Biochemical biomarkers in Oreochromis niloticus exposed to mixtures of benzo[a]pyrene and diazinon.

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

In vitro exposure to fullerene C60 influences redox state and lipid peroxidation in brain and gills from Cyprinus carpio (Cyprinidae)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Burnt sugarcane harvesting: Particulate matter exposure and the effects on lung function, oxidative stress, and urinary 1-hydroxypyrene

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Toxicity of ad lib. overfeeding: effects on cardiac tissue

The aim of the present study was to determine the effects of ad lib, overfeeding and of dietary restriction (DR) on oxidative stress in cardiac tissue. Lipoperoxide concentrations ere decreased and antioxidant enzymes ere increased in moderate-DR-fed rats. Severe-DR induced increased lipoperoxide concentrations. Overfeeding increased lipoperoxide levels in cardiac tissue. Total superoxide dismutase (SOD) and Cu-Zn superoxide dismutase (Cu-Zn SOD) activities were decreased in cardiac tissue at 35 days of overfeeding. As no changes in glutathione peroxidase (GSH-Px) ere observed in overfed rats, awhile SOD and Cu-Zn SOD activities were decreased in these animals. it is assumed that superoxide anion is an important intermediate in the toxicity of ad lib, overfeeding. Overfeeding induced alterations in markers of oxidative stress in cardiac tissue. (C) 2002 Elsevier B.V. Ltd. All rights reserved.

Eucalyptus ESTs related to genes for oxidative stress

Oxidative stress generating active oxygen species has been proved to be one of the underlying agents causing tissue injury after the exposure of Eucalyptus (Eucalyptus spp.) plants to a wide variety of stress conditions. The objective of this study was to perform data mining to identify favorable genes and alleles associated with the enzyme systems superoxide dismutase, catalase, peroxidases, and glutathione S-transferase that are related to tolerance for environmental stresses and damage caused by pests, diseases, herbicides, and by weeds themselves. This was undertaken by using the eucalyptus expressed-sequence database (https//forests.esalq.usp.br). The alignment results between amino acid and nucleotide sequences indicated that the studied enzymes were adequately represented in the ESTs database of the FORESTs project.

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.

Acclimation to short-term low temperatures in two Eucalyptus globulus clones with contrasting drought resistance

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)

Effects of olive oil and its minor phenolic constituents on obesity-induced cardiac metabolic changes

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

The adverse effect of a high energy dense diet on cardiac tissue

Purpose: To determine whether a high energy dense diet intake increases oxidative stress and alters antioxidant enzymes in cardiac tissue. Design: A randomized, controlled study. Ninety-day-old female rats were randomly divided into two groups: one fed with a low energy dense diet (LE; 3.0 kcal g-1) and one with a high energy dense diet (HE; 4.5 kcal g-1). Materials and Methods: After 8 weeks of treatment, the animals were fasted overnight and sacrificed by decapitation. The serum was used for glucose, triacylglycerol, cholesterol, low-density lipoprotein (LDL)-cholesterol and high-density lipoprotein (HDL)-cholesterol determinations. The glycogen, lipoperoxide, lipid hydroperoxide, superoxide dismutase, glutathione peroxidase, lactate dehydrogenase, citrate synthase, total and non-protein sulphhydryl groups were determined in cardiac tissue. Results: HE decreased the myocardial glycogen content and increased the lactate dehydrogenase/citrate synthase ratio, indicating an increased glycolytic pathway and a shift from myocardial aerobic metabolism. HE-treated female rats showed increased lipoperoxide and hydroperoxide levels in cardiac tissue. Although no alterations were observed in the total sulphhydryl group and superoxide dismutase activities, glutathione peroxidase and the non-protein sulphhydryl group were significantly decreased in HE-treated animals. Conclusions: Although no alterations were observed in energy intake, HE induced an increased intake of fat and carbohydrate and an increased rate of weight gain. HE intake induced alterations in markers of oxidative stress in cardiac tissue. Hydrogen peroxide is an important toxic intermediate in the development of cardiac oxidative stress by HE. The specific nutrient content, such as fat and carbohydrate, rather than caloric intake, appears to be the main process inducing oxidative stress in HE-treated female rats.

Dietary restriction: Metabolic shifting for cardiac health

Purpose: To determine the effect of dietary restriction on metabolic pathways and the relationship of the metabolic shifting on antioxidant enzymes in cardiac tissue. Design: Randomized, controlled study. Male rats at 60 days old were randomly divided into four groups. Materials and Methods: The rats of control groups C30 and C60 were given free access to the diet over 30 and 60 days. The rats of the DR30 group were fed 60% of the chow consumed by the control groups over 30 days. The animals of the DR60 group ate 60% of the amount consumed by the C60 group over 60 days. Serum was used for total protein, lactate dehydrogenase (LDH), alanine aminotransferase (ALT) and aspartate aminotransferase (AST). Protein, glycogen, total lipids, superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), LDH, AST and ALT were determined in cardiac tissue. Results: Dietary restriction induced diminished serum and cardiac LDH activities. AST activities were lower in the serum and cardiac muscle of the DR60 animals. Dietary restriction induced elevated total lipid concentrations in cardiac muscle. No significant differences were observed in total protein and glycogen content among the groups. Antioxidant enzyme determinations demonstrated increased cardiac GSH-Px activities in the DR60 animals and increased SOD activities in the cardiac tissue of both feed-restricted groups. Conclusions: Dietary restriction was protective against oxidative stress in the heart by improving cardiac endogenous antioxidant defences and shifting the metabolic pathway for energy production.

Physiological adaptations during endurance training below anaerobic threshold in rats

To assess the effects of continuous exercise training at intensities corresponding to 80 and 90 % of the lactate minimum test (LM), we evaluated antioxidant activity, hormone concentration, biochemical analyses and aerobic and anaerobic performance, as well as glycogen stores, during 12 weeks of swimming training in rats. One-hundred rats were separated into three groups: control (CG, n = 40), exercise at 80 (EG80, n = 30) and 90 % (EG90, n = 30) of LM. The training lasted 12 weeks, with sessions of 60 min/day, 6 days/week. The intensity was based at 80 and 90 % of the LM. The volume did not differ between training groups (Ẋ of EG80 = 52 ± 4 min; Ẋ of EG90 = 56 ± 2 min). The glycogen concentration (mg/100 mg) in the gastrocnemius increased after the training in EG80 (0.788 ± 0.118) and EG90 (0.795 ± 0.157) in comparison to the control (0.390 ± 0.132). The glycogen stores in the soleus enhanced after the training in EG90 (0.677 ± 0.230) in comparison to the control (0.343 ± 0.142). The aerobic performance increased by 43 and 34 % for EG80 and EG90, respectively, in relation to baseline. The antioxidant enzymes remain unchanged during the training. Creatine kinase (U/L) increased after 8 weeks in both groups (EG80 = 427.2 ± 97.4; EG90 = 641.1 ± 90.2) in relation to the control (246.9 ± 66.8), and corticosterone (ng/mL) increased after 12 weeks in EG90 (539 ± 54) in comparison to the control (362 ± 44). The continuous exercise at 80 and 90 % of the LM has a marked aerobic impact on endurance performance without significantly biomarkers changes compared to control. © 2013 Springer-Verlag Berlin Heidelberg.

Diabetes mellitus triggers oxidative stress in the liver of alloxan-treated rats: A mechanism for diabetic chronic liver disease

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Leaf senescence in tomato mutants as affected by irradiance and phytohormones

We explored the interaction between radiation of different wavelength and jasmonic acid (JA) or brassinosteroids (BR) on leaf senescence-induced oxidative stress. Three approaches were used: 1) jasmonic acid insensitive1-1 (jai1-1) and brassinosteroid-deficient [dumpy (dpy)] mutants were treated with red (R) or far-red (FR) radiation; 2) phytochromedeficient aurea (au) and high pigment-1 (hp-1) (radiation exaggerated response) mutants were treated with methyl jasmonate (MeJA) or epibrassinolide (epiBL); and 3) double mutants au jai1-1 and au dpy were produced. Leaf chlorophyll content, lipid peroxidation, and antioxidant enzyme activities were determined. After senescence induction in detached leaves, we verified that the patterns of chlorophyll degradation of hormonal and photomorphogenic mutants were not significantly different in comparison with original cv. Micro-Tom (MT). Moreover, there was no significant change in lipid peroxidation measured as malondialdehyde (MDA) production, as well as catalase (CAT), ascorbate peroxidase (APX), and glutathione reductase (GR) activities in the hormonal mutants. Exogenous BR increased CAT and APX activities in MT, au, and hp-1. As concerns the double mutants, severe reduction in H2O2 production which was not accompanied by changes in MDA content, and CAT and APX activities was observed during senescence in au dpy. The results suggest that JA and BR do not participate in light signaling pathway during leaf senescence-induced oxidative stress. © 2013 Springer Science+Business Media Dordrecht.

Relação entre estresse de radiação ultravioleta-b e óxido nítrico em plantas de eucalipto

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)