RESUMO
We report the synthesis, characterization and anticancer activity of a new Schiff base (H2L) derived from the condensation of pyridoxamine with pyridoxal and its novel copper(II) and oxidovanadium(IV) complexes: [Cu(HL)Cl] (1), [Cu(LH2)(phen)]Cl2 (2), [Cu(LH2)(amphen)]Cl2 (3), [VIVO(HL)Cl] (4), and [VIVO(LH2)(phen)]Cl2 (5), where phen is 1,10-phenanthroline and amphen is its 5-amino derivative. All compounds were characterized by analytical and spectroscopic techniques, namely FTIR, UV-vis and EPR spectroscopy. Their stability in aqueous media was evaluated, revealing that the presence of the phen co-ligand significantly increases the stability. The ternary Cu(II) complexes (2 and 3) impaired cell viability of osteosarcoma cells (MG-63) (IC50 values of 3.6 ± 0.6 and 7 ± 1.9 µM for 2 and 3), while 1 and the VIVO complexes did not show relevant anticancer activity. Complexes 2 and 3 are also more active than cisplatin (CDDP). Synergistic studies between 2 and sorafenib showed significant synergism on MG-63 cells for the following combinations: 2 (2.0 µM) + sorafenib (10.0 µM) and 2 (2.5 µM) + sorafenib (12.5 µM), whilst the combination of 2 and CDDP did not show synergy. Complex 2 interacts with DNA, inducing significant genotoxic effects on MG-63 cells from 1.0 to 2.5 µM and it increases the ROS levels 880% over basal. Moreover, 2 induces apoptosis at 1.0 and 2.0 µM, while its combination with sorafenib induces apoptosis and necrosis. Finally, compound 2 reduces the cell viability of MG-63 spheroids showing an IC50 value 7-fold lower than that of CDDP (8.5 ± 0.4 µM vs. 65 ± 6 µM). The combination of 2 and sorafenib also showed synergism on spheroids, suggesting that the combination of these drugs improves the anticancer effect against bone cancer cells.
Assuntos
Antineoplásicos , Complexos de Coordenação , Osteossarcoma , Humanos , Cobre/química , Bases de Schiff/farmacologia , Bases de Schiff/química , Antineoplásicos/química , Vitamina B 6/farmacologia , Sorafenibe , Cisplatino/farmacologia , Vitaminas , Complexos de Coordenação/químicaRESUMO
The steady rise in the cancer burden and grim statistics set a vital need for new therapeutic solutions. Given their high efficiency, metallodrugs are quite appealing in cancer chemotherapy. This work examined the anticancer activity of an anti-trypanosomal ruthenium-based compound bearing the 5-nitrofuryl pharmacophore, [RuII(dmso)2(5-nitro-2-furaldehyde semicarbazone)] (abbreviated as RuNTF; dmso is the dimethyl sulfoxide ligand). The cytotoxicity of RuNTF was evaluated in vitro against ovarian adenocarcinoma, hormone-dependent breast adenocarcinoma, prostate carcinoma (grade IV) and V79 lung fibroblasts human cells. The activity of RuNTF was similar to the benchmark metallodrug cisplatin for the breast line and inactive against the prostate line and lung fibroblasts. Given the known role of serum protein binding in drug bioavailability and the distribution via blood plasma, this study assessed the interaction of RuNTF with human serum albumin (HSA) by circular dichroism (CD) and fluorescence spectroscopy. The fluorescence emission quenching from the HSA-Trp214 residue and the lifetime data upon RuNTF binding evidenced the formation of a 1:1 {RuNTF-albumin} adduct with log Ksv = (4.58 ± 0.01) and log KB = (4.55 ± 0.01). This is supported by CD data with an induced CD broad band observed at ~450 nm even after short incubation times. Importantly, the binding to either HSA or human apo-transferrin is beneficial to the cytotoxicity of the complex towards human cancer cells by enhancing the cytotoxic activity of RuNTF.
Assuntos
Proteínas Sanguíneas/química , Complexos de Coordenação/química , Rutênio/química , Semicarbazonas/química , Algoritmos , Antineoplásicos/química , Antineoplásicos/farmacologia , Proteínas Sanguíneas/metabolismo , Dicroísmo Circular , Interações Medicamentosas , Humanos , Modelos Moleculares , Modelos Teóricos , Estrutura Molecular , Ligação Proteica , Rutênio/metabolismo , Albumina Sérica Humana/química , Albumina Sérica Humana/metabolismoRESUMO
In Latin America Chagas disease is an endemic illness caused by the parasite Trypanosoma cruzi (T. cruzi), killing more people than any other parasitic disease. Current chemotherapies are old and inadequate, thus the development of efficient ones is urgently needed. Vanadium-based complexes have been shown to be a promising approach both against parasitic diseases and cancer and this study aims to achieve significant advances in the pursue of effective compounds. Heteroleptic vanadium complexes of Schiff bases and polypyridine compounds were prepared and their stability in solution evaluated by EPR (Electronic Paramagnetic Resonance) and NMR spectroscopy. Their in vitro activities were evaluated against T. cruzi and a set of cells lines representative of human cancer conditions, namely ovarian, breast and prostate cancer. In T. cruzi, most of the complexes depicted IC50 values in the low µM range, induced changes of mitochondrial membrane potential and apoptosis. In cancer cells, complexes showed good to moderate activity and in metastatic cells (prostate PC3), some complexes inhibited the migratory ability, this suggesting that they display antimetastatic potential. Interestingly, complex 5 seemed to have a dual effect being the most cytotoxic complex on all cancer cells and also the most active anti-T-cruzi compound of the series. Globally the complexes showed promising anticancer and anti T. cruzi activities and also displayed some characteristics indicating they are worth to be further explored as antimetastatic drugs.
Assuntos
Antineoplásicos , Doença de Chagas/tratamento farmacológico , Complexos de Coordenação , Neoplasias da Próstata/tratamento farmacológico , Piridinas , Tripanossomicidas , Trypanosoma cruzi/metabolismo , Vanadatos , Antineoplásicos/síntese química , Antineoplásicos/química , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Doença de Chagas/metabolismo , Doença de Chagas/patologia , Complexos de Coordenação/síntese química , Complexos de Coordenação/química , Complexos de Coordenação/farmacologia , Humanos , Masculino , Neoplasias da Próstata/metabolismo , Neoplasias da Próstata/patologia , Piridinas/química , Piridinas/farmacologia , Tripanossomicidas/síntese química , Tripanossomicidas/química , Tripanossomicidas/farmacologia , Vanadatos/química , Vanadatos/farmacologiaRESUMO
Searching for prospective vanadium-based drugs for cancer treatment, a new series of structurally related [VIVO(L-2H)(NN)] compounds (1-8) was developed. They include a double deprotonated salicylaldimine Schiff base ligand (L-2H) and different NN-polypyridyl co-ligands having DNA intercalating capacity. Compounds were characterized in solid state and in solution. EPR spectroscopy suggests that the NN ligands act as bidentate and bind through both nitrogen donor atoms in an axial-equatorial mode. The cytotoxicity was evaluated in human tumoral cells (ovarian A2780, breast MCF7, prostate PC3). The cytotoxic activity was dependent on type of cell and incubation time. At 24h PC3 cells presented low sensitivity, but at 72h all complexes showed high cytotoxic activity in all cells. Human kidney HEK293 and ovarian cisplatin resistant A2780cisR cells were also included to evaluate selectivity towards cancer cells and potency to overcome cisplatin resistance, respectively. Most complexes showed no detectable interaction with plasmid DNA, except 2 and 7 which depicted low ability to induce single strand breaks in supercoiled DNA. Based on the overall cytotoxic profile, complexes with 2,2´-bipyridine and 1,10-phenanthroline ligands (1 and 2) were selected for further studies, which consisted on cellular distribution and ultrastructural analyses. In the A2780 cells both depicted different distribution profiles; the former accumulates mostly at the membrane and the latter in the cytoskeleton. Morphology of treated cells showed nuclear atypia and membrane alterations, more severe for 1. Complexes induce different cell death pathways, predominantly necrosis for 1 and apoptosis for 2. Complexes alternative mode of cell death motivates the possibility for further developments.
Assuntos
Antineoplásicos , Membrana Celular , Citotoxinas , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Neoplasias , Salicilatos , Vanadatos , Antineoplásicos/síntese química , Antineoplásicos/química , Antineoplásicos/farmacocinética , Antineoplásicos/farmacologia , Morte Celular/efeitos dos fármacos , Membrana Celular/metabolismo , Membrana Celular/ultraestrutura , Cisplatino/farmacologia , Citotoxinas/síntese química , Citotoxinas/química , Citotoxinas/farmacocinética , Citotoxinas/farmacologia , Ensaios de Seleção de Medicamentos Antitumorais , Células HEK293 , Humanos , Células MCF-7 , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo , Neoplasias/ultraestrutura , Salicilatos/síntese química , Salicilatos/química , Salicilatos/farmacocinética , Salicilatos/farmacologia , Bases de Schiff/síntese química , Bases de Schiff/química , Bases de Schiff/farmacocinética , Bases de Schiff/farmacologia , Vanadatos/síntese química , Vanadatos/química , Vanadatos/farmacocinética , Vanadatos/farmacologiaRESUMO
Searching for prospective metal-based drugs for the treatment of Chagas disease, a new series of ten mixed-ligand oxidovanadium(IV) complexes, [V(IV)O(L-2H)(NN)], where L is a tridentate salicylaldehyde semicarbazone derivative (L1-L5) and NN is either 5-amine-1,10-phenanthroline (aminophen) or 5,6-epoxy-5,6-dihydro-1,10-phenanthroline (epoxyphen), were synthesized. The compounds were characterized in the solid state and in solution. EPR spectroscopy suggests that the NN ligands act as bidentate through both nitrogen donor atoms in an axial-equatorial mode. The stability of the complexes in solution was investigated by EPR and (51)V-nuclear magnetic resonance spectroscopies. The complexes were evaluated in vitro for their activities against Trypanosoma cruzi (T. cruzi), the parasite responsible for the disease, and their selectivity was analyzed using J-774 murine macrophages, as a mammalian model. All the complexes are more active than both the reference drug Nifurtimox and the previously reported [V(IV)O(L-2H)(NN)] complexes. In general they are more active than the corresponding free NN ligands. Complexation led to highly increased selectivities towards the parasite. In addition, the lipophilicity of the compounds was determined and correlated with the observed activity in order to perform a QSAR (quantitative structure-activity relationship) study. A clear quadratic correlation is found. This study also confirms the influence of the structure of the co-ligand on the anti-T. cruzi effect. To get insight into the mechanism of action of the compounds, the changes in biochemical pathways promoted by two of the most active and most selective complexes are studied by analyzing a few of the parasite excreted metabolites by (1)H NMR spectroscopy. The combined information suggests that the mitochondrion could be a target for these complexes. Furthermore, DNA was preliminarily evaluated as a potential target by using atomic force microscopy (AFM), which showed that the complexes display an ability to interact with this biomolecule.
Assuntos
Antiprotozoários/farmacologia , Compostos Organometálicos/farmacologia , Fenantrolinas/farmacologia , Trypanosoma cruzi/efeitos dos fármacos , Vanádio/farmacologia , Antiprotozoários/síntese química , Antiprotozoários/química , Relação Dose-Resposta a Droga , Ligantes , Estrutura Molecular , Compostos Organometálicos/síntese química , Compostos Organometálicos/química , Testes de Sensibilidade Parasitária , Fenantrolinas/química , Relação Estrutura-Atividade , Trypanosoma cruzi/crescimento & desenvolvimento , Vanádio/químicaRESUMO
Four complexes combining the {Ru(p-cym)} moiety (p-cym = para-cymene) with thiosemicarbazone (TSC) ligands containing the 5-nitrofuryl pharmacophore were investigated in vitro for their properties as prospective anti-tumour agents. The compounds are dimeric structures of general formula [Ru2(p-cym)2(L)2]X2 where X = Cl(-), PF6(-) and L = deprotonated 5-nitrofuraldehyde TSC (L1), and the N-methyl (L2), N-ethyl (L3) and N-phenyl (L4) derivatives. The precursor [RuCl2(p-cym)]2, all TSC ligands L1-L4and their corresponding complexes 1-4 were screened in vitro for their cytotoxicity against a range of human cancer cell lines (HL-60 acute promyelocytic leukemia, A2780 ovarian adenocarcinoma, MCF7 breast adenocarcinoma and PC3 grade IV prostate carcinoma). While the precursor complex was found to be inactive and L4 exhibited moderate activity only in the MCF7 cell line, the coordination of L4 to the {Ru(p-cym)} moiety remarkably enhanced the activity of the whole complex. In fact, complex 4 [Ru2(p-cym)2(L4)2]Cl2 was found to be the most active agent of the whole series, and was studied further (as well as complex 1 for comparison). Concerning the mode of action, the mechanism of cell death for both 1 and 4 seemed to be related to apoptotic processes, and they strongly interacted with tubulin (involved in the cell cycle) and with integrin (involved in the cytoskeleton formation). As an approach to their pharmacokinetics, the interaction of 1 and 4 with human serum albumin (HSA) was assessed. A quantitative model for the binding of 4 to HSA is proposed from Circular Dichroism data, and validated by fluorescence results. Models of Förster resonance energy transfer and fluorescence quenching afforded the distance of 4 to the lone Trp214 residue. Importantly, HSA binding enhanced the cytotoxicity of 4 and correlated well with the HSA binding data. Our results consistently indicate that [Ru2(p-cymene)2(L4)2]Cl2 is quite promising as a prospective metallodrug for cancer chemotherapy.