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)

Graminivorous species of grasshoppers develop lethal lesions in their midgut epithelia when they ingest tannic acid, whereas polyphagous grasshoppers are unaffected by ingested tannins. This study tests the hypothesis that polyphagous species are defended by higher activities of antioxidant enzymes (constitutive or inducible) in their guts than are graminivorous species. Comparisons were made between four antioxidant enzymes: superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APOX), and glutathione transferase peroxidase (GSTPX). Enzyme activities were measured in the gut lumens and midgut tissues of Melanoplus sanguinipes (polyphagous) and Aulocara ellioti (graminivorous). The results of this study do not support the hypothesis that M. sanguinipes is better defended by antioxidant enzymes than is A. ellioti, nor are these enzymes more inducible in M. sanguinipes than in A. ellioti when insects consume food containing 15% dry weight tannic acid. Instead, tannic acid consumption reduced SOD, APOX, and GSTPX activities in both species. This study reports the first evidence that SOD is secreted into the midgut lumen in insects, with activities two- to fourfold higher than those found in midgut tissues. The spatial distribution of GSTPX and APOX activities observed in both species suggests that ingested plant antioxidant enzymes may function as acquired defenses in grasshoppers. In addition, the results of this study permit the first comparison between the antioxidant enzyme defenses of Orthoptera and Lepidoptera. Most notably, grasshoppers have higher SOD activities than caterpillars, but completely lack APOX in their midgut tissues.
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PMID:Gut-based antioxidant enzymes in a polyphagous and a graminivorous grasshopper. 1219 99

We demonstrated that exposure of cells to 50 nM okadaic acid for 2 h induced a reduction in cellular glutathione transferase, glutathione reductase and catalase activity. Likewise, this acid prompted an increase in lipid peroxidation. Treatment of cells with 10(-5) M melatonin or 0.5 microg/ml vitamin C prevented the effects of okadaic acid. These results indicate that okadaic acid induces an oxidative stress imbalance, while melatonin and vitamin C prevent the oxidative stress induced by okadaic acid. Likewise, these data indicate the great importance of oxidative stress in both this experimental model and in the development and course of neurodegenerative disease, especially Alzheimer's disease. They show that melatonin is much more efficient than vitamin C in reducing the extent of oxidative stress. This phenomenon was demonstrated by the smaller dose of melatonin needed to obtain effects similar to those obtained with vitamin C on lipid peroxidation and by the protective effect of melatonin on antioxidant enzyme activity.
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PMID:Comparison of melatonin versus vitamin C on oxidative stress and antioxidant enzyme activity in Alzheimer's disease induced by okadaic acid in neuroblastoma cells. 1224 84

Recently, numerous studies have shown antioxidant actions of melatonin. Melatonin at both physiological and pharmacological levels stimulates glutathione peroxidase, glutathione reductase and superoxide dismutase activities in the brains of rats and chickens. This study was designed to evaluate the effect of melatonin on nephropathy and oxidative stress under constant light exposure. Nephropathy was induced by adriamycin administered in a single dose (25 mg kg(-1) b.w., i.p.). Melatonin was injected i.p. (1,000 microg kg(-1) b.w./day). Malondialdehyde, reduced glutathione, glutathione peroxidase, glutathione reductase, glutathione transferase, catalase and superoxide dismutase were determined in kidney. Urea, creatinine and total proteins in plasma and proteinuria were evaluated and melatonin was determined. Results show a decrease in melatonin levels. Similar effects occurred with the antioxidant enzyme activities and reduced glutathione. Likewise, adriamycin and constant light induced significant enhancement of malondialdehyde. All changes induced both by adriamycin and constant light were reverted to normal by melatonin administration. Constant light exposure was associated with an increase in oxidative stress and nephropathy induced by adriamycin. Treatment with melatonin decreased lipid peroxides, and permitted a recovery of reduced glutathione, scavenger enzyme activity and parameters of renal function.
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PMID:Melatonin effect on renal oxidative stress under constant light exposure. 1257 19

To characterize the role of intestinal epithelial cells in mucosal host defense, we have examined endogenous antioxidant reactivity and inflammatory response in Caco-2 cell line. When differentiated Caco-2 cells were incubated with iron/ascorbate for 1-24 h, they exhibited increased malondialdehyde levels and decreased polyunsaturated fatty acid proportion in favor of saturated fatty acids. These modifications were accompanied with alterations in membrane fluidity and permeability. The oxidative stress did not induce changes in the antioxidant enzyme activity of superoxide dismutase, catalase, glutathione peroxidase, and glutathione transferase, or in cellular glutathione content. However, iron/ascorbate-mediated lipid peroxidation promoted inhibitor-kappaB degradation and NF-kappaB activation, as well as gave rise to IL-8, cyclooxygenase-2, and ICAM-1. These results support the importance of oxidant/antioxidant balance in the epithelial cell inflammatory response.
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PMID:Inflammatory reaction without endogenous antioxidant response in Caco-2 cells exposed to iron/ascorbate-mediated lipid peroxidation. 1284 21

We investigated the effect of betaine supplementation on ethanol induced steatosis and alterations in prooxidant and antioxidant status in the liver of guinea pigs. Animals were fed with normal chow or betaine containing chow (2% w/w) for 30 days. Ethanol (3 g/kg, i.p.) was given for the last 10 days. We found that ethanol treatment caused significant increases in plasma transaminase activities, hepatic triglyceride and lipid peroxide levels. Significant decreases in glutathione (GSH), alpha-tocopherol and total ascorbic acid (AA) levels were also observed, but hepatic superoxide dismutase, glutathione peroxidase and glutathione transferase activities remained unchanged as compared with those in controls. Betaine treatment together with ethanol in guinea pigs is found to decrease hepatic triglyceride, lipid peroxide levels and serum transaminase activities and to increase GSH levels. No changes in alpha-tocopherol and total AA levels and antioxidant enzyme activities were observed with betaine treatment in alcohol treated guinea pigs. In addition, histopathological assessment of guinea pigs showed that betaine reduced the alcoholic fat accumulation in the liver. Based on these data, betaine treatment has a restoring effect on the alterations in triglyceride, lipid peroxide and GSH levels following ethanol ingestion.
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PMID:The effect of betaine treatment on triglyceride levels and oxidative stress in the liver of ethanol-treated guinea pigs. 1538 56

Selenium-containing glutathione transferase (seleno-GST) was generated by biologically incorporating selenocysteine into the active site of glutathione transferase (GST) from a blowfly Lucilia cuprina (Diptera: Calliphoridae). Seleno-GST mimicked the antioxidant enzyme glutathione peroxidase (GPx) and catalyzed the reduction of structurally different hydroperoxides by glutathione. Kinetic investigations reveal a ping-pong kinetic mechanism in analogy with that of the natural GPx cycle as opposed to the sequential one of the wild type GST. This difference of the mechanisms might result from the intrinsic chemical properties of the incorporated residue selenocysteine, and the selenium-dependent mechanism is suggested to contribute to enhancement of the enzymatic efficiency.
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PMID:Kinetic studies on the glutathione peroxidase activity of selenium-containing glutathione transferase. 1594 61

Spray-dried milk enriched with n-3 fatty acids from linseed oil (LSO) or fish oil (FO) were fed to rats to study its influence on liver lipid peroxides, hepatic antioxidant enzyme activities, serum prostaglandins and platelet aggregation. Significant level of alpha linolenic acid, eicosapentaenoic acid and docosahexaenoic acid were accumulated at the expense of arachidonic acid in the liver of rats fed n-3 fatty acid enriched formulation. The linseed oil and fish oil enriched formulation fed group had 44 and 112% higher level of lipid peroxides in liver homogenate compared to control rats fed groundnut oil enriched formulation. Catalase activity in liver homogenate was increased by 37 and 183% respectively in linseed oil and fish oil formulation fed rats. The glutathione peroxidase activity decreased to an extent of 25-36% and glutathione transferase activity increased to an extent of 34-39% in rats fed n-3 fatty acids enriched formulation. Feeding n-3 fatty acid enriched formulation significantly elevated the n-3 fatty acids in platelets and increased the lipid peroxide level to an extent of 4.2 to 4.5-fold compared to control. The serum thromboxane B2 level was decreased by 35 and 42% respectively in linseed oil and fish oil enriched formulation fed rats, whereas 6-keto-prostaglandin F1alpha level was decreased by 17 and 23% respectively in linseed oil and fish oil enriched formulation fed rats. The extent and rate of platelet aggregation was decreased significantly in n-3 fatty acids enriched formulation fed rats. This indicated that n-3 fatty acids enriched formulation beneficially reduces platelet aggregation and also enhances the activities of hepatic antioxidant enzymes such as catalase and glutathione transferase.
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PMID:Modulation of antioxidant enzyme activities, platelet aggregation and serum prostaglandins in rats fed spray-dried milk containing n-3 fatty acid. 1613 10

Spray-dried milk enriched with n-3 fatty acids from linseed oil or fish oil were fed to rats to study its influence on liver lipid peroxides, hepatic antioxidant enzyme activities, serum prostaglandins and platelet aggregation. Significant level of alpha linolenic acid, eicosapentaenoic acid and docosahexaenoic acid were accumulated at the expense of arachidonic acid in the liver of rats fed n-3 fatty acid enriched formulation. The linseed oil and fish oil enriched formulation fed group had 44 and 112% higher level of lipid peroxides in liver homogenate compared to control rats fed groundnut oil enriched formulation. Catalase activity in liver homogenate was increased by 37 and 183% respectively in linseed oil and fish oil formulation fed rats. The glutathione peroxidase activity decreased to an extent of 25-36% and glutathione transferase activity increased to an extent of 34-39% in rats fed n-3 fatty acids enriched formulation. Feeding n-3 fatty acid enriched formulation significantly elevated the n-3 fatty acids in platelets and increased the lipid peroxide level to an extent of 4.2-4.5 fold compared to control. The serum thromboxane B2 level was decreased by 35 and 42% respectively in linseed oil and fish oil enriched formulation fed rats, whereas, 6-keto- prostaglandin F1alpha level was decreased by 17 and 23% respectively in linseed oil and fish oil enriched formulation fed rats. The extent and rate of platelet aggregation was decreased significantly in n-3 fatty acids enriched formulation fed rats. This indicated that n-3 fatty acids enriched formulation beneficially reduces platelet aggregation and also enhances the activities of hepatic antioxidant enzymes such as catalase and glutathione transferase.
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PMID:Modulation of antioxidant enzyme activities, platelet aggregation and serum prostaglandins in rats fed spray-dried milk containing n-3 fatty acid. 1631

Individuals affected by liver steatosis seldom have symptoms of liver injury, but may be particularly vulnerable to oxidative insults. In this study, we evaluated liver redox alterations produced by acute ethanol administration to rats that were fed a high-fat diet (HFD). Adult male Wistar rats were fed HFD or standard diet (controls) for 1 month; a group of animals from each condition were gavaged with 35% (vol/vol) ethanol every 12h for the last 3 days of the experiment. Total lipid content determined in liver showed lipid accumulation after HFD or HFD combined with ethanol. HFD alone induced a significant rise of seric alanine aminotransferase levels and a marked reduction of antioxidant enzyme activities (catalase, superoxide dismutase, glutathione transferase). Ethanol alone caused a significant rise of seric cholesterol levels and enhanced mitochondrial H2O2 production, but without apparent oxidative stress as evaluated by thiobarbituric acid-reactive substances (TBARS) assay. The combination of HFD and acute ethanol caused an increase of TBARS, indicating lipid peroxidation, most likely as a consequence of a decrease in antioxidant defenses induced by HFD and of an increase in reactive oxygen species production induced by ethanol. Principal component analysis, based on all the measured parameters, that is, serum liver function tests, antioxidant enzyme activities, mitochondrial H2O2 release, and TBARS, indicated that HFD and ethanol act as two independent factors. In conclusion, our results show that HFD or acute ethanol alone produce, at the most, mild liver injury, whereas their combination triggers oxidative stress, possibly inducing a progression toward liver disease. Hence, our data indicate that a diet too rich in fat is a serious risk factor for the occurrence of liver injury deriving from acute ethanol consumption.
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PMID:Combined effects of high-fat diet and ethanol induce oxidative stress in rat liver. 1741 98

To evaluate potential antioxidant characteristics of organic selenium (Se), double knock-in transgenic mice expressing human mutations in the amyloid precursor protein (APP) and human presenilin-1 (PS1) were provided a Se-deficient diet, a Se-enriched diet (Sel-Plex), or a control diet from 4 to 9 months of age followed by a control diet until 12 months of age. Levels of DNA, RNA, and protein oxidation as well as lipid peroxidation markers were determined in all mice and amyloid beta-peptide (Abeta) plaques were quantified. APP/PS1 mice provided Sel-Plex showed significantly (P<0.05) lower levels of Abeta plaque deposition and significantly decreased levels of DNA and RNA oxidation. Sel-Plex-treated mice showed no significant differences in levels of lipid peroxidation or protein oxidation compared to APP/PS1 mice on a control diet. To determine if diminished oxidative damage was associated with increased antioxidant enzyme activities, brain glutathione peroxidase (GSH-Px), glutathione reductase, and glutathione transferase activities were measured. Sel-Plex-treated mice showed a modest but significant increase in GSH-Px activity compared to mice on a normal diet (P<0.5). Overall, these data suggest that organic Se can reduce Abeta burden and minimize DNA and RNA oxidation and support a role for it as a potential therapeutic agent in neurologic disorders with increased oxidative stress.
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PMID:Organoselenium (Sel-Plex diet) decreases amyloid burden and RNA and DNA oxidative damage in APP/PS1 mice. 1930 33


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