• Journal of Society of Preventive Korean Medicine
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• v.12 no.1
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• pp.103-118
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• 2008

Antioxidants are compounds that protect cells against the damaging effects of reactive oxygen species (ROS). Some ROS, such as superoxide and hydrogen peroxide, are normally produced in cells as by-products of biochemical reactions or as signaling molecules. When ROS-generating reactions are activated excessively, pathological quantities of ROS are released to create an imbalance between antioxidants and ROS, called as oxidative stress. Oxidative stress, which may result in cellular damage, has been linked to cardiovascular disease, diabetes, cancer, and other degenerative conditions. In humans the first line of antioxidant defence are the antioxidant enzymes, especially SOD, glutathione peroxidase (GPX), and to a lesser extent catalase, as well as the tripeptide glutathione(GSH). These enzymes will help destroy ROS(reactive oxygen species) such as hydroxyl radical, $H_2O_2$ and lipid peroxides, while GSH protects against oxidized protein. Many herbal medicines possess antioxidant properties. Herbal antioxidants may protect against these diseases by contributing to the total antioxidant defense system of the human body. Here, many herbal medicines including Ginseng, Licorice, Ligusticum Chuanxiong, Ginkgo biloba and many others was reviewed in terms of anti-oxidant efficiency related to their components.

• Journal of Microbiology and Biotechnology
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• v.14 no.6
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• pp.1333-1337
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• 2004

Oxidants such as hydrogen peroxide are powerful inducers of cell damage, ageing, and apoptosis. Since clusterin, a 75-80 kDa mammalian glycoprotein, is frequently found to be inducible in apoptotic cells and tissues, this study inquired into whether this would be a protective mechanism against further cell death. The aim was to find out whether overexpression of clusterin could protect cells from oxidant­induced stress and apoptosis. To clarify this issue, we generated and analyzed stable cell lines expressing fusion proteins of a rat clusterin with an enhanced green fluorescent protein (EGFP). When treated with varying concentrations of hydrogen peroxides, clusterin transfectants indeed showed increased resistance to apoptosis and exhibited a much higher survival rate than mock-transfected cells. On the other hand, neither intracellular re-distribution nor local concentration of clusterin-EGFP was observed, which leaves the question open about its anti-apoptotic mechanism. In conclusion, the overexpression of clusterin provides a means for protecting cells against oxidative stress and subsequent cell death.

• Journal of Microbiology and Biotechnology
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• v.14 no.5
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• pp.996-1003
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• 2004

Nonsteroidal anti-inflammatory drugs such as indomethacin induce severe gastric mucosal damage in humans and rodents. In the present study, the in vivo protective effect of astaxanthin on indomethacin-induced gastric lesions in rats was investigated. The test groups were injected with indomethacin (25 mg/kg) after the oral administration of astaxanthin (25 mg/kg) for 1, 2, and 3 days, while the control group was treated only with indomethacin. Thiobarbituric acid reactive substances in the gastric mucosa, as an index of lipid peroxidation, increased significantly after indomethacin administration and this increase was inhibited by oral administration of astaxanthin. In addition, pretreatment with astaxanthin resulted in a significant increase of the activities of superoxide dismutase (SOD), catalase, and glutathione peroxidase (GSH-px). Histologic examination clearly revealed acute gastric mucosal lesions induced by indomethacin in the stomach of the control group, but were not observed in that of the test group. These results indicate that astaxanthin activates SOD, catalase, and GSH-px, and removes the lipid peroxides and free radicals induced by indomethacin. It is evident that astaxanthin acts as a free radical quencher and antioxidant, and is an effective molecule in the remedy of gastric mucosal lesions.

• Journal of Microbiology and Biotechnology
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• v.21 no.4
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• pp.400-404
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• 2011

Indomethacin is a nonsteroid anti-inflammatory agent that is known to induce severe gastric mucosal lesions. In this study, we investigated the effect of selenium on gastric mucosal lesions in rats. To confirm the curative effect of selenium against indomethacin-induced gastric ulcers, gastric ulcers were induced by oral administration of 25 mg/kg indomethacin, and then different doses (10, 50, and 100 ${\mu}g$/kg of body weight) of selenium or vehicle were treated by oral gavage for 3 days. Oral administration of indomethacin clearly increased the gastric ulcer area in the stomach, whereas selenium applied for 3 days significantly decreased the gastric ulcer area in a dose-dependent manner. In addition, selenium markedly reduced the increase of lipid peroxidation induced by indomethacin in the gastric mucosa and increased activities of radical scavenging enzymes such as superoxide dismutase, catalase, and glutathione peroxidase in a dose-dependent manner. These results reveal that selenium can heal indomethacin-induced gastric ulcers through elimination of the lipid peroxides and activation of radical scavenging enzymes.

• Food Science and Biotechnology
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• v.16 no.5
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• pp.753-758
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• 2007

This study was conducted to investigate the antioxidant activity of paprika in the lard-pork model system adding ground fresh paprika (3%) and paprika powders (5%). Paprika powders were obtained through 4 drying methods (freeze, vacuum, far infrared-ray, and hot-air). In the lard and meat-fat mixture (containing lard 30%) containing paprika powders, the rate of increase in the peroxide value (POV) and thiobarbituric acid (TBA) value decreased notably during the refrigerated storage ($4^{\circ}C$) compared to the control without paprika. Therefore, paprika powders showed potent antioxidant activity and especially the freeze dried paprika powder revealed the most effective activity among them. However, its antioxidant activity was still lower than that of the fresh paprika because the addition of fresh paprika in the lard and meat-fat mixture merely increased the POV and TBA value. In linoleic acid oxidation, the addition of capsanthin 500 ppm to mixed linoleic acid and 10 ppm of $FeCl_3$ (LF) inhibited the formation of peroxides by 15.2% compared to LF, showing its iron scavenging ability. When mixed antioxidants (${\beta}$-carotene 200 ppm + ascorbic acid 100 ppm, capsanthin 200 ppm + ascorbic acid 100 ppm) were added in LF, synergistic effects were obtained with 57.7 and 60.4% of inhibition of peroxide formation, respectively.

• Elastomers and Composites
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• v.31 no.1
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• pp.33-42
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• 1996

NR, NBR, and CR rubber were prepared by mixing filler in various ratios. Their vulcanization characteristics and thermal properties were studied. Vulcanization characteristics were investigated using cure curve that had been obtained from oscillating disk rheometer study. The Arrhenius law is known to describe the relationship between cure time and temperature of most elastomers. Curing could be done by the addition of sulfur, peroxides, and proper acceleratores. The optimum cure time that affects desirable values of modulus and tensile strength of the vulcanizate is taken as t90 as measured by a rheometer. Rubbers were cured in the rheometer at temperatures ranging from $130^{\circ}C\;to\;180^{\circ}C$ in order to check the validity of the curing system used. A linear relationship between ln(ts2) and ln(t90) was found for all elastomers. The term sensitivity has been used to describe the relationship between a change of ts2 to the corresponding change of t90 due to an increment of temperature. This is related to the formula of the compound.

• Journal of Plant Biotechnology
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• v.6 no.4
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• pp.259-264
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• 2004

The present study describes the ameliorating effect of $Ca^{++}\;on\;Cd^{++}$ toxicity on the germination, early growth of mungbean seedlings, nitrogen assimilation enzyme. s-nitrate reductase (NR), nitrite reductase (NIR), anti-oxidant enzymes (POD, CAT and SOD) and on the accumulation of hydrogen peroxide and sulphydryls. $Cd^{++}$ inhibited seed germination and root and shoot length of seedlings. While NR activity was down- regulated, the activities of NIR, POD and SOD were up- regulated with $Cd^{++}$ treatment. $Cd^{++}$ treatment also increased the accumulation of sulphydryls and peroxides, which is reflective of increased thiol rich proteins and oxidative stress. $Ca^{++}$ reversed the toxic effects of $Cd^{++}$ on germination and on early growth of seedlings as well as on the enzyme activities, which were in turn differentially inhibited with a combined treatment with calcium specific chelator EGTA. The results indicate that the external application of $Ca^{++}$ may increase the tolerance capacity of plants to environmental pollutants by both up and down regulating metabolic activities. Abbreviations: $Cd^{++}= cadmium,\;Ca^{++} = calcium$, NR= nitrate reductase, NIR=nitrite reductase, POD = peroxidse, SOD= superoxide dismutase, CAT= catalase, EGTA= ethylene glycol-bis( $\beta-aminoethyl ether$)-N,N,N,N-tetraacetic acid.

• Korean Journal of Veterinary Research
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• v.28 no.2
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• pp.311-319
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• 1988

This study was designed to elucidate the effects of iron, a well known catalyst of lipid peroxidation, on the contents of phospholipids, unsaturated fatty acids composed in phospholipid molecules and their derivatives, prostaglandins, and the composition changes of fatty acids contained in phospholipids. Iron decreased the contents of phospholipids and its components of unsaturated fatty acids. Catalytic action of iron decreased the composition rates of linoleate and linolenate composed in phospholipid molecules, while that of arachidonate was inclined to increase. The content of arachidonate was increased and that of prostaglandins was decreased without regard to increase the precursor of prostaglandins. It may be concluded that the decreases of prostaglandins and the increase of arachidonate are due to inhibition of the activities of enzyme systems responsible for prostaglandin synthesis by lipid peroxides produced by the catalyst of iron.

• Journal of the Korean Society of Food Science and Nutrition
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• v.19 no.4
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• pp.321-329
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• 1990

The present study was carried out to investigate the antioxidant effects of onion and ginger on the lipid peroxidation of mackerel during frozen storage. mackerels were reated with onion juice ginger juice tocopherol and BHA and stored at -18$^{\circ}C$ for 6 weeks. lipid peroxidation in samples was estimated by the periodical measurements of acid value iodine value peroxide value carbonyl value 2-thiobarbituric acid value and fatty acid composition. The treatments with ginger and onion were effective on the suppression of acid value and carbonyl value of makerel oil during 4 to 6 weeks of frozen storage. The iodine value was not affected by the treatments with various antioxidants, The production of peroxides was delayed by ginger or onion treatment, the TBA value of the sample muscles was not lowered by the treatments, The treatment with onion resulted in less changes in the contents of $\omega$-3 polyunsaturated fatty acids and in the P/S ration of fish oil than the control did. Results indicate that the applica-tion of ginger or onion juice on the surface of fishes may be useful to lower the degree of rancidity of fish during the froxaen storage.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.6
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• pp.799-805
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• 2010

Since the consumption of spent laying hens as roasted skewered meat increases, the effects of various carotenoids on pigmentation and antioxidant activity were tested with 62-wk-old 250 ISA brown laying hens to improve the quality of chicken meat. In a 6-wk feeding trial, 4 carotenoids with different polarity (${\beta}$-8-apo-carotenoic acid ethyl ester (ACAEE)>astaxanthin>canthaxanthin>${\beta}$-carotene) at 100 mg carotenoid/kg feed were used. The more polar the carotenoids, the higher were the levels in blood. After 5-wk adaptation, the concentrations of astaxanthin, canthaxanthin, and ACAEE in blood were -4 ${\mu}g/ml$. Canthaxanthin decreased significantly (p<0.05) the level of total blood cholesterol. Decreases in blood triglyceride by all carotenoids used were significant. ACAEE and astaxanthin tended to increase skin yellowness of thigh, breast, and wing proportionally to feeding period. In the case of polar carotenoids (ACAEE and astaxanthin), the longer the period of feeding, the higher the accumulation in skin was observed. Only astaxanthin was effective against the production of lipid peroxides in skin. Conclusively, out of the commercially available carotenoids we tested, astaxanthin is recommended for pigmentation of skin and inhibition of lipid oxidation.