RESUMO
This study investigated the effects of subchronic administration of lead (Pb) acetate on thiobarbituric acid reactive substances (TBARS), total sulfhydryl content, protein carbonyl content, antioxidant enzymes (superoxide dismutase [SOD], catalase [CAT], glutathione peroxidase [GSHPx]), acetylcholinesterase (AChE), and Na+K+ATPase in the cerebral structures of rats. Male Wistar rats aged 60 days were treated with saline (control group) or Pb (treatment group), at various doses, by gavage, once a day for 35 days. The animals were sacrificed twelve hours after the last administration, and the cerebellum, hippocampus and cerebral cortex were removed. The results showed that Pb did not alter the evaluated oxidative stress parameters. Furthermore, Pb (64 and/or 128 mg/kg) altered SOD in the cerebellum, cerebral cortex and hippocampus. Pb (128 mg/kg) altered CAT in the cerebellum and cerebral cortex and GSHPx in the cerebral cortex. Also, Pb (64 mg/kg and 128 mg/kg) altered GSHPx in the cerebellum. Moreover, Pb (128 mg/kg) increased AChE in the hippocampus and decreased Na+K+ATPase in the cerebellum and hippocampus. In conclusion, subchronic exposure to Pb (occupational and environmental intoxication) altered antioxidant enzymes, AChE, and Na+K+ATPase, contributing to cerebral dysfunction.
Assuntos
Acetilcolinesterase , Antioxidantes , Ratos , Masculino , Animais , Antioxidantes/metabolismo , Acetilcolinesterase/metabolismo , Ratos Wistar , Carbonilação Proteica , Chumbo/toxicidade , Chumbo/metabolismo , Estresse Oxidativo , Catalase/metabolismo , Córtex Cerebral/metabolismo , Superóxido Dismutase/metabolismo , Adenosina Trifosfatases/metabolismo , Adenosina Trifosfatases/farmacologia , Encéfalo/metabolismo , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismo , Substâncias Reativas com Ácido Tiobarbitúrico/farmacologiaRESUMO
During chronic inflammatory disease, such asthma, leukocytes can invade the central nervous system (CNS) and together with CNS-resident cells, generate excessive reactive oxygen species (ROS) production as well as disbalance in the antioxidant system, causing oxidative stress, which contributes a large part to neuroinflammation. In this sense, the aim of this study is to investigate the effects of treatment with neostigmine, known for the ability to control lung inflammation, on oxidative stress in the cerebral cortex of asthmatic mice. Female BALB/cJ mice were submitted to asthma model induced by ovalbumin (OVA). Control group received only Dulbecco's phosphate-buffered saline (DPBS). To evaluate neostigmine effects, mice received 80 µg/kg of neostigmine intraperitoneally 30 min after each OVA challenge. Our results revealed for the first time that treatment with neostigmine (an acetylcholinesterase inhibitor that no crosses the BBB) was able to revert ROS production and change anti-oxidant enzyme catalase in the cerebral cortex in asthmatic mice. These results support the communication between the peripheral immune system and the CNS and suggest that acetylcholinesterase inhibitors, such as neostigmine, should be further studied as possible therapeutic strategies for neuroprotection in asthma.
Assuntos
Asma/tratamento farmacológico , Córtex Cerebral/efeitos dos fármacos , Córtex Cerebral/metabolismo , Inibidores da Colinesterase/farmacologia , Neostigmina/farmacologia , Fármacos Neuroprotetores/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Animais , Antioxidantes/metabolismo , Antioxidantes/farmacologia , Asma/induzido quimicamente , Asma/patologia , Líquido da Lavagem Broncoalveolar , Catalase/metabolismo , Inibidores da Colinesterase/uso terapêutico , Feminino , Injeções Intraperitoneais , Camundongos , Camundongos Endogâmicos BALB C , Neostigmina/uso terapêutico , Neuroproteção , Fármacos Neuroprotetores/uso terapêutico , Ovalbumina , Espécies Reativas de Oxigênio/metabolismo , ATPase Trocadora de Sódio-Potássio/metabolismo , Superóxido Dismutase-1/metabolismoRESUMO
Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are syndromes of acute hypoxemic respiratory failure resulting from a variety of direct and indirect injuries to the gas exchange parenchyma of the lungs. During the ALI, we have an increase release of proinflammatory cytokines and high reactive oxygen species (ROS) formation. These factors are responsible for the release and activation of neutrophil-derived proteases and the formation of neutrophil extracellular traps (NETs). The excessive increase in the release of NETs cause damage to lung tissue. Recent studies have studies involving the administration of mesenchymal stem cells (MSCs) for the treatment of experimental ALI has shown promising results. In this way, the objective of our study is to evaluate the ability of MSCs, in a lipopolysaccharide (LPS)-induced ALI model, to reduce inflammation, oxidative damage, and consequently decrease the release of NETs. Mice were submitted lung injury induced by intratracheal instillation of LPS and subsequently treated or not with MSCs. Treatment with MSCs was able to modulate pulmonary inflammation, decrease oxidative damage, and reduce the release of NETs. These benefits from treatment are evident when we observe a significant increase in the survival curve in the treated animals. Our results demonstrate that MSCs treatment is effective for the treatment of ALI. For the first time, it is described that MSCs can reduce the formation of NETs and an experimental model of ALI. This finding is directly related to these cells modulate the inflammatory response and oxidative damage in the course of the pathology.
Assuntos
Lesão Pulmonar Aguda/cirurgia , Armadilhas Extracelulares/metabolismo , Pulmão/metabolismo , Transplante de Células-Tronco Mesenquimais , Pneumonia/cirurgia , Lesão Pulmonar Aguda/induzido quimicamente , Lesão Pulmonar Aguda/metabolismo , Lesão Pulmonar Aguda/patologia , Animais , Células Cultivadas , Quimiotaxia , Ciclo-Oxigenase 2/metabolismo , Citocinas/metabolismo , Modelos Animais de Doenças , Mediadores da Inflamação/metabolismo , Lipopolissacarídeos , Pulmão/patologia , Macrófagos/metabolismo , Macrófagos/patologia , Masculino , Camundongos Endogâmicos C57BL , NF-kappa B/metabolismo , Infiltração de Neutrófilos , Neutrófilos/metabolismo , Neutrófilos/patologia , Estresse Oxidativo , Pneumonia/induzido quimicamente , Pneumonia/metabolismo , Pneumonia/patologia , Fatores de TempoRESUMO
We investigated the in vitro and in vivo effects of arginine (Arg) on thiobarbituric acid-reactive substances (TBA-RS) and on the activities of catalase (CAT), glutathione peroxidase (GSH-Px), and superoxide dismutase (SOD) in renal tissues of rats. We also studied the influence of antioxidants (α-tocopherol plus ascorbic acid) and nitric oxide synthase inhibitor NG -nitro-l-arginine methyl ester (l-NAME) on the effects elicited by Arg. Results showed that Arg in vitro (1.5 mM) decreased SOD activity and increased the levels of TBA-RS in the renal medulla. Acute administration of Arg [0.8 g/kg, intraperitoneal injection] decreased CAT activity, increased SOD activity and TBA-RS levels in the renal medulla, and decreased CAT activity in the renal cortex of rats. Most results were prevented by antioxidants and/or l-NAME. Data indicate that Arg causes an oxidative imbalance in the renal tissues studied; however, in the presence of antioxidants and l-NAME, some of these alterations in oxidative stress were prevented.
Assuntos
Antioxidantes/farmacologia , Hiperargininemia/prevenção & controle , Rim/metabolismo , NG-Nitroarginina Metil Éster/farmacologia , Estresse Oxidativo/efeitos dos fármacos , alfa-Tocoferol/farmacologia , Animais , Catalase/metabolismo , Glutationa Peroxidase/metabolismo , Hiperargininemia/induzido quimicamente , Hiperargininemia/metabolismo , Masculino , Ratos , Ratos Wistar , Superóxido Dismutase/metabolismoRESUMO
The inflammatory cells infiltrating the airways produce several mediators, such as reactive oxygen species (ROS). ROS and the oxidant-antioxidant imbalance might play an important role in the modulation of airways inflammation. In order to avoid the undesirable effects of ROS, various endogenous antioxidant strategies have evolved, incorporating both enzymatic and non-enzymatic mechanisms. Recombinant human deoxyribonuclease (rhDNase) in clinical studies demonstrated a reduction in sputum viscosity, cleaving extracellular DNA in the airways, and facilitating mucus clearance, but an antioxidant effect was not studied so far. Therefore, we evaluated whether the administration of rhDNase improves oxidative stress in a murine model of asthma. Mice were sensitized by two subcutaneous injections of ovalbumin (OVA), on days 0 and 7, followed by three lung challenges with OVA on days 14, 15, and 16. On days 15 and 16, after 2 h of the challenge with OVA, mice received 1 mg/mL of rhDNase in the lungs. Bronchoalveolar lavage fluid and lung tissue were obtained on day 17, for inflammatory and oxidative stress analysis. We showed that rhDNase did not alter the population of inflammatory cells, such as eosinophil cells, in OVA-treated rhDNase group but significantly improved oxidative stress in lung tissue, by decreasing oxygen reactive species and increasing superoxide dismutase/catalase ratio, glutathione peroxidase activity, and thiol content. Our data provide the first evidence that rhDNase decreases some measures of oxidative stress and antioxidant status in a murine model of asthma, with a potential antioxidant effect to be further studied in human asthma.
Assuntos
Asma/imunologia , Desoxirribonucleases/administração & dosagem , Eosinófilos/metabolismo , Pulmão/imunologia , Estresse Oxidativo/efeitos dos fármacos , Animais , Asma/induzido quimicamente , Asma/metabolismo , Líquido da Lavagem Broncoalveolar/química , Desoxirribonucleases/genética , Desoxirribonucleases/metabolismo , Modelos Animais de Doenças , Feminino , Humanos , Camundongos , Ovalbumina/efeitos adversos , Proteínas Recombinantes/administração & dosagem , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismoRESUMO
Elevated plasma levels of homocysteine (Hcy) are associated with the development of coronary artery disease (CAD), peripheral vascular disease, and atherosclerosis. Hyperhomocysteinemia is likely related to the enhanced production of pro-inflammatory cytokines including IL-1ß. However, the mechanisms underlying the effects of Hcy in immune cells are not completely understood. Recent studies have established a link between macrophage accumulation, cytokine IL-1ß, and the advance of vascular diseases. The purpose of the present study is to investigate the effects of Hcy on IL-1ß secretion by murine macrophages. Hcy (100 µM) increases IL-1ß synthesis via enhancement of P2X7 expression and NF-ĸB and ERK activation in murine macrophages. In addition, the antioxidant agent N-acetylcysteine (NAC) reduces NF-κB activation, ERK phosphorylation, and IL-1ß production in Hcy-exposed macrophages, indicating the importance of ROS in this pro-inflammatory process. In summary, our results show that Hcy may be involved in the synthesis and secretion of IL-1ß via NF-ĸB, ERK, and P2X7 stimulation in murine macrophages.
Assuntos
Homocisteína/toxicidade , Hiper-Homocisteinemia/metabolismo , Interleucina-1beta/biossíntese , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Macrófagos/metabolismo , NF-kappa B/metabolismo , Receptores Purinérgicos P2X7/metabolismo , Acetilcisteína/farmacologia , Animais , Antioxidantes/farmacologia , Macrófagos/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Espécies Reativas de Oxigênio/metabolismo , Receptor 4 Toll-Like/genéticaRESUMO
Alzheimer's disease (AD) is a neurodegenerative disorder whose pathogenesis involves production and aggregation of amyloid-ß peptide (Aß). Aß-induced toxicity is believed to involve alterations on as Na(+),K(+)-ATPase and acetylcholinesterase (AChE) activities, prior to neuronal death. Drugs able to prevent or to reverse these biochemical changes promote neuroprotection. GM1 is a ganglioside proposed to have neuroprotective roles in AD models, through mechanisms not yet fully understood. Therefore, this study aimed to investigate the effect of Aß1-42 infusion and GM1 treatment on recognition memory and on Na(+),K(+)-ATPase and AChE activities, as well as, on antioxidant defense in the brain cortex and the hippocampus. For these purposes, Wistar rats received i.c.v. infusion of fibrilar Aß1-42 (2 nmol) and/or GM1 (0.30 mg/kg). Behavioral and biochemical analyses were conducted 1 month after the infusion procedures. Our results showed that GM1 treatment prevented Aß-induced cognitive deficit, corroborating its neuroprotective function. Aß impaired Na(+),K(+)-ATPase and increase AChE activities in hippocampus and cortex, respectively. GM1, in turn, has partially prevented Aß-induced alteration on Na(+),K(+)-ATPase, though with no impact on AChE activity. Aß caused a decrease in antioxidant defense, specifically in hippocampus, an effect that was prevented by GM1 treatment. GM1, both in cortex and hippocampus, was able to increase antioxidant scavenge capacity. Our results suggest that Aß-triggered cognitive deficit involves region-specific alterations on Na(+),K(+)-ATPase and AChE activities, and that GM1 neuroprotection involves modulation of Na(+),K(+)-ATPase, maybe by its antioxidant properties. Although extrapolation from animal findings is difficult, it is conceivable that GM1 could play an important role in AD treatment.
Assuntos
Acetilcolinesterase/metabolismo , Peptídeos beta-Amiloides/farmacologia , Gangliosídeo G(M1)/farmacologia , Fármacos Neuroprotetores/farmacologia , Fragmentos de Peptídeos/farmacologia , ATPase Trocadora de Sódio-Potássio/metabolismo , Acetilcolinesterase/efeitos dos fármacos , Animais , Injeções Intraventriculares , Masculino , Memória/efeitos dos fármacos , Ratos , Ratos Wistar , ATPase Trocadora de Sódio-Potássio/efeitos dos fármacosRESUMO
Sulfite oxidase (SO) deficiency is biochemically characterized by tissue accumulation and high urinary excretion of sulfite, thiosulfate and S-sulfocysteine. Affected patients present severe neurological symptoms and cortical atrophy, whose pathophysiology is still poorly established. Therefore, in the present work we investigated the in vitro effects of sulfite and thiosulfate on important parameters of energy metabolism in the brain of young rats. We verified that sulfite moderately inhibited the activity of complex IV, whereas thiosulfate did not alter any of the activities of the respiratory chain complexes. It was also found that sulfite and thiosulfate markedly reduced the activity of total creatine kinase (CK) and its mitochondrial and cytosolic isoforms, suggesting that these metabolites impair brain cellular energy buffering and transfer. In contrast, the activity of synaptic Na(+),K(+)-ATPase was not altered by sulfite or thiosulfate. We also observed that the inhibitory effect of sulfite and thiosulfate on CK activity was prevented by melatonin, reduced glutathione and the combination of both antioxidants, as well as by the nitric oxide synthase N(ω)-nitro-l-arginine methyl ester, indicating the involvement of reactive oxygen and nitrogen species in these effects. Sulfite and thiosulfate also increased 2',7'-dichlorofluorescin oxidation and hydrogen peroxide production and decreased the activity of the redox sensor aconitase enzyme, reinforcing a role for oxidative damage in the effects elicited by these metabolites. It may be presumed that the disturbance of cellular energy and redox homeostasis provoked by sulfite and thiosulfate contributes to the neurological symptoms and abnormalities found in patients affected by SO deficiency.
Assuntos
Erros Inatos do Metabolismo dos Aminoácidos/complicações , Encefalopatias Metabólicas/etiologia , Encéfalo/efeitos dos fármacos , Metabolismo Energético/efeitos dos fármacos , Homeostase/efeitos dos fármacos , Sulfito Oxidase/deficiência , Sulfitos/farmacologia , Tiossulfatos/farmacologia , Erros Inatos do Metabolismo dos Aminoácidos/genética , Erros Inatos do Metabolismo dos Aminoácidos/metabolismo , Erros Inatos do Metabolismo dos Aminoácidos/fisiopatologia , Animais , Encéfalo/metabolismo , Encéfalo/patologia , Encéfalo/fisiologia , Encefalopatias Metabólicas/genética , Encefalopatias Metabólicas/metabolismo , Transporte de Elétrons/efeitos dos fármacos , Transporte de Elétrons/genética , Transporte de Elétrons/fisiologia , Metabolismo Energético/fisiologia , Masculino , Oxirredução/efeitos dos fármacos , Ratos , Ratos Wistar , Sulfito Oxidase/genética , Sulfito Oxidase/metabolismo , Sulfitos/metabolismo , Tiossulfatos/metabolismoRESUMO
It has been shown that elevation of plasma methionine (Met) and its metabolites may occur in several genetic abnormalities. In this study we investigated the in vitro and in vivo effects of the Met and methionine sulfoxide (MetO) on oxidative stress parameters in the liver of rats. For in vitro studies, liver homogenates were incubated with Met, MetO, and Mix (Met + MetO). For in vivo studies, the animals were divided into groups: saline, Met 0.4 g/kg, MetO 0.1 g/kg, and Met 0.4 g/kg + MetO 0.1 g/kg. The animals were euthanized 1 and 3 h after injection. In vitro results showed that Met 1 and 2 mM and Mix increased catalase (CAT) activity. Superoxide dismutase (SOD) was enhanced by Met 1 and 2 mM, MetO 0.5 mM, and Mix. Dichlorofluorescein oxidation was increased by Met 1 mM and Mix. In vivo results showed that Met, MetO, and Mix decreased TBARS levels at 1 h. Total thiol content decreased 1 h after and increased 3 h after MetO and Met plus MetO administrations. Carbonyl content was enhanced by Met and was reduced by MetO 1 h after administration. Met, MetO and Met plus MetO decreased CAT activity 1 and 3 h after administration. Furthermore, only MetO increased SOD activity. In addition, Met, MetO, and Mix decreased dichlorofluorescein oxidation at 1 and 3 h. Our data indicate that Met/MetO in vivo and in vitro modify liver homeostasis by altering the redox cellular state. However, the hepatic changes caused by these compounds suggest a short-time adaptation of this tissue.
Assuntos
Catalase/metabolismo , Fígado/metabolismo , Metionina/análogos & derivados , Metionina/metabolismo , Erros Inatos do Metabolismo dos Aminoácidos/metabolismo , Erros Inatos do Metabolismo dos Aminoácidos/patologia , Animais , Fluoresceínas/metabolismo , Glicina N-Metiltransferase/deficiência , Glicina N-Metiltransferase/metabolismo , Fígado/patologia , Masculino , Estresse Oxidativo , Ratos , Ratos Wistar , Espécies Reativas de Oxigênio/farmacologia , Superóxido Dismutase/metabolismo , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismoRESUMO
In the present study, we investigated whether sepsis induced by cecal ligation and puncture (CLP) modifies Na(+), K(+)-ATPase activity, mRNA expression, and cerebral edema in hippocampus and cerebral cortex of rats and if antioxidant (ATX) treatment prevented the alterations induced by sepsis. Rats were subjected to CLP and were divided into three groups: sham; CLP-rats were subjected to CLP without any further treatment; and ATX-CLP plus administration of N-acetylcysteine plus deferoxamine. Several times (6, 12, and 24) after CLP or sham operation, the rats were killed and hippocampus and cerebral cortex were isolated. Na(+), K(+)-ATPase activity was inhibited in the hippocampus 24 h after sepsis, and ATX treatment was not able to prevent this inhibition. The Na(+), K(+)-ATPase activity also was inhibited in cerebral cortex 6, 12, and 24 h after sepsis. No differences on Na(+), K(+)-ATPase catalytic subunit mRNA levels were found in the hippocampus and cerebral cortex after sepsis. ATX treatment prevents Na(+), K(+)-ATPase inhibition only in the cerebral cortex. Na(+), K(+)-ATPase inhibition was not associated to increase brain water content. In conclusion, the present study demonstrated that sepsis induced by CLP inhibits Na(+), K(+)-ATPase activity in a mechanism dependent on oxidative stress, but this is not associated to increase brain water content.