Jun-Hua Yao

Synthesis of ruthenium(II) complexes and characterization of their cytotoxicity in vitro, apoptosis, DNA-binding and antioxidant activity

A new ligand DBHIP and its two ruthenium (II) complexes [Ru(bpy)(2)(DBHIP)](ClO(4))(2) (1) and [Ru(phen)(2)(DBHIP)](ClO(4))(2) (2) have been synthesized and characterized. The binding behaviors of the two complexes to calf thymus DNA were investigated by absorption spectra, viscosity measurements, thermal denaturation and photoactivated cleavage. The DNA-binding constants for complexes 1 and 2 have been determined to be 8.87+/-0.27 x 10(4)M(-1) (s=1.83) and 1.32+/-0.31 x 10(5)M(-1) (s=1.84). The results suggest that these complexes interact with DNA through intercalative mode. The cytotoxicity of DBHIP, complexes 1 and 2 has been evaluated by MTT assay. The apoptosis assay was carried out with acridine orange/ethidium bromide (AO/EB) staining methods. The studies on the mechanism of photocleavage demonstrate that superoxide anion radical (O(2)(-)) and singlet oxygen ((1)O(2)) may play an important role.

The induction of apoptosis in BEL-7402 cells through the ROS-mediated mitochondrial pathway by a ruthenium(II) polypyridyl complex

A new Ru(II) polypyridyl complex [Ru(phen)2(addppn)](ClO4)2 (Ru1) has been synthesized and characterized. The DNA-binding constant of the complex with DNA was determined to be 1.93 (±0.12) × 106 M−1. The complex interacts with DNA by an intercalative mode. Cytotoxicity in vitro, apoptosis, cell cycle distribution, apoptotic pathway, reactive oxygen species and mitochondrial membrane potential assays were performed. The IC50 values of Ru1 toward BEL-7402, HeLa, MG-63 and SKBR-3 cell lines are 3.9 ± 0.4, 9.0 ± 0.8, 6.6 ± 0.6 and 5.1 ± 0.6 μM, respectively. Interestingly, Ru1 shows a higher cytotoxicity than cisplatin on BEL-7402 cells under identical conditions. Ru1 can effectively induce apoptosis in BEL-7402 and induces cell cycle arrest at the G0/G1 phase in BEL-7402 cells and at the G2/M phase in SKBR-3 cells. In addition, Ru1 can enhance the level of reactive oxygen species and induce the decrease of the mitochondrial membrane potential. Western blot analysis shows that Ru1 activates caspase-3 and -7, down-regulates the expression of the anti-apoptotic proteins of Bcl-x and Bag-1, and upregulates the levels of the proapoptotic proteins of Bad, Bak, Bax and Bim in BEL-7402 cells. These results show that Ru1 induces apoptosis in BEL-7402 cells through an ROS-mediated mitochondrial dysfunction pathway.

Ruthenium(II) complexes: DNA-binding, cytotoxicity, apoptosis, cellular localization, cell cycle arrest, reactive oxygen species, mitochondrial membrane potential and western blot analysis.

The aim of our study was to investigate DNA-binding and cytotoxic activity of the four new Ru(II) polypyridyl complexes [Ru(dmb)₂(HMHPIP)](ClO₄)₂ (1), [Ru(bpy)₂(HMHPIP)](ClO₄)₂ (2), [Ru(phen)₂(HMHPIP)](ClO₄)₂ (3) and [Ru(dmp)₂(HMHPIP)](ClO₄)₂ (4). The complexes interact with DNA through intercalative mode and show relatively high cytotoxic activity against A549 cells, no cytotoxicity toward MG-63 cells. Complexes 1-4 can enhance the levels of ROS in A549 cells and induce the decrease of the mitochondrial membrane potential. These complexes inhibit the cell growth in A549 cells at G0/G1 or S phase. Complex 3 activated caspase 7, and down-regulated the expression of the anti-apoptotic protein Bcl-2. Complexes 1-4 induce apoptosis in A549 cells through ROS-mediated mitochondrial dysfunction pathway.

Synthesis, structure, DNA-binding properties, and cytotoxicity of ruthenium(II) polypyridyl complexes.

Many ruthenium(II) complexes show high antitumor activities, and the in vitro antitumor activities are usually related to DNA binding. We designed and synthesized two RuII polypyridyl complexes, [Ru(dmp)2(fpp)]2+ (dmp=2,9‐dimethyl‐1,10‐phenanthroline; fpp=2‐[3,4‐(difluoromethylenedioxy)phenyl]imidazo[4,5‐f] [1,10]phenanthroline and [Ru(phen)2(fpp)]2+ (phen=1,10‐phenanthroline). The DNA‐binding properties of these complexes have been investigated by spectroscopic titration, DNA melting experiments, viscosity measurements, and photoactivated cleavage. The mechanism studies of photocleavage revealed that singlet oxygen (1O2) and superoxide anion radical (O

Cytotoxic activity, DNA damage, cellular uptake, apoptosis and western blot analysis of ruthenium(II) polypyridyl complex against human lung decarcinoma A549 cell

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Cytotoxicity in vitro, cell migration and apoptotic mechanism studies induced by ruthenium(II) complexes

) may play an important role in the photocleavage. The cytotoxicity of complexes 1 and 2 have been evaluated by MTT (3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyl‐2H‐tetrazolium bromide) method; complex 2 shows slightly higher anticancer potency than 1 does against all the cell lines screened.

Cytotoxicity In Vitro, Apoptosis, Cellular Uptake, Cell Cycle Distribution, Mitochondrial Membrane Potential Detection, DNA Binding, and Photocleavage of Ruthenium(ii) Complexes

A new ruthenium(II) polypyridyl complex [Ru(dmp)2(pddppn)](ClO4)2Ru1 was synthesized and characterized. The cytotoxic activity in vitro of the complex was evaluated by MTT method. Ru1 shows high effect on the inhibition of the cell growth against BEL-7402, HeLa, MG-63 and A549 cells with low IC50 values of 1.6±0.4, 9.0±0.8, 1.5±0.2 and 1.5±0.3 μM, respectively. The cellular uptake indicates that Ru1 can enter into the cytoplasm and accumulate in the cell nuclei. Ru1 can induce apoptosis in A549 cells and enhance the levels of reactive oxygen species (ROS) and induce the decrease of mitochondrial membrane potential. In addition, Ru1 can down-regulate the levels of Bcl-2, Bcl-x, Bak, and Bim expression and up-regulate the expression of Bag-1 and Bad. The complex induces apoptosis of A549 cells through an intrinsic ROS-mediated mitochondrial dysfunction pathway, which was accompanied by regulating the expression of caspases and Bcl-2 family proteins.

Effect of the ancillary ligands on the binding of ruthenium(II) complexes [Ru(dmp)2(MCMIP)]2+ and [Ru(dmb)2(MCMIP)]2+ with DNA

Four new ruthenium(II) polypyridyl complexes [Ru(dmb)2(DHBT)](ClO4)2 (1) (DHBT = 12,14-dihydroxyl-4,5,9,10,11,13-hexaazabenzo[b]triphenylene, dmb = 4,4′-dimethyl-2,2′-bipyridine), [Ru(bpy)2(DHBT)](ClO4)2 (2) (bpy = 2,2′-bipyridine), [Ru(phen)2(DHBT)](ClO4)2 (3) (phen = 1,10-phenanthroline) and [Ru(dmp)2(DHBT)](ClO4)2 (4) (dmp = 2,9-dimethyl-1,10-phenanthroline) were synthesized and characterized. The cytotoxicity in vitro of these complexes was evaluated against human HepG-2, HeLa, A549, MG-63 and BEL-7402 cancer cell lines. The IC50 values of the complexes toward selected cell lines range from 14.9 ± 1.1 to 30.1 ± 2.7 μM. The cytotoxicity and the levels of reactive oxygen species were found to increase with increasing concentrations of the complexes. The complexes are sensitive to MG-63 cells and can inhibit the MG-63 cell migration. Morphological and comet assay studies show that the complexes can effectively induce apoptosis in MG-63 cells. Complex 2 inhibits the cell growth at the G0/G1 phase, whereas the other complexes exhibit the antiproliferative mechanism at the S phase in the MG-63 cell line. The complexes can downregulate the expression of Bcl-2 protein and upregulate the levels of Bad protein in MG-63 cells. The complexes induce MG-63 cells apoptosis through a ROS-mediated mitochondrial dysfunction pathway.

Cytotoxicity, Apoptosis, Cellular Uptake, Cell Cycle Arrest, Photocleavage, and Antioxidant Activity of 1, 10-Phenanthroline Ruthenium(II) Complexes

Four new ruthenium(ii) complexes [Ru(bpy)2(NHPIP)](ClO4)2 (Ru-1), [Ru(phen)2(NHPIP)](ClO4)2 (Ru-2), [Ru(bpy)2(AHPIP)](ClO4)2 (Ru-3), and [Ru(phen)2(AHPIP)](ClO4)2 (Ru-4) (bpy = 2,2′-bipyridine; phen = 1,10-phenanthroline; NHPIP = 2-(3-nitro-4-hydroxylphenyl)imidazo[4,5-f][1,10]phenanthroline; AHPIP = 2-(3-amino-4-hydroxylphenyl)imidazo[4,5-f][1,10]phenanthroline) were synthesized and characterized by elemental analysis, electrospray mass spectrometry, and 1H NMR spectroscopy. The cytotoxicity in vitro of these complexes against BEL-7402, HeLa, MG-63, and MCF-7 cells was evaluated by the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) method. Ru-4 shows the highest cytotoxic activity towards the selected cell lines among the four complexes. The morphological apoptosis was assayed by an acridine orange/ethidium bromide staining method, and the percentages of necrotic and apoptotic cells were determined by flow cytometry. The cellular uptake and the cell cycle arrest in BEL-7402 cell was investigated. The results showed these complexes inhibit the proliferation of BEL-7402 cells at G0/G1 phase arrest. The detection of mitochondrial membrane potentials using the fluorescence probe JC-1 (5,5′,6,6′-tetrachloro-1,1′,3,3′-tetraethylbenzimidazolcarbocyanine iodide) exhibited that the mitochondrial membrane potentials decrease. Upon irradiation, these complexes can effectively cleave pBR322 DNA.

DNA interaction, antioxidant activity, and bioactivity studies of two ruthenium(II) complexes

Two polypyridine ruthenium(II) complexes, [Ru(dmp)2(MCMIP)]2+ (1) (MCMIP = 2-(6-methyl-3-chromonyl)imidazo[4,5-f][1,10]-phenanthroline, dmp = 2,9-dimethyl-1,10-phenanthroline) and [Ru(dmb)2(MCMIP)]2+ (2) (dmb = 4,4′-dimethyl-2,2′-bipyridine), have been synthesized and characterized by elemental analysis, ES-MS and 1H NMR. The DNA-binding behaviors of these complexes were investigated by electronic absorption titration, fluorescence spectroscopy, viscosity measurements and thermal denaturation. The results show that 1 and 2 effectively bind to CT-DNA; the DNA-binding affinities are closely related to the ancillary ligand.