• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2002년도 가을 학술발표회 논문집
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• pp.593-596
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• 2002

This study examined the feasibility of Electrokinetic-Fenton process for remediation of contaminated kaolinite by phenanthrene. The test using 7% H$_2$O$_2$as anode purging solution indicated the higher electrical current and electroosmotic flow than the test using 3.5% H$_2$O$_2$. And distribution in the soil of H$_2$O$_2$concentration showed the higher value of the former than the latter. Furthermore, the test using 7% H$_2$O$_2$and 0.01N H$_2$SO$_4$was the highest electrical current and electroosmotic flow and H$_2$O$_2$was effectively introduced to the cathode region. As it turned out, the treatment effect of phenanthrene was improved in compare with the other tests.

• 한국식품영양과학회지
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• 제35권5호
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• pp.524-529
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• 2006

상황버섯의 활용성을 증진시키기 위하여 상황버섯의 화학성분과 그 추출물의 과산화수소 및 아질산염 소거능을 측정하였다. 상황버섯의 총 무기질 함량은 534.3 mg%였으며, K는 224 mg%로 가장 높았고, 총당과 환원당은 각각 56.2%와 9.8%였다. 유리 아미노산 함량은 $16.9{\sim}765.5mg%$범위였으며, 주요 유리 아미노산은 phenylalanine, aspartic acid, glutamic acid, glutamic acid, leucine, serine 및 valine이었는데, 그 중에서 phenylalanine의 함량이 765.5 mg%로 가장 높았다. 상황버섯 메탄올과 열수추출물의 총 페놀성 화합물은 각각 33.3 mg/100 mL와 20.7 mg/100 mL로서, 다른 용매 추출물에 비하여 높은 수치를 나타내었다. $H_2O_2$ 소거효과는 methanol 추출물 10 ${\mu}g/mL$에서 30분간 반응하였을 때 80%를 나타내어 대조구인 tocopherol 83.1%와 비슷하였다. 아질산염 소거효과는 낮은 pH에서 높았으며, pH 1.2에서 물과 methanol추출물 500 mg/mL은 각각 57.3%와 51.8%를 나타내었다. 결론적으로 상황버섯의 물과 메탄올 추출물은 $H_2O_2$와 아질산염 소거에 우수한 효과를 나타내었다.

• 한방비만학회지
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• 제15권2호
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• pp.93-103
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• 2015

Objectives: It was investigated the cytoprotective efficacies of isorhamnetin, a flavonoid originally derived from Hippophae rhamnoides L., against oxidative stress-induced apoptosis in C2C12 myoblasts. Methods: The effects of isorhamnetin on cell growth, apoptosis and reactive oxygen species (ROS) generation were evaluated by trypan blue dye exclusion assay, 4',6-diamidino-2-phenylindole staining and flow cytometry. The levels of apoptosis-regulatory and nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway-related proteins, and caspase activities (caspase-3 and -9) were determined by Western blot analysis and colorimetric assay, respectively. Results: Our results revealed that treatment with isorhamnetin prior to hydrogen peroxide ($H_2O_2$) exposure significantly increased the C2C12 cell viability and, indicating that the exposure of C2C12 cells to isorhamnetin conferred a protective effect against oxidative stress. Isorhamnetin also effectively attenuated $H_2O_2$-induced apoptosis and ROS generation, which was associated with the restoration of the upregulation of Bax and downregulation of Bcl-2 induced by $H_2O_2$. In addition, $H_2O_2$ enhanced the activation of caspase-9 and -3, and degradation of poly (ADP-ribose)-polymerase, a typical substrate protein of activated caspase-3; however, these events were almost totally reversed by pretreatment with isorhamnetin. Moreover, isorhamnetin increased the levels of heme oxygenase-1, a potent antioxidant enzyme, associated with the induction of Nrf2. Conclusions: Our data indicated that isorhamnetin may potentially serve as an agent for the treatment and prevention of muscle disorders caused by oxidative stress.

• 한국환경과학회지
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• 제17권2호
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• pp.203-210
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• 2008

The batch tests were performed to determine the ratio of Fenton reagent on diesel contaminated soil. The objective of a column test was to determine and optimize the hydrogen peroxide requirements for the remediation of a soil contaminated with diesel fuel. The batch test were done on 5 g diesel contaminated soil containing hydrogen peroxide (35%) and Iron (II) sulfate. The $H_2O_2(g):Fe^{2+}(g)$ ratio varied 1:0, 30:1, 15:1, 5:1, 1:1, with contact reaction time 120min. Initial diesel concentration were 2,000 mg/kg, 5,000 mg/kg, and 10,000 mg/kg. Average diesel removal from the contaminated soil is 97% after 2hrs. Results of this study showed possible application of without addition of iron source. In column test, treatment of a diesel-contaminated soil (initial diesel concentration: 2,000 mg/kg, 5,000 mg/kg, and 10,000 mg/kg) with hydrogen peroxide (35%) only was containing natural-occurring minerals. The time required for the column test was approximately 90min, 180min, 270min; column length was 5 em, 10 em, and 15 em. The most effective stoichiometry (final diesel cone.: $200{\sim}300mg/kg$) of 0.2 g peroxide consumed/mg diesel degraded. Further investigation is required to identify the effect of soil organic matter and soil mineral.

• 동의생리병리학회지
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• 제18권3호
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• pp.893-899
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• 2004

To test the cytoprotective effect of sophorae radix (SR) against hydrogen peroxide (H₂O₂)-induced cytotoxicity, we investigated the cell viability using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay in the presence of ethyl acetate subfractions of SR water extracts In H9c2 cells. And to clarify the cytoprotective mechanism of SR extracts, we evaluated the cellular glutathione (GSH) contents in the presence of subfraction 1, 2, 3, and 4 of SR ethyl acetate soluble fractions. Among 1 -12 subfractions of SR ethyl acetate soluble fractions, 1, 2, 3 and 4 subfractions have an efficacy inhibiting the cytotoxicity induced by H₂O₂ in H9c2 cells. Also, the protective effects of 1, 2, 3 and 4 subfractions of SR ethyl acetate soluble fractions resulted from the anti-oxidant effects. These results suggest that ethyl acetate soluble fractions of SR water extracts is effective in the prevention of H₂O₂-induced cytotoxicity and 1, 2, 3 and 4 subfraction of ethyl acetate soluble fractions possess the anti-oxidant component.

• 대한화학회지
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• 제33권6호
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• pp.662-668
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• 1989

Metal-4,4',4",4"'-tetraaminophthalocyanine [Mt-$PcNH_2$, Mt = Fe(III), Co(II), Ni(II), Cu(II)] 및 Mt-$PcNH_2$가 styrene-methacrylic acid 공중합체(STMA)에 고정화된 Mt-PcSTMA를 촉매로 사용한 불균일 수용액계에서 과산화수소의 분해반응에 대한 촉매활성에 대하여 실험하였다. 이 촉매들은 효소반응과 비슷한 촉매활성을 나타내었고, Fe(III)-$PcNH_2$이 공중합체에 결합되어 고정화된 Fe(III)-PcSTMA가 가장 촉매활성이 우수하였다. 분해반응율은 높은 pH 범위에서 증가하였으며, $CN^-,\;CNS^-,\;{C_2O_4}^{-2},\;I^-$ 등의 공존 음이온의 영향을 받았다. 또한, 반응속도론적인 고찰을 통하여 열역학적 특성값을 구한 결과로부터 촉매반응이 Michaelis-Menten형의 반응기구로 진행됨을 알 수 있었다.

• Journal of Korean Society for Atmospheric Environment
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• 제18권E2호
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• pp.85-95
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• 2002

Hydrogen peroxide and methyl hydroperoxide were measured over the northwestern Pacific Ocean during NASA's PEM (Pacific Exploratory Mission) -West. The first experiment (PEM -West A) was conducted in the fall of 1991 and PEM-West B in the early spring of 1994. Hydroperoxide data were obtained on board the NASA DC -8 aircraft through the entire depth of the troposphere. Average concentrations of both H$_2$O$_2$and CH$_3$OOH were higher during PEM -West A than B. The seasonal difference in hydroperoxide distribution was determined by the degree of photochemical activities and the strength and location of jetstream, which led to extensive and rapid continental outflow during the PEM-West B. While for H$_2$O$_2$distribution, a longitudinal gradient was more apparent than a latitudinal gradient, it was opposite for the CH$_3$OOH distribution. The longitudinal gradient indicates the proximity to the anthropogenic sources from the Asian continent, but the latitudinal gradient reflects photochemical activity. During PEM -West B, the ratio of C$_2$H$_2$/CO, a tracer for continental emission was raised and high concentrations of H$_2$O$_2$were associated with high ratios. The flux of hydroperoxide toward the North Pacific was also enhanced in the early spring. The eastward fluxes of H$_2$O$_2$ were 9% and 17% of the average photochemical production over the Pacific Basin between 140°E and 130°W during PEM-West A and B, respectively. For CH$_3$OOH, these ratios were 8% and 13%. Considering the lifetime of hydroperoxide and the rapid transport of pollutants, the export of hydroperoxide with other oxidants would have a significant influence on oxidant cycles over the North Pacific during winter/spring.

• 치위생과학회지
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• 제13권3호
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• pp.321-329
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• 2013

과산화수소는 치아미백에 널리 사용되는 물질로 과다 사용시 치수세포에 손상을 일으킬 수 있다. 본 연구의 목적은 활성산소인 과산화수소에 의해 유도되는 상아모세포의 단계별 분화와 LOX isoforms과의 관계를 밝히고자 하였다. 치수세포에 분화유도 배지와 과산화수소를 시간과 농도별로 처리한 후 LOX 유전자 발현은 RT-PCR로 측정하였고, LOX enzyme activity는 고감도 형광분석으로 확인하였다. 또한 가장 많은 발현억제를 보인 LOX와 LOXL을 선택하여 siRNA 처리 후 분화표지자의 발현변화와 LOX enzyme activity를 확인하였다. 1. 과산화수소 처리에 따라 LOX, LOXL, LOXL3 mRNA 발현은 농도와 시간 의존적으로 감소하였으나 LOXL2와 LOXL4 mRNA는 변화가 없었다. 2. 과산화수소 처리된 LOX enzyme activity는 0.3 mM과 24시간에서 가장 많은 증가를 보였다. 3. ALP, OPN, OCN의 mRNA 발현은 LOX와 LOXL siRNAs 모두에서 억제되었고, DMP1과 DSPP는 LOX siRNA에서 더 많은 억제 효과를 보였다. 하지만, 분화단계별(초기, 중기, 말기) 차이는 보이지 않았다. 4. LOX와 LOXL siRNAs를 처리하여 LOX enzyme activity를 측정한 결과 LOX siRNA를 처리한 실험군에서 더 많은 억제효과를 보였다. 이러한 결과는 상아모세포 성장과 분화과정에 낮은 농도의 과산화수소가 분화를 유도하고 여기에 LOX가 관련됨을 알 수 있었다. 결론적으로, 과산화수소는 LOX 유전자 발현조절을 통해 치수세포의 성장과 분화에서 중추적인 역할을 할 것이라고 생각된다.

• 생약학회지
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• 제44권3호
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• pp.263-268
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• 2013

The protective role against oxidative stress under cellular system using C6 glioma cells was studied using the ethyl acetate (EtOAc) fraction, luteolin (1), and luteolin-7-glucoside (2) of Taraxacum coreanum. C6 glioma cells showed low cell viability and high generation of reactive oxygen species (ROS) by the treatment with generator of hydrogen peroxide ($H_2O_2$) and amyloid beta ($A{\beta}_{25-35}$). However, the treatment of the EtOAc fraction attenuated the cellular oxidative stress, resulting in significant elevation of cell viability. In addition, the production of ROS formation was also decreased by the treatment of the EtOAc fraction. Compounds 1 and 2 were isolated from the EtOAc fraction, and the protective effect was evaluated. Compounds 1 and 2 led to the increase of cell viability and decrease of production of ROS against oxidative stress by $H_2O_2$ and $A{\beta}_{25-35}$. The present study indicated that the EtOAc fraction, compounds 1 and 2 from T. coreanum demonstrated protective effects against oxidative stress, suggesting the preventive role against neurodegenerative diseases.

• International Journal of Oral Biology
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• 제46권1호
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• pp.15-22
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• 2021

Alpha-lipoic acid (ALA) is a naturally occurring antioxidant and has been previously used to treat diabetes and cardiovascular disease. However, the autophagy effects of ALA against oxidative stress-induced dopaminergic neuronal cell injury remain unclear. The aim of this study was to investigate the role of ALA in autophagy and apoptosis against oxidative stress in the SH-SY5Y human dopaminergic neuronal cell line. We examined SH-SY5Y phenotypes using the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide assay (cell viability/proliferation), 4′,6-diamidino-2-phenylindole dihydrochloride nuclear staining, Live/Dead cell assay, cellular reactive oxygen species (ROS) assay, immunoblotting, and immunocytochemistry. Our data showed ALA attenuated hydrogen peroxide (H2O2)-induced ROS generation and cell death. ALA effectively suppressed Bax up-regulation and Bcl-2 and Bcl-xL down-regulation. Furthermore, ALA increased the expression of the antioxidant enzyme, heme oxygenase-1. Moreover, the expression of Beclin-1 and LC-3 autophagy biomarkers was decreased by ALA in our cell model. Combined, these data suggest ALA protects human dopaminergic neuronal cells against H2O2-induced cell injury by inhibiting autophagy and apoptosis.