• Toxicological Research
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• 제26권4호
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• pp.321-327
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• 2010

The ability of 80% ethanol extracts from five medicinal plants, Aralia continentalis, Paeonia suffruticosa, Magnolia denudata, Anemarrhena asphodeloides, and Schizonepeta tenuifolia, to neutralize hydroxyl radical, peroxyl radical and peroxynitrite was examined using the total oxyradical scavenging capacity (TOSC) assay. Peroxyl radical was generated from thermal homolysis of 2,2'-azobis(2-methylpropionamidine) dihydrochloride (ABAP); hydroxyl radical by an iron-ascorbate Fenton reaction; peroxynitrite by spontaneous decomposition of 3-morpholinosydnonimine N-ethylcarbamide (SIN-1). The oxidants generated react with $\alpha$-keto-$\gamma$-methiolbutyric acid (KMBA) to yield ethylene, and the TOSC of the substances tested is quantified from their ability to inhibit ethylene formation. Extracts from P. suffruticosa, M. denudata, and S. tenuifolia were determined to be potent peroxyl radical scavenging agents with a specific TOSC (sTOSC) being at least six-fold greater than that of glutathione (GSH). These three plants also showed sTOSCs toward peroxynitrite markedly greater than sTOSC of GSH, however, only P. suffruticosa revealed a significant hydroxyl radical scavenging capacity. Seven major active constituents isolated from P. suffruticosa, quercetin, (+)-catechin, methyl gallate, gallic acid, benzoic acid, benzoyl paeoniflorin and paeoniflorin, were determined for their antioxidant potential toward peroxynitrite, peroxyl and hydroxyl radicals. Quercetin, (+)-catechin, methyl gallate, and gallic acid exhibited sTOSCs 40~85 times greater than sTOSC of GSH. These four components also showed a peroxynitrite scavenging capacity higher than at least 10-fold of GSH. For antioxidant activity against hydroxyl radical, methyl gallate was greatest followed by gallic acid and quercetin. Further studies need to be conducted to substantiate the significance of scavenging a specific oxidant in the prevention of cellular injury and disease states caused by the reactive free radical species.

• KSBB Journal
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• 제19권1호
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• pp.67-71
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• 2004

본 연구에서는 염생식물의 하나인 해당화의 항산화효과를 탐색하기 위해 해당화의 dichloromethane과 methanol의 조추출물을 합하여 n-hexane, 15% aq. MeOH, n-BuOH, $H_2O$로써 순차적으로 용매 분획하여 DPPH 라디칼, peroxynitrite의 소거 활성과 지질 과산화 저해 활성을 측정하였다. 그 결과 각각의 실험에서 해당화의 유의적인 항산화 효과가 확인되었으며, 특히, 4개의 분획물들 중 n-BuOH 획분이 가장 뛰어난 항산화 효과가 있는 것으로 나타났다. 따라서 해당화의 항산화 효과는 비교적 극성이 큰 2차 대사산물에 의한 것임을 추측할 수 있으며, 해당화의 많은 생물학적인 활성들 중 peroxynitrite 소거 효과와 마우스 간 균질물을 이용한 지질 과산화물 생성 억제 활성에 관한 보고는 이것이 처음이다.

• KSBB Journal
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• 제19권1호
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• pp.57-61
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• 2004

본 연구에서는 항산화 활성을 갖는 유용한 선도 물질을 찾기 위한 일환으로 20종의 염생식물의 추출물에 대해 peroxynitrite와 DPPH 라디칼 소거 활성을 측정하였다. 그 결과 해당화 (Rosa rugosa), 개망초 (Erigeron annus), 냇씀바귀(Ixeris tamagawaensis), 띠 (Imperata cylindrica), 범행초(Tetragonia tetragonoides), 사철쑥 (Artemisia capillaris)의 MeOH 추출물에서 우수한 DPPH 라디칼 소거 효과가 확인되었다. 또한, 해당화(Rosa rugosa), 개망초 (Erigeron annus), 칠면초 (Suaeda japonica), 냇씀바귀 (Ixeris tamagawaensis), 띠 (Imperata cylindrica), 갯방풍 (Glehnia littoralis), 함초(Salicornia herbacea), 해국 (Aster spathulifolius), 범행초 (Tetragonia tetragonoides)의 MeOH 추출물과 CH$_2$Cl$_2$ 추출물에서 각각 peroxynitrite의 소거효과가 관찰되었다. 그 중에서도 해당화 MeOH 추출물의 DPPH 래디칼 소거효과는 100 $\mu\textrm{g}$/$m\ell$ (f.c.) 농도에서 87.51%로 나타났고, peroxynitrite 소거효과는 5 $\mu\textrm{g}$/$m\ell$ 농도에서 표품의 ONOO를 첨가했을 때 97.03%와 SIN-1을 첨가했을 때 98.48%로서 가장 강력한 항산화활성을 가지는 것으로 나타났다. 해당화의 peroxynitrite의 효과는 대조군으로 사용된 penicillamine보다도 우수하며, L-ascorbic acid와 비슷한 효과였다.

• Ocean and Polar Research
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• 제26권1호
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• pp.59-64
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• 2004

As a part of our search for novel antioxidants from the seaweeds, we have investigated radical scavenging effect for their crude extracts using 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical, authentic peroxynitrite, and 3-morpholinsydnonimine (SIN-1), a peroxynitrite-generating species in vitro. Thirty-four seaweeds were screened for $ONOO^-$ and DPPH radical scavenging activities. A potent inhibitory effect against peroxynitrite generated by SIN-1 at $5{\mu}g/ml$ of methanol extracts was observed in order of Ishige okamurae(95.3%), Sargassum hemiphyllum(90.2%), Symphyocladia latiuscula(89.6%), Porphyra suborbiculata(86.7%), and Gelidium amamsii(85.9%), Also, a significant scavenging effect against direct authentic peroxynitrite was revekaled for methanol extracts of Ishige okamurae(66.2%) and Sargassum hemiphyllum(55.2%) and the acetone/methylene chloride(1:1) extract of Gigatina tenella (61.0%). In our measurement for evaluating the capacity to scavenge the stable free radical of DPPH, acetone/methylene chloride(1:1) extracts of Symphyocladia latiuscula, Gloiopeltis furcata, and Sargassum thunbergii and the methanol extract of Sargassum sp. showed an inhibitory potency of 85.8%, 82.8%, 74.1%, and 64.0%, respectively.

• Bulletin of the Korean Chemical Society
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• 제26권6호
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• pp.921-924
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• 2005

It is known that metallothionein (MT) plays a role in the scavenging of free radicals, which is produced under various stress conditions. MT may function as an antioxidant that protects against oxidative damage of DNA, protein, and lipid induced by superoxide anion, hydrogen peroxide, hydroxyl radical, nitric oxide, and peroxynitrite. This study was undertaken to test the hypothesis that MT also protects from RNA damage induced by peroxynitrite, an important reactive nitrogen species that causes a diversity of pathological processes. A cell-free system was used. RNA damage was detected by the mobility of $tRNA^{Phe}$ in electrophoresis. Cleavages on tRNA were not induced by 3-morpholinosydnomine, which produces peroxynitrite directly. MT induced tRNA damage which was site specific.

• 한국자원식물학회지
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• 제21권4호
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• pp.254-259
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• 2008

약용식물 9종의 물 추출물에 대한 항산화 효과를 탐색하기 위해 in vitro 조건에서 강력한 산화력과 독성을 갖는 $ONOO^-$와 ${\cdot}$OH radical의 소거효과를 측정하였다. 그 결과, 감잎, 구기자, 꾸지뽕나무, 담쟁이덩굴, 마디풀, 비파나무, 으름덩굴, 참취 추출물은 10${\mu}g/ml$ 농도에서 50% 이상의$ONOO^$ 소거효과를 나타냈다. 이러한 $ONOO^-$ 소거효과는 양성 대조물인 penicillamine(94.08${\pm}$3.04)에 비해 낮았지만 비파나무 물 추출물(89.87${\pm}$4.57)이 다른 시료에 비해 가장 강력한 $ONOO^-$ 소거효과를 나타냈다. 또한, 가는잎쐐기풀과 감잎 물 추출물은 1mg/ml 농도에서 양성대조물인 thiourea 보다 효과적인${\cdot}$OH radical 억제효 과를 나타냈다. 결론적으로 9종의 약용식물은 $ONOO^-$와${\cdot}$OH radical과 연관된 산화적 스트레스에 의한 세포와 조직의 손상을 억제시킬 수 있는 천연 항산화제로 밝혀졌다.

• 동의생리병리학회지
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• 제21권1호
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• pp.165-170
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• 2007

Pyungwi-san(PWS) have been using as a basic prescription of digestive disorder in Korean traditional medicine. This study was performed to examine the in vitro antioxidant activity of the extract using different antioxidant tests including by 1,1-diphenyl-2-picryl-hydrazil (DPPH) radical scavenging, superoxide anion radical scavenging, metal chelating hydrogen peroxide scavenging, lipid peroxydation protective effect and scavenging effect of nitric oxide and peroxynitrite. Herbal-acupuncture solution of PWS(PWS-HS) exhibited a concentration-dependent inhibition of DPPH radical adduct formation and it showed dose-dependent free radical scavenging activity onto superoxide anions. In addition, the result of metal chelating hydrogen peroxide scavenging and ammonium thiocyanate experiments showed that PWS-HS was an active scavenger of hydroxyl radicals. Furthermore, it was also found to be effective in scavenging nitric oxide and peroxynitrite, well-known cytotoxic species that can oxidize several cellular components such as proteins, lipids and DNA.

• Applied Biological Chemistry
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• 제48권4호
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• pp.435-439
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• 2005

Antioxidant activity of the ethanol extract from boiled-water of Hizikia fusiformis (EBH) were compared with those of BHA, L-ascorbic acid, gallic acid, caffeic acid and (-)-catechin. The free radical scavenging ability against DPPH (1,1-diphenyl-2-picrylhydrazyl), authentic peroxynitrite and reducing power were measured as indices of antioxidant activity. EBH showed the potent DPPH radical and peroxynitrite scavenging activities, showing 85.23 and 96.97% at final concentration of $1000{\mu}g/ml$, respectively. The reducing power increased with the increasing amount of EBH (final concentration of 1, 10, 100 and $1000{\mu}g/ml$). Total phenolic content of EBH was 588 mg (-)-catechin/g at the final concentration $1000{\mu}g/ml$. Total phenolic contents correlated with DPPH radical scavenging activity $(R^2=0.766)$ and reducing power $(R^2=0.944)$. These results suggested that EBH could be a natural antioxidative source containing antioxidative components.

• The Korean Journal of Physiology and Pharmacology
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• 제5권3호
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• pp.205-212
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• 2001

It has been proposed that nitirc oxide is involved in the pathogenesis of cerebral ischemia-reperfusion. Because superoxide production is also enhanced during reperfusion, the cytotoxic oxidant peroxynitrite could be formed, but it is not known if this occurs following global forebrain ischemia-reperfusion. We examined whether peroxynitrite generation is increased in the vulnerable regions after forebrain ischemia-reperfusion. Transient forebrain ischemia was produced in the conscious rat by four-vessel occlusion. Rats were subjected to 10 or 15 min of forebrain ischemia. Immunohistochemical method was used to detect 3-nitrotyrosine, a marker of peroxynitrite production. 3-Nitrotyrosine immunoreactivity was enhanced in the hippocampal CA1 area 3 days after reperfusion. Furthermore, in rats subjected to ischemia for 15 min, this change was also observed in the lateral striatal region and the lateral septal nucleus $2{\sim}3$ days after reperfusion. The cresyl violet staining of adjacent sections showed that neuronal cell death was induced in parallel with the nitrotyrosine immunoreactivity in the hippocampal CA1 area and the lateral striatal region. Our findings suggest that oxygen free radical accumulation and consequent peroxynitrite production play a role in neuronal death caused by cerebral ischemia-reperfusion.

• Toxicological Research
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• 제16권1호
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• pp.1-8
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• 2000

Astrocytes generate free radicals including nitric oxide (NO) and reactive oxygen intermediates(ROI) which in turn play roles in the pathogenesis of degenerative diseases and sclerotic changes of the brain. This study was designed to evaluate the mechanism that free radicals contribute to the cytotoxicty of rat neonatal primary astrocytes. Treatment with NO donors alone including soldium nitroprusside(SNP), S-nitrosoglucathinoe (GSNO), and S-nitroso-n-acetylpenicillamine (SNAP) showed a little effect on the death of rat neonatal primary astrocytes, whereas SNP markedly induced the death of RAW 264.7 cells. ROI inculding H2O2 and O2 donor also slightly induced the death of rat primary astrocytes. However, 3-morpholinosydnonimine(SIN-1), a donor of peroxynitrite (ONOO), which is a reactive compound of NO with superoxide, significantly decreased the viability of rat primary astrocytes in a dose-dependent manner. Cells were retarded in outgrowth of viability of cellular processes with cell shrinkage and detachment from culture dishes. Hoechst staining demonstrated that SIN-1-induced cell death might be due to an apoptosis which was characterized by nuclear condensation and fragmentation. SIN-1-induced apoptosis was prevented by the pretreatment with superoxide dismutase (SOD) and catalase in rat primary astorocytes. Furthermore, prevention of the generation of reduced glutathione (GSH) by DL-buthionine-[S, R]-sulfoximine (BSO) aggravated the cytotoxic effects of SNP, benzene triol, and SIN-1 in rat primary astrocytes. Taken together, it is suggested that peroxynitrite may be a major effector of apoptosis and cellular antioxidant system is important for cell survival in rat prima교 astrocytes.