DNA-binding, cytotoxicity, cellular uptake, apoptosis and photocleavage studies of Ru(II) complexes

• Two Ruthenium(II) polypyridyl complexes were synthesized and characterized.
• The two complexes interact with CT-DNA via intercalative mode of binding.
• Complex 1 shows higher cytotoxic activity than complex 2 toward HeLa, A549 and Du145 cells
• The two complexes effectively induce apoptosis in HeLa cells.

Two Ru(II) complexes [Ru(phen)2bppp](ClO4)2 (1) and [Ru(phen)27-Br-dppz](ClO4)2 (2) [phen = 1,10 phenanthroline, 7-Br-dppz = 7-fluorodipyrido[3,2-a:2′,3′-c]phenazine, bppp = 11-bromo-pyrido[2′,3′:5,6]pyrazino[2,3-f] [1,10]phenanthroline] have been synthesized and characterized by elemental analysis, ES-MS, 1H-NMR, 13C-NMR and IR. The in vitro cytotoxicity of the complexes examined against a panel of cancer cell lines (HeLa, Du145 and A549) by MTT method, both complexes show prominent anticancer activity against various cancer cells. Live cell imaging study and flow cytometric analysis demonstrate that both the complexes 1 and 2 could cross the cell membrane accumulating in the nucleus. Further, flow cytometry experiments showed that the cytotoxic Ru(II) complexes 1 and 2 induced apoptosis of HeLa tumor cell lines. Photo induced DNA cleavage studies have been performed and results indicate that both the complexes efficiently photo cleave pBR322 DNA. The binding properties of two complexes toward CT-DNA were investigated by various optical methods and viscosity measurements. The experimental results suggested that both Ru(II) complexes can intercalate into DNA base pairs. The complexes were docked into DNA-base pairs using the GOLD docking program.