Different exercise protocols improve metabolic syndrome markers, tissue triglycerides content and antioxidant status in rats

Background: An increase in the prevalence of obesity entails great expenditure for governments. Physical exercise is a powerful tool in the combat against obesity and obesity-associated diseases. This study sought to determine the effect of three different exercise protocols on metabolic syndrome and lipid peroxidation markers and the activity of antioxidant enzymes in adult Wistar rats (120 days old).Methods: Animals were randomly divided into four groups: the control (C) group was kept sedentary throughout the study; the aerobic group (A) swam1 h per day, 5 days per week, at 80% lactate threshold intensity; the strength group (S) performed strength training with four series of 10 jumps, 5 days per week; and the Concurrent group (AS) was trained using the aerobic protocol three days per week and the strength protocol two days per week.Results: Groups A and S exhibited a reduction in body weight compared to group C. All exercised animals showed a reduction in triglyceride concentrations in fatty tissues and the liver. Exercised animals also exhibited a reduction in lipid peroxidation markers (TBARS) and an increase in serum superoxide dismutase activity. Animals in group A had increased levels of liver catalase and superoxide dismutase activities.Conclusions: We concluded that all physical activity protocols improved the antioxidant systems of the animals and decreased the storage of triglycerides in the investigated tissues.

The influence of hydroxyurea on oxidative stress in sickle cell anemia

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

Oxidative stress in Nile tilapia (Oreochromis niloticus) and armored catfish (Pterygoplichthys anisitsi) exposed to diesel oil

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

Oxidative stress and antioxidant capacity in sickle cell anaemia patients receiving different treatments and medications for different periods of time

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Relationship between oxidative stress, glutathione S-transferase polymorphisms and hydroxyurea treatment in sickle cell anemia

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Serum melatonin level and oxidative stress in sickle cell anemia

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Iron chelating-mediated antioxidant activity of Plectranthus barbatus extract on mitochondria

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

Mecanismos da intoxicação do fígado de rato causada pelo gossipol

O fígado desempenha uma função central no metabolismo devido à sua interposição entre o trato digestivo e a circulação geral do organismo. Ele é também o principal órgão envolvido na biotransformação de substâncias exógenas (xenobióticos), com capacidade de converter compostos hidrofóbicos em hidrossolúveis, mais facilmente eliminados pelo organismo. O gossipol é uma substância fenólica tóxica presente na semente de algodão (Gossypium sp). Com o objetivo de estudar os mecanismos envolvidos na hepatotoxicidade do gossipol avaliou-se os seus efeitos no sistema antioxidante do fígado de ratos no que diz respeito ao estresse oxidativo e aspectos histopatológicos. Foram utilizados ratos machos da linhagem Wistar, separados em dois grupos, sendo que um recebeu óleo de canola (veículo, grupo Controle) e o outro recebeu gossipol na dosagem de 40 mg/kg de peso vivo do animal por 15 dias (grupo Tratado). O tratamento com gossipol promoveu alterações na atividade sérica das enzimas marcadoras de dano hepático e um significativo estresse oxidativo caracterizado pela diminuição nos níveis da glutationa reduzida (GSH) e consequente aumento da glutationa oxidada (GSSG), incluindo, ainda, danos à membrana plasmática e de organelas demonstrados pela peroxidação lipídica. O resultado da avaliação histopatológica demonstrou degeneração dos hepatócitos.

Lipoperoxidation and cyclooxygenases 1 and 2 inhibitory compounds from Iryanthera juruensis

Plants from Iryanthera genus have been traditionally used as food supplements by South American Indians. The MeOH extract of leaves of Iryanthera juruensis, one of the plants endemic to the Amazon region and consumed in Brazil, and the hexane extract from its seeds inhibited lipid peroxidation (LPO) and cyclooxygenase (COX-1 and -2)) enzymes in in vitro assays. Further analyses of these extracts yielded 5-deoxyflavones (1-5) from the leaf extract and sargachromenol (6), sargaquinoic acid (7), a novel juruenolic acid (8), omega-arylalkanoic acids (9a-c), and the lignan guaiacin (10) from the seed extract. Compounds 3-5 inhibited LPO by 86%, 77%, and 88% at 10 ppm, respectively, and compounds 6 and 9a-c showed inhibition at 76% and 78% at 100 ppm, respectively. However, compounds 7 and 8 were inactive and lignan 10 exhibited LPO inhibitory activity by 99% at 100 ppm compared to commercial antioxidants butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), and vitamin E. The flavones 1-5 also inhibited COX-1 and -2 enzymes by 50-65% at 100 ppm. Compound 6 showed high but nonselective inhibition of COX-1 and COX-2 enzymes, when compared to aspirin and Celebrex, a nonsteroidal anti-inflammatory drug (NSAID). Compounds 7 and 10 inhibited COX-1 by 60% and 65% and COX-2 by 37% and 18%, respectively, whereas compounds 8 and 9a-c showed little or no activity against these enzymes.

Acclimation of broiler chickens to chronic high environmental temperature

The present study was conducted to evaluate the zootechnical parameters and age related changes in physiological responses of broiler chickens exposed to hot environment from early age onwards. The broiler chickens were exposed to high temperature (30 degreesC) at 15 d of age and maintained to Day 38 or maintained under thermoneutral environment (control).No significant decrease in feed consumption (FC) and body weight (BW) gain was observed in high temperature group after 7 d of exposure, but in the subsequent period, heat exposure lowered BW and FC, compared to control group. However, the weight gain was not significantly changed after 24 d of exposure, and the feed efficiency was not affected throughout the experimental period.The venous pCO(2) pressure was only significantly decreased by temperature after 24 d of heat exposure. The glucose, non-esterified fatty acid (NEFA), triglyceride (TG), glucose, lipid peroxidation (LPO), creatine kinase (CK), and corticosterone were not influenced by the temperature treatment. The significant decrease in uric acid and increase in lactate concentration due to high temperature were observed respectively at 28 and 35 d of age. The concentrations of triiodothyronine (T-3) and thyroxine (T-4) were changed oppositely at 28 d of age, as T-3 was decreased and T-4 was elevated by high temperature. However, the concentration of T-4 in plasma was decreased whereas T-3 was not changed at 38 d of age. The relationships between the blood parameters were changed due to the temperature treatment, suggesting that not only absolute values but also their interrelationships have to be considered when studying the effects of a particular treatment on physiological functioning.These results suggest the growth and physiological responses of broiler chickens, exposed to high temperature from early age onwards, differed at different stages of acclimation. The process of heat acclimation is related to the mode of heat exposure imposed and is not only reflected in the changes in the absolute concentrations, but also in the correlations among the blood indices.

Investigations on the new free radical scavenger polynitroxyl-albumin to prevent ischemia and reperfusion injury after orthotopic heart transplantation in the pig model

Objective: Nitroxides have strong antioxidant capacity but their effectiveness is limited by their rapid intracellular inactivation. Poly nitroxyl-Albumin (PNA) is capable of regenerating inactivated nitroxide. We tested the effect of PNA against reperfusion injury in heart transplantation. Methods: Pig hearts were transplanted orthotopically. In the control group (n = 9) reperfusion was performed without reperfusion modifications. In the experimental group (n = 10) 1 ml/kg PNA was given before cross-clamp release. Results: Hemodynamic performance was impaired after transplantation in both groups without significant intergroup differences. Plasma malonedialdehyde levels were significantly diminished in the PNA group as compared to the controls. CK-MB levels in both groups were increased within the first 2 h of reperfusion without significant intergroup differences. In contrast, there were found significant higher values of myocardial specific lactate dehydrogenase (LD1) in the controls versus PNA group. Conclusions: PNA was able to reduce lipid peroxidation and attenuate free radical activity. Contractile dysfunction could no be improved, indicating that (a) the radical scavenging effect was to weak or (b) other mechanisms than free oxygen radicals are responsible for myocardial damage in this experimental model. (C) 2001 Elsevier B.V. B.V. All rights reserved.

Early cytotoxic and genotoxic effects of atrazine on Wistar rat liver: A morphological, immunohistochemical, biochemical, and molecular study

Risk assessments suggest that intermediate and long-term exposure to triazine herbicides and its metabolites through water can cause severe damage to human health. The objective of this study was to investigate the possible effects of atrazine on Wistar rats submitted to subacute treatment. For this purpose, the activity of catalase and alanine aminotransferase was quantified, and the effect of the herbicide on cell membranes was examined based on the measurement of lipid peroxidation and consequent formation of malondialdehyde and on the mRNA expression of antioxidant enzymes (Mn-superoxide dismutase [SOD] and GSTM1) and connexins. In addition, we evaluated histopathological alterations in the liver, cellular expression of SOD and glutathione (GST), activation of heat shock proteins (HSPs) by immunohistochemistry, and the induction of apoptosis. The genotoxic potential of the herbicide was investigated by the micronucleus test in bone marrow smears. Adult male Wistar rats were treated with an aqueous solution of atrazine at a concentration of 400 mg/kg/day, by gavage, for 14 consecutive days. Control groups were also included. The results showed an increase of catalase levels and maintenance of the expression of antioxidant enzymes (SOD and GST). In addition, lipid peroxidation, hepatic tissue degeneration, activation of HSP90, increased levels of connexin mRNA, and genotoxicity were observed. In conclusion, atrazine induced early hepatic oxidative stress that triggered defense mechanisms to maintain the morphophysiological integrity of the liver. Further studies are needed to better understand the effects of this herbicide on human health. (C) 2011 Elsevier B.V. All rights reserved.

Chlorophyll fluorescence as a marker for herbicide mechanisms of action

Photosynthesis is the single most important source of 02 and organic chemical energy necessary to support all non-autotrophic life forms. Plants compartmentalize this elaborate biochemical process within chloroplasts in order to safely harness the power of solar energy and convert it into usable chemical units. Stresses (biotic or abiotic) that challenge the integrity of the plant cell are likely to affect photosynthesis and alter chlorophyll fluorescence. A simple three-step assay was developed to test selected herbicides representative of the known herbicide mechanisms of action and a number of natural phytotoxins to determine their effect on photosynthesis as measured by chlorophyll fluorescence. The most active compounds were those interacting directly with photosynthesis (inhibitors of photosystem I and II), those inhibiting carotenoid synthesis, and those with mechanisms of action generating reactive oxygen species and lipid peroxidation (uncouplers and inhibitors of protoporphyrinogen oxidase). Other active compounds targeted lipids (very-long-chain fatty acid synthase and removal of cuticular waxes). Therefore, induced chlorophyll fluorescence is a good biomarker to help identify certain herbicide modes of action and their dependence on light for bioactivity. Published by Elsevier B.V.

The application of biochemical responses to assess environmental quality of tropical estuaries: field surveys

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Integrated biomarker responses as environmental status descriptors of a coastal zone (São Paulo, Brazil)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)