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)

To protect tissues from damaging effects of reactive oxygen species (ROS), organisms possess enzymatic and non-enzymatic antioxidant systems. Cytosolic-enzyme catalase (CAT) is a component of the antioxidant defence system that reduces hydrogen peroxide (H(2)O(2)) to water (H(2)O). The aim of this study was to assess the variation of antioxidant enzyme CAT activity in brain, kidney and liver of adult male mice according to tissue-specific and temporal patterns within a 24-h period (12:12 L/D). The CAT activity was assayed at 4-h intervals. The Cosinor test programme was used to detect and confirm the best corresponding rhythm. In liver, the circadian rhythm of CAT was associated with ultradian components. The prominent circadian rhythm (with a period tau=24 h) showed a peak located at the middle of the dark phase, more precisely congruent with 17 HALO (Hours After Light Onset). In kidney, only a circadian rhythm of CAT was validated with a peak time located at congruent with 17 HALO. However, in brain, the time pattern of CAT activity showed two peak times at congruent with 1 and congruent with 17 HALO, illustrating the existence of an ultradian rhythm (with a period tau=12 h). The results showed significant organ differences with the highest activity in liver, compared with kidney (-89%) and brain (-98%). This might be related to several factors such as their respective physiological function, the risk of exposure to oxidative damage and the balance between synthesis and degradation of proteins during "normal metabolism". Moreover, CAT activity revealed differences in time-related changes across a 24-h period that were more obvious in peak levels between the three tissues.
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PMID:Catalase activity and rhythmic patterns in mouse brain, kidney and liver. 1704 2

Several environmental pollutants, including metals, can induce oxidative stress. So, the objective of this study was to evaluate the effects of arsenic (As(III), as As(2)O(3)) on the antioxidant responses in the polychaete Laeonereis acuta. Worms were exposed to two environmentally relevant concentrations of As, including the highest previously allowed by Brazilian legislation (50 microg As/l). A control group was kept in saline water (10 per thousand) without added metal. It was observed that: (1) a peak concentration of lipid peroxide was registered after 2 days of exposure to 50 microg As/l (61+/-3.2 nmol CHP/g wet weight) compared to the control group (43+/-4.5 nmol CHP/g wet weight), together with a lowering of the activity of the antioxidant enzyme catalase (-47 and -48%, at 50 or 500 microg As/l respectively) and a higher superoxide dismutase activity (+305% at 50 microg As/l with respect to the control group); (2) a lower conjugation capacity through glutathione-S-transferase activity was observed after 7 days of exposure to 50 microg As/l (-48% compared to the control group); (3) a significant increase in As concentration was verified after 1 week of exposure to both As concentrations (50 and 500 microg/l); (4) worms exposed to As showed a limited accumulation of related methylated As species and the levels of non-toxic As species like arsenobetaine (AsB) and arsenocholine (AsC) remained unchanged during the exposure period when compared with the controls. Overall, it can be concluded that As interfered in the antioxidant defense system of L. acuta, even at low concentrations (50 microg/l) that Brazilian legislation previously considered safe. The fact that worms exposed to As showed high levels of methylated As species indicates the methylation capability of L. acuta, although the high levels of inorganic As suggest that not all the administered As(III) (as As(2)O(3)) is completely removed or biotransformed after 7 days of exposure.
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PMID:Toxicological responses in Laeonereis acuta (annelida, polychaeta) after arsenic exposure. 1708 96

Goldfish (Carassius auratus) were exposed to a mixture of herbicides, namely atrazine, simazine, diuron, and isoproturon (ASDI) at a cumulative concentration of 50microg/l for 12 weeks. Control fish and exposed fish were sampled at 4, 8 and 12 weeks of exposure to observe the combined impact of herbicides on non-specific and specific mechanisms of immunity and antioxidant defenses. The antioxidant defenses were evaluated in haemopoietic organs and liver. ASDI-induced stress was reflected as a significant induction of superoxide (O(2)(-)) production in phagocytic cells of head kidney and spleen. In addition, plasma lysozyme activity was consistently high in the treatment group. Specific immunity was assessed by antibody titre responses following immunization of the fish with sheep red blood cells (SRBCs). Antibody titre was reduced throughout the period of observation in ASDI-treated fish. This reduction was found to be significant at week 4 (p<0.05). Herbicide-exposed fish showed reduced resistance against pathogen invasion but remarkable enhancement in lysozyme activity. The ASDI-induced oxidative stress in spleen, kidney and liver was reflected as a change in the antioxidant enzyme activities in these vital organs of fish. Our data indicate that herbicides at concentrations present in water bodies in Europe cause immune suppression in goldfish.
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PMID:Combined effects of herbicides on biomarkers reflecting immune-endocrine interactions in goldfish. Immune and antioxidant effects. 1719 91

In early reports our research group has demonstrated that 7 microM retinol (vitamin A) treatment leads to many changes in Sertoli cell metabolism, such as up-regulation of antioxidant enzyme activities, increase in damage to biomolecules, abnormal cellular division, pre-neoplasic transformation, and cytoskeleton conformational changes. These effects were observed to be dependent on the production of reactive oxygen species (ROS), suggesting extra-nuclear (non-genomic) effects of retinol metabolism. Besides 7 microM retinol treatment causing oxidative stress, we have demonstrated that changes observed in cytoskeleton of Sertoli cells under these conditions were protective, and seem to be an adaptive phenomenon against a pro-oxidant environment resulting from retinol treatment. We have hypothesized that the cytoskeleton can conduct electrons through actin microfilaments, which would be a natural process necessary for cell homeostasis. In the present study we demonstrate results correlating retinol metabolism, actin architecture, mitochondria physiology and ROS, in order to demonstrate that the electron conduction through actin microfilaments might explain our results. We believe that electrons produced by retinol metabolism are dislocated through actin microfilaments to mitochondria, and are transferred to electron transport chain to produce water. When mitochondria capacity to receive electrons is overloaded, superoxide radical production is increased and the oxidative stress process starts. Our results suggested that actin cytoskeleton is essential to oxidative stress production induced by retinol treatment, and electrons conduction through actin microfilaments can be the key of this correlation.
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PMID:Can electrons travel through actin microfilaments and generate oxidative stress in retinol treated Sertoli cell? 1720 41

Free radical-induced lipid peroxidation has been associated with numerous disease processes including diabetes mellitus. Glutathione-S-transferase (GST) catalyses the conjugation of glutathione with a variety of organic peroxides to form more water-soluble compounds. Glucose-6-phosphate dehydrogenase (G6PDH) is essential to control intracellular reductive potential by increasing glutathione intracellular levels, which in turn decrease the amount of reactive oxygen species. Glyburide decreases glucose production and enhances insulin action in liver. The aim of this study was to examine the effects of glyburide on the antioxidant enzyme activities in the liver tissue of diabetic rat. We investigated the activities of GST and G6PDH in the liver of both control and streptozotocin-induced diabetic rats. Forty male albino rats were included in this study. Liver GST and G6PDH activities decreased significantly in five-week diabetic rats (p<0.001 and p<0.001 respectively) compared to controls and glyburide therapy restored these activities (p<0.001 for GST and p<0.001 for G6PDH). Elevations of hepatic antioxidant enzymes with glyburide administration suggest that glyburide may directly alter hepatic enzyme activities.
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PMID:The effect of the sulfonylurea glyburide on glutathione-S-transferase and glucose-6-phosphate dehydrogenase in streptozotocin-induced diabetic rat liver. 1721 64

Recent studies have demonstrated that chronic cadmium administration induces oxidative stress. In the present study, we investigated the possible therapeutic effect of adrenomedullin, a potent antioxidant, in cadmium-induced morphological, ultrastructural and biochemical alterations. Two groups of rats were exposed to 100 ppm of CdCl(2) in drinking water for four weeks. One of these groups received 3000 ng/kg body weight of adrenomedullin (AdM) intraperitoneally during the last week. Hepatic oxidative stress markers were evaluated by changes in the amount of lipid peroxides and changes in the antioxidant enzyme activities, superoxide dismutase (SOD) and glutathione peroxidase (GPx) and glutathione reductase (GSH) levels. Hepatic damage score was significantly higher in Cd-administered rats than those of controls (p<0.005). Cd-induced ultrastructural changes in hepatocytes included focal parenchymal cell necrosis, dilatation of rough endoplasmic reticulum, proliferation of lysosomes and mitochondrial degeneration. Hepatic damage was accompanied by significant increase in tissue MDA level (p<0.05) and significant decrease in tissue GSH level (p<0.05), and SOD and GPx activities (p>0.05, p>0.005, respectively). Adrenomedullin failed to restore the light and electron microscopic, and biochemical changes. We conclude that although we administered a high dose of adrenomedullin, it failed to reduce cadmium-induced hepatic damage probably because of the irreversibility of Cd-induced hepatic injury.
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PMID:Adrenomedullin fails to reduce cadmium-induced oxidative damage in rat liver. 1726 95

The effect of the thyroid activity on the formation of lipid peroxidation and on liver and heart antioxidant enzyme activities was investigated in Wistar rats. Hypothyroidism and hyperthyroidism conditions were induced for five weeks by the administration of 0.05% benzythiouracile (BTU) and L-thyroxine sodium salt (0.0012%), in drinking water, respectively. No significant effect was observed on the rates of both lipid peroxidation and the vitamin E in hepatic and cardiac tissues of hypothyroidism rats compared to the controls, contrary to the hyperthyroidism rats, which expressed a pronounced increase. The increased glutathione peroxidase activity in rats suffering from hyperthyroidism was associated with a fall of the reduced glutathione in the homogenate and a marked increase in the glutathione reductase activity. An increase in superoxide dismutase and catalase activities was also recorded in hyperthyroidism. Our results explain the thyroid activity variation in relation to the lipid peroxidation and the tissular contents of the enzymatic and the non-enzymatic antioxidants. To conclude, our results show the occurrence of a state of oxidizing stress in relation to hyperthyroidism.
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PMID:The impact of thyroid activity variations on some oxidizing-stress parameters in rats. 1730 37

The aim of the present work was to determine the activities of selected antioxidant enzymes (SOD, Se-GPX, CAT) in two species of bivalves, Scapharca inaequivalvis and Tapes philippinarum, from two sites of the lagoon of Venice that are characterized by different pO(2) (Marghera and Chioggia). The specimens were collected at four times during a 1-year period. In the two species studied, enzyme activities were found to be present in both digestive glands and gills, but with some species-specific differences that may also represent a different adaptation to seasonal variations. The presence of high SOD activities in the gills of both species may be related to their physiological role in respiration. Scapharca inaequivalvis is less sensitive than T. philippinarum to environmental changes, perhaps due to the presence of hemoglobins in this species. Moreover, in the digestive gland of T. philippinarum we found a significant negative correlation between the activities of SOD and GPX that may indicate the presence of oxidative stress. Some correlations between temperature/dissolved oxygen and antioxidant enzyme activity were present in specimens sampled in Marghera. Only GPX adequately responded to changes in dissolved oxygen and temperature, while the decrease in the activity of SOD and CAT in winter may be directly responsible for an enhanced susceptibility of mussels to oxidative stress during this period. We can conclude that the observed differences between Chioggia and Marghera are due to different concentrations of dissolved oxygen. Marghera is an appropriate location to study seasonal variations in water temperature. In fact, in this site, the differences between hot and cold months are quite evident.
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PMID:Antioxidant responses to variations in dissolved oxygen of Scapharca inaequivalvis and Tapes philippinarum, two bivalve species from the lagoon of Venice. 1736 22

We investigated the shielding against solar ultraviolet radiation and inducible damage, as well as the short-term response of whole animal metabolic rate in two Antarctic shallow water amphipod species. Light absorbance by the carapace of Gondogeneia antarctica and Djerboa furcipes was higher in the UVR (UVB+UVA) range (42.1% and 54.5% on average respectively) compared to the PAR (photosynthetically active radiation) range (38.1% and 50.1% respectively) of the solar spectrum. Bands of higher absorbance correlated with maximal absorbance ranges of sunscreening compounds indicating mycosporine-like amino acids (MAAs) and carotenoids to be innate compounds of the exoskeleton of these species. Though the antioxidant enzyme catalase was photoinhibited, protein damage products did not accumulate under experimental exposure to a daily dose of 6.84 kJ m(-2) d(-1) UVB, 66.24 kJ m(-2) d(-1) UVA and 103.14 kJ m(-2) d(-1) PAR. Animal oxygen consumption during UV-exposure was measured as an indicator of immediate behavioural and physiological stress response. UVB as well as UVA induced a response with altered and highly variable respiratory intensity. Our findings indicate that sub-lethal UVR exposure causes increased oxygen consumption in polar amphipods due to radiation avoidance, shelter seeking behaviour, and presumably also from cellular repair processes.
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PMID:UV-tolerance and instantaneous physiological stress responses of two Antarctic amphipod species Gondogeneia antarctica and Djerboa furcipes during exposure to UV radiation. 1737 98

Present study has been carried out to evaluate the protective and curative roles of a 43kD protein isolated from the herb Cajanus indicus L. on sodium fluoride (NaF) induced toxicity in mice erythrocytes. In the preventive study, mice were divided into five groups consisting of six in each for the experiments. Group I animals got water and used as normal controls, animals of groups II and IV were exposed to 600ppm fluoride in water for 7 days. Animals of group III were treated with the protein (2mg/kg body weight) intraperitoneally for 7 days followed by NaF treatment for next 7 days (600ppm). Animals of group V were treated with NaF (600ppm) followed by the protein treatment (2mg/kg body weight) for the same time as mentioned for group III. In the curative study, four groups of six mice were compared. Erythrocytes were isolated, and the antioxidant enzyme superoxide dismutase (SOD) as well as the levels of reduced and oxidized glutathione (GSH and GSSG), total thiols and lipid peroxidation end products were measured in those cells. There was a significant increase in lipid peroxidation along with a decrease in total thiols and SOD activity in the erythrocytes of NaF only and NaF bovine serum albumin treated animals. The 43kD protein treatment in animals either prior or post to fluoride administration normalized the levels of parameters measured and restored the SOD activity in mice erythrocytes. Data suggest that the 43kD protein possesses significant protective and curative activity against NaF induced oxidative stress in erythrocytes.
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PMID:A 43kD protein from the herb, Cajanus indicus L., protects against fluoride induced oxidative stress in mice erythrocytes. 1740 99


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