• Journal of Life Science
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• v.14 no.1
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• pp.141-147
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• 2004

In this study, we investigated the effect of Teminalia Chebula (TC) water extract on liver in Rat. Treatment of TC water extract was orally administered 200, 300 mg/kg daily for one week and two weeks. The clinical parameters of serum, values of AST, ALT showed significantly higher than in normal group. Xanthine oxidase and aldehyde oxidase activities were significantly increased comparison with normal group. Microsomal enzymes, aminopyrine N-demethylase and aniline hydroxylase were not affected. Water extract of TC also increased hepatic rnalondialdehyde formation and reduced glutathione content. We also found that water extract of TC decreased activities of glutathione S-transferase and glutathione reductase but was not affected activities of $\gamma$-glutamylcysteine synthetase Thus, it seems that the water extract of TC induced decrease of oxygen free radical scavenger, glutathione content by inhibition of glutathione reductase which may reform oxidized glutathione to reduced glutathione.

• Journal of Yeungnam Medical Science
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• v.12 no.1
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• pp.32-47
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• 1995

Glutathione(GSH) has a very important role in detoxification of cells and is closely related to antitumor drug-resistance of cancer cells. In order to evaluate the importance of glutathione metabolism in the drug-resistant cancer cells, the concentration of celluar GSH and activities of ${\gamma}$-glutamylcysteine synthetase(GCS), ${\gamma}$-glutamyl transpeptidase (GGT) and glutathione S-transferases(GST) in the adriamycin, vincristine, or cisplatin resistant L1210 (L1210AdR, L1210VcR, or L1210Cis) sublines were measured. Expression and amplification of GCS, GGT, and GST-${\pi}$ genes were also observed in the parent Ll210 and the drug-resistant Ll210 sublines. The concentration of GSH was increased 5.34 fold in L1210Cis, 2.83 fold in L1210VcR, and 1.78 fold in L1210AdR, compared to L1210. The activities of GCS and GGT were increased in drug-resistant L1210 sublines. The GST activity was increased in L1210VcR and L1210Cis but decreased in L1210AdR compared to Ll210. Expression of GCS, GGT, and GST-${\pi}$ genes were increased in the resistant L1210 sublines compare to the parent L1210 in northern blot analyses. Overexpression of GCS, GGT, and GST-${\pi}$ were observed in the resistant sublines, and the increases of the concentration of glutathione and the activities of GCS and GGT in the resistant sublines may be involved in a part of the drug-resistance in the resistant sublines.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.3
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• pp.448-452
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• 2000

실험동물에서 곰피로부터 분리한 phlorglucinol은 acetaminophen의 투여로 현저히 증가된 간조직에 있어서 지질과선화의 함량을 억제하였다. Acetaminophen 투여에 따른 간 cytochrome P-450, aminopyrine N-deme-thylase 및 aniline hydroxylase 활성변동은 관찰할 수 없었다. 곰피 성분 투여군은 glutathione S-transferase의 활성에서는 대조군의 수준에는 미치지 않으나 효소의 활성이 acetaminophen 단독 투여군보다 현저히 증가되었다. 그리고 간조직중 glutathione의 함량은 phlorglucionl을 전처리군에서 acetaminophen 단독 투여군보다 증가되었다. Glutathione reductase 활성에서는 acetaminophen 투여군은 대조군보다 활성이 감소되었으며, 성분으로 전처리한 군은 acetaminophen 단독 투여군보다 증가 되었다. 따라서 곰피에서 분리한 페놀성화합물인 phloroglucinol은 acetaminophen 투여로 증가되던 지질과 산화함량을 감소시키며, acetaminophen 대사효소활성에서는 glutathione S-transferase의 활성이 증가되어 acetaminophen 의 대사를 촉진시키는 것으로 추정된다.

• YAKHAK HOEJI
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• v.35 no.5
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• pp.384-388
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• 1991

To explore the effect of monosodium-L-glutamate(MSG) on CCI$_{4}$-damaged liver in Wister male rat, 5% MSG solution as drink water were administered after S.C. injection of 0.1 mg/kg CC1$_{4}$ twice a week for 4 weeks. After last administration of MSG, heptic glutathione(GSH) dependent system was assayed. It showed that MSG increased significanly hepatic glutathione(GSH) and glutathione peroxidase(GSH$_{px}$), but decreased glutathione-S-transferase(GST) acivity in normal rats. MSG increased significantly the GSH$_{px}$ and GST activities in rats with CCI$_{4}$-induced liver damage. These results indicate that decrease of GSH dependent systems in CC1$_{4}$ liver injury might be partially elevated by coadministration of MSG.

• Journal of the Korean Society of Food Science and Nutrition
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• v.23 no.4
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• pp.581-586
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• 1994

The study was initiated elucidate the mechanism by examining the effect of GE-132 on hepatic glutathione S-transferase (GST) activity. Activity of GST increased with dose-dependent manner in hepatic cytosolic fraction of GE-132 treatment rats. Double reciprocal plotting gave Vmax value 1.4 fold increase by the treatment of GE-132(100mg/kg, p.o.for 6 weeks) compared with control group, but did not change Km value. Ethacryinc acid (85mg/kg, once a day, i.p) was injected to control rat, the GST activity decreased remarkably . However, GE-132 pretreated group, the effect caused by ethacrynic acid was markedly reduced. And activity of ${\gamma}$-glutamylcys- teine synthetase was not changed either by GE-132 treatment , but the activity of glutathione reudctase increased significantly. Decreasing properties of ethacrynic acid decreased level of hepatic glutathione , which was restored to same degree by GE -132 pretreatment . GE-132 protective effect on ethacrynic acid-induced mortality. It is concluded that the efect of GE-132 is partly mediated by increase in hepatic GST activity.

• Analytical Science and Technology
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• v.10 no.5
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• pp.378-385
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• 1997

In order to clarify the functional role of Tyr7 in human glutathione S-transferase P1-1, we extensively investigated the effect of mutation of Tyr7 on the substrate specificity and inhibition characteristics. The mutational replacement of Tyr7 with phenylalanine lowered the specific activities with 1,2-dichloro-4-nitrobenzene and 1,2-epoxy-3-(p-nitrophenoxy) propane for GSH-conjugation reaction to 3~5% of the values for the wild-type enzyme. The pKa of the thiol group of GSH bound in Y7F was about 2.4 pK units higher than that in the wild-type enzyme. The $I_{50}$ of hematin for Y7F was similar to that for the wild-type enzyme and those of benastatin A and S-(2,4-dinitrophenyl)glutathione were only moderately decreased. These results suggest that Tyr7 is considered to be important the catalytic activities not only for GSH-chloronitrobenzene derivatives but also for GSH-epoxide conjugation reaction, rather than to binding of the substrates.

• Korean Journal of Plant Tissue Culture
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• v.28 no.2
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• pp.87-90
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• 2001

BcGRl gene encoding cytosolic glutathione reductase of Chinese cabbage (Brassica campestris var. Pekinensis cv. Seoul) was placed under the control of the CaMV 35S promoter and introduced into tobacco (Nicotiana tabacum L. cv. Samsun) via Agrobacterium-mediated transformation. T$_{0}$ 32 independent plants transformed with BcGRl gene were selected with kanamycin and they were confirmed by polymerase chain reaction (PCR) and Southern blot analysis. Northern blot analysis revealed that the constitutive expression of BcGRl gene and there was no relationship between the copy number of introduced gene and the levels of BcGRl transcripts.

• Bulletin of the Korean Chemical Society
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• v.22 no.1
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• pp.77-83
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• 2001

To gain further insight into the relationship between structure and function of glutathione S-transferase (GST), the four cysteine mutants, C14S, C47S, C101S and C169S, of human GST P1-1 were expressed in Escherichia coli and purified to electrophoretic homogeneity by affinity chromatography on immobilized glutathione (GSH). The catalytic activities of the four mutant enzymes were characterized with five different substrates as well as by their binding to four different inhibitors. Cys14 seems to participate in the catalytic reaction of GST by stabilizing the conformation of the active-site loop, not in the GSH binding directly. The substitution of Cys47 with serine significantly reduces the affinity of GSH binding, although it does not prevent GSH binding. On the other hand, the substitution of Cys101 with serine appears to change the binding affinity of electrophilic substrate by inducing a conformational change of the $\alpha-helix$ D. Cys169 seems to be important for maintaining the stable conformation of the enzyme. In addition, all four cysteine residues are not needed for the steroid isomerase activity of human glutathione S-transferase P1-1.

• Journal of the Korean Society of Food Science and Nutrition
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• v.22 no.1
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• pp.15-18
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• 1993

To evaluate an effect of dietary protein on the intoxication of methanethiol in rats, the methanethiol was intraperitoneally injected to the rats fed a low or high protein diet and then the liver weight per body weight and seurm levels of alanine aminotransferase (ALT) activities were determined to investigate the differences in liver damage between the animal groups fed low protein diet and that fed high protein diet. On the other hand, the hepatic glutathione content and its conjugating enzyme, glutathione S-transferase (GST) activity were determined to clarify the cause of difference in liver function between the two groups. The increasing rate of liver weigh/body wt., serum levels of ALT to its control group were higher in methanethiol-treated rats fed low protein diet than those fed high protein diet. The hepatic content of glutathione and GST activity were higher in rats fed high protein diet than those fed low protein diet and the decreasing rate of hepatic glu-tathione content to its control group was higher in rats fed low protein diet than those fed high protein diet. Furthermore, the hepatic GST activity in methanethiol-treated rats was higher in rats fed high protein diet than those fed low protein diet. In case of control group, the GST activity was also higher in rats fed high protein diet than those fed low protein diet.

• 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.