• Toxicological Research
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• v.17 no.4
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• pp.249-253
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• 2001

Fumonisin B1, a mycotoxin, is thought to induce esophageal cancer in humans and apoptosis in animal cells by inhibiting ceramide synthase. Dumonisin Bl may also generate reactive oxygen species directly or indirectly, leading to DNA damage and lipid peroxidation. In this study, a DNA fragmentation assay, dichlorofluorescein (DCF) analysis, and single cell gel electrophoresis (SCGE) were used to investigate the involvement of cellular free radicals, specifically hydrogen peroxide, in the DNA damaging activity of fumonisin B1. From an in vitro DNA fragmentation assay, E. coli DNA, damage by fumonisin Bl was increased by the addition of superxide dismutase (SOD) and decreased by catalase. SCGE and DCF analysis in vivo showed that the nuclear DNA damage and intracellular free radicals in cultured rat hepatocytes treated with fumonisin B1 were increased with the concentration of fumonisin Bl . DNA damage and free radical generation were inhibited by the addition of catalase. Fumonisin Bl , in the presence of SOD, produces hydrogen peroxide causing oxidative DNA damage and protein malfunction, leading to genotoxicity and cytotoxicity of the toxin.

• Textile Coloration and Finishing
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• v.24 no.2
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• pp.97-105
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• 2012

Compared with conventional adsorption-based coloration, the photoreactions of dyes such as photo-copolymerization and photo-crosslinking under UV irradiation can be employed for the coloration of textiles, which can be carried out without salt addition at room temperature. C.I. Reactive Black 5, a homo-bifunctional reactive dye containing two sulfatoethylsulfone groups, is used as a photo-reactive dye for wool fibers. Upon UV irradiation, the photo-reactive dye was grafted onto wool fabrics without photoinitiators. Since the disulfide bonds in the cystine residues of wool can be easily photodecomposed to active thiyl radicals which initiate the polymerization, the dye can be polymerized to an oligomeric dye of a degree of polymerization of 12 or more. The grafted fabrics reached a grafting yield of 2.3% o.w.f. and a color yield (K/S) of 18.2 by the photografting of an aqueous dye concentration of 9% using a UV energy of 25J/$cm^2$. Furthermore, the photochemically dyed wool fabric showed higher colorfastness properties to light, laundering and rubbing comparable to conventional reactive dyeing.

• Journal of Ginseng Research
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• v.32 no.2
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• pp.150-154
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• 2008

Twenty five albino rats were divided into five groups for conducting this experiment. The first group was for positive control (Vitamin C, ascorbic acid), the second group was of Panax ginseng (10 mg/kg body weight) treated group after bio-activity assay, the third group was of mercuric chloride treated group (0.033 mg/kg body weight) based on calculating $LD_{50}$ 9.26 mg/kg body weight by probit analysis, the fourth group was of mercuric chloride (0.033 mg/kg body weight) followed by Panax ginseng (10 mg/kg body weight) and the fifth group was Panax ginseng (10 mg/kg body weight) followed by mercuric chloride (0.033 mg/kg body weight) treated group. The interval between intake of Panax ginseng and mercuric chloride was of 2 hours in groups, fourth and fifth respectively. Comparative free radical scavenging property of Panax ginseng was studied under three in vitro models (role model for calculating scavenging activity) viz. DPPH method (hydroxyl free radicals), Nitric oxide method (nitrile free radicals) and Lipid peroxidation (mercury free radicals).

• YAKHAK HOEJI
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• v.43 no.5
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• pp.652-658
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• 1999

To reveal the inhibitory mechanism of NO-dependent vasorelaxation by quinone derivatives (OQ1 and OQ21), we have compared the generation of free radicals by oxidative stress and the formation of cellular adducts by arylation. First, we measured oxygen consumption by quinone derivatives as a marker of oxidative stress in order to investigate whether these quinone compounds could generate reactive oxygen species. Both OQ1 and OQ21 generated free radicals and OQ21 was more potent. These results suggested that free radicals be involved in the inhibition of vasorelaxation by quinones. Next, we measured the binding capacity of quinone derivatives with intracellular GSH and protein thiols (-SH) in order to investigate whether these quinones have arylation capacity. Compared to positive control groups (menadione), both OQ1 and OQ21 depleted intracellular GSH and protein thiols very slightly. These compounds have low toxicities in mammalian tissues. From these results, we concluded that the inhibition of vasorelaxation by quinone derivatives (OQ1, OQ21) may be cuased by generation of free radicals.

• Preventive Nutrition and Food Science
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• v.19 no.1
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• pp.34-39
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• 2014

This study evaluated the influence of cooking methods (blanching, pan-frying, and microwaving) on the antioxidant activity of Ligularia fischeri (LF) using myoglobin methods against five different reactive oxygen species (ROS) (i.e., 2,2-diphenyl-1-picrylhydrazyl (DPPH), hypochlorite ions, hydroxyl radicals, peroxyl radicals, and peroxynitrite ions). With respect to DPPH scavenging activity, the antioxidant activities of blanched LF and pan-fried LF were significantly higher (P<0.05) than that of fresh LF for all cooking times. Pan-fried LF and microwaved LF showed higher antioxidant activities against hydroxyl radicals and peroxyl radicals than uncooked LF, while the protective effect of blanched LF was low, except for the at the 3 min cooking time point. Microwaved LF showed high antioxidant activity against all ROS at the 2 min cooking time point. Interestingly, LF that had been microwaved for 2 min and 3 min had high antioxidant values, whereas blanched LF and pan-fried LF had low antioxidant values. The activities of cooked LF against five different ROS were characterized comprehensively by 5-axe cobweb charts.

• Proceedings of the Korea Environmental Mutagen Society Conference
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• 2004.11a
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• pp.110-110
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• 2004

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.10
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• pp.4434-4442
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• 2011

Reactive oxygen species (ROS) are reactive and potentially harmful to cells, causing oxidation of lipids, proteins, and DNA. In humans, the deleterious effects of ROS have been linked with aging, carcinogenesis, and atherosclerosis. In order to investigate an antioxidant activity of wood vinegar by bioconversion, we preferentially analyzed the total acidity, acetic acid, pH, and contents of total polyphenols and flavonoids, respectively. Also, we evaluated the scavenging abilities on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals, superoxide anion radicals, hydrogen peroxide radicals, and nitric oxide radicals. The total acidity and amount of acetic acid of wood vinegar after bioconversion were lower than those of wood vinegar before bioconversion, but the pH was higher than that of wood vinegar before bioconversion. The contents of total polyphenols and flavonoids of wood vinegar after bioconversion were 11.17 mg/$m{\ell}$ and 0.42 mg/$m{\ell}$, respectively. The $SC_{50}$ values were in order of superoxide anion radical scavenging activity < DPPH radical scavenging activity < hydrogen peroxide radical scavenging activity < nitric oxide radical scavenging activity. Therefore, these results suggest that wood vinegar by bioconversion can be useful as primary antioxidants for medicines and cosmetics.

• Preventive Nutrition and Food Science
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• v.10 no.1
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• pp.46-51
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• 2005

The protective effect of Acanthopanax senticosus (AS) extract on alloxan-induced pancreatic β-cell damage was investigated in HIT T-15 cells, a Syrian hamster pancreatic β-cell line. Alloxan caused the pancreatic β-cell damage through the generation of reactive oxygen free radicals, increased DNA fragmentation, and decreased cellular NAD/sup +/ levels. The β-cell damage was significantly prevented by the pretreatment with water soluble extract of AS roots. These results suggest that the protective effect of AS extract, on alloxan-induced β-cell damage, is primarily due to the inhibition of the generation of reactive oxygen free radical species (ROS) by alloxan.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.175.1-175.1
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• 2016

In recent, tract infections such as atopic dermatitis, allergic rhinitis and a respiratory disease are increasing, giving rise to the atmospheric pollution, inflow of micro-size dust and side effect of humidifier disinfectant. In this context, the environment-friendly technology is required to eliminate airborne pathogens. We propose solution of the previous problems, making use of Radical Mist Generator (RMG). Existing technologies of air purification using a gas discharge produce harmful substances such as ozone, NOx, etc. However, the RMG uses a pure water as a plasma forming material. The RMG sprays the water mist, which contains reactive radicals to sterilize microorganisms. RMG is comprised of a power supply, plasma electrodes and a nozzle. In order to analyze the electrical characteristic and concentrations of reactive radicals, we employ an oscilloscope and a titration method. To test the sterilization effect of RMG, we used E.coli. We confirmed that E.coli was killed over 90%. Eventually, we expect that RMG can be promising tool for a purified system.

• Clinical and Experimental Pediatrics
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• v.56 no.3
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• pp.107-111
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• 2013

Preterm infants are vulnerable to the oxidative stress due to the production of large amounts of free radicals, antioxidant system insufficiency, and immature oligodendroglial cells. Reactive oxygen species (ROS) play a pivotal role in the development of periventricular leukomalacia. The three most common ROS are superoxide ($O2^{\cdot-}$), hydroxyl radical ($OH^{\cdot}$), and hydrogen peroxide ($H_2O_2$). Under normal physiological conditions, a balance is maintained between the production of ROS and the capacity of the antioxidant enzyme system. However, if this balance breaks down, ROS can exert toxic effects. Superoxide dismutase, glutathione peroxidase, and catalase are considered the classical antioxidant enzymes. A recently discovered antioxidant enzyme family, peroxiredoxin (Prdx), is also an important scavenger of free radicals. Prdx1 expression is induced at birth, whereas Prdx2 is constitutively expressed, and Prdx6 expression is consistent with the classical antioxidant enzymes. Several antioxidant substances have been studied as potential therapeutic agents; however, further preclinical and clinical studies are required before allowing clinical application.