• 대한한의학방제학회지
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• 제8권1호
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• pp.241-255
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• 2000

Sihosamultang(SST) has been used for the treatment of puerperal fever, liver disease in traditional medicine. The present study was carried out to evaluate the antioxidant effects of SST extract in vitro. The inhibitory effect of SST extract on lipid peroxidant was examined in the linoleic acid autoxidation system. In this test, SST extract significantly inhibited the time course of the lipid peroxidation. And SST extract showed about 73% scavenging effect on DPPH radical. And this extract inhibited not only the lipid peroxide formation induced by hydroxyl radical derived from $ H_{2}O_{2}-Fe^{2+}$ in the rat liver homogenate, but also the superoxide generation from xanthine-xanthine oxidase system in a dose-dependent manner. In addition, SST extract protected the hepatic cell death induced by tert-butyl hydroperoxide. These data indicated that SST might play a protective role against oxidative injury by free radicals.

• Nutrition Research and Practice
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• 제5권6호
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• pp.495-502
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• 2011

In this study, antioxidant and free radical scavenging activities of the natural antioxidative compound, pyrogallol-phloroglucinol-6,6'-bieckol (PPB) isolated from brown algae, Ecklonia cava was assessed in vitro by measuring the radical scavenging activities (DPPH, alkyl, hydroxyl, and superoxide) using electron spin resonance (ESR) spectrometry, intracellular reactive oxygen species (ROS) scavenging activity, and DNA damage assay. According to the results of these experiments, the scavenging activity PPB against difference radicals was in the following order: DPPH, alkyl, hydroxyl, and superoxide radicals ($IC_{50}$; 0.90, 2.54, 62.93 and $109.05{\mu}M$). The antioxidant activities of PPB were higher than that of the commercial antioxidant, ascorbic acid. Furthermore, PPB effectively inhibited DNA damage induced by $H_2O_2$. These results suggest that the natural antioxidative compound, PPB, can be used by the natural food industry.

• 동의신경정신과학회지
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• 제9궈1호
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• pp.45-57
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• 1998

The effect of HWANSODAN(HSD), on the level of brain antioxidants was examined in aged rat. The experimental groups were divided into three groups and treated as follows ; normal group(negative control), Vt.E administrated Group(HSD). The purified microsome from brain tissue, those were measired the amounts of oxidant materials like Malonfialdehyde(MDA) and H2O2, then activities of antioxidants enzymes like superoxide dismutase, catalase, NADPH-cytochrome P-450 reductase.The results were as follows;1. In TBA reaction to measure the amount of MDA, HSD group and Vt.E group did not showed signigicant decrease.2. In the formation of Hydrogen peroxide, HSD group and Vt.E group showed a little increase.3. The activity of Superoxide dismutase was increased significantly in HSD group and Vt.E group.4. In the activity of Catalase, Vt.E group was increased significantly and HSD group a little increased. 5. The activity of NADPH-cytochrome P-450 reductase in the HSD group and Vt.E group showed significantly increase.According to the above results, it is suggested that HWANSODAN(HSD) has some antioxidant effects on the tissue of brain.

• 동의신경정신과학회지
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• 제9궈1호
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• pp.59-71
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• 1998

The effect of Samyonjihwangtang(SJT) on th level of brain antioxidants was examined in aged rat. Samyongjihwangtang(SJT) is assed Cervi Pantiri-chum Cornu, Ginseng Radix to Yukmijihwangtang. The experimental groups were divided into three groups and treated as follows ; normal group(NC), Vt.E administrated group(PC), SJT administrated Group(SJT). From the purified microsome of brain tissue, those were measures the amounts of oxidant materials like malonaldehyde(MDA) and H_2O_2, then activities of antioxidants enxymes like Superoxide dismutase, Catalase, NADPH-cytochrome P-450 reductase.The results were as follows;1. In TBA reaction to measure the amount of MDA, oxidant material of brain tissue of aged rat, both treated groups showed significant decrease.2. In the formation of Hydrogen peroxide, the treated group(SJT) showed a little decrease.3. The activity of Superoxide dismutase was increased significantly in both treated groups than normal group.4. the activity of Catalase was increased significantly in both treated groups than normal group. 5. The activity of NADPH-cytochrome P-450 reductase in the treated group(SJT) showed a little increase.According to the above results, it is suggested that Samyongjihwangtag(SJT) has some antioxidant effects on the tissue of brain.

• 대한한의학회지
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• 제19권1호
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• pp.38-48
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• 1998

This study was undertaken to determine whether Salviae-radix (SVR) extraction prevents the oxidant-induced cell injury and thereby exerts protective effect against oxidant-induced inhibition of tetraethylammonium uptake (TEA) in renal corticaJ sices. SVR (5%) attenuated $H_2O_2-induced$ inhibition of TEA uptake. $H_2O_2$ increased LDH release and lipid peroxidation in a dose-dependent manner. These changes were prevented by SVR extraction. The protective effect of SVR on LDH release was dose-dependent over the concentration range of 0.1-0.5%, and that on lipid peroxidation over the concentration ranges of 0.05-2%. SVR significantly prevented Hg-induced lipid peroxidation. SVR extraction (0.5%) increased cellular GSH content in normal and $H_2O_2-treated$ tissues. When slices were treated with 100 mM $H_2O_2$, catalase activity was decreased, which was prevented by 0.5% SVR extraction. The activity of glutathione peroxidase but not superoxide dismutase was significantly increased by 0.5% SVR extraction in $H_2O_2-treated$ tissuces. These results suggest that SVR has an antioxidant action and thereby exerts benefical effect against oxidant-induced impairment of membrane transport function. This effect of SVR is attributed to an increase in endogenous antioxidants such as GSH, catalase and glutathione peroxidase.

• Bulletin of the Korean Chemical Society
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• 제28권12호
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• pp.2266-2270
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• 2007

Electron transfer of a redox protein at a bare gold electrode is too slow to observe the redox peaks. A novel Nafion-riboflavin functional membrane was constructed during this study and electron transfer of cytochrome c, superoxide dismutase, and hemoglobin were carried out on the functional membrane-modified gold electrode with good stability and repeatability. The immobilized protein-modified electrodes showed quasireversible electrochemical redox behaviors with formal potentials of 0.150, 0.175, and 0.202 V versus Ag/AgCl for the cytochrome c, superoxide dismutase and hemoglobin, respectively. Whole experiment was carried out in the 50 mM MOPS buffer solution with pH 6.0 at 25 oC. For the immobilized protein, the cathodic transfer coefficients were 0.67, 0.68 and 0.67 and electron transfer-rate constants were evaluated to be 2.25, 2.23 and 2.5 s?1, respectively. Hydrogen peroxide concentration was measured by the peroxidase activity of hemoglobin and our experiment revealed that the enzyme was fully functional while immobilized on the Nafion-riboflavin membrane.

• 대한의생명과학회지
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• 제5권1호
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• pp.51-58
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• 1999

실험동물에 있어서 $CCl_4$에 의한 급성 간손상시 피부조직의 oxygen free radical 대사효소 활성 변동을 검토하기 위해 흰쥐에 $CCl_4$와 olive oil의 동량 혼합액을 체중 100g당 0.1 ml씩 복강으로 투여하여 처치하였다. $CCl_4$ 투여로 인한 혈청 alanine aminotransferase 및 xanthine oxidase (XO) 활성은 현저히 증가되었으며 체중당 간무게 (%)및 간조직의 malondialdehyde함량 역시 유의하게 증가되었다. 그리고 병리조직 검사에서도 $CCl_4$투여군에서 간조직의 괴사성 병변이 관찰되었다. 따라서 $CCl_4$를 투여한 실험동물이 급성 간손상 모델로 확인되었다. 이와 같은 간손상 실험동물의 피부조직중 oxygen free radical의 생성 효소인 XO 활성은 대조군과 별다른 차이를 볼 수 없었으나 oxygen free radical의 scavenging 효소인 superoxide dismutase, glutathione peroxidase 및 catalase 활성은 대조군에 비하여 유의하게 감소되었다. 또한 세포화학적 검사에서 cerrous perhydroxide과립이 간손상 실험동물의 피부조직에서 많이 나타났다. 이상 실험결과는 $CCl_4$에 의한 급성 간손상 유도 실험동물의 피부조직에 $H_2O$$_2$의 축적이 나타나는 현상을 시사해주고 있다.

• Environmental Engineering Research
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• 제18권1호
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• pp.29-35
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• 2013

This study noted that the actual mechanism of N-nitrosodimethylamine (NDMA) photodecomposition in the presence of $H_2O_2$ is missing from the previous works. This study investigated a key unknown reactive species (URS) enhanced by the addition of $H_2O_2$ during the photolysis of NDMA with $H_2O_2$, not hydroxyl radicals. In order to provide experimental evidences in support of URS formation, we have mainly used p-nitrosodimethylaniline, methanol, and benzoic acid as well-known probes of ${\cdot}OH$ in this study. Both loss of PNDA and formation of hydroxybenzoic acids were dependent on NDMA concentrations during the photolysis in a constant concentration of $H_2O_2$. In particular, competition kinetics showed that the relative reactivity of an URS was at least identical with ${\cdot}OH$-like reactivity. In addition, the decay of NDMA was estimated to be about 65% by the direct UV light and about 35% by the reactive species or URS generated through the photolysis of NDMA and $H_2O_2$. Therefore, our data suggest that a highly oxidizing URS is formed in the photolysis of NDMA with $H_2O_2$, which could be peroxynitrite ($ONOO^-$) as a potent oxidant by itself as well as a source of ${\cdot}OH$.

• The Plant Pathology Journal
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• 제35권4호
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• pp.287-300
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• 2019

Spot blotch caused by Bipolaris sorokiniana has spread to more than 9 million ha of wheat in the warm, humid areas of the Eastern Gangetic Plains (EGP) of South Asia and is a disease of major concern in other similar wheat growing regions worldwide. Differential lignin content in resistant and susceptible genotypes and its association with free radicals such as hydrogen peroxide ($H_2O_2$), superoxide ($O_2{^-}$) and hydroxyl radical ($OH^-$) were studied after inoculation under field conditions for two consecutive years. $H_2O_2$ significantly influenced lignin content in flag leaves, whereas there was a negative correlation among lignin and $H_2O_2$ to the Area Under Disease Progress Curve (AUDPC). The production of $H_2O_2$ was higher in the resistant genotypes than susceptible ones. The $O_2{^-}$ and $OH^-$ positively correlated with AUDPC but negatively with lignin content. This study illustrates that $H_2O_2$ has a vital role in prompting lignification and thereby resistance to spot blotch in wheat. We used cluster analysis to separate the resistant and susceptible genotypes by phenotypic and biochemical traits. $H_2O_2$ associated lignin production significantly reduced the number of appressoria and penetration pegs. We visualized the effect of lignin in disease resistance using differential histochemical staining of tissue from resistant and susceptible genotypes, which shows the variable accumulation of hydrogen peroxide and lignin around penetration sites.

• Korean Journal of Chemical Engineering
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• 제35권12호
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• pp.2442-2451
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• 2018

Novel highly active visible-light photocatalysts in the form of zinc bismuth oxide ($ZnBi_2O_4$) and graphite hybrid composites were prepared by coupling via a co-precipitation method followed by calcination at $450^{\circ}C$. The asprepared $ZnBi_2O_4$-graphite hybrid composites were tested for the degradation of rhodamine B (RhB) solutions under visible-light irradiation. The existence of strong electronic coupling between the two components within the $ZnBi_2O_4$-graphite heterostructure suppressed the photogenerated recombination of electrons and holes to a remarkable extent. The prepared composite exhibited excellent photocatalytic activity, leading to more than 93% of RhB degradation at an initial concentration of $50mg{\cdot}L^{-1}$ with 1.0 g catalyst per liter in 150 min. The excellent visible-light photocatalytic mineralization of $ZnBi_2O_4-1.0graphite$ in comparison with pristine $ZnBi_2O_4$ could be attributed to synergetic effects, charge transfer between $ZnBi_2O_4$ and graphite, and the separation efficiency of the photogenerated electrons and holes. The photo-induced $h^+$ and the superoxide anion were the major active species responsible for the photodegradation process. The results demonstrate the feasibility of $ZnBi_2O_4-1.0graphite$ as a potential heterogeneous photocatalyst for environmental remediation.