• 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.

• Biomolecules & Therapeutics
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• 제24권3호
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• pp.338-345
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• 2016

Neurodegenerative diseases are often associated with oxidative damage in neuronal cells. This study was conducted to investigate the neuro-protective effect of methanolic (MeOH) extract of Perilla frutescens var. japonica and its one of the major compounds, rosmarinic acid, under oxidative stress induced by hydrogen peroxide ($H_2O_2$) in C6 glial cells. Exposure of C6 glial cells to $H_2O_2$ enhanced oxidative damage as measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and thiobarbituric acid-reactive substance assays. The MeOH extract and rosmarinic acid prevented oxidative stress by increasing cell viability and inhibiting cellular lipid peroxidation. In addition, the MeOH extract and rosmarinic acid reduced $H_2O_2-indcued$ expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) at the transcriptional level. Moreover, iNOS and COX-2 protein expression was down-regulated in $H_2O_2-indcued$ C6 glial cells treated with the MeOH extract and rosmarinic acid. These findings suggest that P. frutescens var. japonica and rosmarinic acid could prevent the progression of neurodegenerative diseases through attenuation of neuronal oxidative stress.

• Food Science and Biotechnology
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• 제16권5호
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• pp.858-862
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• 2007

The present study was conducted to examine the antioxidant activities and neuroprotective effects of methanolic extracts from Schizonepeta tenuifolia Briquet (STE). STE ($100\;{\mu}g/mL$) showed $43.33\;{\mu}M$ of total phenolic content, 64.43% of radical scavenging activity, and 0.157 of reducing power. In addition, the effect of STE on $H_2O_2$-induced DNA damage in human leucocytes was evaluated by the comet assay, where STE was a dose dependent inhibitor of DNA damage induced by $200{\mu}M$ of $H_2O_2$. The protective effect of STE against $H_2O_2$-induced oxidative damage on PC12 cells was investigated by an 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) reduction assay and lactate dehydrogenase (LDH) release assays. After 2 hr of cell exposure to $H_2O_2\;(500\;{\mu}M)$, a marked reduction in cell survival was observed. However, this reduction was significantly prevented by $1-50\;{\mu}g/mL$ of STE. Therefore, these results suggest that STE could be a new antioxidant candidate against neuronal diseases.

• 대한화학회지
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• 제21권4호
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• pp.227-234
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• 1977

황산산성에서 페닐히드라진과 브롬의 반응을 속도론적으로 검토하였다. 겉보기 2차 반응속도상수는 1M 이하의 황산농도에서는 수소이온 농도에 대략 역비례한다. KBr 첨가의 영향을 검토하여 $Br_2\;및\;Br_3^-$가 반응화학종이고, 이들의 속도상수는 $20^{\circ}C$의 0.01M $H_2SO_4$용액에서 각각 $5{\times}10^5M^{-1},sec^{-1}\;및\;0. 7{\times}10^5M^{-1},sec^{-1}$임을 밝혔다. 2,4-디니트로 페닐히드라진의 브롬과의 반응속도상수는 수소이온 농도에 거의 무관계하며 $Br_2\;및\;Br_3^-$에 대하여 각각 $1.2{\times}10^5M^{-1},sec^{-1}\;및\;2.0{\times}10^4M^{-1},sec^{-1}$이다.

• 대한본초학회지
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• 제26권4호
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• pp.133-137
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• 2011

Objectives : Socheongryong-Tang (小靑龍湯, SCRT) has been widely used to treat respiratory disease. In this study, we investigated the protective effects of SCRT on hydrogen peroxide-induced hepatotoxicity. Methods : In the mouse primary liver cells, SCRT was pretreated for 1 h, and 1 mM $H_2O_2$ was treated to mouse primary liver cells. Cell viability was analyzed by using 3- 4,5-Dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide (MTT) assay. Also, the activity of AST, ALT and LDH were measured for the evaluation the protective effect of SCRT on $H_2O_2$-induced hepatotoxicity. Intracellular ROS level was analyzed by FACS. Results : SCRT pretreatment decreased $H_2O_2$-induced hepatotoxicity and intracellular ROS production. Pretreatment of SCRT significantly reduced the cytotoxic effect induced by $H_2O_2$, associated with reducing DNA fragmentation and AST, ALT, LDH activities. Conclusions : These results suggest that SCRT has protective effect against $H_2O_2$-induced hepatotoxicity.

• 대한본초학회지
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• 제25권1호
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• pp.83-91
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• 2010

Objectives : In this study, we compared the anti-oxidant and anti-inflammatory activities of Curcumae longae Radix (CLRa) and Curcumae longae Rhizoma (CLRh). Methods : We performed 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and 2,2-azinobis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) cation scavenging assays, and determined total polyphenolic content to examine the anti-oxidant effects of CLRa and CLRh. We also evaluated the anti-oxidant effects of CLRa and CLRh against hydrogen peroxide ($H_2O_2$)-induced toxicity in PC12 cells using thiazolyl blue tetrazolium bromide (MTT) and reactive oxygen species (ROS) assays. Next, to compare the anti-inflammatory effects of CLRa and CLRh against lipopolysaccharide (LPS)-induced inflammation in microglia BV2 cells, we measured nitric oxide (NO) assay and inducible nitrite synthase (iNOS) using Western blotting analysis. Results : CLRa showed higher activity in DPPH and ABTS assays and lower total polyphenolic contents compared with CLRh. In PC12 cells, CLRa and CLRh showed no difference in H2O2-induced cell toxicity and ROS overproduction. In BV2 cells, CLRa showed higher effect than CLRh in NO and iNOS production induced by LPS. Conclusions : These results demonstrate that CLRa has higher radical scavenging activities and anti-inflammatory effect in BV2 cells comparing CLRh. However, CLRa and CLRh have no effect and no difference in $H_2O_2$-induced toxicity.

• 한국식품영양과학회지
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• 제45권4호
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• pp.510-517
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• 2016

본 연구는 싸리나무 잎에서 분리한 flavonoid 화합물인 eriodictyol의 항산화 활성을 평가하기 위해 hydrogen peroxide로 산화적 스트레스를 유도한 HepG2 세포에서 eriodictyol 화합물의 처리가 SOD-1, SOD-2, CAT 및 GPx의 유전자 발현에 미치는 영향을 분석하였으며, 또한 간 기능 지표효소인 GOT, LDH 및 GGT 활성을 분석하였다. 그리고 세포 내 활성산소종 생성 억제 효능을 분석하기 위하여 DCFH-DA assay를 실시하여 eriodictyol 화합물의 기능성 소재로서의 가능성을 알아보고자 본 실험을 하였다. Eriodictyol 화합물의 세포독성을 확인하기 위하여 HepG2 세포주를 이용하여 실시한 결과 eriodictyol 화합물을 $10{\sim}50{\mu}g/mL$의 농도로 처리한 모든 실험군에서 약 98% 이상의 세포생존율을 나타내었다. 항산화 효소 유전자 발현량을 통한 산화스트레스 억제 효과를 분석하기 위하여 HepG2 세포주에 hydrogen peroxide를 처리하여 산화스트레스가 증가시킨 조건에서 eriodictyol 화합물을 처리하여 SOD-1, SOD-2, CAT 및 GPx 발현량을 분석한 결과 eriodictyol 화합물의 처리 농도가 증가할수록 hydrogen peroxide 처리에 의해 감소한 SOD-1, SOD-2, CAT 및 GPx 발현량이 유의적으로 증가하는 것을 확인할 수 있었다. 간 기능 지표효소 활성을 측정하기 위해 GOT, LDH 및 GGT 활성을 분석한 결과 hydrogen peroxide로 단독 처리한 대조군과 eriodictyol 화합물을 처리한 군을 비교하였을 때 eriodictyol 화합물을 처리한 군에서 hydrogen peroxide 처리에 의해 증가한 GOT, LDH 및 GGT 활성이 유의적으로 감소하였다. HepG2 세포주에 eriodictyol 화합물을 처리하여 세포 내 활성산소종 생성에 미치는 영향을 DCFH-DA assay로 확인한 결과 eriodictyol 화합물의 농도가 증가함에 따라 세포내 활성산소종의 생성을 억제하는 것을 확인할 수 있었다. 따라서 본 실험을 통하여 eriodictyol 화합물은 산화적 스트레스로부터 항산화 효소 활성을 증가시키며, 활성산소종의 생성을 억제하는 효과를 확인할 수 있었다. 또한 간 기능 지표효소의 활성을 감소시켜 세포 보호 효과를 나타내어 항산화 활성 및 세포 보호 효과를 나타내는 기능성 소재로써 이용 가능성이 높을 것으로 판단되며, 후속연구를 통해 싸리나무 유래 eriodictyol 화합물의 세포 내 항산화 단백질 발현에 미치는 영향 및 동물실험을 통한 항산화 효과를 검증하는 것이 필요할 것으로 생각된다.

• 한국식품영양학회지
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• 제8권3호
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• pp.172-183
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• 1995

The nucleophilic substitution reactions of p-substituted benzyl bromide with l-substituted N,N-dimethylanilines in methanol and acetonitrile binary solvent mixture which is known to an isodielectric solvent system kinetically and the results are as follows. The positive charge is developed on the reaction center of the substrate and it means that the bond cleavage is preceded more than bond formation in the transition state on the analogy of Hammett px values. The bond form3tlon is not progressed in the case of electron donating substituent of substrate. However, the bond formation is much developed in the case of electron withdrawing substituent of substrate on the analogy of Hammett py values. The nucleophilic attacking ability is shown a highest at 80% (V/V) methanol content and the bond formation is well progressed at the same methanol composition on the result of a cross interaction coefficient, pxy. The result of transition state structure that is applicated to the potential energy surface model is in accord with the result that Is applicated to the reaction susceptibilities. The reaction Is subject to the polarity-polarizability term more than the hydrogen bond donor acidity term by application to the solvatochromic parameter eouation.

• 한국응용과학기술학회지
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• 제6권2호
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• pp.29-37
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• 1989

Using the quarternary ammonium salts as phase transfer catalyst, the nucleophilic substitution reaction of 1-chlorooctane with sodium-cyanide was investigate kinetically with respect to the formation of octanenitrile. The product was analyzed with gas chromatograph, and quantity of octanenitrile was measured. The reaction condition was considered by the effect of the reaction temperature, of the species and the amount of catalyst, of the speed of strirring, and of the concentration of reactants. The reaction was carried out in the first order on the concentration of 1-chlorooctane and sodium cyanide, respectively. The over-all order was 2nd. The activation energies for the nucleophilic substitution reaction of 1-chlorooctane and 1-bromooctane under tetrabutylammonium hydrogen-sulfate were calculated as 2.05 and 10.08kcal/mol, respectively. The effect of various caltalysts was decreased in the order of tetrabutylammonium bromide, terabutylammonium, tetrabutylammonium hydrogensulfate, and tetrabutylammonium iodide. The reaction rate was dependent on the concentration of sodium-cyanide dissolved in the aqueous phase, and the good result was shown when the mol ratio between 1-chlorooctane and sodium cyanide was one per three.

• Journal of the Korean Wood Science and Technology
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• 제42권5호
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• pp.523-532
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• 2014

This study was done to evaluate the antioxidant effect of oak hot water extracts on the oxidative stress induced by reactive oxygen species (ROS). The cytotoxicity of $H_2O_2$-induced oxidative stress was performed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay for the cell viability according to the dose-dependent treatment. Oak extracts demonstrated a dose-dependent ability to inhibit $H_2O_2$-induced apoptosis in cultured tenofibroblasts, as assessed by MTT assay and FACS analysis. $H_2O_2$ increased the phosphorylation of extracellular regulated kinase1/2 (ERK1/2) and of c-Jun N-terminal kinase (JNK) and the production of reactive oxygen species (ROS). In contrast, treatment with oak extracts was decreased this activation of ERK1/2 and JNK, as confirmed by western blot analysis, and reduced the production of ROS, as verified by fluorescent microscopic and flow cytometry (FACS) analyses. These findings suggest that oak extracts, by suppressing JNK, ERK1/2, and intracellular ROS production, have a concentration-dependent antiapoptotic effect on achilles tenofibroblasts exposed to an oxidative stressor, and may have therapeutic potential.