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)

The present investigation focused, firstly, on the effects of oral administration of thymoquinone (TQ) on antioxidant enzyme activities, lipid peroxidation and DT-diaphorase activity in hepatic, cardiac and kidney tissues of normal mice. Superoxide dismutase (SOD; E.C:1.15.1.1), catalase (CAT; E.C:1.11.1.6), glutathione peroxidase (GSH-Px; E.C:1.11.1.9), glutathione-S-transferase (GST; E.C:2.5.1.18), and DT-diaphorase (E.C:1.6.99.2) enzyme activities in each tissue type were determined. Treatment of mice with the different doses of TQ (25, 50 and 100 mg kg(-1) day(-1) orally) for 5 successive days, produced significant reductions in hepatic SOD, CAT and GSH-Px activities. In addition cardiac SOD activity was markedly inhibited with the higher doses of TQ, (namely 50 and 100 mg kg(-1)). Moreover, TQ (100 mg kg(-1)) significantly reduced hepatic and cardiac lipid peroxidation as compared with the respective control group. Conversely, TQ (50,100 mg kg(-1)) and TQ (100 mg kg(-1)) enhanced cardiac and renal DT-diaphorase activity respectively. However, the selected doses of TQ neither produced any change in GST activity nor influenced reduced glutathione content in all tissues studied. TQ was tested, secondly, as a substrate for hepatic, cardiac and renal DT-diaphorase of normal mice in the presence of NADPH. Kinetic parameters for the reduction of TQ to dihydrothymoquinone (DHTQ) indicated that DT-diaphorase of different tissues can efficiently reduce TQ to DHTQ. K(m) and V(max) values revealed that hepatic DT-diaphorase exhibited the higher values, while the lower values were associated with renal DT-diaphorase. TQ and DHTQ were tested, thirdly, as specific scavengers for superoxide anion (generated biochemically) or as general scavengers for free radicals (generated photochemically). The results revealed that TQ and DHTQ acted not only as superoxide anion scavengers but also as general free radical scavengers. The IC(50) for TQ and DHTQ in biochemical and photochemical assays were in the nanomolar and micromolar range respectively. Our data may explain at least partly the reported beneficial in vivo protective effects of TQ through the combined antioxidant properties of TQ and its metabolite DHTQ.
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PMID:Effects of thymoquinone on antioxidant enzyme activities, lipid peroxidation and DT-diaphorase in different tissues of mice: a possible mechanism of action. 1197 10

Patients with metabolic syndrome show augmented cardio-vascular risk, at least in part mediated through disequilibrium between mechanisms generating free radicals, and antioxidant defense. Carbohydrate and lipid disturbances in metabolic syndrome induce oxidative stress via several non fully understood mechanisms. Glucose overload in oral glucose tolerance test (OGTT) can also induce oxidative stress. The aim of our study was to evaluate changes in superoxide dismutase and glutathione peroxidase activity, as well as total antioxidant status in OGTT in patients with metabolic syndrome and in healthy subjects. OGTT was performed in 36 healthy volunteers and in patients with metabolic syndrome. Glucose, Insulin, and triglycerides were evaluated at 0th, 30th, 60th, 120th, and 180th min. Superoxide dismutase and glutathione peroxidase were measured at 0th, 60th, and 120th min. Total antioxidant status was measured at 0th, and 120th min. At 0th min total, HDL and LDL cholesterol were evaluated. A statistically significant decrease (p < 0.05) in superoxide dismutase activity at 120th as compared with 60th min were observed. Glutathione peroxidase activity decreased significantly (p < 0.05) even though at 60th as compared with 0th min and remained decreased at 120th min. Total antioxidant status was found to be increased (p < 0.05) at 120th as compared with 0th min. The observed dynamic in patients did not differed (p > 0.05) from control group. The study shows a decrease in antioxidant enzyme activity and a compensatory increase in total antioxidant status, indicating a surcharge of antioxidant homeostasis. In context of carbohydrate and lipid disturbances in metabolic syndrome, this is to suggest an existing of complementary pathogenic mechanisms, able to aggravate cardiovascular risk in these patients. Correction of metabolic disturbances may be an efficacious tool for influencing on prooxidant-antioxidant homeostasis too.
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PMID:[Antioxidant parameters in metabolic syndrome -- a dynamic evaluation during oral glucose tolerance test]. 1200 76

Stroke is one of the major causes of morbidity and mortality in recent. Oxygen free radicals produced during cerebral infarction increases the damage to neurons. Superoxide dismutase (SOD) is the endogenous antioxidant enzyme that can effectively scavenge superoxide radicals. Catechin is a hydrophilic antioxidant usually existed in tea, fruits and vegetables. In the cultured rat brain astrocytes (RBA), the activity of SOD (both Cu, Zn-SOD and Mn-SOD subtypes) was markedly increased by incubation with catechin at low concentration (0.1 microM) for 2 days (short-term) and 7 days (long-term). This stimulatory effect of catechin was not related to the incubating concentration. Similar changes were also observed in the gene expression of SOD in RBA. The increase in quantity of SOD-messenger RNA was remarkable and seemed to be more obvious than the other antioxidants such as vitamin E. This result shows that catechin is an effective antioxidant to increase the activity of SOD in RBA which would be beneficial to neurons subjected to oxygen free radical damage.
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PMID:Effect of catechin on the activity and gene expression of superoxide dismutase in cultured rat brain astrocytes. 1214 26

The purpose of this study was to examine the change in lipid peroxidation and antioxidant enzyme activities in healthy subjects and to evaluate the concentrations of superoxide dismutase, glutathione peroxidase and malondialdehyde, an end product of lipid peroxidation in exercise and smoking. Study included 257 appearently healthy individuals, 133 males and 124 females. In all subjects, malondialdehyde (MDA) levels were analyzed as an indicator of the lipid peroxidation activities. Superoxide dismutase, glutathione peroxidase activities were measured as an indicator of antioxidant activities. Oxidative stress was estimated by the method based on thiobarbituric acid reactivity. Erythrocyte superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities were estimated on hemolysates by use of commercial available kits (Randox lab., Dublin, Ireland). For all groups serum lipid peroxidation and erythrocyte SOD and GSH-Px were obtained at the initial and the following periods. Serum MDA level was higher in the elderly than in the children and in the adults. MDA levels were higher in the smoking, acute exercise than their counterparts in the control groups. GSH-Px activity was significantly lower in the acute exercise group, and higher in the trained group than those as controls. SOD decreased in the elderly, smoking and acute exercise groups and increased in trained individuals. There was a significant increase in lipid peroxidation activity and a significant decrease in antioxidant enzyme activity in cases of acute exercise and smoking as well as the elderly.
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PMID:Lipid peroxidation and antioxidant enzymes in Turkish population: relation to age, gender, exercise, and smoking. 1223 85

The oxidative effects of ultraviolet A (UVA) light (320-400 nm) and the antioxidant effects of quercetin were examined in rat blood. For this purpose, rats were divided into three groups: control, ultraviolet (UV) and ultraviolet + quercetin (UV + Q). The UV and UV + Q groups were irradiated for 4 h a day with UVA light (1.25 mW cm(2)) during periods of 3, 6 and 9 days. Quercetin (50 mg kg(-1) body wt.) was administered intraperitoneally in the UV + Q group rats before irradiation periods. Blood was taken 3, 6 and 9 days post-treatment. Plasma malondialdehyde (MDA) levels significantly increased after 9 days of daily exposure to UVA. Whole blood glutathione (GSH) levels significantly declined after 3-9 days of irradiation. Glutathione peroxidase activity on days 6 and 9 and glutathione reductase activities on days 3, 6 and 9 post-irradiation were diminished significantly. Superoxide dismutase and catalase activities decreased significantly 3-9 days post-irradiation. The administration of quercetin before the 9-day period of irradiation significantly reduced the increase in plasma MDA value. Whole blood GSH levels significantly decreased with the administration of quercetin on all days. Quercetin significantly increased antioxidant enzymes diminished by UVA irradiation. Exposure of rats to UVA light leads to oxidative stress, reflected by increased MDA and reduced antioxidant enzyme levels. The administration of quercetin appears to be a useful approach to reduce the damage produced by UVA radiation.
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PMID:Protective effects of quercetin on ultraviolet A light-induced oxidative stress in the blood of rat. 1235 59

Olive oil, the main fat component of the Mediterranean diet, has been found to be protective against oxidative stress and could be beneficial in inflammatory and gastrointestinal disorders. First-pressed, extra-virgin olive oil (EVOO) has appreciable amounts of powerful antioxidants such as polyphenolic compounds that prevent its autoxidation and are responsible for its high stability. The aim of the present study was to determine whether diets supplemented with EVOO could reduce the severity of indomethacin-induced gastric oxidative damage and also to study changes in the activities of certain oxidative stress-related enzymes such as xanthine oxidase, myeloperoxidase as a marker of neutrophil infiltration, and the antioxidant enzyme superoxide dismutase. Lipid peroxidation and possible modifications in gluthatione metabolism were also studied. Weanling rats were maintained on semisynthetic diet for 6 weeks; a standard diet containing 5% (w/w) of fat as control or EVOO supplemented diets (5% and 20% w/w). Gastric lesions were induced on the last day by oral administration of indomethacin (60 mg/kg body wt). In animals fed EVOO diets, gastric lesions were decreased significantly and in parallel with dietary fat, when compared to animals consuming a standard diet. These protective effects were related to a reduction of lipid peroxides generation, neutrophil infiltration, and xanthine oxidase activity. Superoxide dismutase, an important enzyme to scavenger of lipid peroxides, was unaffected by feeding conditions. On the other hand, dietary supplementation with EVOO significantly increased both glutathione peroxidase activity and total glutathione content. In conclusion, this study provides evidence that fat diets containing EVOO reduces indomethacin-induced gastric damage in rats. This effect may be partly due not only to reducing oxidative stress and neutrophil-induced toxicity but also to enhancing the glutathione antioxidant defense system.
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PMID:Extra-virgin olive oil-enriched diets reduce indomethacin-induced gastric oxidative damage in rats. 1249 2

The stratum corneum, as the body's principal barrier to the environment, is continuously exposed to environmental sources of reactive oxygen species like ultraviolet light, ozone, and pollution. Reactive oxygen species are believed to be involved in cancer, aging, and inflammatory skin disorders. We have developed a method to measure catalase and superoxide dismutase activity on tape strippings from the human stratum corneum and demonstrated a gradient of antioxidant enzyme activity across the stratum corneum with decreasing levels towards the skin surface. Sun exposure resulted in a seasonal variation of the catalase activity in stratum corneum, with low activities in summer and higher activities in winter for the same person, whereas superoxide dismutase activity in stratum corneum did not seem to vary in those conditions. Exposure of human skin to broadband ultraviolet-A resulted in a dose-dependent deactivation of the catalase activity in stratum corneum within 24 h, whereas exposure to ultraviolet-B had no effect. Superoxide dismutase activity in stratum corneum was not affected by ultraviolet-A or ultraviolet-B irradiation within 24 h. After exposure to a dose of 15 J per cm2 broadband ultraviolet-A, full recovery of the catalase activity occurred in 3-4 wk at an age-dependent rate. We conclude that sun exposure results in a disturbed catalase to superoxide dismutase ratio in the stratum corneum. This may lead to an increased vulnerability to oxidative damage in stratum corneum barrier components. These results therefore stress the importance of providing efficient protection for this internal defense mechanism in sun-exposed areas of the skin.
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PMID:Antioxidant enzyme activity in human stratum corneum shows seasonal variation with an age-dependent recovery. 1260 57

The effect of sulfur dioxide (SO2) on brain antioxidant status, lipid peroxidation, and somatosensory evoked potentials (SEPs) was investigated in diabetic rats. A total of 40 rats were divided into 4 equal groups: control (C), SO2 + C (SO2), diabetic (D), and SO2 + D (DSO2). Experimental diabetes mellitus was induced by i.v. injection of alloxan at a dose of 50 mg/kg body weight. Ten ppm SO2 was administered to the rats in the sulfur dioxide groups (SO2 and DSO2) in an exposure chamber. Exposure occurred 1 hr/day, 7 days/wk, for 6 wk; control rats were exposed to filtered air during the same time periods. Although SO2 exposure markedly increased copper, zinc Superoxide dismutase activity, it significantly decreased glutathione peroxidase activity in both the diabetic and nondiabetic groups, compared with the C group. Brain catalase activity was unaltered; however, brain thiobarbituric acid reactive substances (TBARS) were elevated in all experimental groups with respect to the C group. SEP components P1, N1, P2, and N2 were significantly increased in all experimental groups, compared with the C group, and these components were also prolonged in the DSO2 group with respect to the other groups. The authors' findings suggest that exposure to SO2, because it increases lipid peroxidation, can change antioxidant enzyme activities and affect SEP components in diabetic rats.
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PMID:Changes in somatosensory evoked potentials, lipid peroxidation, and antioxidant enzymes in experimental diabetes: effect of sulfur dioxide. 1274 14

Recent studies documented that estrogen have antioxidant properties in-vitro, there are conflicting results on the effect of estrogen in vivo. We aimed to investigate the effects of estradiol and Raloxifene on the antioxidant enzyme [superoxide dismutase (SOD) and catalase (CAT)] activities and MDA levels in brain and liver homogenates of ovariectomized female rats. Twelve weeks after ovariectomy, female Sprague-Dawley rats (n = 26) were divided into three groups: (1) Ovariectomized placebo group (n = 6) was given physiologic saline. (2) Estrogen group (n = 10) was given Ethynyl estradiol, 0.1 mg/kg sc. (3) Raloxifene group (n = 10) was given raloxifene, 1 mg/kg sc during 8 weeks. Ten rats were used as naive controls without any treatment (Sham operated group, n = 10). Ovariectomy lead to an increase in the CAT activities in liver tissue samples compared to the sham group (p = 0.056, Mann-Whitney test). While estrogen treatment reversed to normal levels of CAT activities, raloxifene remained as ineffective. Superoxide dismutase activities and MDA levels in liver were remained unchanged in all groups. There was no significant change in the brain tissue SOD and CAT activities between the control ovariectomy, estrogen treated, and raloxifen treated groups. We determined an increase in MDA levels in brain of ovariectmised rat (p = 0.02). While raloxifene treatment reversed to normal levels of MDA (p = estrogen treatment failed. Our data showed that estrogen may play a role in regulation of CAT and SOD activities in liver due to its antioxidative effects. We can suggest estrogen and raloxifene exert their antioxidative effects in brain rather than liver. Since Raloxifene's effect is more clear than estradiol, raloxifene may be suggested primarily for treatment and/or prevention of diseases which can be resulted from oxidative stress in postmenopausal women.
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PMID:The effects of estrogen and raloxifene treatment on antioxidant enzymes in brain and liver of ovarectomized female rats. 1285 5

Plasma vitamin A, C and E levels and erythrocyte antioxidant enzyme activities were investigated in type I and type II diabetic subjects with and without complications, i.e., hypertension, coronary artery disease and renal failure. Reverse phase HPLC was used to quantify vitamin A and E levels. We observed that the vitamin C levels were not significantly different between control and diabetic subjects. However, vitamin A and E levels were significantly lower in type I and type II diabetic subjects compared to controls. Superoxide dismutase (SOD) activity was significantly lower in type II, but not in type I, diabetic patients compared to controls. Interestingly, glutathione reductase and peroxidase activities were diminished in type I, but not in type II, diabetic subjects as compared to controls. Catalase activity was lower in both types of diabetic patients in comparison with their respective controls. Altogether these results suggest that diabetes mellitus may be associated with altered antioxidant status regardless to various complications.
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PMID:Antioxidant status and levels of different vitamins determined by high performance liquid chromatography in diabetic subjects with multiple complications. 1287 Jun 98


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