A Multipurpose Metallophore and Its Copper Complexes with Diverse Catalytic Antioxidant Properties to Deal with Metal and Oxidative Stress Disorders: A Combined Experimental, Theoretical, and In Vitro Study.

We report the discovery that the molecule 1-(pyridin-2-ylmethylamino)propan-2-ol (HL) can reduce oxidative stress in neuronal C6 glioma cells exposed to reactive oxygen species (O2-•, H2O2, and •OH) and metal (Cu+) stress conditions. Furthermore, its association with Cu2+ generates [Cu(HL)Cl2] (1) and [Cu(HL)2](ClO4)2 (2) complexes that also exhibit antioxidant properties. Potentiometric titration data show that HL can coordinate to Cu2+ in 1:1 and 1:2 Cu2+:ligand ratios, which was confirmed by monocrystal X-ray studies. The subsequent ultraviolet-visible, electrospray ionization mass spectrometry, and electron paramagnetic resonance experiments show that they can decompose a variety of reactive oxygen species (ROS). Kinetic studies revealed that 1 and 2 mimic the superoxide dismutase and catalase activities. Complex 1 promotes the fastest decomposition of H2O2 (kobs = 2.32 × 107 M-1 s-1), efficiently dismutases the superoxide anion (kcat = 3.08 × 107 M-1 s-1), and scavenges the hydroxyl radical (RSA50 = 25.7 × 10-6 M). Density functional theory calculations support the formation of dinuclear Cu-peroxide and mononuclear Cu-superoxide species in the reactions of [Cu(HL)Cl2] with H2O2 and O2•-, respectively. Furthermore, both 1 and 2 also reduce the oxidative stress of neuronal glioma C6 cells exposed to different ROS, including O2•- and •OH.

Anti-Acanthamoeba metallopharmaceuticals: Amoebicidal activity and synergistic effect of copper(II) coordination compound.

Acanthamoeba spp. emerged as a clinically important pathogen related to amoebic keratitis. It is among the main causes of corneal transplantation and vision loss in ophthalmology. The treatment protocols have a low cure rate, high toxicity, and need for drug combination. Transition metal compounds have shown promising antiprotozoal effects. This study evaluates the amoebicidal activity of copper(II) coordination compounds in combination with chlorhexidine and the cytotoxicity to topical ocular application. These copper(II) coordination compounds were screened against Acanthamoeba castellanii trophozoites (ATCC 50492). The cytotoxicity on rabbit corneal cell line (ATCC-CCL 60) was performed. The compounds showed high amoebicidal potential, with inhibition of trophozoite viability above 80%. The Cp12 and Cp13 compounds showed Minimal Inhibitory Amoebicidal Concentration (MIAC) at 200 µM and mean inhibitory concentration (IC50) values lower than 10 µM. Against the cysts, Cp12 showed a reduction in viability (48%) in the longest incubation period. A synergistic effect for Cp12 with chlorhexidine was observed. The compounds have a dose-dependent effect against rabbit corneal cells. Compound Cp12 has potential for future application in developing ophthalmic formulations against Acanthamoeba keratitis and its use in multipurpose solutions is highlighted.

In Vitro and In Vivo Relevant Antineoplastic Activity of Platinum(II) Complexes toward Triple-Negative MDA-MB-231 Breast Cancer Cell Line.

Two platinum complexes [Pt(HL3)Cl]·H2O (3) and [Pt(HL4)Cl]·H2O (4) containing α- and ß-naphthyl groups, respectively, were investigated in more detail in vitro and in vivo for antineoplastic activity. The cytotoxicity activity induced by these platinum(II) compounds against breast cancer (MDA-MB-231 and MCF-7), lung (A549), prostate (PC3), pancreas (BXPC-3), and normal peripheral blood mononuclear (PBMC) cells were evaluated by MTT assay. The cell viability MTT assay showed that complex (4) was more cytotoxic to all cancer cell lines tested and less cytotoxic against human PBMC. Therefore, complex (4) was selected to further investigate the mechanism of cytotoxic effects involved against MDA-MB-231 cell line (human triple-negative breast cancer). Sub-G1 analysis of the cell cycle showed that this complex induces cell death by apoptosis due to the cell loss of DNA content detected in flow cytometry. The cytotoxic effect induced by complex (4) was associated with the capability of the complex to induce mitochondrial membrane depolarization, as well as increase ROS levels and caspase activation, as a result of the activation of both extrinsic and intrinsic apoptosis pathways. Ultrastructural alterations were observed using scanning and transmission electron microscopy (SEM and TEM), such as membrane blebbing, filopodia reduction, empty mitochondrial matrix, and DNA fragmentation. Furthermore, complex (4) was tested in an MDA-MB-231 tumor nodule xenograft murine model and demonstrated a remarkable reduction in tumor size in BALB/c nude mice, when compared to the control animals.

Antitumor activity via apoptotic cell death pathway of water soluble copper(II) complexes: effect of the diamino unit on selectivity against lung cancer NCI-H460 cell line.

The cytotoxicity against five human tumor cell lines (THP-1, U937, Molt-4, Colo-205 and NCI-H460) of three water soluble copper(II) coordination compounds containing the ligands 3,3'-(ethane-1,2-diylbis(azanediyl))dipropanamide (BCEN), 3,3'-(piperazine-1,4-diyl)dipropanamide (BPAP) or 3,3'-and (1,4-diazepane-1,4-diyl)dipropanamide (BPAH) are reported in this work. The ligands contain different diamine units (ethylenediamine, piperazine or homopiperazine) and two propanamide units attached to the diamine centers, resulting in N2O2 donor sets. The complex containing homopiperazine unit presented the best antiproliferative effect and selectivity against lung cancer cell line NCI-H460, showing inhibitory concentration (IC50) of 58 µmol dm-3 and Selectivity Index (SI) > 3.4. The mechanism of cell death promoted by the complex was investigated by Sub-G1 cell population analysis and annexin V and propidium iodide (PI) labeling techniques, suggesting that the complex promotes death by apoptosis. Transmission electron microscopy investigations are in agreement with the results presented by mitochondrial membrane potential analysis and also show the impairment of other organelles, including endoplasmic reticulum.

Effect of the hydroxamate group in the antitumoral activity and toxicity toward normal cells of new copper(II) complexes.

The synthesis, physico-chemical characterization and cytotoxicity of four copper(II) coordination complexes, i.e. [Cu(HBPA)Cl2] (1), [Cu(BHA)2] (2), [Cu(HBPA)(BHA)Cl] CH3OH (3) and [Cu(HBPA)2]Cl2·4H2O (4), are reported. HBPA is the tridentate ligand N-(2-hydroxybenzyl)-N-(2-pyridylmethyl)amine and HBHA is the benzohydroxamic acid. The reaction between the HBHA and CuCl2.2H2O has resulted in the new complex (2) and the reaction between complex (1) and HBHA has resulted in the new complex (3). X-ray diffraction studies for complex (3) indicated the effective coordination of HBHA as BHA-. Their cytotoxicity was evaluated against three human tumoral cell lines (Colo-205, NCI-H460 and U937) and PBMC (peripheral blood mononuclear cells), using the MTT cytotoxic assay. The results toward PBMC reveal that the new copper(II) complex (2) presents lower toxicity toward normal cells. Furthermore, complex (2) presents IC50 values lower than cisplatin toward NCI-H460 and the best selectivity index obtained towards NCI-H460 (SI = 2.2) and U937 cell lines (SI = 2.0), as a result of the presence of two molecules of HBHA in its structure. Complex (3) presents IC50 values lower than cisplatin toward NCI-H460, Colo-205 and comparable to cisplatin toward U937. The evaluation of the cell death type promoted by complexes (2) and (4) was investigated toward NCI-H460 revealing better results than the standard drug cisplatin, according to the Annexin V and propidium iodide (PI) labeling experiment. Based on the studies here performed, HBHA seems to be related to lower toxicity toward PBMC and HBPA is improving directly the cytotoxity.

In vitro and in vivo anti-proliferative activity and ultrastructure investigations of a copper(II) complex toward human lung cancer cell NCI-H460.

The aim of our study was to evaluate the in vitro and in vivo anti-proliferative potential of complex (2) [Cu (L1)Cl]Cl.2H2O, where L1 = 1-[2-hydroxybenzyl(2-pyridylmethyl)amino]-3-(1-naphthyloxy)-2-propanol on lung carcinoma cell NCI-H460. Cell viability assay determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) colorimetric assay demonstrated that the complex (2) exhibits higher activity against the NCI-H460 cell, with an IC50 value lower than cisplatin (26.5 µM ± 1.1 and 203 ± 1.2 µM respectively). Cell death by apoptosis was investigated by flow cytometer analysis of sub-G1 populations in the cell cycle and Annexin V/Propidium Iodide assay. Changes on the cell surface and ultrastructure were detected by scanning and transmission electron microscopy. Our work revealed that complex (2) induced changes associated with apoptosis, such as plasma membrane blebbing and a lower microvilli amount, fragmentation and condensation of chromatin, alterations in mitochondria, and enlargement of the endoplasmic reticulum. Mitochondrial function of NCI-H460 cells evaluated by 5,5',6,6'-tetrachloro 1,1',3,3' tetraethylbenzimidazolylcarbocyanine iodide (JC-1) probes showed high loss of mitochondrial membrane potential when treated with complex (2). Moreover, caspase-12 measurement showed an expressive activation level, which is related to endoplasmic reticulum stress. In vivo assay using the murine model of human lung cancer cell showed that complex (2) and cisplatin has similar antineoplastic activity.

Iron and copper complexes with antioxidant activity as inhibitors of the metastatic potential of glioma cells.

Gliomas are the most common type of primary brain tumors, presenting high mortality and recurrence rates that highlight the need for the development of more efficient therapies. In that context, we investigated iron(iii) (FeL) and copper(ii) (CuL) complexes containing the tetradentate ligand 2-{[(3-chloro-2-hydroxy-propyl)-pyridin-2-ylmethyl-amino]-methyl}-phenol (L) as potential antimetastatic compounds in glioma cells. These complexes were designed to act as mimetics of antioxidant metalloenzymes (catalases and superoxide dismutase) and thus interfere with the production of reactive oxygen species (ROS), important signaling molecules that have been linked to the induction of Epithelial-Mesenchymal Transition (EMT) in cancer cells, a process associated with cancer invasion and aggressiveness. The results obtained have revealed that, in vitro, both compounds act as superoxide dismutase or catalase mimetics, and this translated in glioma cells into a decrease in ROS levels in FeL-treated cells. In addition, both complexes were found to inhibit the migration of monolayer-grown H4 cells and lead to decreased expression of EMT markers. More importantly, this behavior was recapitulated in 3D spheroids models, where CuL in particular was found to completely inhibit the invasion ability of glioma cells, with or without cellular irradiation with X-rays, which is suggestive of these compounds' potential to be used in combination with radiotherapy. Overall, the results herein obtained describe the novel use of these complexes as agents that are able to interfere with regulation of EMT and the invasive behavior of glioma cells, an application that deserves to be further explored.

Modulating the antitumoral activity by the design of new platinum(II) compounds: Synthesis, characterization, DFT, ultrastructure and mechanistic studies.

The synthesis, physico-chemical characterization, Density functional theory (DFT) calculation and cytotoxicity against five human tumoral cell lines (THP-1, U937, Molt-4, Colo205 and H460) of four new platinum(II) coordination compounds are reported, i.e. [Pt(HL1)Cl]·H2O (1), [Pt(HL2)Cl]·H2O (2), [Pt(HL3)Cl]·H2O (3) and [Pt(HL4)Cl]·H2O (4). The ligands contain N2O donor sets. Furthermore, H2L3 and H2L4 present α and ß-naphthyl groups respectively, which are absent in HL1 and H2L2. X-ray diffraction studies were performed for complex (3), indicating the formation of a mononuclear platinum(II) complex. Complexes (3) and (4), which contain α and ß-naphthyl groups respectively, have presented lower IC50 (inhibitory concentration) values than those exhibited by complexes (1) and (2). The mechanism of cell death promoted by complexes (3) and (4) was investigated, suggesting that, toward U937 cell line, the α isomer promotes death by apoptosis and the ß isomer by necrosis. Transmission and scanning electron microscopy investigations are in agreement with the loss of mitochondrial membrane potential (ΔΨm) observed by JC-1 mitochondrial potential sensor and indicate that the activity of complex (3) against U937 cell line is mediated by an apoptotic mechanism associated with mitochondrial dysfunction. A quantification of caspases 3, 6, 8 and 9 indicated that both the intrinsic and extrinsic pathways are involved in the apoptotic stimuli. Based on DFT calculations all the Pt(II) complexes present the same coordination environment for the metal centre, indicating that the higher cytotoxic activities exhibited by complexes (3) and (4) are related to the presence of the α and ß-naphthyl groups in the ligand structure.

A new iron(III) complex-containing sulfadiazine inhibits the proliferation and induces cystogenesis of Toxoplasma gondii.

We have previously shown that metallocomplexes can control the growth of Toxoplasma gondii, the agent that causes toxoplasmosis. In order to develop new metallodrugs to treat this disease, we investigated the influence of the coordination of sulfadiazine (SDZ), a drug used to treat toxoplasmosis, on the biological activity of the iron(III) complex [Fe(HBPClNOL)Cl2]·H2O, 1, (H2BPClNOL=N-(2-hydroxybenzyl)-N-(2-pyridylmethyl)(3-chloro)(2-hydroxy)-propylamine). The new complex [(Cl)(SDZ)Fe(III)(µ-BPClNOL)2Fe(III)(SDZ)(Cl)]·2H2O, 2, which was obtained by the reaction between complex 1 and SDZ, was characterized using a range of physico-chemical techniques. The cytotoxic effect of the complexes and the ability of T. gondii to infect LLC-MK2 cells were assessed. It was found that both complexes reduced the growth of T. gondii while also causing low cytotoxicity in the host cells. After 48 h of treatment, complex 2 reduced the parasite's ability to proliferate by about 50% with an IC50 of 1.66 µmol/L. Meanwhile, complex 1 or SDZ alone caused a 40% reduction in proliferation, and SDZ displayed an IC50 of 5.3 µmol/L. In addition, complex 2 treatment induced distinct morphological and ultrastructural changes in the parasites and triggered the formation of cyst-like forms. These results show that the coordination of SDZ to the iron(III) complex is a good strategy for increasing the anti-toxoplasma activity of these compounds.

In vitro and in vivo studies of the antineoplastic activity of copper (II) compounds against human leukemia THP-1 and murine melanoma B16-F10 cell lines.

We investigated the antineoplastic activities of a previously reported copper (II) coordination compound, [Cu(BMPA)Cl2]CH3OH (1), and a new compound, [Cu(HBPA)Cl2]H2O (2), where BMPA is bis(pyridin-2-ylmethyl)amine and HBPA is (2-hydroxybenzyl)(2-pyridylmethyl)amine, using various cellular models of human leukemia (THP-1, U937, HL60, Molt-4, JURKAT) and human colon cancer (COLO 205), as well as a murine highly metastatic melanoma (B16-F10) cell line. Compound (2) was characterized using several physical and chemical techniques, including X-ray diffraction studies. The IC50 values of the copper coordination complexes in the human leukemia cell lines ranged from 87.63 ± 1.02 to ≥400 µM at high cell concentrations and from 19.17 ± 1.06 to 97.67 ± 1.23 µM at low cell concentrations. Both compounds induced cell death, which was determined by cell cycle analyses and phosphatidylserine exposure studies. THP-1 cells released cytochrome c to the cytoplasm 12 h after treatment with 400 µM of compound (2). To evaluate the apoptosis pathway induced by compound (2), we measured the activities of initiator caspases 8 and 9 and executioner caspases 3 and 6. The results were suggestive of the activation of both intrinsic and extrinsic apoptosis pathways. To investigate the activities of the compounds in vivo, we selected two sensitive cell lines from leukemia (THP-1) and solid tumor (B16-F10) lineages. BALB/c nude bearing THP-1 tumors treated with 12 mg·kg(-1) of compound (2) showed a 92.4% inhibition of tumor growth compared with the control group.

Synthesis, characterization and antitumoral activity of new cobalt(II)complexes: Effect of the ligand isomerism on the biological activity of the complexes.

The synthesis, physico-chemical characterization and cytotoxicity against five human tumoral cell lines (THP-1, U937, Molt-4, Colo205 and H460) of three new cobalt(II) coordination compounds are reported (i.e. Co(HL1)Cl (1), Co(HL2)Cl (2) and [Co(HL3)Cl]0.0.5 (CH3)2CHOH (3)). H2L2 (2-{[[2-hydroxy-3-(1-naphthyloxy)propyl](pyridin-2-ylmethyl)amino]methyl}phenol) and H2L3 (2-{[[2-hydroxy-3-(2-naphthyloxy)propyl](pyridin-2-ylmethyl)amino]methyl}phenol) present α and ß-naphthyl groups respectively, which is absent in H2L1 (N-(2-hydroxybenzyl)-N-(2-pyridylmethyl)[(3-chloro)(2-hydroxy)]propylamine. These compounds were characterized by a range of physico-chemical methods. X-ray diffraction studies were performed for complex (3), indicating the formation of a mononuclear complex. Complexes (2) and (3), which contain α and ß-naphthyl groups respectively, have presented lower IC50 values than those exhibited by complex (1). Complex (3) presents IC50 values lower than cisplatin against Colo205 (90 and 196µmolL(-1), respectively) and H460 (147 and 197µmolL(-1), respectively). These human neoplastic cells under investigation were also more susceptible toward complex (3) than peripheral blood mononuclear cells. Transmission electron microscopy investigations are in agreement with the loss of mitochondrial membrane potential (ΔΨm) observed by JC-1 mitochondrial potential sensor and indicate that the activity of complex (3) against leukemic cell line (U937) is mediated by an apoptotic mechanism associated with mitochondrial dysfunction (intrinsic pathway).

Induction of apoptosis in leukemia cell lines by new copper(II) complexes containing naphthyl groups via interaction with death receptors.

The synthesis, physico-chemical characterization and cytotoxicity of four new ligands and their respective copper(II) complexes toward two human leukemia cell lines (THP-1 and U937) are reported (i.e. [(HL1)Cu(µ-Cl)2Cu(HL1)]Cl2·H2O (1), [(H2L2)Cu(µ-Cl)2Cu(H2L2)]Cl2·5H2O (2), [(HL3)Cu(µ-Cl)2Cu(HL3)]Cl2·4H2O (3), [(H2L4)Cu(µ-Cl)2Cu(H2L4)]Cl2·6H2O (4)). Ligands HL1 and HL3 contain two pyridines, amine and alcohol moieties with a naphthyl pendant unit yielding a N3O coordination metal environment. Ligands H2L2 and H2L4 have pyridine, phenol, amine and alcohol groups with a naphthyl pendant unit providing a N2O2 coordination metal environment. These compounds are likely to be dinuclear in the solid state but form mononuclear species in solution. The complexes have an antiproliferative effect against both leukemia cell lines; complex (2) exhibits higher activity than cisplatin against U937 (8.20 vs 16.25µmoldm(-3)) and a comparable one against THP-1. These human neoplastic cells are also more susceptible than peripheral blood mononuclear cells (PBMCs) toward the tested compounds. Using C57BL/6 mice an LD50 of 55mgkg(-1) was determined for complex (2), suggesting that this compound is almost four times less toxic than cisplatin (LD50=14.5mgkg(-1)). The mechanism of cell death promoted by ligand H2L2 and by complexes (2) and (4) was investigated by a range of techniques demonstrating that the apoptosis signal triggered at least by complex (2) starts from an extrinsic pathway involving the activation of caspases 4 and 8. This signal is amplified by mitochondria with the concomitant release of cytochrome c and the activation of caspase 9.

Políticas esportivas do terceiro setor no Estado de Mato Grosso do Sul: uma análise do projeto Córrego Bandeira / Sports of the third sector policies in the State of Mato Grosso do Sul: an analysis of banner project stream / Deporte del tercer sector en las políticas del Estado de Mato Grosso do Sul: un análisis del proyecto "córrego bandeira"

Esse artigo tem como objetivo discutir sobre a atuação do Terceiro Setor nas políticas de esporte e lazer no estado de Mato Grosso do Sul (MS), por meio da parceria firmada entre a Universidade Federal de MS e o Instituto Ayrton Senna, o que resultou no Projeto "Córrego Bandeira". O método de investigação para alcançar o objetivo proposto é o materialismo histórico dialético. Constata-se que as políticas públicas, no âmbito esportivo executadas pelo terceiro setor são ações fragmentadas e focalizadas, que se utilizam do trabalho precário principalmente dos acadêmicos do curso de educação física.

This article aims to discuss the role of the Third Sector in the policies of sport and leisure in the state of Mato Grosso do Sul (MS) especially in the partnership between the Federal University of MS with Instituto Ayrton Senna, which resulted in the Project "Córrego Bandeira". The research method is dialectical historical materialism. It is considered that public policy in sports performed by the third sector are fragmented and focused actions, which are used mainly precarious work of students of physical education.

Este artículo tiene como objetivo discutir sobre el trabajo de las organizaciones del Tercer Sector en las políticas de las actividades deportivas y del ocio en el estado de Mato Grosso do Sul (MS), por medio de una asociación entre la Universidad Federal de MS y el Instituto Ayrton Senna, que dio como resultado el Proyecto "Córrego Bandeira". El método de la investigación para lograr el objetivo propuesto es el materialismo histórico dialéctico. Hay que señalar que las políticas públicas, en el deporte que realiza el tercer sector son acciones fragmentadas y centradas,, que utilizan el trabajo precario principalmente de los estudiantes de educación física.

Iron, copper, and manganese complexes with in vitro superoxide dismutase and/or catalase activities that keep Saccharomyces cerevisiae cells alive under severe oxidative stress.

Due to their aerobic lifestyle, eukaryotic organisms have evolved different strategies to overcome oxidative stress. The recruitment of some specific metalloenzymes such as superoxide dismutases (SODs) and catalases (CATs) is of great importance for eliminating harmful reactive oxygen species (hydrogen peroxide and superoxide anion). Using the ligand HPClNOL {1-[bis(pyridin-2-ylmethyl)amino]-3-chloropropan-2-ol}, we have synthesized three coordination compounds containing iron(III), copper(II), and manganese(II) ions, which are also present in the active site of the above-noted metalloenzymes. These compounds were evaluated as SOD and CAT mimetics. The manganese and iron compounds showed both SOD and CAT activities, while copper showed only SOD activity. The copper and manganese in vitro SOD activities are very similar (IC50~0.4 µmol dm(-3)) and about 70-fold higher than those of iron. The manganese compound showed CAT activity higher than that of the iron species. Analyzing their capacity to protect Saccharomyces cerevisiae cells against oxidative stress (H2O2 and the O2(•-) radical), we observed that all compounds act as antioxidants, increasing the resistance of yeast cells mainly due to a reduction of lipid oxidation. Especially for the iron compound, the data indicate complete protection when wild-type cells were exposed to H2O2 or O2(•-) species. Interestingly, these compounds also compensate for both superoxide dismutase and catalase deficiencies; their antioxidant activity is metal ion dependent, in the order iron(III)>copper(II)>manganese(II). The protection mechanism employed by the complexes proved to be independent of the activation of transcription factors (such as Yap1, Hsf1, Msn2/Msn4) and protein synthesis. There is no direct relation between the in vitro and the in vivo antioxidant activities.

A pesquisa escolar com instrumento pedagógico: um dos caminhos para ampliar as situações didáticas da educação física escolar no ensino fundamental / Research school teaching as a tool: one of ways to enlarge the sutuations of teachinng physical education in schools elementary school / Investigación docente escuela como herramienta: una de las maneras de aumentar las situaciones de enseñanza de la educación física en la escuela primaria de escuelas

Este ensaio discute a respeito de uma prática pedagógica que tem como objeto a pesquisa, considerada como um instrumento para auxiliar no processo de ensino aprendizagem da Educação Física Escolar. Esse instrumento, se bem orientado, dá concretude e expressa a totalidade do corpo teórico/prático da disciplina em questão, contribui para que crianças e jovens aprendam os conteúdos, de forma participativa, compreendendo a realidade e produzindo conhecimentos. Para isso, é necessário conhecer o seu significado e buscar o entendimento de como orientar a pesquisa em sala de aula, evitando concepções equivocadas que podem diminuir as chances desse tipo de atividade alcançar seus objetivos.

This essay discusses about a pedagogical practice that focuses the research, consideredas a pedagogical tool to aid in the teaching and learning of physical education. This instrument is well oriented, gives concreteness and expresses the totality of the theoretical / practical discipline in question, helps children and young people learn the content in a participatory manner, understanding the reality and producing knowledge. For this it is necessary to know its meaning and seek the understanding of how to guide it in the classroom, avoiding misconceptions that may decrease the chances of this type of activity to achieve their goals.

En este ensayo se discute acerca de una práctica pedagógica que se centra la investigación, considerada como una herramienta pedagógica para ayudar en la enseñanza y aprendizaje de la educación física. Este instrumento está bienorientada, da concreción y expresa la totalidad de la disciplina teórica / práctica encuestión, ayuda a los niños y los jóvenes aprenden el contenido de una manera participativa, entendiendo la realidad y producir conocimiento. Para ello, es necesario conocer su significado y buscar la comprensión de cómo guiar en el aula, evitando mal entendidos que pueden disminuir las posibilidades de este tipo de actividades para lograr sus objetivos.

Highly efficient synthetic iron-dependent nucleases activate both intrinsic and extrinsic apoptotic death pathways in leukemia cancer cells.

The nuclease activity and the cytotoxicity toward human leukemia cancer cells of iron complexes, [Fe(HPClNOL)Cl2]NO3 (1), [Cl(HPClNOL)Fe(µ-O)Fe(HPClNOL)Cl]Cl2·2H2O (2), and [(SO4)(HPClNOL)Fe(µ-O)Fe(HPClNOL)(SO4)]·6H2O (3) (HPClNOL=1-(bis-pyridin-2-ylmethyl-amino)-3-chloropropan-2-ol), were investigated. Each complex was able to promote plasmid DNA cleavage and change the supercoiled form of the plasmid to circular and linear ones. Kinetic data revealed that (1), (2) and (3) increase the rate of DNA hydrolysis about 278, 192 and 339 million-fold, respectively. The activity of the complexes was inhibited by distamycin, indicating that they interact with the minor groove of the DNA. The cytotoxic activity of the complexes toward U937, HL-60, Jukart and THP-1 leukemia cancer cells was studied employing 3-(4,5-dimethythiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT), fluorescence and electronic transmission microscopies, flow cytometry and a cytochrome C release assay. Compound (2) has the highest activity toward cancer cells and is the least toxic for normal ones (i.e. peripheral blood mononuclear cells (PBMCs)). In contrast, compound (1) is the least active toward cancer cells but displays the highest toxicity toward normal cells. Transmission electronic microscopy indicates that cell death shows features typical of apoptotic cells, which was confirmed using the annexin V-FITC/PI (fluorescein isothiocyanate/propidium iodide) assay. Furthermore, our data demonstrate that at an early stage during the treatment with complex (2) mitochondria lose their transmembrane potential, resulting in cytochrome C release. A quantification of caspases 3, 9 (intrinsic apoptosis pathway) and caspase 8 (extrinsic apoptosis pathway) indicated that both the intrinsic (via mitochondria) and extrinsic (via death receptors) pathways are involved in the apoptotic stimuli.

Investigation of the interaction of iron(III) complexes with dAMP by ESI-MS, MALDI-MS and potentiometric titration: insights into synthetic nuclease behavior.

We report herein the characterization by electrospray ionization (ESI) mass spectrometry (MS), matrix assisted laser desorption ionization (MALDI-MS) and potentiometric titration of three iron(III) compounds: [Fe(III)(HPClNOL)Cl2]·NO3 (1), [Cl(HPClNOL)Fe(III)-(µ-O)-Fe(III)(HPClNOL)Cl]·Cl2·H2O (2) and [(SO4)(HPClNOL)Fe(III)-(µ-O)-Fe(III)(HPClNOL)(SO4)]·6H2O (3), where HPClNOL= 1-(bis-pyridin-2-ylmethyl-amino)-3-chloropropan-2-ol). Despite the fact that the compounds have distinct structures in solid state and non-buffered solution, all compounds present similar ESI and MALDI mass spectra in a buffered medium (pH 7.0). At this pH, the species [(PClNOL)Fe(III)-(µ-O)-Fe(III)(PClNOL)](2+) (m/z 354) was observed for all the compounds under investigation. Potentiometric titration confirms a similar behavior for all compounds, indicating that the dihydroxo form [(OH)(HPClNOL)Fe(III)-(µ-O)-Fe(III)(HPClNOL)(OH)](2+) is the major species at pH 7.0, for all the compounds. The products of the interaction between compounds (1), (2) and (3) and dAMP (2'-deoxyadenosine-5'-monophosphate) in a buffered medium (pH 7.0) were identified by MALDI-MS/MS. The fragmentation data obtained by MS/MS allow one to identify the nature of the interaction between the iron(III) compounds and dAMP, revealing the direct interaction between the iron center and phosphate groups.

An iron-based cytosolic catalase and superoxide dismutase mimic complex.

The development of metallodrugs with antioxidant activities is of importance as a way to protect organisms exposed to stressful conditions. Although iron chemistry in the presence of H(2)O(2) is usually associated with pro-oxidant activity, mainly via the Fenton reaction, we found that the mononuclear compound [Fe(HPClNOL)Cl(2)]NO(3) (1; C(15)H(18)Cl(3)FeN(4)O(4), a = 8.7751(3) A, b = 9.0778(4) A, c = 24.3869(10) A, beta = 93.370(2) degrees , monoclinic, P2(1)/c, Z = 4), containing the tripodal ligand 1-[bis(pyridin-2-ylmethyl)amino]-3-chloropropan-2-ol, decomposes hydrogen peroxide and superoxide anion in vitro as well as shows in vivo protection because it prevents the harmful effects promoted by H(2)O(2) on Saccharomyces cerevisiae cells, decreasing the level of lipid peroxidation. This protective effect was observed for wild-type cells, as well as for mutant cells, which do not present the antioxidant metalloenzymes catalase (Ctt1) or copper/zinc superoxide dismutase (Sod1).