• Molecular & Cellular Toxicology
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• v.4 no.4
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• pp.300-306
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• 2008

We investigated high light-induced alterations in antioxidant enzymes by exposing green vegetative cells of the alga Haematococcus pluvialis to excess irradiance to induce the production of astaxanthin, a carotenoid pigment. Total activity of catalase decreased approximately 70% after high light exposure, whereas glutathione peroxidase (GPX) activity was slightly enhanced. Total activity of superoxide dismutase and ascorbate peroxidase (APX) also slightly decreased. Overall, we did not observe dramatically elevated levels of antioxidant isozymes, although APXn, GPX2, and GPX3 isozyme increased slightly. ${H_2}{O_2}$ content increased about sixfold after high light exposure, demonstrating severe cellular oxidative stress, whereas lipid peroxidation was notably reduced. Concomitantly, astaxanthin accumulation increased about sevenfold. This result suggests that probably massively accumulated astaxanthin may be one of the antioxidant protector against high light stress.

• Journal of Veterinary Clinics
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• v.29 no.2
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• pp.119-123
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• 2012

The present study evaluated the effects of different anesthesia techniques on oxidative stress in beagle dogs. Ten dogs were randomly assigned to either total intramuscular anesthesia with medetomidine-tiletamine/zolazepam (MTZ) combination (group T, 40 ${\mu}g/kg$ medetomidine and 2 mg/kg tiletamine/zolazepam) or volatile anesthesia with isoflurane (group I, 2% isoflurane and 100% oxygen). Heart rate, respiratory rate, and rectal temperature for vital signs and the concentration of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) for oxidative stress were measured. SOD activity decreased significantly from baseline anesthesia in both groups ($p$ < 0.05). CAT and GPx activities were also decreased significantly after anesthesia between both groups ($p$ < 0.05). CAT activity decreased significantly from baseline after anesthesia in both groups, but activities of group I were significantly higher compared with group T after anesthesia ($p$ < 0.05). GPx activity in group T decreased significantly from baseline after anesthesia, but activities of group I were significantly higher compare with that of group T 1 hour after the conclusion of anesthesia ($p$ < 0.05). In conclusion, general anesthesia seems to induce oxidative stress, and volatile anesthesia with isoflurane attenuates oxidative injuries in beagle dogs.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.2
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• pp.262-265
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• 2006

The antioxidative properties of lactobacilli originating from humans (Lactobacillus acidophilus KCTC 3111, Lactobacillus jonsonii KCTC 3141, Lactobacillus acidophilus KCTC 3151, and Lactobacillus brevis KCTC 3498) were investigated using in vitro methods, including inhibition of lipid peroxidation, resistance to hydrogen peroxide and hydroxyl radical, hydroxyl radical scavenging activity, and glutathione peroxidase (GPX) activity. L. acidophilus KCTC 3111 showed the highest inhibition of lipid peroxidation in both intact cells (49.7%) and cell lysate (65.2%). This strain exhibited resistance to hydrogen peroxide and hydroxyl radical, which was viable for 7 h in the concentration of 1.0 mM hydrogen peroxide. In addition, this strain showed high hydroxyl radical scavenging activity. In the GPX activity assay, the highest activity was measured in L. brevis 3498. GPX activity of L acidophilus 3111 was lower than that of L. brevis 3498.

• Molecules and Cells
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• v.21 no.2
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• pp.276-283
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• 2006

The potent environmental contaminant, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), induces thymus atrophy in experimental animals. However, its mechanism of action is not fully understood. To gain insight into its immunosuppressive effect, Balb/c mice were intraperitoneally injected with TCDD ($30{\mu}g/kg$ body weight) and genes regulated by TCDD were identified using cDNA arrays [Park and Lee (2002)]. One of the regulated genes was that for plasma glutathione peroxidase (pGPx). Upon TCDD injection, pGPx mRNA levels in the thymus increased, in parallel with increases in GPx activity and the frequency of anti-human pGPx antibody-reactive cells. pGPX mRNA levels were also moderately up-regulated in the testis and spleen. This is the first report that a particular isotype of the glutathione peroxidase family is regulated by TCDD at both mRNA and protein levels. pGPx is expressed in various tissues in contact with body fluids, and detoxifies hydrogen peroxides and lipid hydroperoxides. It will be of interest to assess the role of pGPx in TCDD-induced thymic atrophy.

• Journal of Microbiology and Biotechnology
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• v.33 no.3
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• pp.299-309
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• 2023

Glutathione peroxidases (Gpx) are a group of antioxidant enzymes that protect cells or tissues against damage from reactive oxygen species (ROS). The Gpx proteins identified in mammals exhibit high catalytic activity toward glutathione (GSH). In contrast, a variety of non-mammalian Gpx proteins from diverse organisms, including fungi, plants, insects, and rodent parasites, show specificity for thioredoxin (TRX) rather than GSH and are designated as TRX-dependent peroxiredoxins. However, the study of the properties of Gpx in the environmental microbiome or isolated bacteria is limited. In this study, we analyzed the Gpx sequences, identified the characteristics of sequences and structures, and found that the environmental microbiome Gpx proteins should be classified as TRX-dependent, Gpx-like peroxiredoxins. This classification is based on the following three items of evidence: i) the conservation of the peroxidatic Cys residue; ii) the existence and conservation of the resolving Cys residue that forms the disulfide bond with the peroxidatic cysteine; and iii) the absence of dimeric and tetrameric interface domains. The conservation/divergence pattern of all known bacterial Gpx-like proteins in public databases shows that they share common characteristics with that from the environmental microbiome and are also TRX-dependent. Moreover, phylogenetic analysis shows that the bacterial Gpx-like proteins exhibit a star-like radiating phylogenetic structure forming a highly diverse genetic pool of TRX-dependent, Gpx-like peroxidases.

• Korean Journal of Food Science and Technology
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• v.25 no.5
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• pp.517-520
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• 1993

As the pH of ground pork increased from 5.0 to 7.0, the corresponding development of 2-thiobarbituric acid reactive substance (TBARS) during storage at $4^{\circ}C$ decreased significantly (p<.001). At the 4th day of refrigerated storage, with the increase in pH of ground pork from 5.0 to 7.0, the release of free iron decreased significantly (p<.05) from 1.50 to .99 ppm. The decrease in free iron content of pH 7 pork well explains the decrease in TBARS absorbances. The fact that the addition of 2% ethylenediamine tetraacetic acid (EDTA) to pH 5 ground pork decreased the oxidative rancidity development (p<.001) strongly supported the above finding that the increased free iron content of pH 5ground pork catalyze the oxidation during storage. The activity of glutathione peroxidase (GPx) at the 4th day of refrigerated storage decreased significantly (p<.05) when the pH of ground pork decreased from 7.0 to 5.0. Both the lower free iron content and the higher activity of GPx were proved to be important factors in controlling the oxidative rancidity of high pH ground pork.

• Biomedical Science Letters
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• v.7 no.2
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• pp.71-77
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• 2001

To evaluate the effect of occlusive skin on the activity of cutaneous oxygen free radical metabolizing enzymes in rats, the dorsal skin was covered with closed glass chamber shaped petri dish, 46 mm in diameter and 10 mm in height and sealed by an adhesive. Five day-occluded group showed more increased activity of xanthine oxidase (XO) than that of control, and the activity of five day-occluded group was higher than that of ten day-occluded group. The activities of superoxide dismutase (SOD) and glutathione peroxidase (GPx) were significantly higher in ten day-occluded group than in control or five day-occluded group. All the more, five day-occluded group showed the decreasing tendency of SOD and GPx activities compared to those of control. On the other hand, the cerrous perhydroxide deposits were observed in the intercellular space of the stratum basale in five day-occluded group under the electronic microscope using a cytochemistry method. Futhermore, the degree of cerrous perhydroxide reaction was lower in ten day-occluded group than in five day-occluded group. In conclusion, the increased XO activity and the decreased SOD and GPx activities are likely to responsible far the accumulation of $H_2O_2$ in five day-occluded group.

• Journal of Nutrition and Health
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• v.44 no.2
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• pp.112-118
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• 2011

We investigated the selenium (Se) nutrition status in Korean infants. The mean serum Se concentration in infants was 66.9 ${\mu}g/L$, and it increased with increasing in infant age: 57.6 ${\mu}g/L$ at 0-5 months, 71.8 ${\mu}g/L$ at 6-11 months, and 75.5 ${\mu}g/L$ at 12-24 months. Serum glutathione peroxidase (GPx) activity also increased with infant age. Serum Se concentration in infants was positively correlated with serum GPx activity (r = 0.565, p < 0.01). At 0-5 months, human milk-fed infants tended to have higher Se concentrations and GPx activity than those of formula-fed infants, but the result was not significant. With the introduction of supplemental feeding at 6-24 months of age, serum Se concentration was not different between the groups. Therefore, human milk feeding seemed to be more appropriate for infant Se nutrition than infant formula feeding during the first 6 months of life, but supplemental feeding became more important later to maintain good Se nutrition status.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.spc1
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• pp.4-7
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• 2005

The pharmaceutical function of tocotrienol in rice bran was evaluated. Distinctive antioxidative effects by 1,1-diphenyl-2-picrylhydrazyl(DPPH) could be observed. Also, Superoxide Dismutase(SOD) and Glutathione Peroxidase(GPX) activities of the cultured cells such as human firbroblast and hepatocyte, were increased up to 2 fold by the treatment of tocotrienol. The effects on GPX activity were more evident than SOD activity, and the stimulation was up to 2 fold. The changes of gene expression patterns were examined by applying the cell extracts of fibroblast treated with the increasing concentrations of tocotrienol on two-dimensional gel electrophoresis(2-D gel electrophoresis). As the concentrations increasing, many proteins began to appear with the increasing amounts, while several proteins diminished or disappeared. From these results, tocotrienol was clearly shown to have abilities on protecting any oxidizing damages and stimulating anti-oxidizing activities of the organisms.

• Journal of Ginseng Research
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• v.26 no.3
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• pp.139-144
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• 2002

Pregnancy is a physiological state accompained by a high energy demand of many bodily functions and an increased oxygen requirement. Because of the increased intake and utilization of oxygen, increased levels of oxidative stress would be expected. So we observed the activities of the hepatic antioxidant enzymes from rat treated with total saponin from the red ginseng against free raicals produced in pregnant rats. The activity of superoxide dismutase (SOD) in the control group was slightly decreased during pregnancy, and SOD activity in total saponin treated group was not observed any siginificant change compared with the control group. The activities of glutathione peroxidase (GPX), glutathione reductase (GRD) and catalase in the control group have shown the decreasing tendency during pregnancy, whereas the activities of GRD and catalase in total saponin treated group showed significant increased tendency compared with the control group. GPX activity in total saponin treated group was slightly decreased tendnency compared with the control group. The activity of glutathione-S-transferase (GST) in the control group was increased to keep the state of homaeostasis tendency in pregnant rats. On the other hand, the activity of GST after total saponin treatment was increased than control group. Activity of all enzymes in the control group and total saponin treated group recovered the normal level after delivery of rats. In spite of the physiological changes in vivo, the inflaunce of total saponin on activaties of hepatic antioxidant enzyme in pregnant rats seems to be regulated the biological homeostatic adaptation mechanism which protects the maternal liver aganist oxygen induced toxicity