• Molecules and Cells
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• 제37권7호
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• pp.532-539
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• 2014

We isolated a rice (Oryza sativa L.) WRKY gene which is highly upregulated in senescent leaves, denoted OsWRKY42. Analysis of OsWRKY42-GFP expression and its effects on transcriptional activation in maize protoplasts suggested that the OsWRKY42 protein functions as a nuclear transcriptional repressor. OsWRKY42-overexpressing (OsWR KY42OX) transgenic rice plants exhibited an early leaf senescence phenotype with accumulation of the reactive oxygen species (ROS) hydrogen peroxide and a reduced chlorophyll content. Expression analysis of ROS producing and scavenging genes revealed that the metallothionein genes clustered on chromosome 12, especially OsMT1d, were strongly repressed in OsWRKY42OX plants. An OsMT1d promoter:LUC construct was found to be repressed by OsWRKY42 overexpression in rice protoplasts. Finally, chromatin immunoprecipitation analysis demonstrated that OsWRKY42 binds to the W-box of the OsMT1d promoter. Our results thus suggest that OsWRKY42 represses OsMT1d-mediated ROS scavenging and thereby promotes leaf senescence in rice.

• Molecules and Cells
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• 제26권6호
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• pp.616-620
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• 2008

Maintaining redox balance is one of the crucial requirements for a cell to endure stress from the outside. Dehydroascorbate reductase (DHAR; EC 1.8.5.1) plays an important role in the ascorbate-glutathione cycle; one of the major ROS scavenging systems in most known biological systems. A cDNA clone of the DHAR gene from Oryza sativa (OsDHAR) was isolated and overexpressed in Escherichia coli BL21 (DE3) strain from the pET-28a(+) expression vector. The OsDHAR transformed E. coli cells showed significantly higher DHAR activity and a lower level of ROS than the E. coli cells transformed by an empty pET-28a(+) vector. Also, the DHAR-overexpressing E. coli strain was more tolerant to oxidant- and heavy metal-mediated stress conditions than the control E. coli strain. The results suggest that the overexpressed rice DHAR gene effectively functions in a prokaryotic system and provide protection to various oxidative stresses.

• Natural Product Sciences
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• 제18권1호
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• pp.52-59
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• 2012

In our continuous efforts to procure the active materials from natural products in the protective effects of oxidative stress or UV damage to skin cells we found the Prunus persica flesh extract (PPFE) is considerable to meet the demand to protect the skin damage. PPFE attenuated cell damage induced by hypoxanthine-xanthine oxidase in cultured human keratinocytes, indicating that PPFE has the potential of the scavenging effect of reactive oxygen species (ROS) in human skin cell. Moreover, PPFE significantly suppressed UVA-induced ROS production determined by the oxidation of 2,7-dichlorodihydrofluorescein diacetate (DCFH) using FACS analysis. Additional study revealed that UVA irradiation of HaCaT human keratinocytes increased the gelatinolytic activities of matrix metalloproteinase-2, and -9 (MMP-2, -9) and mRNA expression of MMP-9 analyzing by a real-time reverse transcriptase-polymerase chain reaction (RT-PCR), and these events were significantly suppressed by the treatment with PPFE. These results suggest that PPFE might be applicable as natural ingredients for skin antiaging agents via UV-induced ROS scavenging activity and suppression of MMP expression in the skin cells.

• 동의생리병리학회지
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• 제29권6호
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• pp.475-484
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• 2015

In this paper, we studied the anti-oxidative capacities and protective effects of water extract of Gagam-Danguieumja(GDE) against Ultraviolet B(UVB)-induced oxidative damage in human keratinocytes(HaCaT). To evaluate the anti-oxidative activities of GDE, we measured scavenging activities on DPPH radical, hydroxyl radical, hydrogen peroxide, superoxide anion, lipid peroxidation and reducing power of GDE. To detect the protective effects of GDE against UVB, we irradiated with 40 mJ/㎠`s UVB to HaCaT cells then we measured reactive oxygen species(ROS) generation, apoptotic bodies and cell viability using DCFH-DA assay, Hoechst 33342 staining and MTT assay. GDE showed the anti-oxidative activities by scavenging DPPH radical, hydroxyl radical, hydrogen peroxide, superoxide anion, lipid peroxidation. Also GDE showed high reducing values. GDE reduced oxidative stress conditions by inhibition of ROS expression. Also the cell apoptosis by UVB-induced oxidative conditions was decreased by GDE treatment. These results could suggest that GDE had anti-oxidative activities and exhibited protective effects against UVB on HaCaT cells. GDE would be useful for the development of cosmetics treating UVB-induced skin aging.

• The Plant Pathology Journal
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• 제17권2호
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• pp.88-93
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• 2001

Oxidative stress is one of the major limiting factor in plant productivity. Reactive oxygens species (ROS) generated during metabolic processes damage cellular functions and consequently lead to disease, senescence and cell death. Plants have evolved an efficient defense system by which the ROS is scavenged by antioxidant enzymes such as superoxide dismutase (SOD) and ascorbate peroxidase (APX). Attempts to reduce oxidative damages under the stress conditions have included the manipulation of 갠 scavenging enzymes by gene transfer technology. Increased SOD activities of transgenic plants lead to increased resistance against oxidative stresses derived from methyl viologen (MV), and from photooxidative damage caused by high light and low temperature. Transgenic tobacco plants overexpressing APX showed reduced damage following either MV treatment of photooxidative treatment. Overexpression of glutathion reductase (GR) leads to increase in pool of ascorbate and GSH, known as small antioxidant molecules. These results indicate through overexpression of enzymes involved in ROS-scavenging could maintain or improve the plant productivities under environment stress condition. In this study, the rational approaches to develop stress-tolerant plants by gene manipulation of antioxidant enzymes will be introduced to provide solutions for the global food and environmental problems in the $21^\textrm{st}$ century.

• Applied Biological Chemistry
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• 제48권3호
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• pp.285-291
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• 2005

다양한 추출공정에 의하여 제조된 노루궁뎅이버섯의 열수 및 50% 에탄올 추출분획이 대식세포의 활성화에 미치는 효과를 마우스의 대식세포주인 RAW264.7 세포를 사용하여 측정하였다. 실험 결과, NO 생산능은 2시간 열수추출한 분획과 60 W에서 50% 에탄올로 3분간 microwave로 추출한 분획이 높았고, 활성산소종(ROS)에 대한 소거활성은 2시간 또는 3시간 열수추출한 분획과 60W에서 50% 에탄올로 3분간 microwave로 추출한 분획 및 0.5% HCl로 추출한 분획에서 높게 나타났다. 50% 에탄올 추출에 있어서 60W, 80W 및 120W에서 3분간 microwave로 추출한 분획들이 RAW264.7 세포의 Candida albicans에 대한 포식활성을 크게 유도한다는 사실을 알았다. 특히 50% 에탄올을 용매로 사용하여 60W에서 3분간 microwave로 추출한 분획은 NO 생산, ROS 소거 및 C. albicans에 대한 포식활성의 전반적인 대식세포의 활성화를 유도하였다. 이 사실은 노루궁뎅이버섯에 있어서 60 W에서 3분간 microwave에 의한 50% 에탄올 추출조건이 함유된 다당류가 관련된 대식세포 활성화 성분의 농화에 유용하게 사용될 수 있음을 보여주었고, 단백다당류가 활성성분으로서 관련되었을 가능성을 시사하였다.

• 생명과학회지
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• 제26권8호
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• pp.948-954
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• 2016

포도주 가공 중에 발생하는 포도주 부산물의 항산화 활성 검토를 위해 포도주 부산물을 유기용매로 추출 및 분획하여 총 플라보노이드 및 총 페놀 함량을 측정하고 포도주 부산물의 항산화 효과를 분석하였다. 포도주 부산물의 분획 및 추출물의 총 플라보노이드의 양을 측정한 결과 MeOH 추출물은 A+M 추출물보다 높은 함량의 총 플라보노이드를 함유하는 것으로 나타났고 분획물들 중에서는 85% aq. MeOH 분획물이 105.1±0.93 mg/g으로 가장 높았으며 총 페놀 함량은 MeOH 추출물과 n-BuOH 분획물에서 높은 함량을 나타내었다. DPPH를 통한 라디칼 소거활성능을 측정한 결과, 0.5 mg/ml 첨가농도에서 MeOH 추출물은 74%의 소거율을 나타내었으며 분획물들 중에서는 n-BuOH 분획물이 72%의 소거활성을 나타내었다. 또한 ABTS+를 통한 라디칼 소거활성능을 측정한 결과, 0.5 mg/ml 첨가농도에서 85% aq. MeOH 및 n-BuOH 분획물들은 각각 90% 및 92% 소거활성을 나타내어 동일한 BHT 농도에서 92%인 것과 비교해 보았을 경우 합성항산화제만큼 높은 항산화능을 나타내었다. 세포내 활성 산소종 소거 효과를 나타내는 ROS 실험을 통해 0.1 mg/ml 첨가농도에서 MeOH 추출물과 n-BuOH 분획물은 각각 64%와 60%의 소거 활성을 나타었다. 이상의 결과를 종합해 보면 포도 및 포도씨와 비교했을 때 포도주 부산물의 경우 총 플라보노이드 및 총 페놀 함유량은 다소 낮았지만 항산화 효과도 지속되는 것으로 여겨지므로 향후 포도주 부산물의 응용이 기대되어진다.

• Journal of Ecology and Environment
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• 제30권4호
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• pp.307-314
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• 2007

We studied changes in the biochemical and physiological status and ROS-scavenging enzyme (superoxide dismutase, catalase and peroxidase) activity in leaves and roots of rice (Oryza sativa L.) plants exposed to high salinity. Under salt stress, the reduction in RWC (relative water content) in leaves was relatively severe in comparison with that of roots. The proline content was also significantly higher in leaves of rice plants following salt treatment. The activities of CAT and POX in roots increased with increasing NaCl concentration, but the activity of SOD decreased. These results suggest that the increase of endogenous proline is closely associated with the increase of CAT and POX activities, which may play important roles in salt tolerance. Therefore, we conclude that the alleviation of oxidative damage and increased resistance to salinity may result from the presence of efficient antioxidative systems.

• KSBB Journal
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• 제29권3호
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• pp.199-204
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• 2014

To investigate the effect of Plantago asiatica L. Root extract on skin care, we measured anti-oxidant activity and whitening action. As a result of measuring DPPH radical scavenging activity to examine independent anti-oxidation of PRE, there was slight scavenging activity. Fluorescent materials DHE, DCF-DA and DHR were each used to measure superoxide anion, hydrogen peroxide, and hydroperoxide created in RAW 264.7 cells, all concentrations were found to dependently prevent ROS production. Tyrosinase activation was found to be blocked dose-dependant. Melanin production was also prevented dose-dependant, but the effects were slight. Therefore, it is expected to be used effectively in development of functional cosmetic materials.

• Journal of Applied Biological Chemistry
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• 제50권4호
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• pp.270-274
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• 2007

Two acetylmartynosides, 2"-acetylmartynoside and 3"-acetylmartynoside were isolated from the $CH_2Cl_2$ fraction of Clerodendron trichotomum (Verbenaceae) by open column chromatography and MPLC. Their chemical structures were identified by the direct comparison of spectral data reported in the literature, and their antioxidant properties were evaluated. Both compounds showed antioxidant activity based on evaluations of intracellular ROS and DPPH radical scavenging activities.