• 생명과학회지
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• 제21권5호
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• pp.693-699
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• 2011

Spermidine은 spermine의 전구체로 역할을 하는 putrescine로부터 합성되는 polycation의 한 형태이다. 최근에 spermidine는 수명연장에 중요한 역할을 하는 하나의 polyamine으로 알려져 있다. Hydroxyl radical, superoxide 및 hydrogen peroxide와 같은 활성산소(ROS)는 노화뿐만 아니라 다양한 병원성 과정에서 관여한다고 보고되고 있다. DPPH radical, $H_2O_2$ 및 hydroxyl radical에 대한 spermidine의 소거활성과 산화적 스트레스와 관련된 DNA oxidation에 대한 보호 효과가 in-vitro에서 평가되었다. Spermidine은 500 ${\mu}M$ 이상에서 DPPH radical와 $H_2O_2$에 대한 소거 효과를 보여주었다. 특히 활성산소종 중에서 spermidine는 hydroxyl radical에 대한 효과가 탁월하였다. 뿐만 아니라, spermidine는 500 ${\mu}M$에서 DNA oxidation에 대해서도 뚜렷한 보호 효과를 나타내었다. 더욱이 사람피부섬유아세포에서 superoxide dismutase와 같은 항산화 관련 단백질의 발현이 대조군과 비교시 spermidine 존재 하에 증가하였다. 이상의 결과로부터 spermidine은 암, 노화 및 염증을 포함하는 활성산소와 관련 있는 질병들을 예방하기 위한 항산화제로 이용될 수 있을 것이다.

• 대한약침학회지
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• 제13권2호
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• pp.5-12
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• 2010

본 연구의 목적은 자하거약침액의 항산화기능에 관련한 생리활성을 보기 위하여 대한약침학회에서 제공받은 자하거 약침액을 시료로 사용하였다. 총 폴리페놀 함량은 자하거 약침액 원액에서 24.641 mg/L로 이는 산수유 등과 같은 약용식물과 비슷한 수준의 함량이다. 자하거약침액원액에서 DPPH radical 소거능과 Superoxide dismutase(SOD) 유사활성 측정은 각각 49.4%, 50.87%였다. 또한 ABTS radical 소거능과 Nitrite radical 소거능(pH1.5)에서는 각각 50.01%, 52.8%로 ABTS radical과 Nitrite radical 소거능이 우수하였다. 본 실험결과로볼 때, 자하거 약침액은 항산화능력은 뛰어난 것으로 사료된다. 하지만 현재 자하거 약침액과 관련된 실험이 부족한 실정이기 때문에 앞으로 이에 관련된 더 많은 연구가 필요하다고 생각된다.

• 한국환경과학회지
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• 제25권3호
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• pp.373-383
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• 2016

The aim of this study is to determine the exposure concentration of tetrabromobisphenol A(TBBPA) in southwestern coast and their photodecomposition rate. Also, it is to identify the radical species of the photodecomposition of TBBPA and their reactive byproducts using the electron spin resonance(ESR) method. TBBPA was not detected in any of the sea water samples from Mokpo, Gunsan, or Goheung. The sediment samples from Mokpo contained not detection(N.D)~50.0 ng/g dry wt., while those from Gunsan contained N.D~28.5 ng/g dry wt. and those from Goheung contained N.D~7.3 ng/g dry wt. The photodecomposition rates were $2.56{\times}10^{-6}/hr$ by visible light(400 nm), $7.98{\times}10^{-6}/hr$ by ultraviolet light(300 nm <), and $6.78{\times}10^{-6}/hr$ by sunlight. Also, we confirmed that singlet oxygen and hydroxyl radicals are the key reactive oxygen species at wavelengths greater than 400 and 300 nm, respectively. This study shows that the main byproducts formed during irradiation at wavelengths above 300 nm are 2,6-dibromobenzosemiquinone radical(2,6-$DBSQ{\cdot}^-$) and g-value 2.0048 doublet spectrum.

• 대한임상검사과학회지
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• 제46권1호
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• pp.31-37
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• 2014

Metabolic syndrome such as, hypertension, diabetes, obesity, dyslipidemia etc are well known lifestyle diseases which threaten a health state. The purpose of this study is to evaluate antioxidant status and reactive oxygen species (ROS) in various stressful conditions. A group of persons (n=28) were enrolled in this study and stress status was evaluated using questionnaire of psychological well-being index (PWI-SF) and hematologic analysis of free oxygen radical defense (FORD), free oxygen radical test (FORT), lipid profiles and serum cortisol level. Analysis was done according to stress index, BMI status and overtime working. Blood samples from diabetics were used for control. Results are as in followings: Higher PWI-SF group showed higher FORT. Obese persons with BMI > $25kg/m^2$ showed statistically lower FORD (p<0.05) and higher FORT level (p<0.01). When compare with diabetics, an overweight group had similar levels in FORD and FORT while a normal body weight group showed quite different with diabetics in FORD (p<0.001). Higher ROS group has higher triglyceride, CRP and insulin levels but lower in FORD and HDL-cholesterol levels. Overtime working at night showed no meaningful result against our expectations. These results suggested that obesity showed most unfavorable correlations in an antioxidant status in various situations.

• 대한의생명과학회지
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• 제7권3호
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• pp.99-102
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• 2001

Toluene is mainly metabolized in liver by oxidative pathway. Oxigen free radicals occur through the process of toluene metabolism Therefore it causes tissue and cell min by the oxygen free radicals from the metabolism of toluene. Melatonin acts as a highly efficient free radical scavenger that protects cells from damage by oxygen free radicals. To test this hypothesis, toluene hepatotoxicity was induced by an abdominal injection of toluene. To see if the melatonin protects the rat's liver, melatonin was administrated orally, at the time of each toluene injection. Aspartate aminotransferase(AST), alanin aminotransferase(ALT), latic dehydrogenase(LDH) and alkaline phosphatase(ALP) levels in serum were measured to estimate hepatic function. Malondialdehyde(MDA), which gives an indirect index of oxidative injury was also measured. Hippuric acid is the last metabolic Production of toluene was measured by HPLC. There were significantly higher in AST, ALT, LDH, MDA and hippuric acid in toluene group, but there were no significant difference in melatonin group except ALT and hippuric acid. There was significantly lower in ALP level in toluene group, but there was no significant difference melatonin group, suggesting a significant hepatotoxicity due to oxygen free radicals through the process of toluene metabolism Melatonin treatment significantly protected hepatic function and free radical-mediated injury in the liver against toluene-induced changes. Accordingly, this study shows that melatonin is helpful in protecting liver injury by acute toluene intoxication.

• 한국표면공학회지
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• 제29권6호
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• pp.816-823
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• 1996

Chlorine containing high density plasmas are widely used to etch various materials in the microelectronic device fabrication. In this study, the characteristics of inductively coupled $Cl_2(O_2/N_2$) plasmas and their effects on the formation of silicon etching have been investigated using a Langmuir probe, quadrupole mass spectrometry(QMS), X-ray photoelectron spectroscopy(XPS), and Scanning Electron Microscopy(SEM). The addition of oxygen for chlorine plasmas reduced ion current densities and chlorine radical densities compared to the nitrogen addition by the recombination of oxygen with chlorine. Also, when silicon is etched in $Cl_2/O_2$ plasmas, etch products recombined with oxygen such as $SiCl_xO_y$ emerged. However, when nitrogen is added to chlorine, etch products recombined with nitrogen or Si-N bondings on the etched silicon surface were not found. All the silicon etch characteristics were dependent on the plasma conditions such as ion density, radical density, etc. As a result sub micron vertical silicon trench etch profiles could be effectively formed using optimized etch conditions for $Cl_2/O_2\; and \;Cl_2/N_2$ gas combinations.

• International Journal of Oral Biology
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• 제34권1호
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• pp.15-20
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• 2009

In our present study, total methanol extracts prepared from B. platyphylla var. japonica showed a significant increase in cell proliferation upon the induction of oxidative stress by hydrogen peroxide or $\gamma$-ray irradiation. Total methanol extracts were fractionated into five separate preparations i.e. n-hexane, dichloromethane, ethylacetate, n-butanol and water fractions. Among these, the ethylacetate and butanol fractions of B. platyphylla var. japonica showed the highest protective effects against oxidative stress induced by hydrogen peroxide. These fractions also showed strong protective effects against $\gamma$-ray irradiation. When we evaluated the cytotoxicity of these fractions, the butanol fraction showed no effects in a colony formation assay. In addition, the butanol fraction showed a cell proliferation activation effect evidenced by significant increase in the colony formation of $\gamma$-ray irradiated cells. Both a radical scavenging activity and clonogenic activity assay suggested that the mechanism behind this protective effect against reactive oxygen species may be due to the radical scavenging and cell proliferation activity of B. platyphylla var. japonica extracts.

• 동아시아식생활학회지
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• 제5권3호
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• pp.215-221
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• 1995

This study was undertaken to investigate the effect of Taraxacum herba extract on the hepatic xanthine oxidase activity as a oxygen free radical generating enzyme in vitro and in vivo. It was observed that partial purified hepatic xanthine oxidase (type O) activity was strongly inhibited by the addition of Taraxacum herba n-butanol extract in vitro. The Km value of xanthine oxidase without affecting the Vmax value for xanthine was significantly increased by the addition of ta-dase (type O) activity was significantly inhibited by the treatment of Taraxacum gerba n-butanol ex-tract for 5days(over 40mg/kg, i.p), whereas, xanthine oxidase (type D) activity was not changed by the injection of Taracacum herba n-butanol extract. Meanwhile, liver weight / body weight(%), serum alanine aminotransferase activity and hepatic lipid peroxide content in Taraxacum herba n-buta-nol extract-treated rat were not changed. These findings led us to conclude that Taraxacum herba n-butanol extract may regulate the hepatic xanthine oxidase type O activity to prevent toxic effect of oxidative stress by the oxygen free radicals.

• 생약학회지
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• 제36권3호통권142호
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• pp.159-163
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• 2005

We screened the anti-oxidative effect on V79-4 hamster lung fibroblast cells induced by hydrogen peroxide with fifteen herbal extracts. Uncariae rhynchophylla JACKS and Rheum coreanum NAKAI were found to show DPPH radical scavenge activity (25 and 29% compared to control). Rheum coreanum NAKAI and Siegesbeckia orientalis L. were shown to scavenge intracellular reactive oxygen species (57 and 55% compared to control) which is measured by dichlorodihydrofluorescin diacetate method (DCHF-DA). Rheum coreanum NAKAI which showed the most strong intracellular reactive oxygen species scavenging activity had low DPPH radical scavenging activity compared to Uncariae rhynchophylla JACKS.

• 한국환경성돌연변이발암원학회지
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• 제19권2호
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• pp.116-121
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• 1999

Quercetin and its glycosides showed a strong free radical scavenging effect to DPPH radical generation. However, there were not big differences between quercetin aglycone and glycosides under experimental condition of this study. On the other hand, quercetin had pro-oxidant effect in bleomycin-dependent DNA assay. Quercetin aglycone and its glycosides, quercitrin inhibited $H_2$$O_2$- induced DNA damage in CHL cells. They also have an anticlastogenicity toward DNA breakage agent by radical generation like bleomycin. These results indicate that quercetin aglycone and its glycosides are capable of protecting the free radical generation induced by reactive oxygen species like $H_2$$O_2$. The mechanism of inhibition in hydrogen peroxide-induced genotoxicity may be due to their free radical scavenging properties. Therefore, quercetin aglycone and its glycosides may be useful chemopreventive agents by protecting of free radical generation which are involved in carcinogenesis and aging. However, quercetin and its glycosides must also carefully examined for pro-oxidant properties before being proposed for use in vivo.