• 대한수의학회지
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• 제37권3호
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• pp.619-627
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• 1997

It is known that 2-methyl-1,4-naphtoquinone(menadione, MD) induces hepatotoxicities both in vivo and in vitro. These toxic effects are believed to result from oxidative damages to hepatocytes by "active oxygen" species via one-electron reduction of the naphtoquinone. The ginsenoside(GS) is a complex mixture of individual ginsenosides which is known to produce a range of effects on the cardiovascular and central nervous systems. In particular, GS has an antioxidant effect. In this experiment we studied the effect of GS from red panax ginseng(red ginseng total saponin, RGTS) on free radical-induced liver injuries by MD. Administration of MD($150{\mu}M$) caused an increase in aspartate aminotransferase(AST) activities and lipid peroxidation, decrease in alkaline phosphatase(ALP) activities and total bilirubin levels in blood, caused depletion of GSH and changes of antioxidant enzyme(superoxide dismutase, catalase) activities are shown in liver tissue. Administration of RGTS restored the AST levels that increased by MD, but catalase showed no significant changes. RGTS also had an effect of restoring the GSH level and had some synergistic effects with SOD. These data suggest that RGTS may have some protective effects on liver injury which is related with the oxygen free radical.

• Journal of Microbiology
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• 제41권2호
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• pp.109-114
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• 2003

A promoter that is inducible by paraquat and menadione, the superoxide generators, independently of soxRS has been found in front of the sufABCDSE operon in Escherichia coli. Based on the observation that SufA is a holomog of IscA that functions in the assembly of iron sulfur cluster and the sufA promoter (sufAp) contains a putative Fur-binding consensus, we investigated whether this gene is regulated by Fur, a ferric uptake regulator, When examined in several sufAp-lacZ chromosomal fusion strains, sufAp was induced by EDTA, an iron chelator and a well-known Fur-inducer, The basal level of sufA expression increased dramatically in fur mutant, suggesting repression of sufAp by Fur. The derepression in fur mutant and EDTA-induction of sufA expression required nucleotides up to -61, where a putative Fur box is located. Purified Fur protein bound to the DNA fragment containing the putative Fur box between -35 and -10 promoter elements. The regulation by Fur and menadione induction of sufAp acted independently. The rpoS mutation increased sufA induction by menadione, suggesting that the stationary sigma factor RpoS acts negatively on sufA induction.

• BMB Reports
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• 제29권6호
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• pp.513-518
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• 1996

A soluble protein from Saccharomyces cerevisiae specifically provides protection against a thiolcontaining oxidation system but not against an oxidation system without thiol. This 25-kDa protein was thus named thiol-dependent protector protein (TPP). The role of TPP in the cellular defense against oxidative stress was investigated in Escherichia coli containing an expression vector with a yeast genomic DNA fragment that encodes TPP (strain YP) and a mutant in which the catalytically essential amino acid in the active site of TPP (Cys-47) has been replaced with alanine by site-directed mutagenesis (strain YPC47A). There was a distinct difference between these two strains in regard to viability, modulation of activities of superoxide dismutase and catalase, and the oxidative damage of DNA upon exposure to menadione. These results suggest that TPP may play a direct role in the cellular defense against oxidative stress by functioning as an antioxidant protein.

• Bulletin of the Korean Chemical Society
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• 제19권1호
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• pp.29-31
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• 1998

• Bulletin of the Korean Chemical Society
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• 제21권12호
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• pp.1173-1174
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• 2000

• Journal of Microbiology and Biotechnology
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• 제16권3호
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• pp.386-390
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• 2006

A green fluorescent protein-based Pseudomonas putida reporter was successfully constructed and shown to be capable of detecting oxidative stress. In this whole-cell reporter, the promoter of the paraquat-inducible ferredoxin-$NADP^+$ reductase (fpr) was fused to a promoterless gfp gene on a broad-host-range promoter probe vector. Pseudomonas putida KT2440 harboring this reporter plasmid exhibited an increased level of gfp expression in the presence of redox-cycling agents (paraquat and menadione), hydrogen peroxide, and potential environmental pollutant chemicals such as toluene, paint thinner, gasoline, and diesel. Induction of fpr in the presence of these chemicals was confirmed using Northern blot analysis.

• 한국미생물·생명공학회지
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• 제28권1호
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• pp.1-7
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• 2000

The bacterial strain JW-2 which conferred resistance against paraquat (1,1'-dimethyl-4,4'-bipyridinium dichloride) was isolated from soil. The strain was identified as an Ochrobactrum anthropi based on its morphological, physiological, biological and fatty acid composition, and was designated as Ochrobactrum anthropi JW-2. We compard paraquat resistance of O. anthropi JW-2 with Escherichia coli J105. In the presence of 100mM paraquat, E. coli JM105 was not grown whereas the growth rate of O. anthropi was about 70% of control. We compared the sensitivity of O. anthropi JW-2 and E. coli J105 to redox-cycling compounds such as paraquat, plumbagin or menadione, which are known to exacebate wuperoxide generation. O. anthropi JW-2 did not show cross-resistance to plumbagin or menadione. superoxide dismutase activity was increased in paraqunt-treated E. coli JM105 while it was not increased in O.anthropi JW-2. These results suggest that the mechanism of paraquat resistance in O.anthropi JW-2 is probably due to selectively decreased permeability toward paraquat by membrane protein.

• 한국독성학회:학술대회논문집
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• 한국독성학회 1998년도 국제심포지움 및 추계학술대회
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• pp.48-48
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• 1998

• 대한약학회:학술대회논문집
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• 대한약학회 2000년도 NEW STRATEGY FOR DRUG DEVELOPMENT IN POST-GENOMIC ERA(대한약학회)
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• pp.158.2-159
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• 2000

• Bulletin of the Korean Chemical Society
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• 제21권1호
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• pp.35-36
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• 2000