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.

Liposomes encapsulated iridium(III) polypyridyl complexes enhance anticancer activity in vitro and in vivo.

Three iridium(III) complexes [Ir(ppy)2(CPIP)](PF6) (Ir-1, ppy = 2-phenylpyridine, CPIP = 2-(4-chlorophenyl)-1H-imidazo[4,5-f][1,10]phenanthroline), [Ir(ppy)2(DCPIP)](PF6) (Ir-2, DCPIP = 2-(3,4-dichlorophenyl)-1H-imidazo[4,5-f][1,10]phenanthroline) and [Ir(ppy)2(TCPIP)](PF6) (Ir-3, TCPIP = 2,3,5-trichlorophenyl)-1H-imidazo[4,5-f][1,10]phenanthroline) were synthesized and characterized. The complexes Ir-1, Ir-2 and Ir-3 were encapsulated in liposomes to form Ir-1-Lipo, Ir-2-Lipo and Ir-3-Lipo. Morphology, size distribution, and zeta potential of liposomes were examined by transmission electron microscopy (TEM) and Zetasizer. The cytotoxic activity in vitro of Ir-1, Ir-2 and Ir-3 against cancer A549, HTC-116, HepG2, BEL-7402, Eca-109, B16, HeLa SGC-7901 and normal NIH3T3 cells was evaluated by 3-(4,5-dimethylthiazole-2-yl)-2,5-biphenyl tetrazolium bromide (MTT) method. Ir-2 and Ir-3 show no cytotoxic activity against the selected cancer cells, and Ir-1 displays moderate cytotoxic effect on the cell growth in A549 cells. However, Ir-1, Ir-2 and Ir-3 were encapsulated in liposomes, the cytotoxic activity was greatly enhanced. In particular, Ir-1-Lipo and Ir-2-Lipo can effectively inhibit the cell growth in A549 cells with a low IC50 value of 3.1 ± 0.3 and 1.2 ± 0.4 µM. The apoptosis was assayed by flow cytometry. Ir-1, Ir-2 and Ir-3 reveal weak apoptotic effect, whereas Ir-1-Lipo, Ir-2-Lipo and Ir-3-Lipo induce an apoptotic percentage of 55.6%, 69.3% and 16.7% in A549 cells, respectively. Specially, in the assay of antitumor activity in vivo, the inhibiting percentage of tumor growth induced by Ir-2 is 27.65%, while inhibiting percentage of tumor growth caused by Ir-2-Lipo is 57.45%. Obviously, the liposomes can enhance anticancer activity in vitro and in vivo compared with the complexes. The results show that the iridium(III) complexes encapsulated liposomes induce apoptosis in A549 cells through ROS-mediated lysosome-mitochondria dysfunction pathway and target the microtubules.

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 biological evaluation of iridium(III) complexes as potential antitumor agents.

Cisplatin and its analogs have been used for the treatment of various cancers, but their serious side effect has limited clinical application. Presently, scientists are developing other metal drugs as an alternative of cisplatin. In this paper, three new iridium(III) complexes [Ir(ppy)2(adppz)](PF6) (adppz = 7-aminodipyrido[3,2-a:2',3'-c]phenazine; ppy = 2-phenylpyridine 1), [Ir(bzq)2(adppz)](PF6) (bzq = benzo[h]quinolone 2) and [Ir(piq)2(adppz)](PF6) (piq = 1-phenylisoquinoline 3) were synthesized and characterized. The complexes can effectively inhibit the cell colonies. The cytotoxicity in vitro of the complexes against A549, HepG2, SGC-7901, BEL-7402 and normal NIH3T3 cells was evaluated by 3-(4,5-dimethylthiazole)-2,5-diphenyltetraazolium bromide (MTT) methods. The intracellular reactive oxygen species (ROS) levels and Ca2+ concentrations were assayed. The mitochondrial membrane potential, a release of cytochrome c and the expression of B-cell lymphoma/leukemia-2 (Bcl-2) family protein have been investigated. The data reveal that the complexes 1-3 can effectively inhibit the cell proliferation in A549 cells with low IC50 value of 3.2 ±â€¯0.4 µM, 4.8 ±â€¯0.5 µM and 1.2 ±â€¯0.2 µM, respectively. The antitumor in vivo shows that complex 3 can inhibit tumor growth with an inhibitory rate of 76.34%. The studies on the mechanism indicate that these complexes cause apoptosis in A549 cell via a ROS-mediated lysosomal-mitochondrial dysfunction pathway. In addition, the interaction of the complexes with BSA was explored.

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.

Studies of anticancer activity in vitro and in vivo of iridium(III) polypyridyl complexes-loaded liposomes as drug delivery system.

Two iridium(III) polypyridyl complexes [Ir(ppy)2(HPIP)](PF6) (Ir-1), [Ir(ppy)2(BHPIP)](PF6) (Ir-2) and their liposomes Ir-1-Lipo and Ir-2-Lipo were synthesized and characterized by elemental analysis, IR, 1H NMR and 13C NMR. The anticancer activity in vitro and in vivo was evaluated. The cytotoxic activity in vitro of the complexes and their liposomes Ir-1-Lipo and Ir-2-Lipo against cancer cells was investigated by MTT methods. Ir-1 and Ir-2 show no cytotoxic activity, while Ir-1-Lipo and Ir-2-Lipo exhibit high cytotoxic effect. The IC50 values range from 5.2 ±â€¯0.8 to 22.3 ±â€¯1.8 µM. The apoptosis, reactive oxygen species, the change of mitochondrial membrane potential, intracellular Ca2+ levels and a release of cytochrome c were investigated. The effect of Ir-1-Lipo and Ir-2-Lipo on microtubules was also explored. In the C57BL/6 mice model, Ir-1 only displays a tumor inhibitory rate of 23.21%, while lr-1-Lipo exhibits satisfactory in vivo antitumor efficacy with tumor inhibitory rate of 72.55%. This study demonstrates that complexes encapsulated in liposomes induce apoptosis in B16 through ROS-mediated lysosomal-mitochondria dysfunction, inhibition of polymerization of microtubules and induce cell cycle arrest at S phase.

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.