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1.
Int J Pharm ; 651: 123734, 2024 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-38142017

RESUMO

The present investigation was focused on the development of Soluplus®-based nanomicelles (NMs) (10 % w/v) loaded with Efavirenz (EFV) (5 mg/mL) and Curcumin (natural bio-enhancer) (CUR) (5, 10 and 15 mg/mL) to improve the oral bioavalability of EFV. Micellar formulations were obtained employing an acetone-diffusion technique. Apparent aqueous solubility was increased up to ∼1250-fold and 25,000-fold for EFV and CUR, respectively. Drug-loaded nanoformulations showed an excellent colloidal stability with unimodal size distribution and PDI values < 0.30. In vitro drug release was 41.5 % (EFV) and 2.6 % (CUR) from EFV-CUR-NMs over 6 h in simulated gastrointestinal fluids. EFV-CUR-loaded NMs resulted as safe nanoformulations according to the in vitro cytocompatibility assays in Caco-2 cells. Furthermore, CUR bio-enhancer activity was demonstrated for those nanoformulations. A CUR concentration of 15 mg/mL produced a significant (p < 0.05) increment (2.64-fold) of relative EFV oral bioavailability. Finally, the active role of the lymphatic system in the absorption process of EFV, after its oral administration was assessed in a comparative pharmacokinetic study in presence and absence of cycloheximide, a lymphatic transport inhibitor. Overall our EFV-CUR-NMs denoted their potential as a novel nanotechnological platform, representing a step towards an optimized "nano-sized" therapy for AIDS patients.


Assuntos
Alcinos , Curcumina , Ciclopropanos , Humanos , Células CACO-2 , Disponibilidade Biológica , Benzoxazinas , Solubilidade , Micelas , Portadores de Fármacos , Administração Oral , Tamanho da Partícula
2.
Mol Cell Biochem ; 2023 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-37728809

RESUMO

The death of myocytes occurs through different pathways, but the rupture of the plasma membrane is the key point in the transition from reversible to irreversible injury. In the myocytes, three major groups of structural proteins that link the extracellular and intracellular milieus and confer structural stability to the cell membrane: the dystrophin-associated protein complex, the vinculin-integrin link, and the spectrin-based submembranous cytoskeleton. The objective was to determine if remote ischemic preconditioning (rIPC) preserves membrane-associated cytoskeletal proteins (dystrophin and ß-dystroglycan) through the inhibition of metalloproteinase type 2 (MMP-2) activity. A second objective was to describe some of the intracellular signals of the rIPC, that modify mitochondrial function at the early reperfusion. Isolated rat hearts were subjected to 30 min of global ischemia and 120 min of reperfusion (I/R). rIPC was performed by 3 cycles of ischemia/reperfusion in the lower limb (rIPC). rIPC significantly decreased the infarct size, induced Akt/GSK-3 ß phosphorylation and inhibition of the MPTP opening. rIPC improved mitochondrial function, increasing membrane potential, ATP production and respiratory control. I/R increased ONOO- production, which activates MMP-2. This enzyme degrades ß-dystroglycan and dystrophin and collaborates to sarcolemmal disruption. rIPC attenuates the breakdown of ß-dystroglycan and dystrophin through the inhibition of MMP-2 activity. Furthermore, we confirm that rIPC activates different intracellular pathway that involves the an Akt/Gsk3ß and MPTP pore with preservation of mitochondrial function.

3.
Pharmaceutics ; 14(5)2022 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-35631546

RESUMO

Among respiratory infections, tuberculosis was the second deadliest infectious disease in 2020 behind COVID-19. Inhalable nanocarriers offer the possibility of actively targeting anti-tuberculosis drugs to the lungs, especially to alveolar macrophages (cellular reservoirs of the Mycobacterium tuberculosis). Our strategy was based on the development of a mannose-decorated micellar nanoformulation based in Soluplus® to co-encapsulate rifampicin and curcumin. The former is one of the most effective anti-tuberculosis first-line drugs, while curcumin has demonstrated potential anti-mycobacterial properties. Mannose-coated rifampicin (10 mg/mL)-curcumin (5 mg/mL)-loaded polymeric micelles (10% w/v) demonstrated excellent colloidal properties with micellar size ~108 ± 1 nm after freeze-drying, and they remain stable under dilution in simulated interstitial lung fluid. Drug-loaded polymeric micelles were suitable for drug delivery to the deep lung with lung accumulation, according to the in vitro nebulization studies and the in vivo biodistribution assays of radiolabeled (99mTc) polymeric micelles, respectively. Hence, the nanoformulation did not exhibit hemolytic potential. Interestingly, the addition of mannose significantly improved (5.2-fold) the microbicidal efficacy against Mycobacterium tuberculosis H37Rv of the drug-co-loaded systems in comparison with their counterpart mannose-free polymeric micelles. Thus, this novel inhaled nanoformulation has demonstrated its potential for active drug delivery in pulmonary tuberculosis therapy.

4.
Environ Pollut ; 295: 118677, 2022 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-34906594

RESUMO

Air pollution exposure positively correlates with increased cardiovascular morbidity and mortality rates, mainly due to myocardial infarction (MI). Herein, we aimed to study the metabolic mechanisms underlying this association, focusing on the evaluation of cardiac mitochondrial function and dynamics, together with its impact over MI progression. An initial time course study was performed in BALB/c mice breathing filtered air (FA) or urban air (UA) in whole-body exposure chambers located in Buenos Aires City downtown for up to 16 weeks (n = 8 per group and time point). After 12 weeks, lung inflammatory cell recruitment was evident in UA-exposed mice. Interestingly, impaired redox metabolism, characterized by decreased lung SOD activity and increased GSSG levels and NOX activity, precede local inflammation in this group. At this selected time point, additional mice were exposed to FA or UA (n = 12 per group) and alveolar macrophage PM uptake and nitric oxide (NO) production was observed in UA-exposed mice, together with increased pro-inflammatory cytokine levels (TNF-α and IL-6) in BAL and plasma. Consequently, impaired heart tissue oxygen metabolism and altered mitochondrial ultrastructure and function were observed in UA-exposed mice after 12 weeks, characterized by decreased active state respiration and ATP production rates, and enhanced mitochondrial H2O2 production. Moreover, disturbed cardiac mitochondrial dynamics was detected in this group. This scenario led to a significant increase in the area of infarcted tissue following myocardial ischemia reperfusion injury in vivo, from 43 ± 3% of the area at risk in mice breathing FA to 66 ± 4% in UA-exposed mice (n = 6 per group, p < 0.01), together with a sustained increase in LVEDP during myocardial reperfusion. Taken together, our data unravel cardiac mitochondrial mechanisms that contribute to the understanding of the adverse health effects of urban air pollution exposure, and ultimately highlight the importance of considering environmental factors in the development of cardiovascular diseases.


Assuntos
Poluição do Ar , Infarto do Miocárdio , Poluição do Ar/análise , Animais , Peróxido de Hidrogênio , Camundongos , Mitocôndrias , Infarto do Miocárdio/induzido quimicamente , Material Particulado/toxicidade
5.
Toxicology ; 464: 153020, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34740673

RESUMO

There is an increasing concern over the harmful effects that metallic nanoparticles (NP) may produce on human health. Due to their redox properties, nickel (Ni) and Ni-containing NP are particularly relevant. Hence, the aim of this study was to establish the toxicological mechanisms in the cardiorespiratory oxidative metabolism initiated by an acute exposure to Ni-doped-NP. Mice were intranasally instilled with silica NP containing Ni (II) (Ni-NP) (1 mg Ni (II)/kg body weight) or empty NP as control, and 1 h after exposure lung, plasma, and heart samples were obtained to assess the redox metabolism. Results showed that, NP were mainly retained in the lungs triggering a significantly increased tissue O2 consumption rate, leading to Ni-NP-increased reactive oxygen species production by NOX activity, and mitochondrial H2O2 production rate. In addition, an oxidant redox status due to an altered antioxidant system showed by lung GSH/GSSG ratio decreased, and SOD activity increased, resulting in an increased phospholipid oxidation. Activation of circulating polymorphonuclear leukocytes, along with GSH/GSSG ratio decreased, and phospholipid oxidation were found in the Ni-NP-group plasma samples. Consequently, in distant organs such as heart, Ni-NP inhalation alters the tissue redox status. Our results showed that the O2 metabolism analysis is a critical area of study following Ni-NP inhalation. Therefore, this work provides novel data linking the redox metabolisms alterations elicited by exposure to Ni (II) adsorbed to NP and cardiorespiratory toxicity.


Assuntos
Nanopartículas Metálicas/toxicidade , Níquel/química , Oxirredução/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Animais , Antioxidantes/metabolismo , Feminino , Pulmão/efeitos dos fármacos , Pulmão/metabolismo , Masculino , Nanopartículas Metálicas/química , Camundongos , Mitocôndrias/efeitos dos fármacos , Consumo de Oxigênio/efeitos dos fármacos , Dióxido de Silício/química
6.
Arch Biochem Biophys ; 704: 108875, 2021 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-33891961

RESUMO

Previous reports indicate that the central nervous system (CNS) is a target of air pollution, causing tissue damage and functional alterations. Oxidative stress and neuroinflammation have been pointed out as possible mechanisms mediating these effects. The aim of this work was to study the chronic effects of urban air pollution on mice brain cortex, focusing on oxidative stress markers, and mitochondrial function. Male 8-week-old BALB/c mice were exposed to filtered air (FA, control) or urban air (UA) inside whole-body exposure chambers, located in a highly polluted area of Buenos Aires city, for up to 4 weeks. Glutathione levels, assessed as GSH/GSSG ratio, were decreased after 1 and 2 weeks of exposure to UA (45% and 25% respectively vs. FA; p < 0.05). A 38% increase in lipid peroxidation was found after 1 week of UA exposure (p < 0.05). Regarding protein oxidation, carbonyl content was significantly increased at week 2 in UA-exposed mice, compared to FA-group, and an even higher increment was found after 4 weeks of exposure (week 2: 40% p < 0.05, week 4: 54% p < 0.001). NADPH oxidase (NOX) and glutathione peroxidase (GPx) activities were augmented at all the studied time points, while superoxide dismutase (Cu,Zn-SOD cytosolic isoform) and glutathione reductase (GR) activities were increased only after 4 weeks of UA exposure (p < 0.05). The increased NOX activity was accompanied with higher expression levels of NOX2 regulatory subunit p47phox, and NOX4 (p < 0.05). Also, UA mice showed impaired mitochondrial function due to a 50% reduction in O2 consumption in active state respiration (p < 0.05), a 29% decrease in mitochondrial inner membrane potential (p < 0.05), a 65% decrease in ATP production rate (p < 0.01) and a 30% increase in H2O2 production (p < 0.01). Moreover, respiratory complexes I-III and II-III activities were decreased in UA group (30% and 36% respectively vs. FA; p < 0.05). UA exposed mice showed alterations in mitochondrial function, increased oxidant production evidenced by NOX activation, macromolecules damage and the onset of the enzymatic antioxidant system. These data indicate that oxidative stress and impaired mitochondrial function may play a key role in CNS damage mechanisms triggered by air pollution.


Assuntos
Poluentes Atmosféricos/toxicidade , Poluição do Ar/efeitos adversos , Encéfalo/metabolismo , Mitocôndrias/metabolismo , Membranas Mitocondriais/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Animais , Encéfalo/patologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Mitocôndrias/patologia , NADPH Oxidase 2/metabolismo , NADPH Oxidase 4/metabolismo , Oxirredução/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo
7.
Free Radic Biol Med ; 166: 324-336, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33596456

RESUMO

Along with the AgNP applications development, the concern about their possible toxicity has increasingly gained attention. As the respiratory system is one of the main exposure routes, the aim of this study was to evaluate the harmful effects developed in the lung after an acute AgNP exposure. In vivo studies using Balb/c mice intranasally instilled with 0.1 mg AgNP/kg b.w, were performed. 99mTc-AgNP showed the lung as the main organ of deposition, where, in turn, AgNP may exert barrier injury observed by increased protein content and total cell count in BAL samples. In vivo acute exposure showed altered lung tissue O2 consumption due to increased mitochondrial active respiration and NOX activity. Both O2 consumption processes release ROS triggering the antioxidant system as observed by the increased SOD, catalase and GPx activities and a decreased GSH/GSSG ratio. In addition, increased protein oxidation was observed after AgNP exposure. In A549 cells, exposure to 2.5 µg/mL AgNP during 1 h resulted in augment NOX activity, decreased mitochondrial ATP associated respiration and higher H2O2 production rate. Lung 3D tissue model showed AgNP-initiated barrier alterations as TEER values decreased and morphological alterations. Taken together, these results show that AgNP exposure alters O2 metabolism leading to alterations in oxygen metabolism lung toxicity. AgNP-triggered oxidative damage may be responsible for the impaired lung function observed due to alveolar epithelial injury.


Assuntos
Nanopartículas Metálicas , Prata , Animais , Peróxido de Hidrogênio , Pulmão , Nanopartículas Metálicas/toxicidade , Camundongos , Oxigênio
8.
Ecotoxicol Environ Saf ; 205: 111186, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32853868

RESUMO

Exposure to ambient air particulate matter (PM) is associated with increased cardiorespiratory morbidity and mortality. In this context, alveolar macrophages exhibit proinflammatory and oxidative responses as a result of the clearance of particles, thus contributing to lung injury. However, the mechanisms linking these pathways are not completely clarified. Therefore, the oxinflammation phenomenon was studied in RAW 264.7 macrophages exposed to Residual Oil Fly Ash (ROFA), a PM surrogate rich in transition metals. While cell viability was not compromised under the experimental conditions, a proinflammatory phenotype was observed in cells incubated with ROFA 100 µg/mL, characterized by increased levels of TNF-α and NO production, together with PM uptake. This inflammatory response seems to precede alterations in redox metabolism, characterized by augmented levels of H2O2, diminished GSH/GSSG ratio, and increased SOD activity. This scenario resulted in increased oxidative damage to phospholipids. Moreover, alterations in mitochondrial respiration were observed following ROFA incubation, such as diminished coupling efficiency and spare respiratory capacity, together with augmented proton leak. These findings were accompanied by a decrease in mitochondrial membrane potential. Finally, NADPH oxidase (NOX) and mitochondria were identified as the main sources of superoxide anion () in our model. These results indicate that PM exposure induces direct activation of macrophages, leading to inflammation and increased reactive oxygen species production through NOX and mitochondria, which impairs antioxidant defense and may cause mitochondrial dysfunction.


Assuntos
Macrófagos Alveolares/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , NADPH Oxidases/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Material Particulado/toxicidade , Superóxidos/metabolismo , Poluentes Atmosféricos/toxicidade , Animais , Antioxidantes/metabolismo , Cinza de Carvão/toxicidade , Peróxido de Hidrogênio/metabolismo , Inflamação , Macrófagos Alveolares/imunologia , Macrófagos Alveolares/metabolismo , Camundongos , Mitocôndrias/imunologia , Mitocôndrias/metabolismo , Oxirredução , Estresse Oxidativo/imunologia , Células RAW 264.7 , Fator de Necrose Tumoral alfa/metabolismo
9.
Chem Biodivers ; 17(10): e2000302, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32725761

RESUMO

Ligaria cuneifolia (Ruiz & Pav.) Tiegh. (Loranthaceae), the 'Argentine mistletoe', is a hemiparasite species largely used in folk medicine. The aim of this study was to evaluate the antioxidant activity using in vitro, ex vivo, and in vivo methods. A screening of phenolics was performed by UV spectroscopy on different fractions. The antioxidant capacity was evaluated in vitro by the 1,1-diphenyl-2-picrylhydrazyl radical (DPPH. ) assay on a crude extract (CE), ethyl acetate fraction (EAF), and aqueous fraction (AF). The results suggest that EAF concentrates the antioxidant capacity and was selected for further analysis. Capillary electrophoresis was employed to monitor the individual antioxidant capacity and the potential contributors to this effect. Ex vivo assays showed an efficient inhibition of tert-butyl hydroperoxide-induced rat liver phospholipid oxidation, as well as rat brain autoxidation, and H2 O2 -induced DNA damage in blood monocytes. In vivo, the topical application of EAF significantly decreased skin chemiluminescence in a mice model.


Assuntos
Antioxidantes/farmacologia , Flavonoides/farmacologia , Loranthaceae/química , Fosfolipídeos/antagonistas & inibidores , Extratos Vegetais/farmacologia , Animais , Antioxidantes/química , Antioxidantes/isolamento & purificação , Argentina , Compostos de Bifenilo/antagonistas & inibidores , Dano ao DNA , Feminino , Flavonoides/química , Flavonoides/isolamento & purificação , Fígado/efeitos dos fármacos , Fígado/metabolismo , Camundongos , Oxirredução , Fosfolipídeos/metabolismo , Picratos/antagonistas & inibidores , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Ratos , Ratos Sprague-Dawley , terc-Butil Hidroperóxido/antagonistas & inibidores , terc-Butil Hidroperóxido/farmacologia
10.
Basic Res Cardiol ; 114(5): 38, 2019 08 19.
Artigo em Inglês | MEDLINE | ID: mdl-31428876

RESUMO

There is current awareness about the central role of mitochondrial dysfunction in the development of cardiac dysfunction in systemic inflammatory syndromes, especially in sepsis and endotoxemia. The aim of this work was to elucidate the mechanism that governs the link between the severity of the systemic inflammatory insult and mitochondrial function, analysing the consequences on heart function, particularly in cardiac contractile state. Female Sprague-Dawley rats were subjected to low-grade endotoxemia (i.p. injection LPS 0.5 mg kg-1 body weight) and severe endotoxemia (i.p. injection LPS 8 mg kg-1 body weight) for 6 h. Blood NO, as well as cardiac TNF-α and IL-1ß mRNA, were found increased as the severity of the endotoxemia increases. Cardiac relaxation was altered only in severe endotoxemia, although contractile and lusitropic reserves were found impaired in both treatments in response to work-overload. Cardiac ultrastructure showed disorientation of myofibrillar structure in both endotoxemia degrees, but mitochondrial swelling and cristae disruption were only observed in severe endotoxemia. Mitochondrial ATP production, O2 consumption and mitochondrial inner membrane potential decreases were related to blood NO levels and mitochondrial protein nitration, leading to diminished ATP availability and impairment of contractile state. Co-treatment with the NOS inhibitor L-NAME or the administration of the NO scavenger c-PTIO leads to the observation that mitochondrial bioenergetics status depends on the degree of the inflammatory insult mainly determined by blood NO levels. Unravelling the mechanisms involved in the onset of sepsis and endotoxemia improves the interpretation of the pathology, and provides new horizons for novel therapeutic targets.


Assuntos
Endotoxemia/fisiopatologia , Insuficiência Cardíaca/fisiopatologia , Inflamação/fisiopatologia , Mitocôndrias Cardíacas/fisiologia , Contração Miocárdica/fisiologia , Animais , Endotoxemia/complicações , Metabolismo Energético , Feminino , Insuficiência Cardíaca/etiologia , Mitocôndrias Cardíacas/patologia , Ratos , Ratos Sprague-Dawley
11.
Am J Physiol Heart Circ Physiol ; 316(3): H743-H750, 2019 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-30681368

RESUMO

Adenosine is involved in classic preconditioning in most species and acts especially through adenosine A1 and A3 receptors. The aim of the present study was to evaluate whether remote ischemic preconditioning (rIPC) activates adenosine A1 receptors and improves mitochondrial function, thereby reducing myocardial infarct size. Isolated rat hearts were subjected to 30 min of global ischemia and 60 min of reperfusion [ischemia-reperfusion (I/R)]. In a second group, before isolation of the heart, a rIPC protocol (3 cycles of hindlimb I/R) was performed. Infarct size was measured with tetrazolium staining, and Akt/endothelial nitric oxide (NO) synthase (eNOS) expression/phosphorylation and mitochondrial function were evaluated after ischemia at 10 and 60 min of reperfusion. As expected, rIPC significantly decreased infarct size. This beneficial effect was abolished only when 8-cyclopentyl-1,3-dipropylxanthine (adenosine A1 receptor blocker) and NG-nitro-l-arginine methyl ester (NO synthesis inhibitor) were administered during the reperfusion phase. At the early reperfusion phase, rIPC induced significant Akt and eNOS phosphorylation, which was abolished by the perfusion with an adenosine A1 receptor blocker. I/R led to impaired mitochondrial function, which was attenuated by rIPC and mediated by adenosine A1 receptors. In conclusion, we demonstrated that rIPC limits myocardial infarct by activation of adenosine A1 receptors at early reperfusion in the isolated rat heart. Interestingly, rIPC appears to reduce myocardial infarct size by the Akt/eNOS pathway and improves mitochondrial function during myocardial reperfusion. NEW & NOTEWORTHY Adenosine is involved in classic preconditioning and acts especially through adenosine A1 and A3 receptors. However, its role in the mechanism of remote ischemic preconditioning is controversial. In this study, we demonstrated that remote ischemic preconditioning activates adenosine A1 receptors during early reperfusion, inducing Akt/endothelial nitric oxide synthase phosphorylation and improving mitochondrial function, thereby reducing myocardial infarct size.


Assuntos
Precondicionamento Isquêmico Miocárdico , Mitocôndrias Cardíacas , Receptor A1 de Adenosina , Antagonistas do Receptor A1 de Adenosina/uso terapêutico , Trifosfato de Adenosina/biossíntese , Animais , Inibidores Enzimáticos/uso terapêutico , Masculino , Potencial da Membrana Mitocondrial , Infarto do Miocárdio/diagnóstico por imagem , Infarto do Miocárdio/fisiopatologia , Traumatismo por Reperfusão Miocárdica/diagnóstico por imagem , Traumatismo por Reperfusão Miocárdica/fisiopatologia , Óxido Nítrico Sintase Tipo III/antagonistas & inibidores , Óxido Nítrico Sintase Tipo III/metabolismo , Nitroarginina/uso terapêutico , Consumo de Oxigênio , Ratos , Ratos Sprague-Dawley , Xantinas/uso terapêutico
12.
Int J Biochem Cell Biol ; 81(Pt B): 419-426, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27751881

RESUMO

Several epidemiological studies have shown a positive correlation between daily increases in airborne particulate matter (PM) concentration and the occurrence of respiratory and cardiovascular diseases. Transition metals present in air PM were associated with adverse health effects after PM exposure. The aim of this work was to study lung O2 metabolism after an acute exposure to transition metal-coated nanoparticles (NPs). Female Swiss mice (25g) were intranasally instilled with a suspension of silica NP containing Ni (II), Cd (II), Fe (III), or Cr (VI) at 0, 0.01, 0.05, 0.1, and 1.0mg metal/kg body weight. Lung O2 consumption was found to be significantly increased after the exposure to most doses of Ni-NP and Fe-NP, and the 0.05mg metal/kg body weight dose of Cr-NP, while no changes were observed for Cd-NP. Lucigenin chemiluminescence (as an indicator of NADPH oxidase (NOX) activity) was evaluated in lung homogenates. Only Ni-NP and Fe-NP have shown the ability to induce a significant increase in lucigenin chemiluminescence. In order to establish the possible occurrence of pulmonary oxidative stress, TBARS levels and the GSH/GSSG ratio were determined. The higher doses of Ni-NP and Fe-NP were able to induce an oxidative stress condition, as shown by changes in both TBARS levels and the GSH/GSSG ratio. Taken together, the present results show differential effects for all the metals tested. These findings emphasize the importance of transition metals present air PM in PM adverse health effects, and contribute to the understanding of the pathological mechanisms triggered by the exposure to environmental PM.


Assuntos
Pulmão/efeitos dos fármacos , Oxigênio/metabolismo , Material Particulado , Elementos de Transição/toxicidade , Animais , Relação Dose-Resposta a Droga , Exposição Ambiental , Feminino , Pulmão/química , Camundongos , Modelos Animais , Oxigênio/química , Material Particulado/química , Material Particulado/toxicidade , Elementos de Transição/química
14.
Exp Physiol ; 101(6): 708-16, 2016 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-27028009

RESUMO

NEW FINDINGS: What is the central question of this study? Ischaemia-reperfusion of peripheral tissues protects the heart from subsequent myocardial ischaemia-reperfusion injury, a phenomenon referred to as remote ischaemic preconditioning (rIPC). This study evaluated the possible myocardial triggers of rIPC. What is the main finding and its importance? Remote ischaemic preconditioning reduces infarct size through a vagal pathway and a mechanism involving phosphorylation of Akt and endothelial nitric oxide synthase, opening of mitochondrial ATP-dependent K(+) channels and an increase in mitochondrial H2 O2 production. All these phenomena occur before the myocardial ischaemia; hence, they could act as 'triggers' of rIPC. It has been proposed that remote ischaemic preconditioning (rIPC) activates a parasympathetic neural pathway. However, the myocardial intracellular mechanism of rIPC remains unclear. Here, we characterized some of the intracellular signals participating as rIPC triggers. Isolated rat hearts were subjected to 30 min of global ischaemia and 120 min of reperfusion (Non-rIPC group). In a second group, before the isolation of the heart, an rIPC protocol (three cycles of hindlimb ischaemia-reperfusion) was performed. The infarct size was measured with tetrazolium staining. Expression/phosphorylation of Akt and endothelial nitric oxide synthase (eNOS) and mitochondrial H2 O2 production were evaluated at the end of the rIPC protocol, before myocardial ischaemia-reperfusion. The rIPC significantly decreased the infarct size and induced Akt and eNOS phosphorylation. The protective effect on infarct size was abolished by cervical vagal section, l-NAME (an NO synthesis inhibitor) and 5-hydroxydecanoate (a mitochondrial ATP-dependent K(+) channel blocker). Mitochondrial production of H2 O2 was increased by rIPC, whereas it was abolished by cervical vagal section, l-NAME and 5-hydroxydecanoate. We conclude that rIPC activates a parasympathetic vagal pathway and a mechanism involving the phosphorylation of Akt and eNOS, the opening of mitochondrial ATP-dependent K(+) channels and the release of H2 O2 by the mitochondria. All these phenomena occur before myocardial ischaemia and could act as triggers of rIPC.


Assuntos
Infarto do Miocárdio/metabolismo , Isquemia Miocárdica/metabolismo , Traumatismo por Reperfusão Miocárdica/metabolismo , Miocárdio/metabolismo , Trifosfato de Adenosina/metabolismo , Animais , Ácidos Decanoicos/farmacologia , Coração/efeitos dos fármacos , Coração/fisiopatologia , Membro Posterior/efeitos dos fármacos , Membro Posterior/metabolismo , Peróxido de Hidrogênio/metabolismo , Hidroxiácidos/farmacologia , Precondicionamento Isquêmico Miocárdico/métodos , Masculino , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Reperfusão Miocárdica/métodos , NG-Nitroarginina Metil Éster/farmacologia , Óxido Nítrico Sintase Tipo III/metabolismo , Sistema Nervoso Parassimpático/efeitos dos fármacos , Sistema Nervoso Parassimpático/metabolismo , Fosforilação/efeitos dos fármacos , Fosforilação/fisiologia , Canais de Potássio/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Ratos , Ratos Wistar , Nervo Vago/efeitos dos fármacos , Nervo Vago/metabolismo
15.
Am J Physiol Heart Circ Physiol ; 309(10): H1621-8, 2015 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-26386109

RESUMO

Inflammation plays a central role in the onset and progression of cardiovascular diseases associated with the exposure to air pollution particulate matter (PM). The aim of this work was to analyze the cardioprotective effect of selective TNF-α targeting with a blocking anti-TNF-α antibody (infliximab) in an in vivo mice model of acute exposure to residual oil fly ash (ROFA). Female Swiss mice received an intraperitoneal injection of infliximab (10 mg/kg body wt) or saline solution, and were intranasally instilled with a ROFA suspension (1 mg/kg body wt). Control animals were instilled with saline solution and handled in parallel. After 3 h, heart O2 consumption was assessed by high-resolution respirometry in left ventricle tissue cubes and isolated mitochondria, and ventricular contractile reserve and lusitropic reserve were evaluated according to the Langendorff technique. ROFA instillation induced a significant decrease in tissue O2 consumption and active mitochondrial respiration by 32 and 31%, respectively, compared with the control group. While ventricular contractile state and isovolumic relaxation were not altered in ROFA-exposed mice, impaired contractile reserve and lusitropic reserve were observed in this group. Infliximab pretreatment significantly attenuated the decrease in heart O2 consumption and prevented the decrease in ventricular contractile and lusitropic reserve in ROFA-exposed mice. Moreover, infliximab-pretreated ROFA-exposed mice showed conserved left ventricular developed pressure and cardiac O2 consumption in response to a ß-adrenergic stimulus with isoproterenol. These results provides direct evidence linking systemic inflammation and altered cardiac function following an acute exposure to PM and contribute to the understanding of PM-associated cardiovascular morbidity and mortality.


Assuntos
Antirreumáticos/farmacologia , Cinza de Carvão/farmacologia , Coração/efeitos dos fármacos , Infliximab/farmacologia , Mitocôndrias Cardíacas/efeitos dos fármacos , Contração Miocárdica/efeitos dos fármacos , Miocárdio/metabolismo , Consumo de Oxigênio/efeitos dos fármacos , Fator de Necrose Tumoral alfa/antagonistas & inibidores , Agonistas Adrenérgicos beta/farmacologia , Animais , Feminino , Ventrículos do Coração/efeitos dos fármacos , Ventrículos do Coração/metabolismo , Inflamação , Preparação de Coração Isolado , Isoproterenol/farmacologia , Camundongos , Mitocôndrias Cardíacas/metabolismo , Material Particulado/farmacologia
16.
Bol. latinoam. Caribe plantas med. aromát ; 10(4): 325-332, jul. 2011. ilus, tab
Artigo em Espanhol | LILACS | ID: lil-654644

RESUMO

Equisetum giganteum L. (Equisetaceae) is a species native to South America and Central America, which is used in traditional medicine as a diuretic and in treating of various diseases. The aim of this paper was to study the polyphenol profile and antioxidant activity of extracts obtained from lateral branches and main stem of the plants. Quali- and quantitative differences were detected with higher contents of phenols, tannins, condensed tannins, flavonoids and hydroxicinnamic acids in the lateral branches. The proanthocyanidins propelargonidin and procyanidin only were detected in lateral branches. These extracts showed the highest antioxidant activity. Due to their higher concentration and chemical composition, lateral branches could be considered as a sort of source of compounds that would act as antioxidant.


Equisetum giganteum L. (Equisetaceae) es una especie nativa de Sudamérica y América Central, que es empleada en la medicina tradicional como diurético y en el tratamiento de diversas patologías. El objetivo de este trabajo fue estudiar el perfil de polifenoles y la actividad antioxidante de extractos obtenidos de las ramas laterales (tallos finos), tallos entrenudos y tallos basales. Se detectaron diferencias cuali-cuantitativas, con mayor contenido de fenoles, taninos, taninos condensados, flavonoides y ácidos hidroxicinámicos en las ramas laterales. Las proantocianidinas propelargonidina y procianidina sólo se detectaron en las ramas laterales. En estos extractos se detectó la mayor actividad antioxidante. Debido a la alta concentración y composición química, los tallos laterales podrían ser empleados como fuente de compuestos con actividad antioxidante.


Assuntos
Antioxidantes/farmacologia , Equisetum/química , Extratos Vegetais/farmacologia , Flavonoides/análise , Polifenóis/análise , Taninos/análise , Ácidos Cumáricos/análise , Extratos Vegetais/química , Caules de Planta/química
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