• Food Science of Animal Resources
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• v.40 no.3
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• pp.338-349
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• 2020

The effects of organic Zn-L-selenomethionine (Zn-L-SeMet) at 0.3 ppm on carcass composition, meat characteristics, fatty acid composition, glutathione peroxidase activity, and ribonucleotide content were compared against the commercial inorganic sodium selenite (Na-Se) and the combination of the two, in commercial broilers. A total of 540 one day-old chicks were assigned at random to 3 dietary treatments : i) commercial inorganic selenium as control or T1, ii) a 1:1 ratio of inorganic and organic selenium as T2, and iii) organic selenium as T3. Carcass composition, meat characteristics, cholesterol content, fatty acid composition, and ribonucleotide content were generally unaffected by treatments. However, discrepancy were significantly observed in glutathione peroxidase activity (GSH-Px) and water holding capacity, with organic selenium showing higher glutathione peroxidase activity (p<0.01) and lower shrinkage loss (p<0.05), respectively. These findings could be explained by the contribution of organic selenium in bioavailability of GSH-Px. However, having conducted in a commercial close house system with sufficient amount of nutritional supplementation, the present study demonstrated little or no effects of organic Zn-L-SeMet on meat characteristics, fatty acid composition, and ribonucleotide content (flavor characteristic) in broiler chickens.

• The Korean Journal of Zoology
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• v.27 no.4
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• pp.221-230
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• 1984

The activities of aminopyrine demethylase which is marker enzyme of the microsomal drug-metabolizing system, NADPH-cytochrome a reductase and glutathione peroxidase were measured during the course of liver regeneration after about seventy percent hepatectomy in Wistar rats. In addition, the extent of lipid peroxidation and contents of cytochrome P-450 were also measured. Partial hepatectomy produced a significant depression in aminopyrine demethylase, to reach a minium about 24 hours after operation, but this activity was increased to normal value during regeneration. On the other hand, in sham-operated animals, this showed no change. All the activities of NADPH-chrome P-450 contents of liver microsomes were rapidly decreased at the early stage of regeneration. These values returned to normal after 7 days. By contrast, the activity of glutathione peroxidase was nearly unchanged. According to these results, at the early stage of regeneration, the decrease of cytochrome P-450 and NADPH-cytochrome c reductase activity lead to decrease of lipid peroxidation and drug metabolizing enzyme activity. But these phenomena were not detected after 7 days of regeneration.

• Applied Biological Chemistry
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• v.48 no.1
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• pp.53-59
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• 2005

The effect of various stressors such as reductant ascorbic acid, signalling molecules (salicylic acid and methyl jasmonic acid), heavy metals $(NiCl_2,\;and\;MnSO_4)$ and NaCl on the glutathione peroxidase (GPX) activities and isoenzyme expression patterns were investigated in rice seedling roots. Total GPX activity increased according to the increase of ascorbic acid concentration. Prominent enhancement of GPX1 isozyme due to ascorbic acid contributed to the increase of total GPX activity. GPX showed different reactivity toward salicylic acid and methyl jasmonic acid. GPX activity increased at 0.1 mM salicylic acid, and then decreased thereafter. However, GPX increased gradually in a methyl jasmonic acid concentration-dependent manner, and 3 fold increase of GPX activity was found at 1 mM methyl jasmonic acid. Moreover, GPX1 isozyme increased according to the increase of salicylic acid, while GPX1 isozyme decreased according to the increase of methyl jasmonic acid. When metal ions were treated, GPX activity increased considerably according to the increase of $NiCl_2$ concentration, however, GPX activity increased about 2 fold at 0.5 mM $CuSO_4$ and then decreased. Enhancement of GPX1 isozyme contributed to the increase of total GPX activities in $NiCl_2-treated$ and $MnSO_4-treated$ rice seedlings. Total GPX activity increased 1.7 fold in response to 300 mM NaCl. Especially GPX2 isozyme showed gradual increase according to the increase of NaCl concentration.

• Nutritional Sciences
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• v.3 no.1
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• pp.11-17
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• 2000

This study was intended to examine whether dehydroepiandrosterone (DHEA) and dietary fat level or source could modulate glutathione utilizing detoxifying system activity and the cytosolic NADPH generation in rat liver. Male Sprague-Dawley rats were fed semipurifed diet containing either 2%(w/w) corn oil (low level of corn oil diet: 5 ca% of fat) 15% corn oil (high level of corn oil diet: 31 cal% of fat) or 13% sardine oil plus 2% corn oil(high level of fish oil diet: 31 cal% of fat) for 9 weeks. Half of the rats in each diet group were fed a diet supplemented with 0.2% DHEA (w/w). DHEA administration increased plasma total cholesterol level in low corn oil diet-fed rats. The high fish oil diet significantly decreased plasma total cholesterol level compared to the high corn oil diet. Plasma triglyceride level was not significantly changed by DHEA administration and dietary fat level and source. Fasting plasma glucose level was increased by DHEA administration and fish oil diet. Glucose 6-phosphate dehydrogenase activity in liver tissue was significantly increased by DHEA administration and high fat diet, especially fish oil diet. Malic enzyme activity in liver tissue was significantly increased by DHEA administration and high fat diet, especially fish oil diet. Malic enzyme activity in liver tissue was significantly increased by DHEA administration. DHEA suppressed the glutathione peroxidase, glutathione-dependent enzymes compared to the low corn oil diet, while fish oil diet elevated the activity of glutathione peroxidase and glutathione reductase compared to corn oil diet. These results suggest that DHEA administration and high level of corn oil diet may suppress the cellular detoxifying system activity through reduction of glutathione utilization, while the fish oil diet did not show these effects.

• Journal of the Korean Society of Food Science and Nutrition
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• v.23 no.3
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• pp.429-435
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• 1994

The effect of methionine (Met) supplementation on glutathione peroxidase(GSHPx) activity in young and 14 month-old rat and mice was investigated. GSHPx activity was more enhanced by methionine supplementation in young rats when selenium (Se) was given as selenite than given in the form of selenomethione (Se-Met). However, GSHPx activity was not influenced by Met supplementation in the old rats. When diets were low in Se, the biopotency of ht eenzyme by Met was facilitated. No significant differences in GSHPx activity was observed with Met supplement in growing mice when Met was given 0.3% and 0.8% iin the diet at high levels of Se (2 ppm). The peak GSHPx in liver and kidney occurred at day 18, thereafter it decreased. Particularly, the liver GSHPx at day 18 increased 4.2 times than that at day 4 by 0.5% Met supplementation, while the unsupplemented group remained only 2.5 times increase. It is considered that in some tissues Met requirement may be met by Se-Met when rats were fed a diet suboptimal in Met. In addition, at lower levels of Se the utilization of Se is more enhanced by Met than at higher levels of dietary Se. Therefore, GSHPx activity may be influenced greatly by Met status along with dietary Se.

• The Journal of Internal Korean Medicine
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• v.19 no.1
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• pp.442-451
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• 1998

This study was carried out to examine mechanisms by which Holotrichia (HTC) produces protective effect against renal cell injury. HTC extraction (5%) prevented $H_2O_2(50mM)$-induced LDH release and lipid peroxidation in renal cortical slices. When slices were treated with 5% HTC extraction, cellular glutathione content and the superoxide dismutase activity were not altered in control and $H_2O_2$-treated tissues. When slices were treated with 50 mM $H_2O_2$, the catalase activity was significantly inhibited, which was completely restored by addition of 5% HTC. Treatment of slices with 5% HTC extraction increased the glutation peroxidase activity in $H_2O_2$-treated tissues. These results suggest that HTC prevents oxidant-induced cell injury and lipid peroxidation by increasing the activities of catalase and glutathione peroxidase in renal cortical slices.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.30 no.1
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• pp.73-77
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• 2004

Selenium containing peptide was produced by culturing yeast with selenium, Selenium was broadly incorporated in the various size of proteins based on the GPC analysis of the total yeast protein. The ratio of selenium to protein increased with the concentration of added selenium in the culture medium. Antioxidant activity (glutathione peroxidase-like activity) was proportional to the concentration of selenium concentration in the peptide. Different size of proteins were obtained by hydrolyzing the total yeast protein by protease XIV. Average molecular weight of selenium peptide was analyzed by GPC. Glutathione peroxidase (GPx) activity of the selenium peptide increased as the size of peptide decreased. Sodium selenite had strong inhibition on the yeast growth than sodium selenate. The ratio of selenium to protein was higher with sodium selenate than with sodium selenite. These results showed the potentials of selenium peptide production by yeast cultivation.

• Applied Biological Chemistry
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• v.43 no.1
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• pp.46-51
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• 2000

The resistance of Cornyza bonariensis to herbicide paraquat was investigated by evaluating the activities of three enzymes concerning in scavenging paraquat-generated toxic oxygen species such as superoxide radical and hydrogen peroxide in resistant and susceptible biotypes. Conyza bonariensis inhabited in cultivated area was more tolerant to paraquat than that of uncultivated area. This is the first report that a biotype of Cornyza bonariensis has appeared in an area with repeated paraquat treatments of Korea. Superoxide dismutase activity of resistant biotype was 20% higher as 150 than that of susceptible biotype. Ascorbate peroxidase activity of resistant biotype was 44% higher than that of susceptible biotype. Glutathione reductase activity of resistant biotype was 64% higher than that of susceptible biotype. It can be concluded from above results that the resistance of Conyza bonariensis to paraquat depends partially on the toxic oxygen species-scavenging efficiency of protective multienzymatic system which is composed of three enzymes, superoxide dismutase, ascorbate peroxidase, and glutathione reductase.

• BMB Reports
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• v.42 no.10
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• pp.648-654
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• 2009

Overexpression of phospholipid hydroperoxide glutathione peroxidase (PHGPx) genes has been reported to play an important role in protecting host cells from oxidative injury in several model systems. A radish phospholipid hydroperoxide glutathione peroxidase (RsPHGPx) known to have high catalytic activity was applied to mouse 3T3 fibroblasts to determine the protective effects of PHGPx against oxidative injury triggered by hydroperoxides such as hydrogen peroxide ($H_2O_2$), tert-butyl hydroperoxide (t-BHP) and phosphatidylcholine hydroperoxide (PCOOH). We observed that preincubation of cells with RsPHGPx significantly increased cell viability, reduced levels of malondialdehyde (MDA), inhibited generation of reactive oxygen species (ROS), and maintained natural cell shapes after treatment with $H_2O_2$, t-BHP or PCOOH, indicating that the exogenous RsPHGPx can act as an effective hydroperoxide-scavenger and may also protect target cells from oxidative damage. These results suggest the possibility for use of RsPHGPx as a therapeutic protectant.

• 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.