Most of the complexes generated significant ROS on the tumor cells following cell death. The cell cycle analysis with the complexes was studied on MCF-7 cells by flow-cytometric method to verify their vital role in cell apoptosis.