• Korean Journal of Environmental Biology
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• v.39 no.3
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• pp.354-361
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• 2021

Understanding the phytotoxic mechanism of methyl bromide (MB), an essential fumigant during the quarantine and pre-shipment process, is urgently needed to ensure its proper use and reduce international economic losses. In a previous study, two main MB-induced toxic mechanisms such as reactive oxygen species (ROS) and auxin distribution were selected by analyzing transcriptomic analysis. In the study, a 3-week-old A. thaliana was supplied with 1 mM ROS scavengers [N-acetyl-L-cysteine (NAC) or L-glutathione (GSH)] and 1µM indole-3-acetic acid(IAA) three times every 12 h, and visual and gene expression assessments were performed to evaluate the reduction in phytotoxicity by supplements. Phytotoxic effects on the MB-4h exposed group were decreased with GSH application compared to the other single supplements and a combination of supplements at 7 days post fumigation. Among these supplements, GSH at a concentration of 1, 2, and 5mM was suppled to A. thaliana with MB-fumigation. During a long-term observation of 2 weeks after the fumigation, 5 mM GSH application was the most effective in minimizing MB-induced phytotoxic effects with up-regulation of HSP70 expression and increase in main stem length. These results indicated that ROS was a main key factor of MB-induced phytotoxicity and that GSH can be used as a supplement to reduce the phytotoxicity of MB.

• Bulletin of the Korean Chemical Society
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• v.24 no.8
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• pp.1188-1192
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• 2003

In order to study the role of residue in the active site of glutathione S-transferase (GST), Tyr 108 residue in human GST P1-1 was replaced with alanine, phenylalanine and tryptophan by site-directed mutagenesis to obtain mutants Y108A, Y108F and Y108W. These three mutant enzymes were expressed in Escherichia coli and purified to electrophoretic homogeneity by affinity chromatography on immobilized GSH. The substitutions of Tyr108 significantly affected $K_m^{CDNB}$ and $K_m^{ETA}$, whereas scarcely affected $K_m^{GSH}$. The substitutions of Tyr108 also significantly affected $I_{50}$ of ETA, an electrophilic substrate-like compound. The effect of these substitutions on kinetic parameters and the response to inhibition suggests that tyrosine 108 in hGST P1-1 contributes to the binding of the electrophilic substrate and a major determinant in the binding of CDNB is the aromatic ring of Tyr108, not its hydroxyl group.

• Journal of Microbiology and Biotechnology
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• v.10 no.6
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• pp.851-857
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• 2000

The activities of phase II and antioxidant enzymes in the liver, lung, kidney, stomach, and colon of mice were examined following intragastric application of polysaccharides extracted from soybeans fermented with either Agrocybe Cylindracea (AC) or Phellinus ignarius (PI). The intragastric application of the extracts to mice for 14 days significantly increased the activities of quinone reductase (QP) and glutathione S-transferase (GST) in the liver and kidney, glutathione (GSH) and superoxide dismutase (SOD) in the liver, kidney, lung, and stomach, and glutathione peroxidase (GSH-Px) in the liver, lung, and kidney. In general, the elevation of the phase II and antioxidant enzymes activities was more pronounced in the liver and kidney as compared to the lung, stomach, and colon. Accordingly, these finding suggest that polysaccharides extracted from soybeans fermented with A. cylindracea or P. igniarius have a cancer chemopreventive potential in various target organs.

• Natural Product Sciences
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• v.15 no.3
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• pp.156-161
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• 2009

Rubus coreanus, commonly known as 'red raspberry' is used as a traditional oriental medicine in Korea for the management of diseases such as impotence, spermatorrhea and athsma, and for allergies, in combination with other herbal preparations, in many centuries. We undertook a comparison of the hepatoprotective effect of ethanol extracts of the unripe (UREx) and ripe (RREx) R. coreanus extract against acetaminophen (AAP) induced hepatotoxicity in rats. UREx reduced the elevated alanine aminotransferase (ALP), aspartate aminotransferase (AST), total bilirubin (TB), alkaline phosphatase (AP), lipid peroxide and nitric oxide content which had been increased by AAP administration. UREx also increased the cellular glutathione (GSH) content and induced the glutathione-S-transferase (GST), glutathione peroxidase (GSH-Px) content which had been decreased by AAP. RREx did not exhibit strong hepatoprotective effect or antioxidant activity under the same conditions. The experimental results show that the degree of the ripening of R. coreanus affects the hepatoprotective activity in the AAP-intoxicated rats. These findings of a protective mechanism are supportive evidence for the utility of unripened R. coreanus in traditional medicine for liver ailments.

• Toxicological Research
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• v.18 no.2
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• pp.159-165
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• 2002

Recently, we reported (korean J. Biomed. Lab. Sci., 6(4): 245-251, 2000) that cyclohexane (l.56 g/kg of body wt., i.p.) administration led to lung injury in rats. However the detailed mechanism remain to be elucidated. This study was designed to clarify the mechanism of lung damage induced by cyclohexane in rats. First, lung damage was assessed by quantifying bronchoalveolar lavage fluid (BAL) protein content as well us by histopathological examination. Second, activities of serum xanthine oxidase (XO), pulmonary XO and oxygen free radical scavenging enzymes. XO tope conversion (O/D + O, %) ratio and content of reduced glutathione (GSH) were determined. In the histopathological findings, the vasodilation, local edema and hemorrhage were demonstrated in alveoli of lung. And vascular lumens filled with lipid droplets, increased macrophages in luminal margin and increased fibroblast-like interstitial cells in interstitial space were observed in electron micrographs. The introperitoneal treatment of cyclohexane dramatically increased BAL protein by 21-fold compared with control. Cyclohexane administration to rats led to a significant rise of serum and pulmonary XO activities and O/D + O ratio by 47%,30% and 24%, respectively, compared witれ control. Furthermore, activities of pulmonary oxygen free radical scavenging enzymes such as superoxide dismutase, glutathione peroxidase and glutathione S-transferase, and GSH content were not found to be statistically different between control and cyclohexane-treated rats. These results indicate that intraperitoneal injection of cyclohexane to rats may induce the lipid embolism in pulmonary blood vessel and lead to the hypoxia with the ensuing of oxygen free radical generation, and which may be responsible for the pulmonary injury.

• Korean Journal of Acupuncture
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• v.19 no.2
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• pp.51-56
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• 2002

Induction of phase II enzymes such as quinone reductase (QR) and glutathione S-transferase (GST) is considered a major mechanism of protection against initiation of carcinogenesis. The present study was performed to evaluate the chemopreventive activity of Acori Graminei Rhizoma aqua-acupuncture solution (AGRAS) and Acori Graminei Rhizoma water-extracted solution (AGRWS) by measuring the induction of phase II enzymes. AGRAS and AGRWS are potent inducers of quinone reductase activity in murine hepatoma Hepa1c1c7 cells. The levels of GSH and GST was increased sightly with AGRAS and AGRWS. These results suggest that AGRAS and AGRWS may act as blocking agents against carcinogenesis by induction of phase II enzymes.

• Preventive Nutrition and Food Science
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• v.8 no.2
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• pp.158-161
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• 2003

This study investigated the effects of a ${\gamma}$-irradiated pork (0-30 kGy) diet on lipid peroxidation, cytochrome P-450 content, microsomal glucose 6-phosphatase (G-6-Pase) activity and antioxidative defense systems in diethylnitrosamine (DEN)-induced rat hepatocarcinogenesis. The body weight of rats fed irradiated diets did not change significantly. Liver weight was significantly increased by the administration of DEN, but not by irradiated diets at any dose level. There were no significant effects of gamma irradiation on the content of microsomal malondialdehyde (MDA), cytochrome P-450, or on the activity of G-6-Pase. However, with DEN treatment, cytochrome P-450 content was significantly increased while microsomal G-6-Pase activity was significantly decreased. The ${\gamma}$-irradiated diet supplement did not affect serum retinol or $\alpha$-tocopherol concentrations. However, it did cause a significant decrease in hepatic retinol at 30 kGy. With DEN treatment, hepatic retinol content was even more significantly (p<0.05) decreased compared to the non-irradiated control. The enzyme activities related to antioxidative defense systems, including glutathione peroxidase (GSH-Px), glutathione reductase (GSH-Rx) and glutathione S-transferase (GST) were not affected by gamma irradiation. Those results suggest that an irradiated pork diet up to 30 kGy may not cause a health hazard in experimental animals.

• BMB Reports
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• v.33 no.6
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• pp.514-518
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• 2000

Two open reading frames of Haemophilus influenzae, HI0572 and HI0751, showing homology to a yeast thioredoxin peroxidase II (TPx II) and an E. coli thiol peroxidase $P_{20}$, respectively, were cloned and expressed in E. coli, and then the proteins were subsequently purified and characterized. HI0751 protein showed the thioredoxin (Trx)-dependent peroxidase activity, whereas HI0572 protein showed glutathione-dependent peroxidase. The HI0572 is the first peroxiredoxin with glutathione peroxidase activity rather than thioredoxin peroxidase. Purified HI0572 and HI0751 proteins protected specifically the inactivation of glutamine synthetase by metal catalyzed oxidation (MCO) systems composed of $Fe^{3+}$, $O_2$ and mercaptans such as dithiothreitol, ${\beta}-mercaptoethanol$ and glutathione (GSH). Unlike the HI0751 protein, the HI0572 protein was more effective in protecting glutamine synthetase from inactivation by the $GSH/Fe^{3+}/O_2$ system. It seems that these unique properties of the HI0572 protein are due to the structure containing a glutaredoxin domain at it's C-terminal in addition to a peroxiredoxin domain.

• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.4
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• pp.537-541
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• 1995

This study was designed to investigate the effects of methionine(Met) on the activities of heart lipid peroxidation related enzymes in ethanol administrated rats. Male Sprague-Dawley rats were fed on diets containing one of the three levels of Met(0%, 0.3%, 0.9% of kg diet) and ethanol(2.5g/kg of body weight) was administrated as 25v/v% ethanol to ethanol treated groups orally. The rats were sacrificed after 5 and 10 weeks of feeding. Xanthine oxidase(XO) and catalase activities increased with ethanol administration and those activities were higher n Met excessive and deficiency group than those of Met normal group at 5 and 10 weeks dieting. Superoxide dismutase(SOD) activity in heart decreased significantly in Met deficiency and Met excessive group as compared to that of control. Glutathione peroxidase(GSH-Px) activity in heart significantly decreased in Met deficiency group as compared to that of Met excessive and normal group. Glutathione S-transferase(GST) activity of heart tissue significantly increased by ethanol administration. Glutathione(GSH) content in heart decreased with ethanol administration and shwoed no significant differences with Met levels. Ethanol administration increased the content of lipid peroxide(LPO).

• The Korean Journal of Food And Nutrition
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• v.7 no.4
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• pp.373-382
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• 1994

This study was observed the effect of n6 and n3 polyunsaturated fatty acids of dietary corn oil and fish oil which was supplemented with similar levels of tocopherol in high fat diet on the levels of tocopherol, malondialdehyde ( MDA) productions of plasma and tissues of rats. Also RBC hemolysis, superoxide dismutase (SOD) and glutathione peroxidase (GSH Px) activities In liver were determined. Male Sprague Dawley rats were fed high fat (40%Cal) diet which was different only In fatty acid composition for 6 weeks. Dietary (arts were beef tallow(BT) as a source of saturated fatty acid, corn oil(CO) for n6 linoleic acid (LA) and fish oil(FO) for n3 eicosapentaenoic acid(EPA) + docosahexaenoic acid (DHA). Plasma and liver tocopherol levels were lowered by n3 PUy4 but there was no difference in malondialdehyde(MDA) level by different dietary PUFA. However, MDA content of RBC and hemolysis were increased by n3 PUFA. MDA content, superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities in liver were increased in more unsaturated dietary fat groups. Especially, SOD activity was increased in proportion to the degree of fat unsaturation.