Systematic evaluation of the antitumor activity of three ruthenium polypyridyl complexes.

Ruthenium-containing complexes have emerged as good alternative to the currently used platinum-containing drugs for malignant tumor therapy. In this work, cytotoxic effects of recently synthesized ruthenium polypyridyl complexes [Ru(bpy)2(CFPIP)](ClO4)2 (bpy = 2,2'-bipyridine, CFPIP = (E)-2-(4-fluorostyryl)-1H-imidazo[4,5-f][1,10]phenanthroline, Ru(II)-1), [Ru(phen)2(CFPIP)](ClO4)2 (phen = 1,10-phenanthroline, Ru(II)-2) and [Ru(dmb)2(CFPIP)](ClO4)2 (dmb = 4,4'-dimethyl-2,2'-bipyridine, Ru(II)-3) toward different tumor cells were investigated in vitro and compared with cisplatin, the most widely used chemotherapeutic drug against hepatocellular carcinoma (HepG-2). The results demonstrate that target complexes show excellent cytotoxicity against HepG-2 cells with low IC50 value of 21.4 ± 1.5, 18.0 ± 2.1 and 22.3 ± 1.7 µM, respectively. It was important noting that target Ru(II) complexes exhibited better antitumor activity than cisplatin (IC50 = 28.5 ± 2.4 µM) against HepG-2 cells, and has no obvious toxicity to normal cell LO2. DNA binding results suggest that Ru(II)-1, Ru(II)-2 and Ru(II)-3 interact with CT DNA (calf thymus DNA) through intercalative mode. Complexes exerted its antitumor activity through increasing anti-migration and inducing cell cycle arrest at the S phase. In addition, the apoptosis was tested by AO (acridine orange)/EB (ethidium bromide) staining and flow cytometry. Mitochondrial membrane potential (MMP), reactive oxygen species (ROS), and colocalization tests were also evaluated by ImageXpress Micro XLS system. Overall, the results show that the ruthenium polypyridyl complexes induce apoptosis in HepG-2 cells through ROS-mediated mitochondria dysfunction pathway.

Development of four ruthenium polypyridyl complexes as antitumor agents: Design, biological evaluation and mechanism investigation.

Ruthenium complexes are expected to be new opportunities for the development of antitumor agents. Herein, four ruthenium polypyridyl complexes ([Ru(bpy)2(CAPIP)](ClO4)2 (Ru(II)-1, bpy = 2,2'-bipyridine; CAPIP = (E)-2-(2-(furan-2-yl)vinyl)-1H-imidazo[4,5-f][1,10]phenanthroline), [Ru(phen)2(CA-PIP)](ClO4)2 (Ru(II)-2, phen = 1,10-phenanthroline), [Ru(dmb)2(CAPIP)](ClO4)2 (Ru(II)-3, dmb = 4,4'-dimethyl-2,2'-bipyridine), [Ru(dmb)2(ETPIP)](ClO4)2 (Ru(II)-4, ETPIP = 2-(4-(thiophen-2-ylethynyl)phenyl)-1H-imidazo[4,5-f][1,10]phen-anthroline)) have been investigated as mitochondria-targeted antitumor metallodrugs. DNA binding studies indicated that target Ru(II) complexes interacts with CT DNA (calf thymus DNA) by an intercalative mode. Cytotoxicity assay results demonstrate that Ru(II) complexes show high cytotoxicity against A549 cells with low IC50 value of 23.6 ± 2.3, 20.1 ± 1.9, 22.7 ± 1.8 and 18.4 ± 2.3 µM, respectively. Flow cytometry and morphological analysis revealed that these Ru(II) complexes can induce apoptosis in A549 cells. Intracellular reactive oxygen species (ROS) and mitochondrial membrane potential were also investigated by ImageXpress Micro XLS system. The experimental results indicate that the reactive oxygen species in A549 cells increased significantly and mitochondrial membrane potential decreased obviously. In addition, colocalization studies shown these complexes could get to the cytoplasm through the cell membrane and accumulate in the mitochondria. Furthermore, Ru(II) complexes can effectively induces cell cycle arrest at the S phase in A549 cells. Finally, cell invasion assay and quantitative studies were also performed to investigate the mechanism of this process. All in together, this study suggested that these Ru(II) complexes could induce apoptosis in A549 cells through cell cycle arrest and ROS-mediated mitochondrial dysfunction pathway.

New ruthenium polypyridyl complexes functionalized with fluorine atom or furan: Synthesis, DNA-binding, cytotoxicity and antitumor mechanism studies.

Two novel ruthenium(II) polypyridyl complexes, namely, [Ru(dmp)2(CAPIP)](ClO4)2 (Ru(II)-1) and [Ru(dmp)2(CFPIP)](ClO4)2 (Ru(II)-2), which respectively contain (E)-2-(2-(furan-2-yl)vinyl)-1H-imidazo[4,5-f][1,10]phen-anthroline (CAPIP) and (E)-2-(4-fluorostyryl)-1H-imidazo[4,5-f][1,10]phenanthroline. (CFPIP), were first designed and characterized (dmp = 2,9-dimethyl-1,10-phenanthroline). DNA binding experiments indicated that Ru(II) complexes interact with CT DNA through intercalative mode. In addition, the complexes Ru(II)-1 and Ru(II)-2, showed remarkable cell cytotoxicity, giving the respective IC50 values of 4.1 ±â€¯1.4 µM and 6.1 ±â€¯1.4 µM on the A549 cancer cells. These values indicated higher activity than CAPIP, CFPIP, cisplatin (8.2 ±â€¯1.4 µM) and other corresponding Ru(II) polypyridyl complexes. Furthermore, the Ru(II) complexes could arrive the cytoplasm through the cell membrane and accumulate in the mitochondria. Significantly, complexes Ru(II)-1 and Ru(II)-2 induced A549 cells apoptosis was mediated by increase of ROS levels and dysfunction of mitochondria, and resulted in cell cycle arrest and increased anti-migration activity on A549 cells. Overall, these results indicated that complexes Ru(II)-1 and Ru(II)-2 could be suitable candidates for further investigation as a chemotherapeutic agent in the treatment of tumors.

Design, Synthesis, and Anticancer Effect Studies of Iridium(III) Polypyridyl Complexes against SGC-7901 Cells.

Three iridium(III) complexes ([Ir(Hppy)2(L)](PF6) (Hppy = 2-phenylpyridine, L = 5-nitrophenanthroline, NP), 1; 5-nitro-6-amino-phenanthroline (NAP), 2; and 5,6-diamino-phenanthroline (DAP) 3 were synthesized and characterized. The cytotoxicities of Ir(III) complexes 1-3 against cancer cell lines SGC-7901, A549, HeLa, Eca-109, HepG2, BEL-7402, and normal NIH 3T3 cells were investigated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazoliumbromide (MTT) method. The results showed that the three iridium(III) complexes had moderate in vitro anti-tumor activity toward SGC-7901 cells with IC50 values of 3.6 ± 0.1 µM for 1, 14.1 ± 0.5 µM for 2, and 11.1 ± 1.3 µM for 3. Further studies showed that 1-3 induce cell apoptosis/death through DNA damage, cell cycle arrest at the S or G0/G1 phase, ROS elevation, increased levels of Ca2+, high mitochondrial membrane depolarization, and cellular ATP depletion. Transwell and Colony-Forming assays revealed that complexes 1-3 can also effectively inhibit the metastasis and proliferation of tumor cells. These results demonstrate that 1-3 induce apoptosis in SGC-7901 cells through ROS-mediated mitochondrial damage and DNA damage pathways, as well as by inhibiting cell invasion, thereby exerting anti-tumor cell proliferation activity in vitro.

Evaluation of anticancer effect in vitro and in vivo of iridium(III) complexes on gastric carcinoma SGC-7901 cells.

This work mainly introduces the synthesis and characterization of three iridium(III) complexes [Ir(ppy)2(adppz)](PF6) (Ir-1), [Ir(bzq)2(addpz)](PF6) (Ir-2) and [Ir(piq)2(adppz)](PF6) (Ir-3). The complexes are more cytotoxic than cisplatin against tumor cell lines such as SGC-7901, A549, HeLa, Eca-109, HepG2 and BEL-7402. The toxicity test results indicated that complexes Ir-1, Ir-2 and Ir-3 can effectively inhibit the cell growth of SGC-7901 cells, and the measured IC50 values are 1.8 ±â€¯0.4, 1.6 ±â€¯0.3 and 0.8 ±â€¯0.1 µM, respectively. AO/EB staining and flow apoptosis confirmed that SGC-7901 cells were caused apoptosis after being treated with the complexes. Along with the increase of endogenous ROS and Ca2+ levels, mitochondrial membrane potential collapse and massive release of cytochrome c, it is fully demonstrated that these complexes induce apoptosis through ROS-mediated mitochondrial pathway. At the same time, the complex Ir-3 is outstanding in the inhibition of tumor growth in vivo. Combined with the above results, it provides a favorable foundation for the future development of more effective anti-tumor drugs.

Design and synthesis of new ruthenium polypyridyl complexes with potent antitumor activity in vitro.

We herein report the synthesis, characterization and anticancer activity of BTPIP (2-(4-(benzo[b]thiophen-2-yl)phenyl)-1H-imidazo[4,5-f][1,10]phenanthroline) and its four ruthenium(II) polypyridyl complexes [Ru(NN)2(BTPIP)](ClO4)2 (N-N = bpy = 2,2'-bipyridine, Ru(II)-1; phen = 1,10-phenanthroline, Ru(II)-2; dmb = 4,4'-dimethyl-2,2'-bipyridine, Ru(II)-3; dmp = 2,9-dimethyl-1,10-phenanthroline, Ru(II)-4). The DNA binding behaviors reveal that the complexes bind to calf thymus DNA by intercalation. Cytotoxicity of the complexes against A549, HepG-2, SGC-7901 and Hela cells were evaluated in vitro. Complexes Ru(II)-1, Ru(II)-2, Ru(II)-3, Ru(II)-4 show moderate activity on the cell proliferation in A549 cells with IC50 values of 9.3 ±â€¯1.2, 12.1 ±â€¯1.6, 10.3 ±â€¯1.6, 8.9 ±â€¯1.2 µM, respectively. Apoptosis assessment, intracellular mitochondrial membrane potential (MMP), location in mitochondria, reactive oxygen species (ROS), cell invasion assay and cell cycle arrest were also performed to explore the mechanism of this action. When the concentration of the ruthenium(II) complexes is increased, the amount of reactive oxygen species increases obviously and the mitochondrial membrane potential decreases dramatically in A549 cells. Most importantly, the ruthenium(II) polypyridyl complexes could arrive the cytoplasm through the cell membrane and accumulate in the mitochondria. These results showed that the ruthenium(II) complexes could induce apoptosis in A549 cells through an ROS-mediated mitochondrial dysfunction pathway.

Anticancer and antibacterial activity in vitro evaluation of iridium(III) polypyridyl complexes.

Three iridium(III) polypyridyl complexes [Ir(ppy)2(PYTA)](PF6) (1) (ppy = 2-phenylpyridine), [Ir(bzq)2(PYTA)](PF6) (2) (bzq = benzo[h]quinolone) and [Ir(piq)2(PYTA)](PF6) (3) (piq = 1-phenylisoquinoline, PYTA = 2,4-diamino-6-(2'-pyridyl)-1,3,5-triazine) were synthesized and characterized by elemental analysis, IR, 1H NMR and 13C NMR. The cytotoxic activity of the complexes toward cancer SGC-7901, Eca-109, A549, HeLa, HepG2, BEL-7402 and normal LO2 cell lines was investigated by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method. Complex 3 shows the most effective on inhibiting the above cell growth among these complexes. The complexes locate at the lysosomes and mitochondria. AO/EB, Annex V and PI and comet assays indicate that the complexes can induce apoptosis in SGC-7901 cells. Intracellular ROS and mitochondrial membrane potential were examined under fluorescence microscopy. The results demonstrate that the complexes increase the intracellular ROS levels and induce a decrease in the mitochondrial membrane potential. The complexes can enhance intracellular Ca2+ concentration and cause a release of cytochrome c. The autophagy was studied using MDC staining and western blot. Complexes 1-3 can effectively inhibit the cell invasion with a concentration-dependent manner. Additionally, the complexes target tubules and inhibit the polymerization of tubules. The antimicrobial activity of the complexes against S. aureus, E. coli, Salmonella and L. monocytogenes was explored. The mechanism shows that the complexes induce apoptosis in SGC-7901 cells through ROS-mediated lysosomal-mitochondrial, targeting tubules and damage DNA pathways. Three iridium(III) complexes [Ir(N-C)2(PYTA)](PF6) (N-C = ppy, 1; bzq, 2; piq, 3) were synthesized and characterized. The anticancer activity of the complexes against SGC-7901 cells was studied by apoptosis, comet assay, autophagy, ROS, mitochondrial membrane potential, intracellular Ca2+ levels, release of cytochrome c, tubules and western blot analysis. The antibacterial activity in vitro was also assayed.

Photoinduced anticancer activity studies of iridium(III) complexes targeting mitochondria and tubules.

Three new iridium (III) complexes [Ir (ppy)2 (ipbc)](PF6) (1), [Ir (bzq)2 (ipbc)](PF6) (2) and [Ir (piq)2 (ipbc)](PF6) (3) were designed and synthesized. All the complexes were tested for anticancer activity using 3-(4,5-dimethylthiazole)-2,5-diphenyltetraazolium bromide (MTT) method. The complexes show no cytotoxic activity toward cancer BEL-7402, SGC-7901, Eca-109, A549, HeLa and HepG2 cells. However, upon irradiation with white light, the complexes display high cytotoxicity against BEL-7402 cells with an IC50 value of 5.5 ±â€¯0.8, 7.3 ±â€¯1.3 and 11.5 ±â€¯1.6 µM for 1, 2 and 3, respectively. AO/EB staining and comet assay show that the complexes can induce apoptosis in BEL-7402 cells. The complexes can increase intracellular ROS and Ca2+ levels and cause a decrease in the mitochondrial membrane potential. Autophagic assays exhibit that the complexes can induce autophagy and regulate the expression of Beclin-1 and LC3 proteins. The cell cycle distribution in BEL-7402 cells was carried out by flow cytometry. The expression of Bcl-2 family proteins was studied by western blot. Additionally, the complexes can release cytochrome c and inhibit the polymerization of α-tubulin. Our study reveals that the complexes inhibit the cell growth in BEL-7402 cells through an ROS-mediated mitochondria dysfunction and targeting tubules pathways. These complexes are a promising new entity for the development of multi-target anticancer drugs.

An iridium (III) complex as potent anticancer agent induces apoptosis and autophagy in B16 cells through inhibition of the AKT/mTOR pathway.

A new ligand THPDP (THPDP = 11-(6,7,8,9-tetrahydrophenazin-2-yl)dipyrido[3,2-a:2',3'-c]phenazine) and its iridium(III) complex [Ir(ppy)2(THPDP)]PF6 (Ir-1) was synthesized and characterized by elemental analysis, IR, ESI-MS, 1H NMR and 13C NMR. The cytotoxicity in vitro of the complex against cancer cells B16, A549, Eca-109, SGC-7901, BEL-7402 and normal NIH 3T3 cell lines was evaluated using MTT method. The IC50 values of the complex toward B16, A549 and Eca-109 cells are 1.0 ±â€¯0.02, 1.4 ±â€¯0.03 and 1.6 ±â€¯0.06 µM, respectively. The apoptosis was investigated with AO/EB and DAPI staining methods. The complex shows strong ability to inhibit the cell growth in B16, A549 and Eca-109 cells. Ir-1 can induce apoptosis, increase the intracellular ROS level, and cause a decrease in the mitochondrial membrane potential. The intracellular Ca2+ level and the release of cytochrome c were studied under a fluorescent microscope. The cell invasion and autophagy were also performed, and the cell cycle arrest was assayed by flow cytometry. The expression of Bcl-2 family proteins, PI3K, AKT, mTOR, P-mTOR was investigated by western blot. The results show that the complex induces apoptosis through ROS-mediated mitochondria dysfunction and inhibition of AKT/mTOR pathways. These findings are helpful for design and synthesis of iridium(III) complexes as potent anticancer drugs.

Synthesis, characterization and anticancer activity in vitro and in vivo evaluation of an iridium (III) polypyridyl complex.

An iridium (III) complex [Ir(ppy)2(BDPIP)]PF6 (Ir-1) was reported to show high anticancer activity and may be used as a potent anticancer drug. In the current study, we designed and synthesized a novel iridium (III) complex and evaluated its potential inhibitory effect on the cancer cell growth in vitro and in vivo. This complex was found to display high cytotoxic activity in vitro and in vivo against A549 cell with a low IC50 value of 3.6 ± 0.3 µM and inhibiting percentage of tumor growth is 63.84% compared with the control. The complex also exhibited potencies superior to that of cisplatin toward A549 cell in vitro and in vivo. Further studies revealed that the complex can induce apoptosis and autophagy, enhance the ROS level, cause a decrease in the mitochondrial membrane potential and inhibit the cell invasion. Our findings indicated that the complex induced apoptosis in A549 through mitochondria dysfunction and PI3K/AKT/mTOR signaling pathways.

Synthesis and anticancer properties of ruthenium (II) complexes as potent apoptosis inducers through mitochondrial disruption.

A new ligand MHPIP (MHPIP = 2-(1-methyl-1H-pyrazol-4-yl)-1H-imidazo[4,5-f][1,10]phenanthroline) and its three ruthenium (II) complexes [Ru(N-N)2(MHPIP)](ClO4)2 (N-N = phen: 1,10-phenanthroline 1; dmp = 2,9-dimethyl-1,10-phenanthroline 2; ttbpy = 4,4'-ditertiarybutyl-2,2'-bipyridine 3) were synthesized and characterized. The cytotoxic activity in vitro was studied by MTT method. The complexes 1-3 show moderate cytotoxic effects on the cell growth in HepG2 cells with an IC50 value of 25.5 ± 3.5, 35.6 ± 1.9 and 27.4 ± 2.3 µM, respectively. The apoptosis was investigated with AO/EB and Annex V/PI staining methods and comet assay. The reactive oxygen species, mitochondrial membrane potential were investigated under a fluorescent microscope. Autophagy assay shows that the complexes can cause autophagy and up-regulate the expression of Beclin-1 protein. Additionally, the complexes inhibit the cell growth in HepG2 cells at G0/G1 phase, and the complexes can regulate the expression of caspase 3 and Bcl-2 family proteins. The studies demonstrate that the complexes induce apoptosis in HepG2 cells through DNA damage and ROS-mediated mitochondrial dysfunction pathways.