• BMB Reports
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• v.32 no.2
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• pp.203-209
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• 1999

Three-week grown Arabidopsis thaliana leaves were wounded by cutting whole leaves with a razor blade into pieces (about$3\;mm\;{\times}\;3\;mm$) submerged in various solutions, and incubated in a growth chamber for 24 h. We measured and compared activities of several enzymes such as phenylalanine ammonia-lyase (PAL), tyrosine ammonia-lyase (TAL), thioredoxin, thioredoxin reductase, thioltransferase, glutathione reductase, and $NADP^+$ -malate dehydrogenase. PAL activity was decreased in $HgCl_2$-, $CdCl_2$-, and glyphosate-treated leaf slices, and could not be detected after treatment with $CdCl_2$. TAL activity was found to be maximal in the $CdCl_2$-treated leaf slices. Activity of thioredoxin, a small protein known as a cofactor of ribonucleotide reductase and a regulator of photosynthesis, was significantly increased in the $CdCl_2$-treated leaf slices, while thioredoxin reductase activity was maximal in the $HgCl_2$-treated leaf slices. Thioltransferase and glutathione reductase activities were significantly decreased in the $HgCl_2$-treated leaf slices. $NADP^+$ -malate dehydrogenase activity remained relatively constant after the chemical treatments. Our results strongly indicate that sulfhydryl-related and phenylpropanoid-synthesizing enzyme activities are affected by chemical treatments such as hydrogen peroxide, heavy metals, and glyphosate.

• Korean Journal of Plant Tissue Culture
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• v.27 no.2
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• pp.95-100
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• 2000

The cytosolic glutathione reductase (GR) gene of Brassica campestris L. was introduced into several Japonica cultivars of rice by Agrobacterium tumefaciens and a large number of transgenic plants were produced. Three-week old calli were co-cultivated with A. tumefaciens strain EHA101 carrying the plasmid pIGR1. The efficiency of transformation was differed from rice cultivars. A Japonica cultivar, 'Daeribbyeo' appeared the highest efficiency (42.5%) of transformation among the four cultivars tested. The addition of acetosyringone (50 $\mu$M) during co-cultivation was a key to successful transformation. Transgene fragments were identified by PCR amplification and further confirmed by Southern blot analysis. Mendelian inheritance of the transgenes was confirmed in T$_1$ progeny.

• Journal of The Korean Society of Grassland and Forage Science
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• v.18 no.1
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• pp.69-76
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• 1998

This study was conducted to construct of the transgenic plants wliich are resistant to oxidative stresses including ozone with B. mpestris cytosolic glutathione reductase cDNA using the binary vector system of Agrobacterium tumefaciens. The 1.8kb B. campestris cytosolic GR cDNA was subcloned into the unique Sma I site of the plant transformation vector pBKSI- I, downstream of the constitutive CaMV 35s promoter and upstream of the nos termination sequence, in place of the uidA (GUS) reporter gene. The resulting plant transformation vector, pBKS-GRI, was introduced into A. tumefaciens LBA4404 by two cycles of tkeze-thaw method. The B. nqus cotyledonary petioles were transformed by the Agrubaferium harboring pBKS-GRI. Transformed shoots were induced and selected on regeneration medium supplemented with kanarnycin. The shoot formation was increased remarkably by addition of Ag$NO_3$, in MS media. The transgenic plants were analyzed for the presence of the B. campestris GR gene by Southern blot analysis and it was confirmed that a foregin gene was stably integrated into the genomes of B. nqus plants.

• 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.

• Journal of Nutrition and Health
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• v.25 no.2
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• pp.116-122
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• 1992

This study determined hepatic microsomal lipid peroxide values glucose 6-phosphatase NA-DPH-cytochrome P450 reductase and cytosolic glutathione S-transferase activites to examine the effects of methyl group deficiency on hepatic lipid peroxidation in rats treated with diethylni-trosamine(DEN) and 2-acetylamionfluorene(AAF) Weanling sprague Dawley male rats were fed the diet with methyl group supplemented or deficient. Two weeks after feeding rate were injected with a single of 200mg/kg body weight DEN intraperitoneally and after four weeks 0.02% AAF containing diets were fed for two weeks. Animals were sacrificed at 6th week. Microsomal lipid peroxide values were tended to increase in methyl group deficiency(MD). Especially in case of carcinogen tratments lipid peroxide values were increased significantly in MD. Microsomal glucose 6-phophatase activities were decreased by MD and carcinogens and in MD with carcinogen group (MD+C) the enzyme activites were the lowest Glucose 6-phosphatase activities were negatively correlated with lipid peroxidation. Microsomal NADPH-cytochrome P450 reductase activities were the highest in MD+C and correlated positively with lipid peroxidation. Cytosolic glutathione S-transferase activities were the highest in MD+C Methyl group deficiency induces lipid peroxidation especially in case of being exposed to carcinogens. Therefore the results suggest that lipid peroxidation may be one of the meachanisms of carcinogensis by methyl group deficiency.

• Journal of Nutrition and Health
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• v.32 no.2
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• pp.175-181
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• 1999

The prevalence of alcoholism among elderly population is reported to be high in rural areas in Korea. Chronic abuse of alcohol can lead to the development of vitamin B deficiency through inadequate intake, altered absorption and metabolism, and increased excretion. The present study was conducted to assess vitamin B1 and B2 status in seventeen alcohol dependent subjects who do not exhibit any clinical neurological symptoms. Vitamin B1 and B2 nutritional states were determined enzymatically by measurement of transketolase and glutathione reductase activities in erythrocytes, respectively. And dietary intakes of nutrients were determined by a 24-hr recall method. The mean percent activation of erythrocyte transketolase was significantly higher in alcoholics than in alcoholics than in control (p<0.05). The proportion of subjects with a low and borderline status of vitamin B1, was significantly higher in alcoholics than in control (p<0.05). The mean percent activation of erythrocyte glutathione reductase was not different between alcoholics and control. And the proportion of subjects with low and borderline status of Vitamin B2, was higher in alcoholics than in control (p<0.1). Vitamin B1 and B2 status were significantly decreased in alcoholics who were smoking cigarettes compared to non-smoking and non-alcoholic subjects(p<0.05). Whether vitamin supplementation improves the vitamin status of alcohol dependent subjects remains to be researched.

• YAKHAK HOEJI
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• v.45 no.3
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• pp.258-268
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• 2001

Garlic has been known to be effective against the gastrointestinal diseases which can be induced by production of oxygen-derived free radical. It has been shown that bamboo salt is effective on the treatment and prevention of various gastrointestinal disorders. Bamboo salt is a processed salt invented by a Korean, ll-Hoon Kim. It has been reported that garlic and bamboo-salt are useful to the treatment of gastric disorders in Korea. To clarify the protective mechanism of the garlic-bamboo salt mixture, the gas-tropathy was induced in rats with alcohol-salicylate and the activities of the free radical scavenging enzymes were examined. In this study, we found that the garlic-bamboo salt mixture reduced the severity of hemorrhagic lesion in gastric mucosa in the rats. In addition, the activities of superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione reductase (GR) were significnatly increased and the total content of GSH was recovered. From those results, we concluded that the protective effect of the garlic-bamboo salt mixture on gastropathy in rats is its ability to recover the level of GSH and to increase the activities of the free radical scavenging enzymes (SOD, GPx, GR).

• YAKHAK HOEJI
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• v.40 no.5
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• pp.574-581
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• 1996

The study was initiated to elucidate the protective mechanism by examining in vivo effect of some marine natural products, Styela plicata, Ecklonia stolonifera and Pachymeniopsis elliptica on acetaminophen-induced lipid peroxidation. The methanol extract of S. plicata prevented acetaminophen (800mg/kg, i.p.)-induced hepatotoxicity in rats as evidenced by the decreased formation of lipid peroxide. But the methanol extracts of E. stolonifera and P. elliptica were not affected on the formation of lipid peroxidation. The activities of cytochrome P-450, animopyrine N-demethylase and aniline hydroxylase were not changed by the treatment with S. plicata in comparison with acetaminophen-teated group. In acetaminophen-treated control rats, the glutathione S-transferase activity was decreased markably. However. in S. plicata pretreated group, the effect caused by acetaminophen was markably reduced. A-cetaminophen decreased the level of hepatic, glutathione, which was restored to same degree by S. plicata pretreatment. And activity of ${\gamma}$-glutamylcystein synthetase was not changed by S. plicata pretreatment, but the activity of glutathione reductase was increased significantly.

• Preventive Nutrition and Food Science
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• v.5 no.1
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• pp.48-53
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• 2000

Inhibitory effects of the methanol extract, hexane extract, methanol soluble fraction (MSF) and juice from 3 weeks fermented Kimchi on the tumor formation in sarcoma-180 cell transplanted mice were studied. Effects of the solvent extracts and juice of the Kimchi on the levels of lipid peroxide, glutathione, and the enzyme activities of the liver were also investigated in normal and sarcoma-180 cell transplanted mice. At 32 days following trans-plantation, MSF reduced the tumor formation by 54% compared with the control group, resulting in the smallest tumor weight. Lipid peroxided content in liver increased by the transplantation of sarcoma-180 cells. However, it decreased when MSF of Kimchi was treated to the mice. MSF also suppressed xanthine oxidase activity in cytosol of the liver cells in mice transplanted by sarcoma-180 cells. Kimchi extracts had no inhibitory effect on hepatic aminopyrine-N-demethylase activity in sarcoma-180 cell transplanted or normal mice. Methanol extract and hexane extract of Kimchi slightly increased hepatic glutathione contents in sarcoma-180 treated mice. The injection of MSF from Kimchi markedly increased glutathione levels in the liver of sarcoma-180 treated mice. The injection of MSF from Kimchi markedly increased glutathione levels in the liver of sarcoma-180 treated mice compared to the controls. The MSF recovered the activities of hepatic glutathione reductase and glutathione S-transferase that decreased by the injection of sarcoma-180 cells. These results showed that MSF of Kimchi could suppress the growth of tumors, inhibiting lipid peroxide production and xanthine oxidase activity, in mice. We also suggested that Kimchi extract might play an important role in the prevention of cancer by enhancement of the glutathione level itself as well as via glutathione reductase and glutathione S-transferase.

• Molecules and Cells
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• v.28 no.5
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• pp.479-487
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• 2009

Glutathione reductase (GR) is an enzyme that recycles a key cellular antioxidant molecule glutathione (GSH) from its oxidized form (GSSG) thus maintaining cellular redox homeostasis. A recombinant plasmid to overexpress a GR of Brassica rapa subsp. pekinensis (BrGR) in E. coli BL21 (DE3) was constructed using an expression vector pKM260. Expression of the introduced gene was confirmed by semi-quantitative RT-PCR, immunoblotting and enzyme assays. Purification of the BrGR protein was performed by IMAC method and indicated that the BrGR was a dimmer. The BrGR required NADPH as a cofactor and specific activity was approximately 458 U. The BrGR-expressing E. coli cells showed increased GR activity and tolerance to $H_2O_2$, menadione, and heavy metal ($CdCl_2$, $ZnCl_2$ and $AlCl_2$)-mediated growth inhibition. The ectopic expression of BrGR provoked the co-regulation of a variety of antioxidant enzymes including catalase, superoxide dismutase, glutathione peroxidase, and glucose-6-phosphate dehydrogenase. Consequently, the transformed cells showed decreased hydroperoxide levels when exposed to stressful conditions. A proteomic analysis demonstrated the higher level of induction of proteins involved in glycolysis, detoxification/oxidative stress response, protein folding, transport/binding proteins, cell envelope/porins, and protein translation and modification when exposed to $H_2O_2$ stress. Taken together, these results indicate that the plant GR protein is functional in a cooperative way in the E. coli system to protect cells against oxidative stress.