• Proceedings of the Korea Environmental Mutagen Society Conference
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• 2001.10b
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• pp.7-8
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• 2001

• Preventive Nutrition and Food Science
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• v.18 no.1
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• pp.18-22
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• 2013

To investigate radical scavenging effects and protective activities of bitter melon (Momordica charantia) against oxidative stress, in vitro and a cellular system using LLC-$PK_1$ renal epithelial cells were used in this study. The butanol (BuOH) fraction of bitter melon scavenged 63.4% and 87.1% of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals at concentrations of 250 and $500{\mu}g/mL$, respectively. In addition, the BuOH fraction of bitter melon effectively scavenged hydroxyl radicals (${\cdot}OH$). At all concentrations tested, the scavenging activity of the BuOH fraction was more potent than that of the positive control, ascorbic acid. Furthermore, under the LLC-$PK_1$ cellular model, the cells showed a decline in viability and an increase in lipid peroxidation through oxidative stress induced by pyrogallol, a generator of superoxide anion ($O_2{^-}$). However, the BuOH fraction of bitter melon significantly and dose-dependently inhibited cytotoxicity. In addition, 3-morpholinosydnonimine (SIN-1), a generator of peroxynitrite ($ONOO^-$) formed by simultaneous releases of nitric oxide and $O_2{^-}$, caused cytotoxicity in the LLC-$PK_1$ cells while the BuOH fraction of bitter melon ameliorated oxidative damage induced by $ONOO^-$. These results indicate that BuOH fraction of bitter melon has protective activities against oxidative damage induced by free radicals.

• Journal of Ginseng Research
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• v.14 no.2
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• pp.187-190
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• 1990

Maltol(2-methyl-3-hydroxy-r-pyrone), a component known to be present in Korean Ginseng root showed an antioxidant action but its potency as an antioxidant was low: about 1150th that of other antioxidants such as pphenylenediamine, BHA and BHT. However, maltol was able to protect the oxidation damages in biological systems such as adriamycin-induced membrane damage in isolated cardiomyocytes, paraquat-induced toxicities in isolated hepatocytes and reperfusion injury in isolated hearts. The antioxidant action of maltol was also shown to be effective in vivo. The antioxidant action of this compound was probably due to the removal of hydroxyl radicals. In view of the roles of oxygen radical in various pathological proceises, Korean Ginseng root which contains several antioxidants including maltol is expected to have beneficial effects on the oxygen radical-involved processes.

• The Journal of Korean Medicine
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• v.26 no.3 s.63
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• pp.204-214
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• 2005

Objectives : The verity extract of the Gagam-Hyungbang-Gihwang-tang (GHG) was assessed to determine the mechanisms of its antioxidant activity. Methods : The fellowing effects were measured : GHG exhibited a concentration-treatment; scavenging ${\alpha},\;{\alpha}-diphenyl-\beta-picrylhydrazyl$ (DPPH) radical, linoleic acid oxidation in a thiocyanate assay system, and superoxide anion, hydroxyl radical-induced DNA nicking. We investigated mRNA levels such as superoxide-dismutase. Results : The GHG extract showed dose-dependent free radical scavenging activity, including DPPH radicals, hydroxyl radicals, and superoxide anion, using different systems. The GHG was also found to be effective in protecting plasmid DNA against the strand breakage induced by hydroxyl radicals in Fenton's reaction mixture. Furthermore, SOD-1 mRNA expression levels increased in tat hepatoma H4IIE cells Conclusions : We expect that GHG will to helpful to the development of antioxidant activity treatments.

• Proceedings of the Korea Crystallographic Association Conference
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• 2002.11a
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• pp.53-53
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• 2002

Alkali-soluble random copolymer (ASR) was used as a functional resin in the emulsion polymerization of styrene to prepare structured nanoparticles. The calorimetric technique was applied to study the kinetics of emulsion polymerization of styrene using ASR and conventional ionic emulsifier, sodium dodecyl benzene sulfonate (SDBS). ASR could form aggregates like micelles and the solubilization ability of the aggregates was dependent on the neutralization degree of ASR. The rate of polymerization in ASR system was lower than that in SDBS system. This result can be explained by the creation of a hairy ASR layer around the particle surface, which decreases the diffusion rate of free radicals through this region. Although a decrease in particle size was observed, the rate of polymerization decreased with increasing ASR concentration. The higher the concentration of ASR is, the thicker and denser ASR layer may be, and the more difficult it would therefore be for radicals to reach the particle through this layer of ASR. The rate of polymerization decreased with increasing the neutralization degree of ASR. The aggregates with high neutralization of ASR are less efficient in solubilizing the monomer and capturing initiator radicals than that of the lower neutralization degree, which leads to decrease in rate of polymerization.

• Journal of the Korean Society of Tobacco Science
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• v.12 no.1
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• pp.19-27
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• 1990

To evaluate tobacco quality, several mathods including sensory test, or measurement of some toxic compounds such as tar, nicotine and carbon monoxide in cigarette smoke have been used. However, many detrimental effects of smoking on the physiological functions including respiratory system reported were turned out to be the action of reactive oxygen species. Therefore, the amounts of oxygen free radicals such as superoxide, hydroxyl radical, even hydrogen peroxide in the cigarette smoke are thought the very important factors. In the present study, we have determined the generation of superoxide and the content of hydrogen peroxide using superoxide dismutase and catalase in the gas and particulate phases obtained from cigarette smoke, respectively. In the aqueous extracts of total particulate materials, suproxide and hydrogen peroxide were detected, and there was an excellent correlation between oxygen tint of oxygen free radicals in cigarette smoke may be a useful index for evaluation of cigarette quality in the aspect of smoking and health.

• BMB Reports
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• v.39 no.4
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• pp.452-456
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• 2006

To elaborate the peroxidase activity of cytochrome c in the generation of free radicals from $H_2O_2$, the mechanism of DNA cleavage mediated by the cytochrome c/$H_2O_2$ system was investigated. When plasmid DNA was incubated with cytochrome c and $H_2O_2$, the cleavage of DNA was proportional to the cytochrome c and $H_2O_2$ concentrations. Radical scavengers, such as azide, mannitol, and ethanol, significantly inhibited the cytochrome c/$H_2O_2$ system-mediated DNA cleavage. These results indicated that free radicals might participate in the DNA cleavage by the cytochrome c and $H_2O_2$ system. Incubation of cytochrome c with $H_2O_2$ resulted in a time-dependent release of iron ions from the cytochrome c molecule. During the incubation of deoxyribose with cytochrome c and $H_2O_2$, the damage to deoxyribose increased in a time-dependent manner, suggesting that the released iron ions may participate in a Fenton-like reaction to produce $\cdot$OH radicals that may cause the DNA cleavage. Evidence that the iron-specific chelator, desferoxamine (DFX), prevented the DNA cleavage induced by the cytochrome c/$H_2O_2$ system supports this mechanism. Thus we suggest that DNA cleavage is mediated via the generation of $\cdot$OH by a combination of the peroxidase reaction of cytochrome c and the Fenton-like reaction of free iron ions released from oxidatively damaged cytochrome c in the cytochrome c/$H_2O_2$ system.

• Korean Journal of Biological Psychiatry
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• v.5 no.2
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• pp.235-242
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• 1998

Objectives : Alcohol-induced oxidative stress has been known to injure various tissues or organs. This stress is related with free radicals which are produced as the result of long-term alcohol consumption. Malonyldialdehyde(MDA) is produced by the interaction of free radicals and cell membrane lipids, and indicates the degree of lipid peroxidation indirectly. The purpose of this study was to investigate the relationship between red blood cell(RBC) membrane lipid peroxidation by free radicals, and associated hepatic injuries and hematologic changes. Methods : Thirty-three subjects diagnosed as alcohol dependence according to DSM-IV diagnostic criteria were evaluated within 72 hours after discontinuing alcohol drinking. Clinical characteristics were evaluated by CAGE questionnaire and Korean Michigan Alcoholism Screening Test(MAST). RBC membrane MDA level was measured as the marker of RBC membrane lipid peroxidation. Aspartate aminotransferase(AST), alanine aminotransferase(ALT) and gamma-glutamyltransferase(GGT) were used as the biochemical markers of liver damage due to alcohol ingestion. The alcohol-induced hematologic change was assessed by mean corpuscular volume(MCV). Results : The results were as follows. Clinical characteristics were not different between two groups having normal and abnormal levels of AST, ALT, GGT or MCV. The levels of MDA were not correlated with the clinical characteristics and serum levels of AST, ALT and GGT. However, there was a significant correlation between the levels of MDA and the value of MCV(p=0.017). Conclusions : These findings suggest that oxidative stress in alcohol dependence may not be reflected in liver enzyme markers such as AST, ALT and GGT, but may be reflected in MCV.

• Journal of Society of Preventive Korean Medicine
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• v.1 no.1
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• pp.48-54
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• 1997

Scutellariae radix, has been used as a natural drug for fever, inflammation, cataract, and liver disease in traditional medicine. This study was performed in order to investigate the antioxidative effects of Scutellariae radix aqua-acupuncture solution (SRAS) on lipid peroxidation by free radicals. Lipid peroxidation levels were determined by TBA method during the autoxidation of linoleic acid. In this linoleic acid autoxidation system, SRAS markedly exhibited antioxidant activity, which inhibited 89% of linoleic acid peroxidation. SRAS showed scavenging effects on ${\alpha},{\alpha}-diphenyl-{\beta}-picrylhydrazyl$(DPPH) radical, inhibited superoxide generation in xanthine-xathine oxidase system, and also inhibited lipid peroxidation of rat liver tissue by hydroxyl radical derived from $H_2O_2-FE^{+2}$ system. These effects were similar to those of $dl-{\alpha}-tocopherol$, BHA and BHT. In addition, SRAS protected the cell death induced by ter-butyl hydroperoxide (t-BHP) and significantly increased cell viability in the normal rat liver cell (Ac2F). On the basis of these results, it is suggested that SRAS might play a protective role in lipid peroxidation by free radicals.

• Food Science of Animal Resources
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• v.36 no.6
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• pp.791-798
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• 2016

Free radicals may attack cells or tissue, leading to chronic diseases, and antioxidant consumption is potentially useful for removing free radicals. Egg proteins may be used as potential sources of antioxidant considering their ability of scavenging free radicals to apply for food or cosmetics industry. In this study, we obtained a natural antioxidant protein from fertilized eggs, which was a dietary supplement in some Asian countries. Meanwhile, antioxidant activities of these proteins were evaluated using different oxidation systems. With increasing incubation time, the antioxidant activity of these proteins increased during 15 d of incubation. The samples on day 15 were performed for isolation of antioxidant protein. The protein, named P4-1 (MW, 45 kDa), was isolated and purified by consecutive chromatographic methods. P4-1 contained 17 amino acids, which was determined by liquid chromatography-mass spectrometry and Amino Acid Analyzer. Moreover, the amino acid sequence was highly similar to that of ovalbumin. Differential scanning calorimetry showed that the denaturation temperature of P4-1 was $57.16^{\circ}C$. Furthermore, P4-1 suggested high oxygen radical-absorbance activity in ${\cdot}OH$ assays, and its antioxidant activity was stable at $30-50^{\circ}C$ in acidic and neutral pH. Thus, these results revealed that P4-1 may be a potential resource as a natural antioxidant.