Synthesis, interaction with DNA, cytotoxicity, cell cycle arrest and apoptotic inducing properties of ruthenium(II) molecular “light switch” complexes

In an endeavor toward the development of metal-based anticancer drugs, we present here the design, synthesis and characterization of three ruthenium(II) functionalized phenanthroline complexes with extended π-conjugation. These complexes have been shown to act as promising CT-DNA intercalators as evidenced by UV–visible, luminescence, emission quenching by [Fe(CN)6]4−, DNA competitive binding with ethidium bromide and salt dependent studies. All three complexes [Ru(Hdpa)2PPIP]2+ (1), [Ru(Hdpa)2PIP]2+ (2), [Ru(Hdpa)24HEPIP]2+ (3) clearly demonstrated that they can bind to DNA through the intercalation mode. Cell viability experiments indicated that all complexes showed significant dose dependent cytotoxicity in selected cell lines. The apoptosis and cell cycle arrest were also investigated. The complexes were docked into DNA-base-pairs using the ‘GOLD’ (Genetic Optimization for Ligand Docking), docking program. [Display omitted] Ru(II) polypyridyl complex on treatment with HeLa cell line showed clearly, cell shrinkage and membrane blebbing. •The synthesis and characterization of three Ru(II) complexes have been described.•The cytotoxicity of these complexes has been evaluated by MTT assay.•The cellular uptake was studied by flow cytometry.•The reasons causing cells death are G0/G1 cell cycle arrest and apoptosis.•Docking studies of these complexes were done using Gold Dock software.