• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.2
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• pp.344-350
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• 1997

The present study was carried out to investigate the effects of zinc and vitamin E on the antioxidative defense mechanism in the liver of streptozotocin(STZ)-induced diabetic rats. Levels of blood glucose of STZ-diabetic rats were higher than that of control, but ZDM($ZnSO_{4}$ 10mg/kg injection+STZ) group was lower than those of DM(STZ injection) and EDM(vitamin E 400mg/kg diet+STZ) group. Levels of plasma insulin were lower in all three STZ-diabetic groups than those of control. Thiobarbituric acid reactive substances(TBARS) peroxide values(LPO) in liver were increased 2.3-fold in DM group compared with those of control, while LPG in ZDM group was lower than that of DM group, and EDM group had similar tendency compared with that of control. Reduced glutathione(GSH) contents of liver were decreased in DM group compared with those of control, but increased 2.3, 1.7-fold in ZDM and EDM groups, respectively, compared with those of DM group. Oxidized glutathione(GSSG) was increased in DM group compared with control and GSSG in ZDM and EDM group were lower than that of DM group. GSH/GSSG ratio had similar tendency compared with results of GSH. The activities of free radical scavenging enzymes such as superoxide dismutase, glutathione peroxidase and glutathione S-transferase were significantly decreased in DM group compared to those of control, but higher in ZDM and EDM groups than those of DM group. The metallothionein contents in liver and kidney were increased in DM and EDM groups were remarkably increased 20, 5.3-fold in ZDM group, compared with those of control.

• Toxicological Research
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• v.14 no.2
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• pp.177-181
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• 1998

Dithiocarbamate and mixed disulfide containing allyl functions were designed and synthesized as putative chemopreventive agents, i.e. N,N-diallyldithiocarbamate (DATC) and S-(N,N-diallyldithiocarbamoyl)-N-acetylcysteine (AC-DATC). DATC and AC-DATC were administered and the activities of cytosolic glutathione S-transferase (GST), glutathione reductase (GR) and microsomal N-nitrosodiethylamine (NDEA) deethylase were assayed in order to test the effects of these organosulfur com-pounds on the detoxification and metabolic activation system of NDEA. The amounts of hepatic glutathione (GSH and GSSG) was also determined. The administration of DATC to rats led to an increase in the activity of GR and to an inhibition of CYP2E1-mediated NDEA deethylation. AC-DATC induced the activity of GR and GST, increased the hepatic GSH content and inhibited the rate of NDEA deethylation. The level of GSSG was decreased as a consequence of the increased activity of GR. These effects may contribute to possible antimutagenic and anticarcinogenic action of the dithiocarbamates investigated.

• Toxicological Research
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• v.16 no.2
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• pp.133-139
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• 2000

This study was designed to evaluate the mechanism by which reactive nitrogen intermediates (RNI) induced the cytotoxicity of human doparminergic neuroblastoma SH-SY5Y cells. 3-Morpholino-sydnonimine (SIN-l), a donor of peroxynitrite (ONOO) and sodium nitroprusside (SNP), a donor of nitric oxide (NO) induced cell detachment and apoptotic death, as characterized by chromatin condensation, the ladder pattern fragmentation of genomic DNA and morphological nuclear changes. SIN-l also induced the activation of caspase 3-like protease in a time-dependent manner. Exogenous antioxidants, such as reduced glutathione (GSH), N-acetylcysteine (NAC), and selenium protected the cells from apoptotic death and reduced the activation of caspase 3-like protease by SIN-1. Furthermore, SIN-l directly reduced the intracellular levels of glutathione. Taken together, these data suggested that RNI including NO and peroxynitrite decrease the concentration of intracellular antioxidant such as GSH, which lead to the apoptotic death of human neuroblastoma SH-SY5Y cells.

• Analytical Science and Technology
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• v.22 no.3
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• pp.228-234
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• 2009

To gain further insight into herbicide detoxification of plant, we purified a glutathione S-transferase from Brassica oleracea (BoGST) and studied its substrate specificity towards several xenobiotic compounds. The BoGST was purified to electrophoretic homogeneity with approximately 10% activity yield by DEAE-Sephacel and GSHSepharose column chromatography. The molecular weight of the BoGST was determined to be approximately 23,000 by SDS-polyacrylamide gel electrophoresis and 48,000 by gel chromatography, indicating a homodimeric structure. The activity of the BoGST was significantly inhibited by S-hexyl-GSH and S-(2,4-dinitrophenyl)GSH. The substrate specificity of the BoGST displayed high activities towards CDNB, a general GST substrate and ethacrynic acid. It also exhibited GSH peroxidase activity toward cumene hydroperoxide.

• Journal of fish pathology
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• v.27 no.2
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• pp.115-125
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• 2014

The effects of waterborne arsenic (As) exposure on antioxidant defense were studied in liver and gills of tilapia, Oreochromis niloticus under thermal stress. Tilapia were exposed to different As concentrations (0, 200 and $400{\mu}g/L$) at three water-temperatures (WT; 20, 25 and $30^{\circ}C$) for 10 days. In antioxidant response, glutathione (GSH) levels, glutathione reductase (GR), glutathione peroxidase (GPx) and glutathione S-treansferase (GST) activities were significantly decreased depend on WT in the gills after As exposure. Also, the range of fluctuation in these enzymes activities was most significantly increased at $30^{\circ}C$ in the liver of tilapia exposed to As. The present findings suggest that a simultaneous stress by temperature change and As exposure could accelerate the alteration in antioxidant enzymes activities of tilapia.

• YAKHAK HOEJI
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• v.53 no.6
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• pp.314-320
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• 2009

We examined metabolic conversion of cysteine into glutathione (GSH) and taurine in rat liver under oxidative stress. Administration of tert-butylhydroperoxide (t-BHP) into the portal vein of male rats resulted in a rapid elevation of serum sorbitol dehydrogenase, alanine aminotransferase, and aspartate aminotransferase activities, which decreased gradually in 24 hr. Hepatic cysteine concentration was reduced in 3 hr, and recovered progressively, reaching a level greater than 200% of the normal value in 24 hr. GSH was increased both in liver and blood at 9 hr after t-BHP challenge, whereas hypotaurine or taurine was not altered. $\gamma$-Glutamylcysteine synthetase (GCS) activity was increased from 9 hr after t-BHP treatment, but protein expression of the GCS-heavy subunit was not changed in liver. Activity or expression of cysteine dioxygenase was not affected by t-BHP treatment. Taken together, these data show that an acute oxidant challenge to the rats may induce upregulation of cysteine availability and GCS activity, resulting in an enhancement of hepatic GSH synthesis, but the increased cysteine level does not stimulate taurine synthesis via cysteine sulfinate pathway. It is indicated that the regulation of GSH and taurine biosynthesis from cysteine is not solely dependent on the cysteine concentration in rat liver under oxidative stress.

• Bulletin of the Korean Chemical Society
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• v.28 no.5
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• pp.772-776
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• 2007

In order to study the role of residue in the active site of glutathione S-transferase (GST), Arg13 residue in human GST P1-1 was replaced with alanine, lysine and leucine by site-directed mutagenesis to obtain mutants R13A, R13K and R13L. These three mutant enzymes were expressed in Escherichia coli and purified to electrophoretic homogeneity by affinity chromatography on immobilized GSH. Mutation of Arg13 into Ala caused a substantial reduction of the specific activity by 10-fold. Km GSH, Km DCNB and Km EPNP values of R13A were approximately 2-3 fold larger than those of the wild type. Mutation of Arg13 into Ala also significantly affected I50 values of S-methyl-GSH that compete with GSH and ethacrynic acid, an electrophilic substrate-like compound. These results appeared that the substitution of Arg13 with Ala resulted in significant structural change of the active site. Mutation of Arg13 into Leu reduced the catalytic activity by approximately 2-fold, whereas substitution by Lys scarcely affected the activity, indicating the significance of a positively charged residue at position 13. Therefore, arginine 13 participates in catalytic activity as mainly involved in the construction of the proper electrostatic field and conformation of the active site in human GST P1-1.

• Analytical Science and Technology
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• v.12 no.1
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• pp.28-33
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• 1999

Glutathione(GSH) in biological samples was determined by high performance liquid chromatographic(HPLC) method with fluorescence detector(FLD) after monobromobimane(MBB) or 4-fluoro-7-sulfobenzofurazan(SBD-F) derivatization. The detection limit of $0.03{\mu}g/mL$ was obtained after MBB derivatization, derivative of MBB was about 200 times more sensitive than that of SBD-F. N-acetylcysteine was used as internal standard and tetrabutylammonium ion as counter ion for better separation. The determination by ion-pairing chromatography after MBB derivatization was characterized by linearity in the range between $0.08{\sim}8.33{\mu}g/mL$ with a good correlation coefficient of 0.998. By precision test appeared relative standard deviation at less than 5% at three different concentrations. This method can be used for the analysis of GSH in plasma and tissue.

• Herbal Formula Science
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• v.9 no.1
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• pp.355-366
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• 2001

Objectives : Oldenlandiae Diffusae herba has been used as a natural drug for tumor, inflammation and liver disease in traditional medicine. This study was performed in order to investigate the antioxidative effects of Oldenlandiae Diffusae herba methanol extract(ODHM) on acetaminophen induced acute liver injury in mice. Methods : In order to investigate the protective effect of ODHM on acute hepatic injury in vivo, ICR mice were pretreated with ODHM, and then treated with acetaminophen(500mg/kg). And the levels of LPO and glutathione(GSH), antioxidative enzyme activities were measured. The levels of LPO were measured by TBA method. And catalase activity was measured as the decrease in hydrogen peroxide absorbance at 240nm on spectrophotometer using 30mM hydrogen peroxide. Superoxide dismutase(SOD) was assayed by recording the inhibition of nitro blue tetrazolium reduction with xanthine and xanthine oxidase. Glutathione peroxidase(GPX) activity was determined by the modified coupled assay developed by Paglia and Lawrence. The reaction was started by addition of 2.2mM hydrogen peroxide as substrate. The change in absorbance at 340nm was measured for 1min on spectrophotometer. Glutathione-S-transferase(GST) activity was assayed with CDNB as substrate and enzyme activity of GST towards the glutathione conjugation of CDNB. And Total SH and GSH levels were measured. Results : In vivo study, LPO levels of acetaminophen treatment group were significantly higher than other groups. This increased level was significantly reduced by ODHM pretreatment. The acetaminophen treatment resulted in a decrease of catalase, GPX, SOD and GST activities. By contrast, ODHM pretreatment markedly increased compare to those of untreated groups. Total SH and GSH levels were reduced by of acetaminophen treatment, and ODHM pretreatment significantly increased GSH levels.

• Korean Journal of Pharmacognosy
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• v.32 no.4 s.127
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• pp.269-273
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• 2001

Ethanol extracts from Xanthii Fructus (XFE) and Prunellae Spica (PSE) were investigated for the effects on the induction of cancer chemoprevention-associated enzymes. The following effects were measured: (a) induction of quinone reductase (QR) (b) induction of glutathione S-transferase (GST) (c) reduced glutathione (GSH) level. XFE and PSE were potent inducers of quinone reductase activity in Hepa1c1c7 murine hepatoma cells. Glutathione levels were increased with XFE and PSE. In addition, glutathione S-transferase activity was increased with XFE. However, GST activity was not increased with PSE. These results suggest that XFE and PSE have chemopreventive potentials by inducing quinone reductase and increasing GSH levels.