Influência do hipoestrogenismo por ooforectomia na adaptação antioxidante em ratas wistar exercitadas regularmente

Post-menopause is a period of women s life cycle that is characterized by estrogen depletion and therefore increasing cardiovascular diseases, neurodegenerative disorders, urogenital atrophy, osteoporosis, hot flushes and sexual discomfort incidences. Estrogen is a hormone with comfirmed antioxidant action and its depletion is related to oxidative stress instalation and damaging various important biomolecules. Regular physical activity has been identified as a factor involved in reducing women s post-menopausal complications in addition to improving antioxidant defense by reducing the oxidative damage and consequently improving life s quality in this part of the population. This study aims to evaluate the influence of hypoestrogenism in antioxidant adaptation due to regular exercise, by determining reduced glutathione (GSH) and Thiobarbituric Acid Reactive Substances (SRAT) concentrations and antioxidant enzymes glutathione peroxidase (GPx), Superoxide Dismutase (SOD) and Catalase (CAT) activities in blood, brain and liver of rats. To achieve this goal we used 50 Wistar rats, weighing 180-250g which were divided into two groups, control - GC (25) and ooforectomized - GO (25). Each group was subdivided into five subgroups: Not-trained - S (5), Not-trained Acute Exercise - SEA (5), regular exercise 30 days - E30 (5), regular exercise 60 days - E60 (5) and regular exercise 90 days - E90 (5). Each of the three subgroups exercised regularly was subjected to acute exercise on the eve and the day of sacrifice to collect biological samples of blood, liver and brain and subsequent determination of SRAT concentration, GSH content and antioxidant enzymes GPx, SOD and CAT activities. The results indicated that the sedentary animals acutely exercised presented oxidative stress and regular physical activity led to antioxidant adaptation. In ooforectomized group the antioxidant adaptation seen in control animals showed to be impaired. Unlike the results from blood and liver, in brain there was a shield against oxidative damage originated by the exercise and that hypoestrogenism led to a loss of this natural antioxidant potential. Therefore, hypoestrogenism interferes negatively in antioxidant adaptation due to regular exercise

Avaliação do status antioxidante, expressão gênica e polimorfismos dos genes SOD1, SOD2 e GPx1 em crianças, adolescentes e adultos jovens com diabetes tipo 1

Studies report that the pathophysiological mechanism of diabetes complications is associated with increased production of Reactive Oxygen Species (ROS)-induced by hyperglycemia and changes in the capacity the antioxidant defense system. In this sense, the aim of this study was to evaluate changes in the capacity of antioxidant defense system, by evaluating antioxidant status, gene expression and polymorphisms in the genes of GPx1, SOD1 and SOD2 in children, adolescents and young adults with type 1 diabetes. We studied 101 individuals with type 1 diabetes (T1D) and 106 normoglycemic individuals (NG) aged between 6 and 20 years. Individuals with type 1 diabetes were evaluated as a whole group and subdivided according to glycemic control in DM1G good glycemic control and DM1P poor glycemic control. Glycemic and metabolic control was evaluate by serum glucose, glycated hemoglobin, triglycerides, total cholesterol and fractions (HDL and LDL). Renal function was assessed by measurement of serum urea and creatinine and albumin-to-creatinine ratio (ACR) in spot urine. Antioxidant status was evaluate by content of reduced glutathione (GSH) in whole blood and the activity of erythrocyte enzymes glutathione peroxidase (GPx) and superoxide dismutase (SOD). We also analyzed gene expression and gene polymorphisms of GPx1 (rs1050450), SOD1 (rs17881135) and SOD2 (rs4880) by the technique of real-time PCR (Taqman®). Most individuals with DM1 (70.3%) had poor glycemic control (glycated hemoglobin> 8%). Regarding the lipid profile, individuals with type 1 diabetes had significantly elevated total cholesterol (p <0.001) and LDL (p <0.000) compared to NG; for triglycerides only DM1NC group showed significant increase compared to NG. There was an increase in serum urea and RAC of individuals with DM1 compared to NG. Nine individuals with type 1 diabetes showed microalbuminuria (ACR> 30 mg / mg). There was a decrease in GSH content (p = 0.006) and increased erythrocyte GPx activity (p <0.001) and SOD (p <0.001) in DM1 group compared to NG. There was no significant difference in the expression of GPx1 (p = 0.305), SOD1 (.365) and SOD2 (0.385) between NG and DM1. The allele and genotype frequencies of the polymorphisms studied showed no statistically significant difference between the groups DM1 and NG. However, the GPx1 polymorphism showed the influence of erythrocyte enzyme activity. There was a decrease in GPx activity in individuals with type 1 diabetes who had a polymorphic variant T (p = 0.012). DM1 patients with the polymorphic variant G (AG + GG) for polymorphism of SOD2 (rs4880) showed an increase in the RAC (p <0.05). The combined data suggest that glucose control seems to be the predominant factor for the emergence of changes in lipid profile, renal function and antioxidant system, but the presence of the polymorphisms studied may partly contribute to the onset of complications

Efeito do ácido alfa-lipóico sobre biomarcadores de estresse oxidativo, inflamação e fatores de risco cardiovascular em hipertensos

Alpha-lipoic acid (ALA) is a potent antioxidant with favourable anti-inflammatory, metabolic and endothelial effects, and has been widely investigated due to its potential against cardiovascular risk factors. This study aimed to evaluate the effect of oral ALA supplementation on oxidative stress biomarkers, inflammation and cardiovascular risk factors in patients with hypertension. This is a double-blind placebo-controlled randomized clinical trial, where the intervention was evaluated prospectively comparing results in both groups. The sample consisted of 64 hypertensive patients who were randomly distributed into ALA group (n = 32), receiving 600 mg / day ALA for twelve weeks and control group (n = 32), receiving placebo for the same period. The following parameters were evaluated before and after intervention: lipid peroxidation, content of reduced glutathione (GSH), enzymatic activities of glutathione peroxidase (GPx) and superoxide dismustase, ultrasensitive C-reactive protein (hs-CRP), triglycerides, total cholesterol and fractions, fasting glucose and anthropometric indicators. There was a statistically significant reduction (p <0.05) in serum concentrations of total cholesterol, very low density lipoprotein (VLDL), high density lipoprotein (HDL), triglycerides and blood glucose. There was a reduction in body weight and waist, abdominal and hip circumferences in the group that received ALA. In addition, there was a statistically significant increase (p <0.05) in the contents of reduced glutathione (GSH) and glutathione peroxidase (GPx) in the group receiving ALA. Oral administration of ALA appears to be a valuable adjuvant therapy, which may contribute to decrease the damage caused by oxidative stress and other risk factors associated with the atherosclerotic process

Cellular and molecular characterization of an embryonic cell line (BME26) from the tick Rhipicephalus (Boophilus) microplus

The cellular and molecular characteristics of a cell line (BME26) derived from embryos of the cattle tick Rhipicephalus (Boophilus) microplus were studied. The cells contained glycogen inclusions, numerous mitochondria, and vesicles with heterogeneous electron densities dispersed throughout the cytoplasm. Vesicles contained lipids and sequestered palladium meso-porphyrin (Pd-mP) and rhodamine-hemoglobin, suggesting their involvement in the autophagic and endocytic pathways. The cells phagocytosed yeast and expressed genes encoding the antimicrobial peptides (microplusin and defensin). A cDNA library was made and 898 unique mRNA sequences were obtained. Among them, 556 sequences were not significantly similar to any sequence found in public databases. Annotation using Gene Ontology revealed transcripts related to several different functional classes. We identified transcripts involved in immune response such as ferritin, serine proteases, protease inhibitors,. antimicrobial peptides, heat shock protein, glutathione S-transferase, peroxidase, and NADPH oxidase. BME26 cells transfected with a plasmid carrying a red fluorescent protein reporter gene (DsRed2) transiently expressed DsRed2 for up to 5 weeks. We conclude that BME26 can be used to experimentally analyze diverse biological processes that occur in R. (B.) microplus such as the innate immune response to tick-borne pathogens. (C) 2008 Elsevier Ltd. All rights reserved.

Hypolipemic and antioxidant activities from Tamarindus indica L. pulp fruit extract in hypercholesterolemic hamsters

Dietary modifications may significantly reduce cardiovascular disease (CVD) risk factors, including cholesterol and atherosclerosis. The present study addressed the effects of the crude extract from the pulp fruit of Tamarindus indica L. on lipid serum levels and early atherosclerotic lesions in hypercholesterolemic hamsters in vivo, and the extract's antioxidant action, in vitro. Animals were fed on either chow or atherogenic diet during 10 weeks and concomitantly received either water or T indica L. extract for drinking. Treatment of hypercholesterolemic hamsters with the T. indica pulp fruit extract (5%) led to a decrease in the levels of serum total cholesterol (50%), non-HDL cholesterol (73%) and triglyceride (60%), and to an increase of high-density lipoprotein (HDL) cholesterol levels (61%). In vitro, the extract presented radical scavenging ability, as assessed by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and superoxide radicals assays, and led to decreased lipid peroxidation in serum, as assessed by the thiobarbituric acid reactive substances (TBARS) assay. In vivo, the extract improved the efficiency of the antioxidant defense system, as assessed by the superoxide dismutase, catalase and glutathione peroxidase activities. Together these results indicate the potential of tamarind extracts in diminishing the risk of atherosclerosis development in humans. (c) 2005 Elsevier Ltd. All rights reserved.

Avaliações fisiológicas e bioquímicas de plantas de aguapé (Eichhornia crassipes) cultivadas com níveis excessivos de nutrientes

Plantas de aguapé foram cultivadas em solução nutritiva de Hoagland & Arnon n.2, cujo aumento dos níveis de N, P e Cu estabeleceu as diferenças entre os tratamentos. Utilizou-se o delineamento experimental inteiramente casualizado, com quatro repetições. As variáveis fisiológicas avaliadas foram área foliar, peso de matéria seca e taxa de crescimento absoluto, taxa de crescimento relativo, taxa assimilatória líquida, razão de área foliar, peso específico de folha, área foliar específica. Foram determinados também os teores de açúcares totais e redutores e de aminoácidos totais e a atividade das enzimas glutationa S-transferase e superóxido dismutase. Os extratos enzimáticos foram obtidos da matéria fresca da parte aérea das plantas. Após a coleta, foram determinados os pesos de material seco de raízes, pecíolos e folhas, que foram utilizados para a determinação de açúcares solúveis totais e redutores e de aminoácidos. O excesso de nitrogênio causou aumento de açúcares nas folhas e de aminoácidos nas raízes. Já o tratamento com excesso de fósforo levou ao aumento de açúcares nas raízes. Os resultados apresentados sugerem que, entre os nutrientes em excesso avaliados, o cobre (0,12 mg L-1) foi o maior indutor da atividade da GST e SOD, sugerindo que este elemento induziu estresse nas plantas de aguapé.

CARNITINE SUPPLEMENTATION EFFECTS on NONENZYMATIC ANTIOXIDANTS IN YOUNG RATS SUBMITTED TO EXHAUSTIVE EXERCISE STRESS

Bucioli, SA, de Abreu, LC, Valenti, VE, and Vannucchi, H. Carnitine supplementation effects on nonenzymatic antioxidants in young rats submitted to exhaustive exercise stress. J Strength Cond Res 26(6): 1695-1700, 2012-Previous studies have demonstrated that exercise stress increases oxidative stress in rats. However, antioxidant supplement therapy effects on reactive oxygen substances are conflicting. We evaluated the effects of carnitine on renal nonenzymatic antioxidants in young rats submitted to exhaustive exercise stress. Wistar rats were divided into 3 groups: (a) control group (not submitted to exercise stress), (b) exercise stress group, and (c) exercise stress and carnitine group. The rats from group 3 were treated with gavage administration of 1 ml of carnitine (5 mg.kg(-1)) for 7 consecutive days. The animals from groups 2 and 3 were submitted to a bout of swimming exhaustive exercise stress. Kidney samples were analyzed for reactive substances to thiobarbituric acid by malondialdehyde (MDA), reduced glutathione (GSH), and vitamin-E levels. Carnitine treatment attenuated MDA increase caused by exercise stress (1:0.16 +/- 0.02 vs. 2:0.34 +/- 0.07 vs. 3:0.1 +/- 0.01 mmmol per milligram of protein; p < 0.0001). It also increased the renal levels of GSH (1:23 +/- 4 vs. 2:23 +/- 2 vs. 3:58 +/- 9 mu mol per gram of protein; p, 0.0001); however, it did not change renal vitamin E (1:24 +/- 5 vs. 2:27 +/- 1 vs. 3:28 +/- 5 mu M per gram of tissue; p < 0.001). In conclusion, carnitine improved oxidative stress and partially improved the nonenzymatic antioxidant activity in young rats submitted to exhaustive exercise stress.

The oxidation of apocynin catalyzed by myeloperoxidase: Proposal for NADPH oxidase inhibition

Apocynin has been used as an efficient inhibitor of the NADPH oxidase complex and its mechanism of inhibition is linked to prior activation through the action of peroxidascs. Here we studied the oxidation of apocynin catalyzed by myeloperoxidase (MPO) and activated neutrophils. We found that apocynin is easily oxidized by MPO/H2O2 or activated neutrophils and has as products dimer and trimer derivatives. Since apocynin impedes the migration of the cytosolic component p47phox to the membrane and this effect could be related to its conjugation with essential thiol groups, we studied the reactivity of apocynin and its MPO-catalyzed oxidation products with glutathione (GSH). We found that apocynin and its oxidation products do not react with GSH. However, this thiol compound was efficiently oxidized by the apocynin radical during the MPO-catalyzed oxidation. We suggest that the reactivity of apocynin radical with thiol compounds could be involved in the inhibitory effect of this methoxy-catechol on NADPH oxidase complex. (c) 2006 Elsevier B.V. All rights reserved.

The reactivity of oytho-methoxy-substituted catechol radicals with sulfhydryl groups: Contribution for the comprehension of the mechanism of inhibition of NADPH oxidase by apocynin

Redox processes are involved in the mechanism of action of NADPH oxidase inhibitors such as diphenyleneiodonium and apocynin. Here, we studied the structure-activity relationship for apocynin and analogous ortho-methoxy-substituted catechols as inhibitors of the NADPH oxidase in neutrophils and their reactivity with peroxidase. Aiming to alter the reduction potential, the ortho-methoxy-catechol moiety was kept constant and the substituents at para position related to the hydroxyl group were varied. Two series of compounds were employed: methoxy-catechols bearing electron-withdrawing groups (MC-W) such as apocynin, vanillin, 4-nitroguaiacol, 4-cyanoguaiacol, and methoxy-catechol bearing electron-donating groups (MC-D) such as 4-methylguaiacol and 4-ethylguaiacol. We found that MC-D were weaker inhibitors compared to MD-W. Furthermore, the radicals generated by oxidation of MC-W via MPO/H(2)O(2), but not for MC-D, were able to oxidize glutathione (GSH) as verified by the formation of thiyl radicals, depletion of GSH, and recycling of the ortho-methoxy-catechols during their oxidations. The capacity of oxidizing sulfhydryl (SH) groups was also verified when ovalbumin was incubated with MC-W, but not for MC-D. Since the effect of apocynin has been correlated with inactivation of the cytosolic fractions of the NADPH oxidase complex and its oxidation during the inhibitory process develops a special role in this process, we suggest that the close relationship between the reactivity of the radicals of MC-W compounds with thiol groups and their efficacy as NADPH oxidase inhibitor could be the chemical pathway behind the mechanism of action of apocynin and should be taken into account in the design of new and specific NADPH oxidase inhibitors. (c) 2007 Elsevier B.V. All rights reserved.

The effects of oral glutamine on cisplatin-induced nephrotoxicity in rats

The antioxidant activity of the amino acid glutamine was investigated to obtain protection against peroxidative damage in rat kidney and nephrotoxicity induced by the treatment with a single dose of the antitumoral cisplatin (5 mg kg(-1) body weight). The animals were divided into four treatment and control groups of six rats each (n = 6). Cisplatin was injected i.p. and glutamine (300 mg kg(-1) body weight) was given by gavage 24 h before the cisplatin injection. After 24 h and 7 days of cisplatin administration, the rats were sacrificed. A single dose of cisplatin resulted in significant reduction in body weight and creatinine clearance, and higher urinary volumes were observed in all groups treated with this antitumor drug (P < 0.05). Renal tissue from cisplatin-treated rats showed an increase in malondialdehyde production and increase in glutathione contents 24 h and 7 days after cisplatin administration. Pretreatment of rats with glutamine substantially inhibited the increase in the levels of renal glutathione induced by cisplatin 24 h after the i.p. injection. The malondialdehyde, in the renal tissues was significantly reduced 7 days after cisplatin treatment. However, the reduction in the peroxidative damage did not reach the value of the control group. The protective effects obtained by glutamine pretreatment in peroxidative alterations were not observed in the other parameters studied. These results suggest that glutamine partially protect against cisplatin-induced lipid peroxidation damage, but it was not enough to inhibit cisplatin-induced nephrotoxicity in rats. (C) 2003 Elsevier B.V. Ltd. All rights reserved.

2-Bromo-1,4-naphthoquinone: a potentially improved substitute of menadione in Apatone therapy

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Oxidation of melatonin by AAPH-derived peroxyl radicals: Evidence of a pro-oxidant effect of melatonin

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effects of vitamin E supplementation on renal non-enzymatic antioxidants in young rats submitted to exhaustive exercise stress

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effects of pancreas transplantation on oxidative stress in pulmonary tissue from alloxan-induced diabetic rats

Purpose. There is considerable evidence that cellular oxidative stress caused by hyperglycemia plays an important role in the genesis and evolution of chronic diabetic lesions. In this study, we determined the effectiveness of pancreas transplantation (PT) in preventing the imbalance caused by excessive production of reactive oxygen species over antioxidant defenses in lungs of rats rendered diabetic by alloxan injection.Methods. Sixty inbred male Lewis rats, weighing 250-280 g, were randomly assigned to 3 experimental groups: NC, 20 nondiabetic control rats; DC, 20 untreated diabetic control rats; and PT, 20 diabetic rats that received syngeneic PT from normal donor Lewis rats. Each group was further divided into 2 subgroups of 10 rats each which were killed after 4 and 12 weeks of follow-up. Plasma glucose, glycosylated hemoglobin, and insulin levels were determined in all rats. Lipid hydroperoxide (LPO) concentrations and enzyme activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) were measured in the pulmonary tissue of all rats.Results. The DC rats showed elevated blood glucose and glycosylated hemoglobin levels, with insulin blood levels significantly lower than the NC rats (P < .001). They also showed significantly increased LPO concentrations in the lungs (P < .01) after 4 and 12 weeks of follow-up. In contrast, SOD, CAT, and GSH-Px antioxidant activities were significantly reduced in these periods (P < .01) 12 weeks after diabetes induction. Successful PT corrected all clinical and metabolic changes in the diabetic rats, with sustained normoglycemia throughout the study. Excessive lung LPO production and low SOD, CAT, and GSH-Px antioxidant activities were already back to normal 4 weeks after PT.Conclusion. PT can control oxidative stress in pulmonary tissue of diabetic rats. It may be the basis for preventing chronic diabetic lesions in lungs.

Pancreas transplantation prevents cellular oxidative stress in kidneys of alloxan-induced diabetic rats

Purpose. Oxidative stress is one of the most important mechanisms to explain genesis of the complications in the chronic progression of diabetes. In this investigation we studied the effects of pancreas transplantation (PT) on the imbalance caused by excessive production of free oxygen radicals by antioxidant defenses of rats with serious chronic hyperglycemia induced by alloxan.Methods. Ninety inbred male Lewis rats were randomly distributed into three groups: NC-30 nondiabetic controls; DC-30 diabetic controls without any treatment; PT-30 diabetic rats undergoing syngeneic PT from normal donor Lewis rats. Each experimental group was then split into three subgroups of 10 animals for sacrifice after 1, 3, or 6 months. Clinical and laboratory parameters from all rats as well as lipid hydroperoxide (LPO) concentrations and renal tissue enzyme activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) were recorded for all rats.Results. Successful PT corrected clinical and laboratory alterations in diabetic rats with sustained normoglycemia throughout the study. A significant increase in LPO concentration and a marked reduction in SOD and CAT enzyme activity were observed in DC rats; there was no significant variation in renal tissue GSH-Px in this group. However, alterations in DC rats were completely restored from 1st month after PT; all evaluated enzyme levels did not significantly differ (P < .01) from those in NC controls.Conclusion. Successful PT controlled cellular oxidative stress in diabetic kidneys, which may prevent chronic lesions.