• 한국미생물·생명공학회지
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• 제19권6호
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• pp.575-582
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• 1991

글루타치온 생산증대를 도모하기 위하여 글루타치온 합성에 관여하는 효소들인 GSH-I 및 GSH-II 유전자들 pBR322 벡터에 클로닝하였다. gshI 유전자를 클로닝하기 위하여 GSH-I 효소활성이 결여된 GS903 균주를 분리하였다. E. coli K-12 염색체 DNA로부터 분리된 3.6Kb PstI DNA 절편을 pBR322 벡터에 클로닝하였다. gshII 유전자는 2.2Kb PstI-BamHI DNA 절편내에 존재하며 이 절편을 pUC13 벡터에 클로닝하였다. 플라스미드의 copy number와 gsh 유전자들을 포함하고 있는 삽입 DNA의 크기의 차이에 의한 gsh 유전자들의 발현 정도를 조사하기 위하여 pGH1090, pGH101, pGH200, pGH201, pLF4, pLF6 그리고 pGH300같은 여러 플라스미드를 사용함으로써 gshI 유전자의 발현이 의해 2배이상 증가하였다. 그러나 벡터 플라스미드내에 존재하는 gsh 유전자들을 포함하는 삽입 DNA의 크기의 차이에 의해서는 gsh 유전자들의 발현이 영향을 받지 않았다.

• Environmental Analysis Health and Toxicology
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• 제24권4호
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• pp.303-309
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• 2009

Hepatic antioxidant defense systems were examined in rats treated with tetrabromobisphenol-A (TBBPA), a brominated flame retardant, at the doses of 0, 250, 500 and 1,000 mg/kg for four weeks. Hepatic ratio of glutathione disulfide to glutathione (GSH) and levels of malondialdehyde, oxidative stress markers were not changed in rats treated with TBBPA. Hepatic expression of antioxidant enzymes including GSH peroxdiase-1 (GPX-1)/GSH reductase (GR), alpha-, mu- and pi-class glutathione-S-transferase (GST) and gamma-glutamylcysteine ligase catalytic subunit was determined using immunoblot analysis. Alpha-class GSTs, GPX-1 and GR levels were significantly decreased in rats treated with TBBPA at the dose of 500 or 1,000 mg/kg. These results show that TBBPA results in down-regulation of hepatic expression of antioxidant enzymes related with GSH, suggesting the liver in TBBPA-treated rats may be more sensitive to oxidants.

• Preventive Nutrition and Food Science
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• 제16권4호
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• pp.313-320
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• 2011

The oxidative stress level and antioxidant activities in two green algae (Ulva pertusa and Ulva linza), two brown algae (Agarum cribrosum and Dictyota dichotoma), and three red algae (Grateloupia lanceolata, Carpopeltis affinis, and Gracilaria verrucosa) collected from intertidal regions of Korea were assessed. In the two green algae, although the total glutathione content was not as high as that of the brown algae, the glutathione pool was extremely reduced, and the glutathione reductase (GRd)/glutathione peroxidase (GPx) activity ratio was high, which apparently plays an important role for protection against oxidative damage, as manifested by low lipid peroxidation. In the brown algae, which exhibited a low lipid peroxidation level that was comparable to the green algal species, the highest glutathione content, together with high GPx activity, appears to be the most important factor in their antioxidant protection. The red algal species exhibited extremely high lipid peroxidation levels. They also contained the lowest and most oxidized glutathione among the species, as well as the lowest GRd activity. In spite of the marked difference in the glutathione content, the significant difference in the activity of ${\gamma}$-glutamylcysteine ligase, the rate limiting enzyme for glutathione synthesis, among the species was not exhibited. Our results suggest that there is a significant difference in the levels of oxidative stress and antioxidant capacity among the algal species, and that the glutathione system, especially the efficiency of glutathione recycling, plays a vital role in antioxidative protection in algal species.

• Natural Product Sciences
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• 제15권1호
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• pp.37-43
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• 2009

Oxidative stress is caused by an imbalance between the production of reactive oxygen and an ability of a biological system, to readily detoxify the reactive intermediates or easily repair the resulting damage. It has been suggested that developmental alloxan-induced liver damage is mediated through increases in oxidative stress. The anti-diabetic effect and antioxidant activity of Phaleria macrocarpa (PM) fractions were investigated in alloxan-induced diabetic rats. After two weeks administration of PM, the liver antioxidant enzyme and hyperglycemic state were evaluated. The results showed that oral administration of PM treatments reduced blood glucose levels in diabetic rats by oral administration (P < 0.05). Serum glutamic-oxaloacetic transaminase (sGOT) and serum glutamic-pyruvate-transaminase (sGPT) were also diminished by PM supplementation. The superoxide dismutase (SOD), catalase (CAT) and glutathione-peroxidase (GPx) activities, and glutathione (GSH) level in the alloxan-induced diabetic rats were significantly decreased (P < 0.05) compared to those in the normal rats but were restored by PM treatments. PM fractions also repressed the level of malondialdehyde (MDA) in the liver. Glutathione reductase (GR), glutathione-S-transferase (GST) and $\gamma$-glutamylcysteine synthase (GCS) were also reduced in alloxan-induced diabetic rats. PM fractions could restore the GR and GST activities, but the GCS activity was not affected in rat livers. From the results of the present study, the diabetic effect of the butanol fraction of PM against alloxan-induced diabetic rats was concluded to be mediated either by preventing the decline of hepatic antioxidant status or due to its indirect radical scavenging capacity.

• Biomolecules & Therapeutics
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• 제26권2호
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• pp.167-174
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• 2018

Alterations in sulfur amino acid metabolism are associated with an increased risk of a number of common late-life diseases, which raises the possibility that metabolism of sulfur amino acids may change with age. The present study was conducted to understand the age-related changes in hepatic metabolism of sulfur amino acids in 2-, 6-, 18- and 30-month-old male C57BL/6 mice. For this purpose, metabolite profiling of sulfur amino acids from methionine to taurine or glutathione (GSH) was performed. The levels of sulfur amino acids and their metabolites were not significantly different among 2-, 6- and 18-month-old mice, except for plasma GSH and hepatic homocysteine. Plasma total GSH and hepatic total homocysteine levels were significantly higher in 2-month-old mice than those in the other age groups. In contrast, 30-month-old mice exhibited increased hepatic methionine and cysteine, compared with all other groups, but decreased hepatic S-adenosylmethionine (SAM), S-adenosylhomocysteine and homocysteine, relative to 2-month-old mice. No differences in hepatic reduced GSH, GSH disulfide, or taurine were observed. The hepatic changes in homocysteine and cysteine may be attributed to upregulation of cystathionine ${\beta}-synthase$ and down-regulation of ${\gamma}-glutamylcysteine$ ligase in the aged mice. The elevation of hepatic cysteine levels may be involved in the maintenance of hepatic GSH levels. The opposite changes of methionine and SAM suggest that the regulatory role of SAM in hepatic sulfur amino acid metabolism may be impaired in 30-month-old mice.

• Preventive Nutrition and Food Science
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• 제15권4호
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• pp.267-274
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• 2010

We assessed the effect of Se-methylselenocysteine (MSC) treatment, at a dose of 0.75 mg/rat/day for 1 or 2 weeks, on the activities of antioxidant systems in Sprague-Dawley rat tissues. Significant changes in glutathione and antioxidant enzyme activities, with different patterns among tissues, were evidenced. Glutathione content and its reduction state in the liver, lung, and kidney were elevated upon MSC treatment, whereas they were significantly lowered in the spleen. Among the tissues exhibiting glutathione increase, there were different enzymatic responses: $\gamma$-glutamylcysteine ligase activity, the rate-limiting enzyme in the glutathione synthesis pathway, was increased in the liver, whereas the activities of the enzymes associated with glutathione recycling, namely, glutathione peroxidase, glutathione reductase, and glucose 6-phosphate dehydrogenase, were significantly increased in the lung and the kidney. The superoxide dismutase activity was decreased in all tissues upon MSC treatment, whereas catalase activity was increased in all tissues but the liver. Lipid peroxidation level was transiently increased at 1 week in the lung and the kidney, whereas it was persistently increased in the spleen. The increase was not evident in the liver. The results indicate that the MSC treatment results in an increase in the antioxidant capacity of the liver, lung, and kidney principally via an increase in glutathione content and reduction, which appeared to be a result of increased synthesis or recycling of glutathione via tissue-dependent adaptive response to oxidative stress triggered by MSC. The spleen appeared to be very sensitive to oxidative stress, and therefore, the adaptive response could not provide protection against oxidative damage.

• 대한본초학회지
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• 제28권6호
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• pp.79-86
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• 2013

Objectives : The purpose of this study is to investigate neuroprotective effects and molecular mechanisms of luteolin against ${\beta}$-amyloid ($A{\beta}_{25-35}$)-induced oxidative cell death in BV-2 cells. Methods : The protective effects of luteolin against $A{\beta}_{25-35}$-induced cytotoxicity and apoptotic cell death were determined by MTT dye reduction assay and TUNEL staining, respectively. The apoptotic cell death was further analyzed by measuring mitochondrial transmembrane potential and expression of pro- and/or anti-apoptotic proteins. To elucidate the molecular mechanisms underlying the protective effects of luteolin, intracellular accumulation of reactive oxygen species, oxidative damages, and expression of antioxidant enzymes were examined. Results : Luteolin pretreatment effectively attenuated $A{\beta}_{25-35}$-induced apoptotic cell death indices such as DNA fragmentation, dissipation of mitochondrial transmembrane potential, increased Bax/Bcl-2 ratio, and activation of c-Jun N-terminal kinase and caspase-3 in BV-2 cells. Furthermore, $A{\beta}_{25-35}$-induced intracellular formation of reactive oxygen species and subsequent oxidative damages such as lipid peroxidation and depletion of endogenous antioxidant glutathione were suppressed by luteolin treatment. The neuroprotective effects of luteolin might be mediated by up-regulation of cellular antioxidant defense system via up-regulation of ${\gamma}$-glutamylcysteine ligase, a rate-limiting enzyme in the glutathione biosynthesis and superoxide dismutase, an enzyme involved in dismutation of superoxide anion into oxygen and hydrogen peroxide. Conclusions : These findings suggest that luteolin has a potential to protect against $A{\beta}_{25-35}$-induced neuronal cell death and damages thereby exhibiting therapeutic utilization for the prevention and/or treatment of Alzheimer's disease.

• Natural Product Sciences
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• 제11권2호
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• pp.67-74
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• 2005

The ethanolic extracts of the leaves and bulbs of Allium victorialis var. platyphyllum (Liliaceae) collected from Daegwallyoung (D) and Ullung Island (U) in Korea were obtained using three different extracting methods. The first extracts, DL-1 DB-1, UL-1 and UB-1, were obtained from leaves (L) and bulbs (B) dried at $90^{\circ}C$, respectively, and the second extracts, DL-2, DB-2, UL-2 and UB-2, were obtained by extracting the leaves and bulbs of fresh plant parts. The third extracts DL-3, DB-3, UL-3 and UB-3 were obtained by incubating leaves and bulbs at $36^{\circ}C$. The six extracts obtained from A. victorialis var. platyphyllum at Daegwanllyoung (cultivated site) were orally administered to examine for a possible antihepatotoxic effect in $CCl_4-induced$ rats. DL-1 exhibited the most pronounced effect. The extracts inhibited serum ALT, AST, SDH, ${\gamma}-GT$, ALP and LDH activities elevated by $CCl_4$ injection and attenuated decreased glutathione S-transferase, glutatione reductase and ${\gamma}-glutamylcysteine$ synthetase activities and a decreased hepatic glutathione. However, the extracts obtained from Ullung Is. (native site) were less active than the extracts from Daegwallyoung, suggesting that A. victorialis var. platyphyllum from the cultivated site is more useful for functional food than of native site. These results also suggest that the antihepatotoxic effect is due to a higher content of hepatic glutathione. Gas chromatography of the twelve extracts showed significantly different sulfides, disulfides or trisulfides contents belonging to volatile sulfur substances (VSS). Nine components were identified on the basis of their mass spectra, namely, dimethyl disulfide, dimethyl trisulfide, diallyl disulfide, dipropyl disulfide, allyl methyl sulfide, allyl methyl trisulfide, 2-vinyl-4H-1,3-dithiin, 3,4-dihydro-3-vinyl-1,2-dithiin, and allithiamine. Extract DL-1 had the highest VSS content. Dried plant materials contained larger amounts of the VSSs than other extracts, and the leaves contained larger amount than the bulbs. These results suggest that heat treatment increases the antiheaptotoxic ability of A. victorialis var. platyphyllum by increasing the proportion of VSSs.

• 생명과학회지
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• 제16권2호
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• pp.259-265
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• 2006

엽산과 유사한 구조를 가져 관절염 치료제로 쓰이는 methotrexate (MTX)의 당뇨병 쥐에서의 신독성 기전을 구명할 목적으로 실험동물 정상군과 STZ로 당뇨를 유발한군에 MTX률 투여하여 신장 독성을 유발하여 혈중 생화학적 변화를 관찰하고 free radical의 생성계와 해독계의 활성에 미치는 영향을 관찰하였다. 혈중 신장기능 지표 효소 및 신장조직의 지질과산화 함량이 정상군에 MTX를 투여한 군에 비해 당뇨쥐에 MTX를 투여한 군에서 현저히 증가하였다. 당뇨쥐에 MTX를 투여함으로써 활성산소 생성계인 phase I 단계 중 cytosol 효소계 활성이 정상쥐에 MTX를 투여한 군에 비하여 현저히 증가하였고, phase II 단계 중 glutathione S-transferase의 활성이 정상쥐에 MTX를 투여하였을때에 비하여 당뇨쥐에 MTX를 투여하였을때 현저히 감소하였다. 신조직 중 glutathione의 함량 또한 당뇨쥐에 MTX를 투여했을때 현저히 감소하였고 이러한 결과는 $\gamma$-glutamylcysteine synthetase와 glutathione reductase의 활성을 감소시킨 결과로 생각된다. 이상의 결과를 종합하여 볼때 당뇨쥐에 MTX를 투여하면 신독성이 증가함을 확인할 수 있었고, 그 기전은 cytosol계 효소 활성을 증가시켜 MTX의 대사계를 촉진시킴으로 독성물질의 생성을 증가시키고, 이로 인한 신조직중의 지질과산화 함량의 증가는 glutathione의 함량 감소에 의해 나타나는 결과로 사료되어진다.

• 생명과학회지
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• 제15권3호
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• pp.461-467
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• 2005

간기능 보호 작용이 있는 것으로 알려진 DDB, selenium과 glutathione의 혼합제제인 DWP-04의 간보호 작용을 검토할 목적으로 DWP-04를 실험동물에 경구로 투여하고서 D-galactosamine으로 간독성을 유발하여 혈액의 변동 및 간 조직에서의 활성산소 생성계 및 해독계의 활성에 미치는 영향을 관찰한 결과 GaIN의 단독투여는 대조군에 비하여 혈중 간 기능 지표효소 및 간 조직에서의 지질과산화의 함량이 현저히 증가하였으나, DWP-04의 전처리로 현저히 감소되었다. CaIN의 단독 투여로 활성산소의 생성계인 phase 1계의 효소가 현저히 증가하던 것이 DWP-04의 처리로 억제되었으며 해독계인 phase II계의 효소는 GaIN의 투여로 대조군에 비하여 억제되던 것이 DWP-04의 전처리로 정상군에는 미치지 않으나 유의성 있게 증가되었다. 간 조직중 glutathine의 함량은 CaIN의 투여로 현저히 억제되었으며 DWP-04의 투여로 증가하였는데 이러한 결과는 DWP-04의 투여로 glutathione peroxidase의 활성보다는 $\gamma-glutamylcysteine$ synthetase의 활성을 조절한 결과로 생각된다. 이상의 결과를 종합하여 볼 때 DWP-04의 투여는 활성산소의 생성 및 해독계를 조절하므로서 GaIN으로 인한 간손상을 보호하는 효과가 있는 것으로 사료된다.