Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P30044 (antioxidant enzyme)
 8,037 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Although the effects of cigarette smoking on a variety of diseases, from cancer through emphysema and cardiovascular illness are well documented, direct effects on the levels of macro- and micronutrients in the body are reported less frequently. In fact, imbalances in these nutrients may have a role in many of the pathological conditions attributed to smoking. Tobacco smoke contains numerous compounds emitted as gases and condensed tar particles, many of them being oxidants and prooxidants, capable of producing free radicals thus enhancing lipid peroxidation in biological membranes. Vitamin E, vitamin C, B-carotene and selenium are involved in the overall cellular anti-oxidant defense against deleterious effects of reactive oxygen species. Smoking has been shown to lower the level of vitamin C and B-carotene in plasma. Cadmium, naturally found in tobacco, decreases the bioavailability of selenium and acts antagonistically to zinc, a cofactor for the antioxidant enzyme, superoxide dismutase. Vitamin E, the principle lipid-soluble antioxidant, may be at suboptimal levels in tissues of smokers. In addition, tobacco constituents have been shown to reduce levels of several vitamins of the B-complex. Nutritional status in smokers may be further compromised by an inadequate diet. Data from the Second National Health and Nutrition Examination Survey indicates that smokers are less likely to consume fruits and vegetables, particularly those high in vitamin C and carotenes. Cessation of smoking is the obvious solution to ending cigarette-related problems. In the world as it is, however, the medical community should be responsible for making recommendations to lower the risk in smokers to tobacco related diseases. Nutritionists could have a role in this process. There exists a lively debate as to where levels of nutrients should be set. Additional vitamin C has already been recommended for smokers. Should other antioxidants also be increased? Arguments for the against are considered.
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PMID:Cigarette smoking-nutritional implications. 178 36

Endotoxin treatment in normal rats has a marked protective effect against O2 toxicity (J. Appl. Physiol.: Respirat. Environ. Exercise Physiol. 47: 577-581, 1979 and 51: 577-583, 1981), and endotoxin's protective action is associated with stimulation of the lung's enzymatic antioxidant defense system (superoxide dismutase, catalase, glutathione peroxidase, and glucose-6-phosphate dehydrogenase). Vitamin E-deficient animals are especially sensitive to hyperoxidant stresses, including pulmonary O2 toxicity. In these studies we tested whether endotoxin could reverse the increased susceptibility of vitamin E-deficient rats to hyperoxic challenge. We found that untreated vitamin E-deficient rats do succumb more readily to O2 toxicity [0/11 alive at 72 h in greater than 95% O2, lethal time for 50% of the animals (LT50) = 50 h] than rats fed a regular diet (4/14 alive, LT50 = 69 h). In contrast, 15 of 16 vitamin E-deficient rats treated with endotoxin survived the same O2 exposures (P less than 0.001) and showed significantly reduced pulmonary edema compared with the other groups. The endotoxin-treated vitamin E-deficient group was also the only one to demonstrate significant elevations of all the antioxidant enzymes during O2 exposure, suggesting that the antioxidant enzyme defenses of the lung have a more primary and important role in prevention of O2-induced lung injury than the lipid-associated antioxidant, vitamin E.
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PMID:Endotoxin treatment protects vitamin E-deficient rats from pulmonary O2 toxicity. 638 80

1. During all aerobic metabolism, free radicals generated by the partial reduction of oxygen are potentially injurious to cells. Highly efficient antioxidant defence systems exist to inhibit oxidative damage to cellular lipids and proteins. Specific enzymes have a crucial role in these antioxidant defences, and their activity may be induced by regulatory mechanisms that respond to oxygen metabolite concentration. 2. To assess whether smoking induces an additional adaptive response, we compared antioxidant defence systems in erythrocytes from smokers and non-smokers and assessed whether a high intake of vitamin E (280 mg/day), a major lipophilic free-radical-scavenging antioxidant, affects the activity of antioxidant enzymes. 3. A total of 100 men, 50 smokers and 50 non-smokers, were allocated to four treatment groups in a 2 x 2 factorial design (smokers versus non-smokers and placebo versus vitamin E). For 10 weeks each subject took one capsule per day of either 280 mg dl-alpha-tocopherol acetate or a visually identical placebo (hydrogenated coconut oil with negligible vitamin E content). 4. Despite increased erythrocyte cytosolic antioxidant enzyme activities in smokers compared with non-smokers, erythrocytes from smokers were more susceptible to hydrogen peroxide-induced lipid peroxidation in vitro. 5. Vitamin E supplementation further increased erythrocyte catalase (EC 1.11.1.6) activity in both smokers and non-smokers (P < 0.001) and erythrocyte glutathione peroxidase (EC 1.11.1.9) and glutathione reductase (EC 1.6.4.2) activities in non-smokers (P < 0.001). After supplementation with vitamin E there was a concomitant fall in erythrocyte superoxide dismutase (EC 1.15.1.1) activity (P < 0.001) and total glutathione concentration (P < 0.01). Furthermore, in both smokers and non-smokers there was a significant decrease in the susceptibility of erythrocytes to peroxidation (P < 0.001). 6. Various endogenous and exogenous factors exert control over cellular protection against reactive oxygen species, and our data suggest that one such factor is the supply of vitamin E.
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PMID:Effects of vitamin E supplementation on erythrocyte antioxidant defence mechanisms of smoking and non-smoking men. 877 68

The effects of Vitamin E administration on antioxidant enzyme activities and nitrite-nitrate levels of the reperfused rat kidney tissues were investigated by performing a 60 min ischemia followed by 24 and 72 hours of reperfusion. Vitamin E administration or the placebo (SF) was applied as 100 mg/kg BW. As expected, catalase (CAT) (p<0.05) and superoxide dismutase (SOD) (p<0.05) activities of ischemia/reperfused (I/R) kidney tissue were lower and malondialdehyde (MDA) levels were higher than control kidneys in both SF and vitamin E treated groups following 24 h reperfusion. During reperfusion of long term (72 h), vitamin E triggered a decrease in the MDA levels in the ischemic tissue, while it did not provoke a significant effect on SOD and catalase activities. Total nitrite levels of ischemic tissues in both of the groups were higher than matched control kidneys and this elevation was more clear in the vitamin E treated group. Our results showed that vitamin E has a protective effect on I/R injury, by a direct chain breaking effect on lipid peroxidation (LPO) and hence preventing the nitric oxide (NO) reservoir of ischemic tissue. Alfa-tocopherol may be a promising agent for the prevention of tissue injury caused by free oxygen radicals.
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PMID:Effect of vitamin E on antioxidant enzymes and nitric oxide in ischemia-reperfused kidney injury. 962 81

This study was designed to investigate the effects of fish oil and vitamin E on the antioxidant defense system in hypercholesterolemic rabbits. A high fat and cholesterol diet, with or without supplement by fish oil and/or a vitamin E supplement, was fed to rabbits for 6 weeks. Compared to the reference diet of regular laboratory rabbit chow, a high fat and cholesterol-enriched diet increased atheroma formation, plasma lipid and peroxide levels, decreased blood glutathione levels, and reduced plasma glutathione reductase, glutathione peroxidase, and catalase activities. Fish oil supplementation significantly reduced atheroma and increased glutathione reductase and glutathione peroxidase activities and blood glutathione levels, but increased plasma lipid peroxide levels. Vitamin E supplementation of the fish oil diet enhanced the beneficial effects by increasing glutathione reductase activity and decreasing peroxide levels. These results indicate that a high fat and cholesterol diet attenuates blood glutathione levels and plasma antioxidant enzyme activities, which may account for some of its atherogenic properties. Consumption of fish oil enhances antioxidative defenses against the oxidative stress imposed by hypercholesterolemia, and vitamin E further enhances these beneficial effects.
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PMID:Effects of fish oil and vitamin E on the antioxidant defense system in diet-induced hypercholesterolemic rabbits. 1152 55

The mechanism(s) by which exercise reduces atherogenic risk remains unknown. This study tested the hypothesis that sustained exercise-induced oxidative stress may increase antioxidant defense in the arterial wall. Acute exercise induced an increase in antibodies to oxidatively modified proteins and catalase in the aortic walls of normal mice compared with sedentary control mice. In male atherogenic diet-fed low density lipoprotein (LDL) receptor-deficient mice, exercise lowered plasma cholesterol (15%) and decreased atherosclerotic lesions by 40% compared with values in sedentary control mice, with a concomitant increase in arterial catalase and endothelial NO synthase. Because these mice lack the LDL receptor, the results indicate that the LDL receptor might not be responsible for the exercise-induced lowering of plasma cholesterol. Vitamin E supplementation to exercising LDL receptor-deficient mice did not reduce atherosclerotic lesion formation significantly as opposed to lesion formation in untreated exercised mice. Moreover, vitamin E counteracted the beneficial effects of exercise by preventing the induction of aortic catalase activity and endothelial NO synthase expression. These results might indicate that although vitamin E might have prevented the exercise-induced oxidative stress, its availability in the artery was insufficient to prevent the atherosclerotic process. These results indicate that exercise-induced plasma oxidative stress could be responsible for the prevention of atherosclerosis by stimulating arterial antioxidant response. Furthermore, vitamin E supplementation could be deleterious in exercisers by inhibiting antioxidant enzyme buildup in the arterial wall.
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PMID:Role of arterial wall antioxidant defense in beneficial effects of exercise on atherosclerosis in mice. 1159 45

Amyloid-beta, (Abeta) is a cytotoxic peptide implicated in the pathology of Alzheimers disease. The antioxidant enzyme catalase has been suggested to protect against Abeta cytotoxicity in both neuronal and non-neuronal cell types. Inhibition of endogenous catalase using 3-amino-1,2,4-triazole (3AT) in neuronal (NT-2) and myeloma (SP2/0-Ag-14) cell lines increases Abeta toxicity, suggesting that any protective role for endogenous catalase requires active enzyme. In Abeta treated mveloma cells there was a significant decrease in the total cell catalase activity and immunoreactivity. However, when the surviving live cell population was isolated following Abeta treatment the levels of catalase were significantly increased. The surviving live cell population from groups treated with both 3AT and Abeta contain elevated immunoreactive catalase levels suggesting that the protective role for endogenous catalase may have a component independent of the antioxidant activity, possibly by acting as an Abeta binding protein. Amyloid-beta (Abeta) cytotoxicity can be prevented by Vitamin E treatment or an anti-Abeta monoclonal antibody (ALIOI), both of which also prevent Abeta cytotoxicity in cells treated with 3AT These observations suggest that Abeta mediated cell death in both neuronal and non-neuronal cells is mediated in part by actions to increase hydrogen peroxide. Catalase has a protective role, as a hydrogen peroxide-degrading enzyme and catalase inhibition by Abeta is not the direct cause of cytotoxicity.
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PMID:Inhibition of catalase activity with 3-amino-triazole enhances the cytotoxicity of the Alzheimer's amyloid-beta peptide. 1182 10

The cellular antioxidant system appears to protect cochlear hair cells from oxidative stress due to noise and aging. The role of individual metabolic variables remains poorly understood, however. We examined the role of a number of metabolic factors on human cochlear function in noise-exposed individuals. In 58 factory workers we measured audiometry and distortion product otoacoustic emissions prior to a workshift. Simultaneously we measured levels of vitamin E, vitamin C, and polymorphism status for two metabolic genes related to glutathione S-transferase function (GSTM1 and GSTT1). Age and total noise exposure were predictive of hearing status. Vitamin E levels were negatively correlated with hearing function, and this effect was partly explained by an increase in vitamin E levels with age. No effect was found for vitamin C. Individuals possessing the GSTM1 gene had significantly better high frequency otoacoustic emissions compared to GSTM1 null individuals. The protective effect of GSTM1 was present even after adjusting for age, race, sex, and years of noise exposure. GSTT1 did not exhibit a similarly protective effect. While the cross-sectional nature of the study precludes drawing conclusions about causation, these data suggest that GSTM1, an antioxidant enzyme which is found in the mammalian cochlea, may play a protective role in humans against hair cell damage due to noise or aging.
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PMID:Antioxidant status and hearing function in noise-exposed workers. 1237 44

Determination of reliable bioindicators of diabetes-induced oxidative stress and the role of dietary vitamin E supplementation were investigated. Blood (plasma) chemistries, lipid peroxidation (LPO), and antioxidant enzyme activities were measured over 12 weeks in New Zealand White rabbits (control, diabetic, and diabetic + vitamin E). Cholesterol and triglyceride levels did not correlate with diabetic state. Plasma LPO was influenced by diabetes and positively correlated with glucose concentration only, not cholesterol or triglycerides. Liver glutathione peroxidase (GPX) activity negatively correlated with glucose and triglyceride levels. Plasma and erythrocyte GPX activities positively correlated with glucose, cholesterol, and triglyceride concentrations. Liver superoxide dismutase activity positively correlated with glucose and cholesterol concentration. Vitamin E reduced plasma LPO, but did not affect the diabetic state. Thus, plasma LPO was the most reliable indicator of diabetes-induced oxidative stress. Antioxidant enzyme activities and types of reactive oxygen species generated were tissue dependent. Diabetes-induced oxidative stress is diminished by vitamin E supplementation.
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PMID:Differential indicators of diabetes-induced oxidative stress in New Zealand White rabbits: role of dietary vitamin E supplementation. 1245 60

Oxidative stress plays a role in many disease states. These diseases have an increased incidence in uremia, and particularly in hemodialysis (HD) patients. This suggests an increased exposure to oxidative stress. An imbalance between oxidants and antioxidants has been suggested in uremic patients on HD. However, the respective influence of uremia and dialysis procedure has not been evaluated. It is postulated that antioxidant capacity in uremic patients is reduced, yet the mechanism remains unclear. We have determined the levels of lipid peroxidation expressed as thiobarbituric acid-reactive substances. We assessed oxidative protein damage by carbonyl content and activities of antioxidant enzymes including superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) in predialysis uremic patients and in end-stage renal disease (ESRD) patients before and after hemodialysis. Vitamin E and vitamin C levels, reduced glutathione and sulfhydryl content were also studied. We found enhanced oxidative stress in ESRD patients undergoing HD and in predialysis uremic patients. This was mostly due to defective antioxidant enzyme levels. Preventive modalities, including use of biocompatible membranes, ultrapure dialysate, exogenous supplementation of antioxidant vitamins, extracorporeal removal of reactive oxygen species (ROS) and oxidatively modified substances, would appear highly desirable to reduce complications in the long-term dialysis patients.
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PMID:Effect of hemodialysis on the oxidative stress and antioxidants. 1247 39


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