Interaction of hypercaloric diet and physical exercise on lipid profile, oxidative stress and antioxidant defenses

The present study examined the interaction of hypercaloric diet (HD) and physical exercise on lipid profile and oxidative stress in serum and liver of rats. Male Wistar rats (60-days-old) were fed with a control (C) and hypercaloric diet (H). Each of the two dietary groups (C and H) was divided into three subgroups (n = 8), sedentary (CS and HS), exercised 2 days a week (CE2 and HE2) and exercised 5 days a week (CE5 and HE5). The swimming was selected as a model for exercise performance. After 8-weeks exercised rats showed decreased lactate dehydrogenase serum activities, demonstrating the effectiveness of the swimming as an aerobic-training protocol. Exercise 5-days a week reduced the body weight gain. Triacylglycerol (TG) and very low-density lipoprotein (VLDL-C) were increased in HD-fed rats. HE5 and CE5 rats had decreased TG, VLDL-C and cholesterol. HE2 rats had enhanced high-density lipoprotein (HDL-C) in serum. No alterations were observed in lipid hydroperoxide (LH), while total antioxidant substances (TAS) were increased in serum of exercised rats. HD-fed rats had hepatic TG accumulation. Superoxide dismutase activities were increased and catalase was decreased in liver of exercised rats. The interaction of HD and physical exercise reduced TAS and enhanced LH levels in hepatic tissue. In conclusion, this study confirmed the beneficial effect of physical exercise as a dyslipidemic-lowering component. Interaction of HD and physical exercise had discrepant effects on serum and liver oxidative stress. The interaction of HID and physical exercise reduced the oxidative stress in serum. HD and physical exercise interaction had pro-oxidant effect on hepatic tissue, suggesting that more studies should be done before using physical exercise as an adjunct therapy to reduce the adverse effects of HD. (c) 2006 Elsevier Ltd. All rights reserved.

The use of the oxidative stress responses as biomarkers in Nile tilapia (Oreochromis niloticus) exposed to in vivo cadmium contamination

Water contaminants have a high potential risk for the health of populations. Protection from toxic effects of environmental water pollutants primarily involves considering the mechanism of low level toxicity and likely biological effects in organisms who live in these polluted waters. The biomarkers assessment of oxidative stress and metabolic alterations to cadmium exposure were evaluated in Nile tilapia, Oreochromis niloticus. The fish were exposed to 0.35, 0.75, 1.5, and 3.0 mg/l concentrations of Cd2+ (CdCl2) in water for 60 days. Fish that survived cadmium exposure showed a metabolic shift and a compensatory development for maintenance of the body weight gain. We observed a decreased glycogen content and decreased glucose uptake in white muscle. Lactate dehydrogenase (LDH) and creatine phosphokinase (CK) activities were also decreased, indicating that the glycolytic capacity was decreased in this tissue. No alterations were observed in total protein content in white muscle due to cadmium exposure suggesting a metabolic shift of carbohydrate metabolism to maintenance of the muscle protein reserve. There was an increase in glucose uptake, CK increased activity, and a clear increase of LDH activity in red muscle of fish with cadmium exposure. Since no alterations were observed in lipoperoxide concentration, while antioxidant enzymes glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) were changed in the liver and the red and white muscle of fish with cadmium exposure, we can conclude that oxygen free radicals are produced as a mediator of cadmium toxicity. Resistance development is related with increased activities of antioxidant enzymes, which were important in the protection against cadmium damage, inhibiting lipoperoxide formation. (C) 2002 Elsevier B.V. Ltd. All rights reserved.

Effects of N-acetylcysteine on sucrose-rich diet-induced hyperglycaemia, dyslipidemia and oxidative stress in rats

This study examined whether sucrose-rich diet (SRD)-induced hyperglycaemia, dyslipidemia and oxidative stress may be inhibited by N-acetylcysteine (C5H9-NO3S), an organosulfur from Allium plants. Male Wistar 40 rats were divided into four groups (n = 10): (C) given standard chow and water; (N) receiving standard chow and 2 mg/l N-acetylcysteine in its drinking water; (SRD) given standard chow and 30% sucrose in its drinking water; and (SRD-N) receiving standard chow, 30% sucrose and N-acetylcysteine in its drinking water. After 30 days of treatment, SRD rats had obesity with increased abdominal circumference, hyperglycaemia, by dyslipidemia and hepatic triacylglycerol accumulation. These adverse effects were associated with oxidative stress and depressed lipid degradation in hepatic tissue. The SRD adverse effects were not observed in SDR-N rats. N-Acetylcysteine reduced the oxidative stress, enhancing glutathione-peroxidase activity, and normalizing lipid hydroperoxyde, reduced glutathione and superoxide dismutase in hepatic tissue of SRD-N rats. The beta-hydroxyacyl coenzyme-A dehydrogenase and citrate-synthase activities were increased in SRD-N rats, indicating enhanced lipid degradation in hepatic tissue as compared to SRD. SRD-N rats had reduced serum oxidative stress and diminished glucose, triacylglycerol, very-low-density lipoprotein (VLDL), oxidized low-density lipoprotein (alpha-LDL) and cholesterol/highdensity lipoprotein (HDL) ratio in relation to SRD. In conclusion, NAC offers promising therapeutic values in prevention of dyslipidemic profile and alleviation of hyperglycaemia in high-sucrose intake condition by improving antioxidant defences. N-Acetylcysteine had also effects preventing metabolic shifting in hepatic tissue, thus enhancing fat degradation and reducing body weight gain in conditions of excess sucrose intake. The application of this agent in food system via exogenous addition may be feasible and beneficial for antioxidant protection. (c) 2006 Elsevier B.V All rights reserved.

Toxicity of copper intake: lipid profile, oxidative stress and susceptibility to renal dysfunction

The present study was carried out to investigate the effects of copper (Cu) intake on lipid profile, oxidative stress and tissue damage in normal and in diabetic condition. Since diabetes mellitus is a situation of high-risk susceptibility to toxic compounds, we examined potential early markers of Cu excess in diabetic animals. Male Wistar rats, at 60-days-old were divided into six groups of eight rats each. The control(C) received saline from gastric tube, the no-diabetic(Cu-10), treated with 10 mg/kg of Cu(Cu(++)-CuSO(4), gastric tube), no-diabetic with Cu-60mg/kg(Cu-60), diabetic(D), diabetic low-Cu(DCu-10) and diabetic high-Cu(DCu-60). Diabetes was induced by an ip injection of streptozotocin (60mg/kg). After 30 days of treatments, no changes we're observed in serum lactate dehydrogenase, alanine transaminase and alkaline phosphatase; indicating no adverse effects on cardiac and hepatic tissues. D-rats had glucose intolerance and dyslipidemic profile. Cholesterol and LDL-cholesterol were higher in Cu-60 and DCu-60 than in C, Cu-10 and D and DCu-10 groups respectively. Cu-60 rats had higher lipid hydroperoxide (HP) and lower superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) serum activities than C and Cu-10 rats. LH was increased and GSH-Px was decreased, while no alterations were observed in SOD and catalase in serum of DCu-60 animals. DCu-60 rats had increased urinary glucose, creatinine and albumin. In conclusion, Cu intake at high concentration induced adverse effects on lipid profile, associated with oxidative stress and diminished activities of antioxidant enzymes. Diabetic animals were more susceptible to copper toxicity. High Cu intake induced dyslipidemic profile, oxidative stress and kidney dysfunction in diabetic condition. Copper renal toxicity was associated with oxidative stress and reduction at least, one of the antioxidant enzymes. (C) 2004 Elsevier Ltd. All rights reserved.

Evaluation of lipid profile and oxidative stress in STZ-induced rats treated with antioxidant vitamin

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Differential responses between mature and young leaves of sunflower plants to oxidative stress caused by water deficit

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

Ultraviolet-B and water stress effects on growth, gas exchange and oxidative stress in sunflower plants

The effects and interaction of drought and UV-B radiation were studied in sunflower plants (Helianthus annuus L. var. Catissol-01), growing in a greenhouse under natural photoperiod conditions. The plants received approximately 1.7 W m(-2) (controls) or 8.6 W m(-2) (+UV-B) of UV-B radiation for 7 h per day. The UV-B and water stress treatments started 18 days after sowing. After a period of 12 days of stress, half of the water-stressed plants (including both UV-B irradiated or non-irradiated) were rehydrated. Both drought and UV-B radiation treatments resulted in lower shoot dry matter per plant, but there was no significant interaction between the two treatments. Water stress and UV-B radiation reduced photosynthesis, stomatal conductance and transpiration. However, the amplitude of the effects of both stressors was dependent on the interactions. This resulted in alleviation of the negative effect of drought on photosynthesis and transpiration by UV-B radiation as the water stress intensified. Intercelluar CO(2) concentration was initially reduced in all treatments compared to control plants but it increased with time. Photosynthetic pigments were not affected by UV-B radiation. Water stress reduced photosynthetic pigments only under high UV-B radiation. The decrease was more accentuated for chlorophyll a than for chlorophyll b. As a measure for the maximum efficiency of photosystem II in darkness F (v)/F (m) was used, which was not affected by drought stress but initially reduced by UV-B radiation. Independent of water supply, UV-B radiation increased the activity of pirogalol peroxidase and did not increase the level of malondialdehyde. on the other hand, water stress did not alter the activity of pirogalol peroxidase and caused membrane damage as assessed by lipid peroxidation. The application of UV-B radiation together with drought seemed to have a protective effect by lowering the intensity of lipid peroxidation caused by water stress. The content of proline was not affected by UV-B radiation but was increased by water stress under both low and high UV-B radiation. After 24 h of rehydration, most of the parameters analyzed recovered to the same level as the unstressed plants.

Alcoholism and alcohol abstinence: N-acetylcysteine to improve energy expenditure, myocardial oxidative stress, and energy metabolism in alcoholic heart disease

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

Effects of aerobic exercise on the blood pressure, oxidative stress and eNOS gene polymorphism in pre-hypertensive older people

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

The influence of hydroxyurea on oxidative stress in sickle cell anemia

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

Oxidative stress markers and apoptosis in the prostate of diabetic rats and the influence of vitamin C treatment

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Oxidative Stability and alpha-Tocopherol Retention in Soybean Oil with Lemon Seed Extract (Citrus Limon) under Thermoxidation

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Loss in tocopherols and oxidative stability during the frying of frozen cassava chips

The present study was aimed at verifying tocopherols losses and oxidative stability changes in vegetable oils used in discontinuous frying. The frying of frozen cassava chips was carried out in a household electric frying pan, where the oil was heated to a temperature of 180 degrees C for 25 hours, with fresh oil replacement. The results obtained from the analytical determinations were submitted to variance analysis, in a factorial scheme, using a completely randomized design, making it possible to determine the influence of the type of oil and frying times on changes in the oil. The data show that the smallest changes occur in palm oil, which is more saturated. For sunflower and cottonseed oils, which are more unsaturated, there was a clear decrease in both tocopherol concentration and oxidative stability.