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)

Chronic intake of cassava has been thought to play a role in the pathogenesis of diabetes. We investigated the effects of dietary cassava (Manihot esculenta), which naturally contains cyanogenic glycosides, in the progression of diabetes mellitus in rats. Diabetes was induced by five mild doses of streptozotocin, in male Wistar rats which were fed a standard or cyanide-free cassava (CFC) diet containing or not containing exogenous cyanide with or without methionine. Methionine was employed to counterbalance the toxic effects of cyanide. During diabetes progression, we determined glycaemia and antioxidant status, by measuring vitamin C levels and activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and glutathione reductase (GSSG-Red). Feeding CFC diet did not induce diabetes in control rats; rather this diet, in diabetic animals, aggravated hyperglycaemia the severity of which was increased in these animals fed CFC diet, supplemented with cyanide. Addition of methionine curtailed the toxic effects of cyanide supplementation in CFC diet-fed diabetic animals. In standard diet-fed animals, the activities of SOD, GSH-Px and GSSG-Red were lower in diabetic rats than control rats. Interestingly, all of the CFC diets with or without cyanide or methionine, increased vitamin C levels and antioxidant enzyme activities in both control and diabetic animals. However, supplementing cyanide to CFC diet (without methionine) curtailed SOD and GSH-Px activities in diabetic rats. Our study shows that cassava diet containing cyanide is 'diabetes-aggravating'.
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PMID:Cassava-enriched diet is not diabetogenic rather it aggravates diabetes in rats. 1710 51

Up-regulation of the antioxidant system provides protection against NaCl-induced oxidative damage in plants. Antioxidants and activity of enzymes involved in the ascorbate-glutathione (ASC-GSH) cycle in tobacco Bright Yellow-2 (BY-2) were investigated to assess the antioxidant protection offered by exogenous proline and glycinebetaine (betaine from now on) against salt stress using cells grown in suspension culture. Reduced ascorbate (ASC) was detected in BY-2 cells but dehydroascorbate (DHA) was not. Large quantities of a reduced form of glutathione (GSH) and smaller quantities of an oxidized form of glutathione (GSSG) were detected in BY-2 cells. Salt stress significantly reduced the contents of ASC and GSH as well as activities of ASC-GSH cycle enzymes such as ascorbate peroxidase (APX), monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR), and glutathione reductase (GR). Exogenous proline or betaine increased the activities of all enzymes except MDHAR involved in NaCl-induced ASC-GSH cycle. Levels of ASC and GSH in BY-2 cells under salt stress were lower in the presence of proline or betaine than in the absence of proline or betaine whereas there was no difference in redox status. Proline proved more effective than betaine in maintaining the activity of enzymes involved in NaCl-induced ASC-GSH cycle. Neither proline nor betaine had any direct protective effect on NaCl-induced enzyme activity involved in the antioxidant system; however, both improved salt tolerance by increasing enzyme activity. The present study, together with our earlier findings [Hoque MA, Okuma E, Banu MNA, Nakamura Y, Shimoishi Y, Murata Y. Exogenous proline mitigates the detrimental effects of salt stress more than exogenous betaine by increasing antioxidant enzyme activities. J Plant Physiol 2006;164:553-61.], suggests that proline offered greater protection against salt stress than betaine did because proline was more effective in increasing the activity of enzymes involved in the antioxidant system.
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PMID:Exogenous proline and glycinebetaine increase NaCl-induced ascorbate-glutathione cycle enzyme activities, and proline improves salt tolerance more than glycinebetaine in tobacco Bright Yellow-2 suspension-cultured cells. 1722 25

Oxidative damage of biomolecules increases with age and is postulated to be a major causal factor of various physiological function disorders. Consequently, the concept of anti-age by antioxidants has been developed. Lycium barbarum fruits have been used as a traditional Chinese herbal medicine and the data obtained in in vitro models have clearly established the antioxidant potency of the polysaccharides isolated from the fruits. In the present study, the age-dependent changes in the antioxidant enzyme activity, immune function and lipid peroxidation product were investigated and effect of Lycium barbarum polysaccharides on age-induced oxidative stress in different organs of aged mice was checked. Lycium barbarum polysaccharides (200, 350 and 500 mg/kg b.w. in physiological saline) were orally administrated to aged mice over a period of 30 days. Aged mice receiving vitamin C served as positive control. Enzymatic and non-enzymatic antioxidants, lipid peroxides in serum and tested organs, and immune function were measured. Result showed that increased endogenous lipid peroxidation, and decreased antioxidant activities, as assessed by superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px) and total antioxidant capacity (TAOC), and immune function were observed in aged mice and restored to normal levels in the polysaccharides-treated groups. Antioxidant activities of Lycium barbarum polysaccharides can be compable with normal antioxidant, vitamin C. Moreover, addition of vitamin C to the polysaccharides further increased the in vivo antioxidant activity of the latter. It is concluded that the Lycium barbarum polysaccharides can be used in compensating the decline in TAOC, immune function and the activities of antioxidant enzymes and thereby reduces the risks of lipid peroxidation accelerated by age-induced free radical.
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PMID:Effect of the Lycium barbarum polysaccharides on age-related oxidative stress in aged mice. 1722 53

This study aims at exploring the oxidative stress in keratinocytes induced by UVB irradiation and the protective effect of nutritional antioxidants. Cultured Colo-16 cells were exposed to UVB in vitro followed by measurement of reactive oxygen species (ROS), endogenous antioxidant enzyme activity, as well as cell death in the presence or absence of supplementation with vitamin C, vitamin E, or Ginsenoside Panoxatriol. Intracellular ROS content was found significantly reduced 1 h after exposure, but increased at later time points. After exposure to 150-600 J m(-2) UVB, reduction of ROS content was accompanied by increased activity of catalase and CuZn-superoxide dismutase at early time points. Vitamins C and E, and Ginsenoside Panoxatriol counteracted the increase of ROS in the Colo-16 cells induced by acute UVB irradiation. At the same time, Ginsenoside Panoxatriol protected the activity of CuZn-superoxide dismutase, while vitamin E showed only a moderate protective role. Vitamins C and E, and Ginsenoside Panoxatriol in combination protected the Colo-16 cells from UVB-induced apoptosis, but not necrosis. These findings suggest that vitamins C and E as well as Ginsenoside Panoxatriol are promising protective agents against UVB-induced damage in skin cells.
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PMID:UVB induced oxidative stress in human keratinocytes and protective effect of antioxidant agents. 1727 58

An exposure of isolated rat brain genomic DNA to oxidative stress in the form of iron salts (Fe2+) and ascorbate results in gene-specific DNA lesions detectable by a quantitative polymerase chain reaction (PCR) based assay in which PCR amplification efficiency of the affected genes (e.g. beta-actin and p53) is grossly impaired. Such oxidative DNA lesions are prevented by hydroxyl radical scavengers like mannitol (20 mM) and sodium benzoate (20 mM) or by the antioxidant enzyme catalase (50 microg/ml) present in the incubation mixture during exposure to Fe2+ and ascorbate. When brain DNA isolated from young (4-6 months of age) and aged (20-24 months of age) rats are analyzed similarly by the PCR based method, the amplification levels of beta-actin and p53 genes are noticeably decreased in the case of aged rat indicating an accumulation of gene-specific DNA lesions during brain aging.
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PMID:Gene-specific oxidative lesions in aged rat brain detected by polymerase chain reaction inhibition assay. 1736 57

Recently, beta-glucan has been postulated to modulate antioxidant enzyme activity (superoxide dismutase-SOD) as well as to inhibit lipid peroxidation in studies concerning rats or rabbits. There are very few reports on antioxidant effect of beta-glucan in the human blood. The study was aimed to estimate influence of Vita Glucan (VG) on SOD and catalase (CAT) activities as well as on total antioxidant power measured as ferric reducing activity and ascorbate concentration (FRASC) in the human blood in vitro. SOD activities were measured according to Fridovich's method, CAT activity by Aebi's and FRASC value by Benzi's one. Results of this study have shown that Vita Glucan at concentrations 42.5, 85, 170, and 340 mg x 100 mL(-1) increased markedly activities of antioxidant enzymes and FRASC values in human red blood cells hemolysates.
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PMID:Effect of Vita Glucan on some antioxidant parameters of the human blood. In vitro study. 1743 73

Oxidative stress underlies postoperative atrial fibrillation and electrophysiological remodelling associated with rapid atrial pacing. An increasing body of evidence indicates that the formation of reactive oxygen species (ROS) released following extracorporeal circulation are involved in the structural and functional myocardial impairment derived from the ischemia-reperfusion cycle. ROS behave as intracellular messengers mediating pathological processes, such as inflammation, apoptosis and necrosis, thereby participating in the pathophysiology of atrial fibrillation. Thus, increased superoxide (O(2)(.-)) production has been found in isolated atrial cardiomyocytes from patients with atrial fibrillation. Therefore, it seems reasonable to assume that the reinforcement of the antioxidant defense system should protect the heart against functional alterations in the cardiac rhythm. On this line, antioxidant enzyme induction through in vivo exposure to moderate concentration of ROS is associated with a reduction in the susceptibility of myocytes to ROS-induced injury. This response could be due to a prevailing effect of survival over apoptotic pathway. Previously, tissue preconditioning caused by prior exposure to an ischemia/reperfusion cycle has been successfully applied in experimental models and clinical settings associated with oxidative damage by ROS. However, such hypoxic preconditioning method is harmful to be applied to many clinical conditions associated with oxidative stress. In turn, experimental studies have revealed that non-enzymatic antioxidants produce a significant functional amelioration in cardiomyocytes subjected to an oxidative challenge. Moreover, clinical studies with patients scheduled for primary coronary artery bypass graft surgery had a reduced incidence of postoperative atrial fibrillation. We present the hypothesis of non-hypoxic preconditioning based on the association of pretreatment with n-3 polyunsaturated fatty acids followed by ascorbate plus alpha-tocoferol supplementation diminishes the incidence of postoperative atrial fibrillation in patients subjected to cardiac surgery with extracorporeal circulation.
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PMID:Non-hypoxic preconditioning of myocardium against postoperative atrial fibrillation: mechanism based on enhancement of the antioxidant defense system. 1754 71

In order to determine the different roles of rice (Oryza sativa L.) cytosolic ascorbate peroxidases (OsAPXa and OsAPXb, GenBank accession nos. D45423 and AB053297, respectively) under salt stress, transgenic Arabidopsis plants over-expressing OsAPXa or OsAPXb were generated, and they all exhibited increased tolerance to salt stress compared to wild-type plants. Moreover, transgenic lines over-expressing OsAPXb showed higher salt tolerance than OsAPXa transgenic lines as indicated by root length and total chlorophyll content. In addition to ascorbate peroxidase (APX) activity, antioxidant enzyme activities of catalase (CAT), superoxide dismutase (SOD) and glutathione reductase (GR), which are also involved in the salt tolerance process, and the content of H2O2 were also assayed in both transgenic and wild-type plants. The results showed that the overproduction of OsAPXb enhanced and maintained APX activity to a much higher degree than OsAPXa in transgenic Arabidopsis during treatment with different concentrations of NaCl, enhanced the active oxygen scavenging system, and protected plants from salt stress by equilibrating H2O2 metabolism. Our findings suggest that the rice cytosolic OsAPXb gene has a more functional role than OsAPXa in the improvement of salt tolerance in transgenic plants.
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PMID:Two rice cytosolic ascorbate peroxidases differentially improve salt tolerance in transgenic Arabidopsis. 1757 Dec 67

A 6A,6A'-dicyclohexylamine-6B,6B'-diselenide-bis-beta-cyclodextrin (6-CySeCD) was designed and synthesized to imitate the antioxidant enzyme glutathione peroxidase (GPX). In this novel GPX model, beta-cyclodextrin provided a hydrophobic environment for substrate binding within its cavity, and a cyclohexylamine group was incorporated into cyclodextrin in proximity to the catalytic selenium in order to increase the stability of the nucleophilic intermediate selenolate. 6-CySeCD exhibits better GPX activity than 6,6'-diselenide-bis-cyclodextrin (6-SeCD) and 2-phenyl-1,2-benzoisoselenazol-3(2H)-one (Ebselen) in the reduction of H(2)O(2), tert-butyl hydroperoxide and cumenyl hydroperoxide by glutathione, respectively. A ping-pong mechanism was observed in steady-state kinetic studies on 6-CySeCD-catalyzed reactions. The enzymatic properties showed that there are two major factors for improving the catalytic efficiency of GPX mimics. First, the substrate-binding site should match the size and shape of the substrate and second, incorporation of an imido-group increases the stability of selenolate in the catalytic cycle. More efficient antioxidant ability compared with 6-SeCD and Ebselen was also seen in the ferrous sulfate/ascorbate-induced mitochondria damage system, and this implies its prospective therapeutic application.
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PMID:A novel dicyclodextrinyl diselenide compound with glutathione peroxidase activity. 1761 30

Oxidative stress and ultrastructural changes under hexavalent chromium stress were investigated in developing rice seedlings. Chromium treatment for 24 or 48h resulted in inhibition of root length and dry biomass. Atomic absorption spectrometry analysis of roots showed that chromium accumulation increased with increase in concentration and duration of metal treatment. Chromium resulted in increased production of hydrogen peroxide and superoxide radical in root cells, which was a significant change after 48h of treatment. Time-course analysis of malondialdehyde content showed no substantial variation during early treatment periods (2, 6 or 12h). Increase in malondialdehyde content was observed only after 18h and it continued to increase until 48h after treatment. Loss of membrane integrity, analyzed in terms of Evans blue uptake in root cells, showed an increase in uptake of the reagent, indicating loss of membrane integrity. The antioxidant enzyme, viz., guaiacol peroxidase, was least affected, while glutathione reductase showed significant decline after 24 or 48h of metal treatment, followed by increased activity of superoxide dismutase. The level of ascorbate was not affected by chromium, while an increase in the level of glutathione was observed. At the ultrastructural level, potential damage to the root cell was noted after 48h at 100microM of chromium compared with controls.
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PMID:Chromium-mediated oxidative stress and ultrastructural changes in root cells of developing rice seedlings. 1768


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