• Bulletin of the Korean Chemical Society
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• v.27 no.5
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• pp.663-666
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• 2006

Carnosine, homocarnosine and anserine might act as anti-oxidants and free radical scavengers in vivo. In the present study, the protective effects of carnosine and related compounds on the $H_2O_2$-mediated cytochrome c modification were studied. Carnosine, homocarnosine and anserine significantly inhibited the oligomerization of cytchrome c induced by $H_2O_2$. All three compounds also inhibited the formation of carbonyl compound and dityrosine during the incubation of cytochrome c with $H_2O_2$. These compounds effectively inhibited the peroxidase activity in the cytchrome c treated with $H_2O_2$. The results suggested that carnosine, homocarnosine, and anserine might protect cytochrome c against $H_2O_2$-mediated oxidative damage through a free radical scavenging.

• YAKHAK HOEJI
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• v.50 no.1
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• pp.58-63
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• 2006

The antioxidant enzyme (AOE) system plays an important role in the defense against oxidative stress damage. To determine whether myricetin or myricetin/taurine can exert antioxidative effects not only by modulating the AOE system directly but also by scavenging free radical, we investigated the influence of the myricetin and taurine on cell viability ROS level, activities of different antioxidant enzyme, and the expression of different antioxidant enzyme. As results, the cell viability showed inhibition of the proliferation with treatment of 'myricetin' or 'myricetin with taruine', respectively, with dose-dependent manner. Compared to control, the treatment of 'myricetin' decreased activities and gene expressions of superoxide dismutase (SOD), and glutathione peroxidase (GPx). However, combined treatment of 'myricetin with taurine' increased activities and gene expressions of the SOD, GPx, and catalase (CAT). In addition, the combined treatment of 'myricetin with taurine' somewhat decreased ROS levels, compared to the treatment of 'myricetin'. In conclusion, our study provides that the combined treatment of different antioxidants can enhance antioxidant effects.

• Proceedings of the Korean Society of Sericultural Science Conference
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• 2003.10a
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• pp.112-113
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• 2003

Kynurenic acid (KYNA), tryptophan metabolite is known to have cell protective effect against various insults in the brain. But so far, the protective mechanism is largely unknown. In this study, we investigated how the KYNA exerts protective effect against 6-OHDA, a causative molecule of Parkinsonian syndrome, using SH-SY5Y cells. (omitted)

• 대한예방의학회:학술대회논문집
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• 2005.10a
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• pp.406-406
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• 2005

• 대한예방의학회:학술대회논문집
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• 2005.10a
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• pp.432-432
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• 2005

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2002.05a
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• pp.88-95
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• 2002

Fretting of fuel rod cladding material, Zircaloy-4 Tube, in PWR nuclear power plants must be reduced and avoided. Nowadays the introduction of surface treatments or coatings is expected to bean ideal solution to fretting damage since fretting is closely related to wear, corrosion and fatigue. Therefore, in this study the fretting wear experiment was peformed using TiAIN coated Zircaloy-4 tube as the fuel rod cladding and uncoated Zircaioy-4 tube as one of grids, especially concentrating on the sliding component. Fretting wear resistance of TiAIN coated Zircaloy-4 tubes was improved compared with that of TiN coated tubes and uncoated tubes and the fretting wear mechanisms were delamination and plastic flow following by brittle fracture at lower slip amplitude but severe oxidation and spallation of oxidative layer at higher slip amplitude.

• BMB Reports
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• v.32 no.5
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• pp.440-444
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• 1999

Membrane lipid peroxidation processes yield reactive aldehydes that may react with copper,zinc superoxide dismutase (Cu,Zn SOD), one of the key antioxidant enzymes against oxidative stress. We investigated this possibility and found that exposing Cu,Zn SOD to malondialdehyde (MDA) or 4-hydroxynonenal (HNE) caused the loss of dismutase activity, cross-linking of peptides, and an increase in protein oxidation, reflected by the increased level of carbonyl groups. When Cu,Zn SOD that had been exposed to MDA or HNE was subsequently analyzed by amino acid analysis, histidine content was found to be significantly lost. Both MDA-and HNE-treated Cu,Zn SOD were resistant to proteolysis, which may imply that damaged proteins exist in vivo for a longer period of time than the native enzyme. The lipid peroxidation-mediated damage to Cu,Zn SOD may result in the perturbation of cellular antioxidant defense mechanisms, and subsequently lead to a pro-oxidant condition.

• Proceedings of the Korean Society of Toxicology Conference
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• 2001.05a
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• pp.146-146
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• 2001

Gastroesophageal reflux disease (GERD) is multifactorial in etiology and is characterized by movement of acid and other noxious substances from the stomach into the esophagus. The most severe histologic consequence of chronic gastroesophgeal reflux is Barrett's esophagus, which has been considered as a premalignant condition often leading to the formation of adenocarcinoma of esophagus.(omitted)

• Proceedings of the Korean Society of Applied Pharmacology
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• 1997.04a
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• pp.105-105
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• 1997

Reactive oxygen species(ROS)에 의한 세포독성이나 DNA손상은 노화와 암에 밀접한 관련이 있다. 본연구에서는 ROS중 hydroxyl radical 생성에 관여되는 $H_2O$$_2$에 의해 유도되는 산화적 세포독성이나 DNA손상에 억제적으로 작용할 수 있는 천연물을 창출하기 위한 연구를 하였다. 인삼(Panax Ginseng)C.A. Meyer의 석유에텔의 추출물(GPE)과 일부분획성분(P2)에 대하여 in vitro에서 지질과산화억제효과 및 프리라디칼소거효과를 시험하고 CHL Cell에서의 $H_2O$$_2$ 유도 세포독성과 산화적 DNA손상에 미치는 영향을 연구하였다. 한편 이들 물질을 기존의 항산화제인 ascorbic acid, dl-$\alpha$-tocopheorl 및 $\beta$-carotene등과 비교하였다.

• Proceedings of the KSAR Conference
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• 2002.06a
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• pp.63-63
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• 2002

Peroxiredoxin (Prx) has been known to play an important role in the protection against oxidative damage of reactive oxygen species (ROS). Recent reports implied that the ROS may be closely related with the reproductive system. To define the possible roles of Prx family in reproduction, the expression profiles were investigated in reproductive organs of four murine strains. (omitted)