• Journal of Life Science
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• v.19 no.3
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• pp.343-348
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• 2009

Magnaporthe oryzae, a major cause of rice blast, is one of the most destructive plant fungal pathogens. Secretion of reactive oxygen species (ROS) during the infection phase of plant pathogenic fungus plays a key role in the defense mechanism of a plant. ROS causes oxidative damage and functional modification to the proteins in a pathogenic fungus. Methionine, especially, is a major target of ROS, which oxidizes it to methionine sulfoxide. To survive from the attack of ROS, plant pathogenic fungus has antioxidative systems - one example would be methionine sulfoxide reductase B (MSRB), which reverses the oxidative alteration of methionine to methionine sulfoxide. In the present study, identification and molecular characterization of the MSRB gene in M. oryzae KJ201 were investigated. The MSRB gene was amplified by PCR from the M. oryzae KJ201 genomic DNA. The copy number of MSRB in the genome of M. oryzae KJ201 was identified by Southern blot analysis, which revealed that the gene exists as a single copy. To study the molecular function of an MSRB gene, the expression level of the MSRB gene was assayed with hydrogen peroxide treatment by Northern blot analysis and RT-PCR. The expression of the MSRB gene was increased by treatment of hydrogen peroxide, without significant correlation to hydrogen peroxide concentrations. These results indicate that the MSRB gene in M. oryzae KJ201 could contribute to protection against plant defense compounds such as ROS and offer a novel strategy for the control of rice blast.

• Journal of Life Science
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• v.18 no.12
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• pp.1705-1711
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• 2008

To investigate the relationship between cold stress and the activity of ascorbate peroxidase(APX), dehydroascorbate reductase (DHAR), mRNA expression level of two enzymes, hydrogen peroxide content was studied in lettuce leaves under stress condition imposed by cold stress at $4^{\circ}C$ for 24 hr in the dark and following recovery at $20^{\circ}C$ from cold stress. Hydrogen peroxide content increased gradually in lettuce leaves during cold stress, but decreased slightly following recovery from cold stress. Soluble protein content, however, decreased gradually during cold stress, and then rapidly returned to normal levels following recovery. Total chlorophyll content decreased gradually during cold stress, and then keep constant following recovery. The patterns of chlorophyll a and b content similar to that of total chlorophyll content, and carotenoid content didn't change. The ratio of chlorophyll a and total chlorophyll was increased during cold stress, but decreased with rapid during cold stress, and then the ratio returned to normal levels following recovery. During cold stress, the activity of APX and DHAR in the lettuce leaves increased dramatically, and also transcript levels of mRNA of APX and DHAR, as determined by probing 32P-labeled single stranded RNA of APX and DHAR, highly increased and returned to normal levels following recovery, respectively. Relationship between APX and DHAR activity and hydrogen peroxide highly related ($R^2$=0.8715 and 0.8643), whereas between hydrogen peroxide and total chlorophyll content and soluble content related reversely ($R^2$=0.5021 and 0.8915).

• Molecules and Cells
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• v.22 no.1
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• pp.113-118
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• 2006

Thioredoxin reductase (TrxR), a component of the redox control system involving thioredoxin (Trx), is implicated in defense against oxidative stress, control of cell growth and proliferation, and regulation of apoptosis. In the present study a stable transfectant was made by introducing the vector pcDNA3.0 harboring the fission yeast TrxR gene into COS-7 African green monkey kidney fibroblast cells. The exogenous TrxR gene led to an increase in TrxR activity of up to 3.2-fold but did not affect glutathione (GSH) content, or glutaredoxin and caspase-3 activities. Levels of reactive oxygen species (ROS), but not those of nitric oxide (NO), were reduced. Conversely, 1-chloro-2,4-dinitrobezene (CDNB), an irreversible inhibitor of mammalian TrxR, enhanced ROS levels in the COS-7 cells. After treatment with hydrogen peroxide, the level of intracellular ROS was lower in the transfectants than in the vector control cells. These results confirm that TrxR is a crucial determinant of the level of cellular ROS during oxidative stress as well as in the normal state.

• Molecules and Cells
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• v.39 no.1
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• pp.53-59
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• 2016

Peroxiredoxins are cysteine-dependent peroxide reductases that group into 6 different, structurally discernable classes. In 2011, our research team reported the application of a bioinformatic approach called active site profiling to extract active site-proximal sequence segments from the 29 distinct, structurally-characterized peroxiredoxins available at the time. These extracted sequences were then used to create unique profiles for the six groups which were subsequently used to search GenBank(nr), allowing identification of ~3500 peroxiredoxin sequences and their respective subgroups. Summarized in this minireview are the features and phylogenetic distributions of each of these peroxiredoxin subgroups; an example is also provided illustrating the use of the web accessible, searchable database known as PREX to identify subfamily-specific peroxiredoxin sequences for the organism Vitis vinifera (grape).

• Biomolecules & Therapeutics
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• v.20 no.5
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• pp.487-491
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• 2012

The aim of this study was to investigate the inhibitory effects of rutaecarpine on DNA strand breaks and apoptosis induced by hydrogen peroxide ($H_2O_2$) in murine Hepa-1c1c7 cells. Oxidative DNA damage was estimated by nuclear condensation assessment, fluorescence-activated cell sorting analysis, and Comet assay. Rutaecarpine inhibited cell death induced by $500{\mu}M$ $H_2O_2$, as assessed by 4',6-diamidino-2-phenylindole (DAPI) staining. Treatment with rutaecarpine reduced the number of DNA strand breaks induced by $H_2O_2$, as assessed by DAPI staining and Comet assay, and increased quinone reductase, phosphatidylinositol 3-kinase, and pAkt protein levels, as assessed by western blotting.

• Journal of Haehwa Medicine
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• v.8 no.1
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• pp.625-641
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• 1999

Aging occurs as a part of maturation as the time progresses which manifests in the human body causing morphological and functional degeneration, eventually leading to death. This experimental study was conducted to investigate a herbal formula to fortify the heart with easy clinical applications. Sungshimsan was chosen to study its effects in heart lipid peroxide and metabolic enzyme system in senescence induced rats. After pre-treatment of Sungshimsan for 2 weeks at the dosage of A (100mg/kg), B (250mg/kg), C (350mg/kg), and D (500mg/kg), a lipid peroxide and metabolic enzyme system changes of the heart were meaured in 32 weeks old rats. The following results were obtained in this study: 1. The contents of lipid peroxide was significantly reduced in the experimental groups treated with greater than 2 weeks at 250mg/kg. 2. The enzymatic activity of cytochrome P-450, cytochrome b5, and NADPH-cytochrome P450 reductase were significantly decreased in the 250mg/kg, 350mg/kg, and 500mg/kg experimental groups. 3. The activity of glutathione and glutathione S-transferase were significantly increased in the 250mg/kg, 350mg/kg, and 500mg/kg experimental groups. 4. The activity of glutathione reductase and glutathione peroxidase were not influenced compared to the control group. 5. The activity of ${\gamma}$-glutamylcystein synthetase was significantly increased in the 250mg/kg, 350mg/kg, and 500mg/kg experimental groups. 6. The activity of enzymes detoxificatioon superoxide dismutase and catalase were not influenced compared to the control group. Summarizing above results suggest that the Sungshimsan has profound effects in the heart lipid peroxide, free radicals, and delaying the heart aging process. Further clinical researches and application can be anticipated on the topic of senility and gerontology.

• 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.4 no.4
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• pp.260-264
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• 1999

Korean traditional fermented soy paste (doenjang) prolonged the life span of Balb/c mice injected with the sarcoma-180 cells. The activities of liver enzymes, such as xanthine oxidase, aminopyrine N-demethylase, aniline hydroxylase, ${\gamma}$-glutamylcysteine synthetase, glutathione reductase and glutathione S-transferase (GST), and the contents of lipid peroxide and glutathione were determined from the sarcoma-180 cell injected mice that were treated with methanol extracts from doenjang, miso and soybean. The content of lipid peroxide and the activity of xanthine oxidase in the liver of Balb/c mice which were increased by the transplantation of the sarcoma-180 cells were decreased by treatment with the methanol extract from doenjang. But the activities of aminopyrine N-dementhylase and aniline hydroxylase were not affected by the treatment of methanol extracts from doenjang to the mice injected with the sarcoma-180 cells. The content of glutathione, the activities of glutamylcysteine synthetase, glutathione reductase and glutathione S-transferase decreased by the injection of the sarcoma-180 were recovered considerably by the treatment of the methanol extract from doenjang.

• Toxicological Research
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• v.11 no.2
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• pp.205-213
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• 1995

This study was undertaken to investigate the effects of organic solvents on xenobiotic metabollzing enzyme system in vivo by meaas of experimental conditions i.e. (1) single group which was treated by benzene (B), toluene (T) and xylene (X), respectively, (2) combination group which was treated by mixture of benzene+toluene (BT), benzene+xylene (BX), and toluene+xylene (TX), respectively, (3) mixture group which was treated by benzene+ toluene+xylene mixture (M), and to interpreat the interaction between the organic solvents metabolizing enzymes. 1. The contents of cytochrome P-450 in liver microsomes were increased (p < 0.01) in organic solvents treated groups, and the contents of cytochrome P-450 were increased by following order of B < T < M < BT=BX < X < TX. 2. The activity of cytochrome P-450 dependent AHHase was significantly higher in organic solvents treated groups than in control group (p < 0.01), and the activity of AHHase was increased by following order of B < T < BT=BX=TX=xylene < M. 3. The activity of NADPH P-450 reductase was significantly higher in organic solvents treated groups than in control group (p < 0.01), and the order of M < combinated group < X < T

• 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.