Search results for "Oxidants"
showing 10 items of 878 documents
Changes in antioxidant defense status in hypercholesterolemic rats treated with Ajuga iva.
2007
Abstract The aim of the study was to investigate the effect of aqueous extract of Ajuga iva ( Ai ) on serum and tissues lipid peroxidation as well as antioxidant enzymes activities in red blood cells (RBC) and tissues, in high hypercholesterolemic rats (HC). Male Wistar rats ( n =12) were fed on 1% cholesterol-enriched diet for 15 d. After this adaptation phase, hypercholesterolemic rats (total cholesterol=6.5±0.6 mol/l) were divided into two groups fed the same diet and treated or not with Ai for 15 d. Thiobarbituric acid reactive substances (TBARS) concentrations in serum, LDL-HDL 1 , HDL 2 and HDL 3 were respectively, 5-, 7.8-, 2.3- and 5-fold lower in Ai treated than untreated hyperchol…
Mitochondria from females exhibit higher antioxidant gene expression and lower oxidative damage than males
2003
We have investigated the differential mitochondrial oxidative stress between males and females to understand the molecular mechanisms enabling females to live longer than males. Mitochondria are a major source of free radicals in cells. Those from female rats generate half the amount of peroxides than those of males. This does not occur in ovariectomized animals. Estrogen replacement therapy prevents the effect of ovariectomy. Mitochondria from females have higher levels of reduced glutathione than those from males. Those from ovariectomized rats have similar levels to males, and estrogen therapy prevents the fall in glutathione levels that occurs in ovariectomized animals. Oxidative damage…
Changes inα-tocopherol and retinol levels during cardiopulmonary bypass correlate with maximal arterial partial pressure of oxygen
2007
Cardiopulmonary bypass (CPB) is associated with oxidative stress. This study examined antioxidant levels in adults undergoing CPB surgery and their correlation with clinical variables. Arterial blood samples were obtained from 27 patients undergoing CPB. The time-course variation of vitamin C (spectrofluorimetry), alpha-tocopherol and retinol (HPLC) levels were determined. Plasma vitamin C rose initially but gradually decayed during reperfusion until 60% reduction of baseline values post-surgery. alpha-Tocopherol and retinol were reduced along CPB with post-operative values approximately 25% lower than baseline. No significant changes were found for selenium and glutathione peroxidase. PaO(…
Human milk enhances antioxidant defenses against hydroxyl radical aggression in preterm infants
2008
Background: Preterm infants endowed with an immature antioxidant defense system are prone to oxidative stress. Hydroxyl radicals are very aggressive reactive oxygen species that lack specific antioxidants. These radicals cannot be measured directly, but oxidation byproducts of DNA or phenylalanine in urine are reliable markers of their activity. Human milk has a higher antioxidant capacity than formula. Objective: We hypothesized that oxidative stress associated with prematurity could be diminished by feeding human milk. Design: We recruited a cohort of stable preterm infants who lacked perinatal conditions associated with oxidative stress; were not receiving prooxidant or antioxidant drugs…
Decreased level of cardiac antioxidants in endurance-trained rats.
1989
Han-Wistar rats were exposed to a 194-200 h swimming protocol which caused a significant increase in the cardiac weight. The levels of various tissue antioxidants were assayed from the myocardium of the right ventricle and from the left ventricle (subendo- and subepimyocardium). This endurance training decreased the activities of catalase in the right ventricle and in the subendo- and subepimyocardium and Cu,Zn-superoxide dismutase in the subendomyocardium as well as the concentration of vitamin E in the right ventricle and in the subendomyocardium. Also, the activity of thioredoxin reductase decreased in each part of myocardium and that of glutathione reductase in the right ventricle and i…
Exhaustive physical exercise causes oxidation of glutathione status in blood: Prevention by antioxidant administration
1992
We have studied the effect of exhaustive concentric physical exercise on glutathione redox status and the possible relationship between blood glutathione oxidation and blood lactate and pyruvate levels. Levels of oxidized glutathione (GSSG) in blood increase after exhaustive concentric physical exercise in trained humans. GSSG levels were 72% higher immediately after exercise than at rest. They returned to normal values 1 h after exercise. Blood reduced glutathione (GSH) levels did not change significantly after the exercise. We have found a linear relationship between GSSG-to-GSH and lactate-to-pyruvate ratios in human blood before, during, and after exhaustive exercise. In rats, physical…
Early lipoic acid intake protects retina of diabetic mice
2008
The aim of this study was to test the effect of lipoic acid treatment on the retina after a short diabetic insult. Diabetes was induced by alloxan and mice were divided into sub-groups; control, diabetic, diabetic+insulin and all groups received+/-lipoic acid (100 mg/kg body weight) for 3 weeks. GSH content, MDA concentration, GPx activity were measured and electroretinograms (ERG) were recorded. Early administration of lipoic acid to diabetic mice prevented the statistically significant decreases of GSH content and GPx activity and normalized MDA concentration. Moreover, lipoic acid restored electroretinogram b-wave amplitude of diabetic animals to control values. Lipoic acid has a protect…
Hydralazine is a powerful inhibitor of peroxynitrite formation as a possible explanation for its beneficial effects on prognosis in patients with con…
2005
The hemodynamic and anti-ischemic effects of nitroglycerin (GTN) are rapidly blunted as a result of the development of nitrate tolerance. Hydralazine has been shown to prevent tolerance in experimental and clinical studies, all of which may be at least in part secondary to antioxidant properties of this compound. The antioxidant effects of hydralazine were tested in cell free systems, cultured smooth muscle cells, isolated mitochondria, and isolated vessels. Inhibitory effects on the formation of superoxide and/or peroxynitrite formation were tested using lucigenin and L-012 enhanced chemiluminescence as well as DHE-fluorescence. The peroxynitrite scavenging properties were also assessed by…
Antioxidant enzyme activities and the production of MDA and 8-oxo-dG in chronic lymphocytic leukemia.
2001
Abstract Chronic lymphocytic leukemia (CLL) is a neoplastic disease susceptible to antioxidant enzyme alterations and oxidative stress. We have examined the activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx), and the oxidized/reduced glutathione (GSSG/GSH) ratio together with the levels of malondialdehyde (MDA) and 8-oxo-2′-deoxyguanosine (8-oxo-dG) in lymphocytes of CLL patients and compared them with those of normal subjects of the same age. SOD and CAT activity decreased in CLL lymphocytes while GPx activity increased. GSH content of CLL lymphocytes also increased, and GSSG concentration remained constant. Thus, a reduced GSSG/GSH ratio was obtaine…
Retinol, at concentrations greater than the physiological limit, induces oxidative stress and apoptosis in human dermal fibroblasts
2004
We have investigated the dose (in the range of microM) and time-dependent effects of four different retinoids (retinol, retinal, retinoic acid and retinol palmitate) on human dermal fibroblasts cultivated in vitro. Retinol and retinal, at a concentration of 20 microM, caused cell damage as evaluated by lactate dehydrogenase activity released into the culture medium. The oxidised glutathione (GSSG)/reduced glutathione (GSH) ratio and malondialdehyde production indicated that 20 microM of retinol provoked oxidative stress in the cultivated human fibroblasts. In the first 8 h after retinol treatment the levels of p53 and Bax proteins as well as caspase 3 activity increased, suggesting apoptoti…