• 대한의생명과학회지
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• 제26권3호
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• pp.164-169
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• 2020

Atherosclerosis is a cardiovascular disease in which plaque builds up inside of an artery and can lead to various complications such as myocardial infarction, stroke, and thrombosis. Recently, hypertriglyceridemia has attracted significant attention as contributors to development of atherosclerosis. However, molecular mechanism of its contribution to atherosclerosis is poorly understood. Here we proposed a potential link between triglyceride (TG) and atherosclerosis. TG treatment promoted downregulation of certain scavenger receptor, macrophage scavenger receptor-1 (MSR-1) in phorbol myristate acetate (PMA)-derived human macrophages. TG treatment caused reduction of MSR-1 mRNA expression in a time- and dose-dependent manner. Using chemical inhibitors, we found that inhibition of signaling pathways associated with PI3K and PLC enhances TG-induced reduction of MSR-1 expression in THP-1 macrophages implying that PI3K and PLC is implicated in the expression of MSR-1 in macrophages. Since MSR-1 is associated with uptake and clearance of atherogenic lipoprotein, oxidized low density lipoprotein (oxi-LDL), our data suggest that increase of oxi-LDL due to TG-mediated reduction of its receptor MSR-1 can promote atherosclerosis.

• BMB Reports
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• 제29권5호
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• pp.423-428
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• 1996

A superoxide anion radical scavenger isolated from Capsella bursa-pastoris was characterized by infrared (IR) spectroscopy, sugar analysis, ultraviolet (UV) spectroscopy, $^{1}H$ and $^{13}C$ nuclear magnetic resonance (NMR) spectroscopies, and fast atom bombardment (FAB) mass analysis. The compound was assumed to be a flavonoid-O-glycoside from IR spectrum and UV absorption maxima. When the sugar composition of the compound was examined by thin layer chromatography (TLC) and gas chromatography (GC) of the acid hydrolysate, only glucose was detected. According to the results of UV spectrotroscopy by using shift reagents, the compound was supposed to be luteolin (5,7,3',4'-tetrahydroxy flavone) or chrysoeriol (5,7,4'-trihydroxy-3'-methoxy flavone) with glucose. Based on $^{1}H$- and $^{13}C-NMR$ spectroscopies, the compound was deduced as 7,4'-dihydroxy-5,3'-dimethoxy-${\alpha}$-6-c-glucosyl-${\beta}$-2"-o-glucosyl flavone. In FAB mass analysis the compound was finally characterized as 7,4'-dihydroxy-5,3'-dimethoxy-${\alpha}$-6-c-glucosyl-${\beta}$-2"-o-glucosyl flavone ($C_{29}H_{34}O_{16}$, M.W.=638).

• 대한한의학회지
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• 제23권4호
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• pp.55-63
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• 2002

Objectives: Peroxynitrite ($ONOO^{-}$), formed from the reaction of superoxide <${\cdot}O_2^{-}$) and nitric oxide (NO), is a cytotoxic species that can oxidize several cellular components such as proteins, lipids and DNA. It has been implicated in diseases such as aging process, Alzheimer's disease, rheumatoid arthritis, cancer and arteriosclerosis. Due to the lack of endogenous enzymes responsible for $ONOO^{-}$ inactivation, developing a specific $ONOO^{-}$ scavenger is of considerable importance. The aim of this study was to evaluate $ONOO^{-}$ scavenging activity and its mechanism in Cheonga-hwan (CAH). Methods: The $ONOO^{-}$ scavenging activity in CAH was assayed by measuring oxidized dihydrorhodamine 123 (DHR 123) by fluorescence. The scavenging efficacy was expressed as $IC_{50}$, showing the concentration of each sample required to cause 50% inhibition of DHR 123 oxidation. In a separate study, the protective effect of CAR on $ONOO^{-}$-induced nitration of bovine serum albumin (BSA) was investigated using immunoassay with a monoclonal anti-nitrotyrosine antibody, and a horseradish peroxidase-conjugated anti-mouse secondary antibody from sheep. Results: CAH showed potent scavenging activities of $ONOO^{-}$, NO and ${\cdot}O_2^{-}$. The data demonstrated that CAH led to decreased $ONOO^{-}$-mediated nitration of tyrosine through electron donation. CAH showed significant inhibition on nitration of bovine serum albumin by $ONOO^{-}$ in a dose-dependent manner. Conclusions: CAH can be developed as an effective peroxynitrite scavenger for the prevention of the $ONOO^{-}$ involved diseases.

• 한국식품위생안전성학회지
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• 제14권2호
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• pp.179-185
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• 1999

Previous studies have shown that methanol extract and its butanol fraction of Carthamus tinctorius L. Semen have the hepatoprotective effect on the CCl4-induced hepatotoxicity. The hepatoprotective effect of the subfractions of butanol fraction has been evaluated by analyzing oxygen free radical scavenging enzyme activities and histopathological examinations. In BS-5 subfraction treated group, the activity of superoxide dismutase has been significantly increased as compared with that of CCl4, treated rats. Antioxidant activity has been evaluated by the examination of the scavenging activity against 1,1-diphenyl-2-picrylhydrazyl radical. BS-5 subfraction has shown strong antioxidant activities. The histopathological examination showed that the treatment of BS-5 subfraction has relieved the ballooning degeneration of hepatocytes which had been generated by CCl4. It appears that the protective effect of BS-5 subfraction would be mediated of the attenuation of lipid peroxidation by acting as a free radical scavenger, which were based on the increase of superoxide dismutase activity.

• Archives of Pharmacal Research
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• 제28권10호
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• pp.1164-1169
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• 2005

Brain microglia are phagocytic cells that are the major inflammatory response cells of the central nervous system and widely held to play important pathophysiologic roles in Alzheimer's disease (AD) in both potentially neurotoxic responses and potentially beneficial phagocytic responses. In the study, we examined whether ginsonoside Rg3, a by-product of red ginseng, enhances the microglial phagocytosis of $A{\beta}$. We found that Rg3 promoted $A{\beta}$ uptake, internalization, and digestion. Increased maximal $A{\beta}$ uptake was observed at 4 and 8 h after Rg3 pretreatment (25 ${\mu}g/mL$), and the internalized $A{\beta}$ was almost completely digested from cells within 36 h when pretreated with Rg3 comparing with single non-Rg3-treated groups. The expression of MSRA (type A MSR) was also up-regulated by Rg3 treatment in a dose- and time-dependent manner which was coincidently identified in western blots for MSRA proteins in cytosol. These results indicate that microglial phagocytosis of $A{\beta}$ may be enhanced by Rg3 and the effect of Rg3 on promoting clearance of $A{\beta}$ may be related to the MSRA-associated action of Rg3. Thus, stimulation of the MSRA might contribute to the therapeutic potentials of Rg3 in microglial phagocytosis and digestion in the treatment of AD.

• Journal of Applied Biological Chemistry
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• 제43권3호
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• pp.156-160
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• 2000

The possible mechanism of the DNA strand breaking activity of the hot-water extract of Fructus Chaenomelis (dried fruit of Chaenomeles sinensis) in a closed circular duplex replica form DNA (RFI DNA) was studied through agarose gel electrophresis under various conditions. Induction of DNA strand scission by the hot-water extract of C. sinensis occurred in dose and time-dependent manners. $Cu^{2+}$ was indispensable for the induction of DNA strand breakage. Exogeneous chelating agents inhibited the DNA breaking activity, conforming the catalytic action of $Cu^{2+}$ on generation of free radicals responsible for oxidative damage. Antioxidant enzymes and some radical scavengers were used to investigate the major radical species triggering the DNA strand scission, demonstrating that a highest inhibitory activity was found in the presence of catalase, while less in the presence of tiron (a scavenger for superoxide radical), 2-aminoethyl-isothiuroniumbromide-HBr, cysteamine (scavengers for hydroxyl radical), and 1,4-diazabicyclo [2,2,2] octane (a scavenger for singlet oxygen) in decreasing order. The findings implied that oxygen radical species generated in presence of transition divalent cation during the oxidation of some compounds contained in the hot-water extract of C. sinensis is mainly responsible for inducing genotoxicity.

• 한국잠사곤충학회지
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• 제41권3호
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• pp.216-221
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• 1999

This study was designed to investigate the effects of silk fibroin powder on oxygen radicals and their scavenger enzymes in serum of rats. Sprague-Dawley(SD) male rats (160${\pm}$10 g) were fed experimental diets (SFP-2.5 and SFP-5.0 groups)added 2.5 and 5.0 g/kg BW/day for 6 weeks. Triglyceride levels were remarkably inhibited (15∼25%) in SFP-2.5 and SFP-5.0 groups compared with control group. Hydroxyl radical ($.$OH) formations resulted in a marked decrease (15%∼25%) compared with control group, while superoxide radical and hydrogen peroxide formations resulted in a significant decrease (6∼12% and 10%). Lipid peroxide and oxidized protein (>C=O group) productions resulted in a significant decrease (6∼12% and 6%) compared with control group. Superoxide dismutase (SOD) and catalase (CAT) activities were remarkably increased (35∼55% and 40∼50%), but glutathione peroxidase (GSHPX) activities were significantly increased (13%) compared with control group. These results suggest that anti-aging effect of silk fibroin powder (SFP) may play a pivotal role in attenuating a various age-related changes.

• 한국잠사곤충학회지
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• 제41권3호
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• pp.141-146
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• 1999

This study was designed to investigate the effects of silkworm powder (SWP) on oxygen radicals and their scavenger enzymes in serum of rats. Sprague Dawley (SD) male rats (160${\pm}$10g) were fed experimental diets (SWP-200and SWP-400 groups)added 200 and 400mg/kg BW/day for 6 weeks. Triglyceride (TG)levels were significantly inhibited (10% and 25%) in SWP-200 and SWP-400 groups, but there were no singificant differences in total, LDL-and HDL-cholesterol levels in both SWP-200 and SWP-400 groups. Hydroxyl radical ($.$OH) formations resulted in a marked decreases (about 20%) in both SWP-200 and SWP-400 groups compared with control group. Superoxide radical (O2.-)and hydrogen peroxide formations resulted in a significant decreases in SWP-400 group compared with control group. Lipid peroxide (LPO)and oxidized protein(>C=O group) productions resulted in a significant decreases (SOD) and catalase (CAT) activiteies were remarkably increased (10∼25% and 40∼50%)in SWP-200 and SWP-400groups. Glutathione peroxidase(GSHPX) activities were significantly increased (about 10%) in SWP-400 groups compared with control group. These results suggest that anti-aging effect of silkworm powder (SWP) may play a pivotal role in attenuation a various chronic degenerative diseases age-related changes.

• Bulletin of the Korean Chemical Society
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• 제1권1호
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• pp.35-39
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• 1980

A vacuum ultraviolet photolysis of ethyl bromide was studied in the pressure range of 0.5-19.9 torr and at 123.6 nm krypton resonance line. The pressure effect on the reaction was studied by increasing the reactant pressure and by adding an inert gas, e.g., He. In the observation the monatomic gas is found to be no effect in the reaction. A scavenger effect of the reaction was also performed by adding NO gas as a radical scavenger and was found to be quite efficient to scavenge a radical product $C_2H_6$. The observation of the major reaction product $C_2H_6$ was interpreted in terms of a molecular elimination. Nontheless the decreasing phenomenon of ${\phi}_{C_2H_4}/{\phi}_{C_2H_6}$ with pressure rise was attributed to the existence of the two electronically excited states. One state proceeds to the molecular elimination and the other to carbon-bromine bond fission. The excitation and the decomposition mechanisms between two excited states and the reaction products were interpreted in terms of the first excitation which proceeds the molecular elimination, and the second excitation which resulted from the first excited state by collisional cross over decomposes by carbon-bromine bond fission.

• 한국포장학회지
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• 제25권3호
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• pp.95-99
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• 2019

질소 치환한 소용량 조제분유 포장에서 초기 잔존 산소와 저장 중 투과 유입되는 산소를 제거하여 추가적인 산화 방지 효과를 얻고자 산소흡수제를 함입하는 포장을 구성 설계하였다. 조제분유 13 g을 담은 5 × 7 cm의 폴리에틸렌/펄프 다층 세공성 여과 봉지와 함께 산소흡수제를 8 × 9 cm의 알루미늄 적층 필름 포장에 넣은 후, 질소 기체로 치환포장하여 30℃에서 254일 동안 저장하였고, 같은 조건에서 산소흡수제가 함입되지 않은 대조구 포장 조건과 비교하였다. 산소흡수제는 조제분유와 직접적인 접촉을 하지 않으면서도 포장 내부의 산소를 전량 흡수할 수 있었으며 산소의 제거에 따른 산화 방지로 인하여 이산화탄소 발생을 보이지 않았다. 전 저장기간 동안 대조구 포장 제품에 비하여 산소흡수제 함입 포장의 제품에서는 0.7~2.2 meq/kg 만큼의 낮은 과산화물가를 보여서 조제분유 포장에서 산소흡수제의 산화 지연 효과를 확인할 수 있었다. 초기 갈변지표 물질인 HMF 함량은 두 처리구간 큰 차이를 보이지 않았다. 본 연구의 산소흡수제 함입 조제분유 포장은 소용량 포장의 유통기한을 연장하고 제품 품질을 향상시킬 수 있는 가능성을 제공하였다.