Sparfloxacin - Cu(II) - aromatic heterocyclic complexes: synthesis, characterization and in vitro anticancer evaluation.

Two new copper(II) complexes of sparfloxacin (sf), [Cu(Hsf)(HPB)(H2O)](ClO4)2 (1) and [Cu(Hsf)(PBT)(H2O)](ClO4)2 (2) (where HPB = 2-(2'-pyridyl)benzimidazole and PBT = 2-(4'-pyridyl) benzothiazole), have been synthesized and characterized by physicochemical and spectroscopic techniques. The oil-water partition coefficient (log P) values of complexes 1 and 2 were 1.47 and 1.71, respectively. By studying the interaction between the complexes and DNA, it was found that the complexes could bind to DNA through an intercalation mode. Moreover, both complexes were evaluated for antitumor activity, revealing that the complexes displayed good inhibitory activity toward the tested cancer cell lines (human lung carcinoma A549 cells, human hepatocellular carcinoma Bel-7402 cells and human esophageal carcinoma Eca-109 cells), but showed relatively low toxicity against normal human hepatic LO2 cells. In particular, the antitumor mechanism of the complexes on Eca-109 cells was investigated by morphological analysis, apoptosis analysis and determination of cell cycle arrest, mitochondrial membrane potential, reactive oxygen species (ROS) levels, and release of cytochrome c and Ca2+. The results demonstrated that the complexes could induce loss of intracellular mitochondrial functions and increase of ROS levels, which led to an increase of Ca2+ levels and the release of cytochrome c into the cytoplasm. In addition, the cell cycle was arrested in the G2/M phase, and western blot analysis showed that the caspase family was activated. These results fully proved that the complexes could induce apoptosis through DNA damage and loss of mitochondrial functions, accompanied by the regulation of endogenous proteins.

Synthesis, DNA binding, antibacterial and anticancer properties of two novel water-soluble copper(II) complexes containing gluconate.

In this paper, two new Cu(II) complexes, [Cu(Gluc)(HPB)(H2O)]Gluc (CuG1) and [Cu(Gluc)(HPBC)(H2O)]Gluc (CuG2) (where HPB = 2-(2'-pyridyl)benzimidazole, HPBC = 5-chloro-2-(2'-pyridyl)benzimidazole, Gluc = d-Gluconic acid), with good water solubility were synthesized and characterized. These complexes exhibited a five-coordinated tetragonal pyramidal geometry. The DNA binding and cleavage properties of the complexes were investigated using multi-spectroscopy, viscosity measurement, molecular docking and gel electrophoresis analysis methods. The results showed that the complexes could interact with DNA by insertion and groove binding, and cleave CT-DNA through a singlet oxygen-dependent pathway in the presence of ascorbic acid. The studies on antibacterial and anticancer activities in vitro demonstrated that both complexes had good inhibitory activity against three Gram-positive bacteria (Staphylococcus aureus, Bacillus subtilis, Listeria monocytogenes) and one Gram-negative bacterium (Escherichia coli) and good cytotoxic activity toward the tested cancer cells (A549, HeLa and SGC-7901). CuG2 showed higher antimicrobial and cytotoxic activities than CuG1, which was consistent with their binding strength and cleavage ability to DNA, indicating that their antimicrobial and cytotoxic activities may be related to the DNA interaction. Moreover, the cell-based mechanism studies have indicated that CuG1 and CuG2 could arrest the cell cycle at G2/M phase, elevate the levels of intracellular reactive oxygen species (ROS) and decrease the mitochondrial membrane potential (MMP). The results showed that the complexes could induce apoptosis through DNA-damaged and ROS-mediated mitochondrial dysfunction pathways. Finally, the in vivo antitumor study revealed that CuG2 inhibited tumor growth by 50.44%, which is better than that of cisplatin (40.94%).

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.

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.

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.

miR-1306-3p targets FBXL5 to promote metastasis of hepatocellular carcinoma through suppressing snail degradation.

This study aimed to elucidate the effect of miR-1306-3p on metastasis of hepatocellular carcinoma (HCC) and potential mechanism involved. miR-1306-3p promoted migration and invasion of HCC in vivo and in vitro. Moreover, miR-1306-3p inhibited snail to enhance its expression via directly targeting FBXL5, thus inducing the epithelial-mesenchymal transition (EMT) in HCC. Intriguingly, miR-1306-3p expression was transcriptionally enhanced by FoxM1. Consistently, miR-1306-3p was upregulated in HCC compared with paracarcinoma and correlated with poor prognosis of HCC patients. Our researches suggest that miR-1306-3p is a tumor enhancer in regulating of HCC metastasis, and miR-1306-3p may be clinically utilized as a factor for the clinical diagnosis and prognosis of HCC.

Dibenzoxanthenes induce apoptosis and autophagy in HeLa cells by modeling the PI3K/Akt pathway.

A new series of dibenzoxanthene derivatives 4a-4d (4a: 1-oxo-5-bromo-11-cyano-13c-methoxy-1,13c-dihydroxyl-dibenzo[a,kl]xanthene, 4b: 1-oxo-5-bromo-11-cyano-13c-ethoxy-1,13c-dihydroxyl-dibenzo[a,kl]xanthene, 4c: 1-oxo-5-bromo-11-cyano-13c-propoxy-1,13c-dihydroxyl-dibenzo[a,kl]xanthene and 4d: 1-oxo-5-bromo-11-cyano-13c-butoxy-1,13c-dihydroxyl-dibenzo[a,kl]xanthene) were synthesized and the molecular mechanisms of anti-cancer activities were investigated. These compounds showed excellent anti-tumor activity against A549, Eca-109, HeLa, HepG2 and SGC-7901 cell lines. Compounds 4a-4d could effectively inhibit the migration and invasion of HeLa cells in wound healing and transwell assays. Compounds induced the DNA damage and arrested in cell cycle distribution at G0/G1 phase. Apoptosis induced by compounds was detected using morphological observation of nuclear changes and FITC-Annexin V/PI staining. Additionally, compounds also induced the autophagy of HeLa cells through observing AO staining and upregulated the expression of LC3II and Beclin-1 proteins. Furthermore, treatment with autophagy inhibitor 3-methyladenine induced an obvious decrease in apoptotic rate in HeLa cells. This indicated that autophagy further promoted the HeLa cells apoptosis. Compounds 4a-4d enhanced the intracellular Ca2+ and ROS. Then the mitochondrial membrane potential of HeLa cells was depolarized and the cytochrome C was released from mitochondria into cytoplasm. Activities of the apoptotic factors Bcl-2, Bax, caspase-3 were measured using western blotting. After HeLa cells were exposed to compounds, the expressions of PI3K and Akt protein were decreased. Compounds exhibit anti-cancer activity via apoptosis and autophagy through inhibition of PI3K/Akt signaling pathway in HeLa cells.

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.

Synthetic Dibenzoxanthene Derivatives Induce Apoptosis Through Mitochondrial Pathway in Human Hepatocellular Cancer Cells.

A new series of dibenzoxanthenes 4a-4f were synthesized through the nucleophilic substitution and characterized by NMR and MS spectra. Their antitumor activity was screened by MTT assay. Compounds (except 4b and 4c) displayed strong growth inhibitory effects against chosen five tumor cells under light irradiation. The molecular mechanism of compound-induced cell apoptosis was investigated by AO/EB staining, comet assay, DCFH-DA, JC-1 fluorescent probe, and western blotting. Compounds induced the apoptosis of HepG2 cells and DNA damage. Location assay showed that compounds entered the nucleus of tumor cells. Furthermore, it was found that compounds induced loss of mitochondrial membrane potential, acceleration of ROS production, and activation of caspse-3, caspase-7, and caspase-9 proteins. Compounds upregulated the expression of pro-apoptotic Bim and Bax and downregulated the expression of anti-apoptotic Bcl-xl and Bcl-2. These results indicated that compounds induced the apoptosis of HepG2 cells through ROS-mediated mitochondrial pathway. The induction of apoptosis by dibenzoxanthenes may provide an important mechanism for their cancer chemopreventive function.

Novel ethanocycloheptono [3,4,5-kl]benzo[a]xanthene induces apoptosis in BEL-7402 cells.

A novel polycyclic bridged-ring xanthene 2 was synthesized by nucleophilic substitution followed by Michael addition reaction between parent dibenzoxanthene 1 and acetylacetone. The structure of compound 2 was also confirmed by single-crystal X-ray diffraction. We studied the binding activity of this compound with bovine serum albumin (BSA) by fluorescent and UV-visible spectra. The results showed that compound had strong binding ability with BSA. Cell viability in five tumor cell lines was studied by MTT assay. The cytotoxic effect of bridged-ring xanthene 2 against BEL-7402 cells was examined by morphological analyses and biochemical assays. Significant nuclear damages of BEL-7402 cells were observed after cells were treated with compound in a comet assay. The compound also caused DNA damage and S phase arrest in BEL-7402 cells. The efficient induction of apoptosis by the compound was confirmed by flow cytometry. Additionally, the characteristic nuclear and morphological changes during apoptotic cell death were investigated by fluorescent microscopy. The compound 2 enhanced the reactive oxygen species (ROS) and decreased the mitochondrial membrane potential. Western blot assay indicated that the compound can active caspase-3, caspase-7, down-regulate the level of Bcl-2, Bcl-x, and up-regulate the level of pro-apoptosis protein Bax. The compound 2 induces apoptosis of BEL-7402 cells through a ROS-mediated mitochondrial dysfunction pathway.

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.

Isoliquiritigenin Induces Cytotoxicity in PC-12 Cells In Vitro.

Isoliquiritigenin (ISL) has been reported to have a wide range of biological activities. This study evaluated the cytotoxic effect of ISL on norvegicus pheochromocytoma cell line (PC-12 cells) and its possible molecular mechanism. The cytotoxicity in vitro of ISL against PC-12 cells was investigated by MTT assay. The migration and invasion of PC-12 cells were performed by scratch test and transwell assay. Apoptosis was evaluated by microscopy and flow cytometry. The reactive oxygen species (ROS) and mitochondrial membrane potential were studied by fluorescent microscopy. DNA damage of PC-12 cells was analyzed by comet assay. The protein expression of caspase, Bcl-2 family member, autophagy-associated protein Beclin-1, and LC3 was detected by western blot. The autophagy of PC-12 cells was investigated by acridine orange (AO) and monodansylcadaverine (MDC) staining. The IC50 value of ISL against PC-12 cell is 17.8 ± 1.8 µM. ISL could suppress PC-12 cell migration and invasion. AO/ethidium bromide staining and flow cytometry suggested that ISL caused apoptosis of PC-12 cells. Significant DNA damages of PC-12 cells treated with ISL were observed in a comet assay. ISL inhibited the cell growth of PC-12 cells at S phase. Exposure of PC-12 cells to ISL increased the levels of cellular reactive oxygen species (ROS) and decreased the mitochondrial membrane potential. Additionally, ISL trigged the release of cytochrome c from the mitochondria to the cytoplasm. The expression levels of caspase-9, caspase-3, caspase-7, Bax, and Bim were upregulated, whereas the expression levels of Bcl-2 and Bcl-x were downregulated. AO and monodansylcadaverine (MDC) staining assay showed that ISL caused autophagy of PC-12 cells. The upregulation of protein Beclin-1 and LC3 was observed in PC-12 cells. Therefore, the results show that ISL induces apoptosis of PC-12 cells through ROS-mediated activation of the intrinsic mitochondria-cytochrome c-caspase protease mechanism and causes the autophagy of PC-12 cells. Graphical Abstract The in vitro cytotoxicity, apoptosis, comet assay, ROS, mitochondrial membrane potential, cell cycle arrest, autophagy, and western blot induced by ISL were investigated.

Ruthenium(II) polypyridyl complexes: Synthesis, characterization and anticancer activity studies on BEL-7402 cells.

Two new ligand PTTP (2-phenoxy-1,4,8,9-tetraazatriphenylene) and FTTP (2-(3-fluoronaphthalen-2-yloxy)-1,4,8,9-tetraazatriphenylene) and their six ruthenium(II) polypyridyl complexes [Ru(N-N)2(PTTP)](ClO4)2 and [Ru(N-N)2(FTTP)](ClO4)2 (N-N=dmb: 4,4'-dimethyl-2,2'-bipiridine; dmp: 2,9-dimethyl-1,10-phenanthroline; ttbpy: 4,4'-ditertiarybutyl-2,2'-bipyridine) were synthesized and characterized. The cytotoxic activity of the complexes against cancer cells HeLa, BEL-7402, A549, HepG-2, HOS and normal cell LO2 was evaluated by MTT method. The IC50 values range from 1.5±0.1 to 55.9±7.5µM. Complex 3 shows the highest cytotoxic activity toward BEL-7402 cells (IC50=1.5±0.1µM). Complex 5 displays most effective inhibition of the cell growth in A549 and HOS cells with low IC50 values of 2.5±0.6 and 2.6±0.1µM, respectively. The apoptosis, reactive oxygen species, mitochondrial membrane potential, DNA damage, autophagy and anti-metastasis assay were investigated under a fluorescent microscope. The cell cycle arrest was assayed by flow cytometry, and the expression of caspases and Bcl-2 family proteins was studied by western blot. The results obtained show that the complexes induce apoptosis in BEL-7402 cells through a ROS-mediated mitochondrial dysfunction pathway.

Design, synthesis and evaluation of anticancer activity of ruthenium (II) polypyridyl complexes.

A new ligand PFPIP (PFPIP=2-(2,3,4,5,6-pentafluorophenyl)[4,5-f]imadazo [1,10]phenanthroline) and its four ruthenium(II) polypyridyl complexes [Ru(NN)2(PFPIP)](ClO4)2 (NN=dmb: 4,4'-dimethyl-2,2'-bipyridine, 1; bpy: 2,2'-bipyridine, 2; phen: 1,10-phenanthroline, 3; dmp: 2,9-dimethyl-1,10-phenanthroline, 4) were synthesized and characterized by elemental analysis, IR, 1H NMR, 13C NMR and ESI-MS. The cytotoxic activity in vitro of the ligand and complexes toward BEL-7402, A549, HeLa, HepG2 and MG-63 cell lines was evaluated using MTT method (MTT=(3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide). Complexes 1, 3 and 4 show moderate cytotoxic effect on the cell growth in BEL-7402 cells with IC50 values of 32.1±0.9, 37.9±1.7 and 42.1±3.0µM, respectively. The apoptosis in BEL-7402 cell was investigated with AO/EB and Hoechst 33,258 staining methods. The autophagy in BEL-7402 cell induced by complexes was assayed using MDC staining cell nuclei. The cell invasion, reactive oxygen species (ROS), mitochondrial membrane potential, cell cycle arrest, cellular uptake, comet assay and wound healing were studied under a fluorescent microscope. The complexes can cause autophagy and inhibit the cell invasion, and increase the ROS levels and induce a decrease in the mitochondrial membrane potential. The expression of the proteins related with apoptosis induced by the complexes was assayed by western blot analysis.

Synthesis of novel dibenzoxanthene derivatives and observation of apoptosis in human hepatocellular cancer cells.

We have synthesized dibenzoxanthene derivatives 2a-2i via nucleophilic substitution of methoxyl group and evaluated underlying antitumor molecular mechanism of target compounds. Compounds showed high cytotoxic activities against BEL-7402, A549, HeLa and MG-63 cancer cells in the µM range. These compounds inhibited the cell growth of BEL-7402 cells at S or G2/M phase. The compounds 2a-2i also induced the apoptosis of BEL-7402 cells. In addition, compounds enhanced the level of intramolecular ROS and decreased the mitochondrial membrane potential. Western blot analysis showed caspase-3 were activated and the expression of Bcl-2 and Bcl-xl was down-regulated. According to given results, these dibenzoxanthenes exhibited a broad spectrum of antiproliferative effects on various tumors and therapeutic efficacy. Molecular mechanism indicated that induction of apoptosis was associated with DNA fragmentation, ROS generation, mitochondria dysfunction. Compounds induced apoptosis in BEL-7402 cells through the intrinsic ROS-mediated mitochondrial pathway.