• Journal of the Korean Applied Science and Technology
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• v.6 no.1
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• pp.15-19
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• 1989

The oxidative stability of palm oil with moisture addition during heationg was investigated and the antioxidant effects of tocopherol, citric acid and sodium polyphosphate were evaluated. The addition of natural tocopherol up to 200 ppm level did not improve the oxidative stability of palm oil with moisture (1m1 $H_2O$ additive to 200g of oil at $180^{\circ}C$). The maximum antioxidant effect was observed at the Concentration of 400 ppm. Addition of citirc acid did not influence the effective concentration of tocopherol. Whereas addition of sodium polyphosphate and citric acid increased the antioxidant effect of tocopherol. The maximum synergistice effect was observed at the concentrations of 50 ppm citric acid and 50 ppm of sodium polyphosphate. Addition of 50 ppm citric acid and 50 ppm sodium polyphosphate to 100 ppm of tocopherol exceeded the antioxidant effect of 400 ppm tocopherol alone.

• Food Science of Animal Resources
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• v.34 no.5
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• pp.638-646
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• 2014

The effects of two levels (1.4 vs 2.8%) of fresh garlic on lipid oxidation and microbial growth in pork patties were evaluated. Hunter color (L, a, b), pH, thiobarbituric acid reactive substances (TBARS), oxidative volatile compounds, total bacteria and Enterobacteriaceae in the pork patties with or without fresh garlic were measured during storage at $4^{\circ}C$. Addition of fresh garlic decreased redness (a), while increased pH and yellowness (b) values of the fresh pork patties were observed, regardless of the levels added. The TBARS values of the pork patties were increased with the addition of fresh garlic (p<0.05). Similar results were observed in oxidative volatile compounds. A total of 13 volatile compounds were detected in the patties (5 sulfur-containing compounds, including allyl mercaptan, allyl methyl sulfide, diallyl sulfide, methyl-(E)-propenyl-disulfide, and diallyl disulfide, and the 8 other oxidative compounds, including 1-pentanol, hexanal, 1-hexanol, heptanal, (E)-2-heptenal, 1-octen-3-ol, (E)-2-octenal and nonanal). Fresh garlic accelerated development of oxidative products in the pork patties, especially hexanal and the total oxidative volatile compounds. However, the addition of 1.4 and 2.8% of fresh garlic inhibited the growth of total bacteria and Enterobacteriaceae, indicating low total bacterial counts and Enterobacteriaceae than the controls.

• Preventive Nutrition and Food Science
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• v.14 no.1
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• pp.37-42
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• 2009

The protective activity of seolitae chungkukjang added with green tea against oxidative stress was investigated under the cellular systems using LLC-$PK_1$ cells. The treatment of 2,2'-azobis(2-aminopropane) dihydrochloride (AAPH) showed increase in lipid peroxidation, and decrease in endogenous antioxidant enzymes activity and cell viability. However, the methanol extract of seolitae chungkukjang inhibited lipid peroxidation by 58.3%, and increased cell viability up to more than 60%. In addition, it enhanced superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities. Seolitae chungkukjang improved oxidative stress-induced cellular injury through the radical scavenging activities. In particular, the addition of green tea in seolitae chungkukjang showed stronger effect against oxidative stress induced by AAPH. The more addition of green tea resulted in the greater antioxidative effect through elevation in activities of SOD and GSH-Px, and inhibition of lipid peroxidation, eventually leading to increase in cell viability. Theses results suggested that seolitae chungkukjang added with green tea have protective effects from cellular oxidative damage and could be considered as an application for the development of chungkukjang with functionality.

• Journal of Photoscience
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• v.9 no.2
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• pp.142-145
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• 2002

A strict anaerobe, Prevotella melaninogenica is highly sensitive to oxidative stress. Oxidative stress such as exposure to oxygen or addition of hydrogen peroxide, increased 8-hydroxydeoxyguanosine (80HdG), a typical of oxidative DNA damage, and decreased the bacterial cell survival rate. We could detect the generation of reactive oxygen species in P. melaninogenica after exposure to oxygen. UVA irradiation also increased 80HdG in the bacterium. On the other hand, such oxidative stress did not increase 80HdG in a facultative anaerobe. These findings suggest that P. melaninogenica is a suitable material to study the biological effects of oxidative stress, to evaluate antioxidants, and to study the effects of oxygen or reactive oxygen species on molecular evolution.

• Journal of Pharmacopuncture
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• v.12 no.2
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• pp.31-40
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• 2009

Objective : This study was carried out to investigate protective effects of Pharmacopuncture Solutions (PSs) made by Carthmi Flos (CF), Cnidii Rhizoma (CR) and Astragali Radix (AR) on C6 glioma cells Methods : We investigated the effects of PSs on proliferation rates and types of C6 cells, and also investigated the effects on LDH release. In addition, protective effects of PSs on oxidative stress induced by hydrogen peroxide and SOD-like activities were also investigated. Results : PSs made by CF, CR and AR did not show cytotoxicity in various concentrations. CF-PS and AR-PS elevated levels of proliferation rates significantly. Treatment with CF-PS lowered level of LDH release in C6 cells. In addition, CF-PS and CR-PS showed protective effects on cell death induced by hydrogen peroxide respectively. Finally, CF-PS group showed high level of SOD-like activity compared to that in CR-PS group. Conclusion : These results suggest that CF-PS can accelerate proliferation of neuroglial cells, and has protective action against oxidative stress, which was involved in anti-oxidative effects such as SODlike activities. In addition, CR has protective effects against oxidative stress, and AR can accelerate proliferation of neuroglial cells.

• The Korea Journal of Herbology
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• v.27 no.6
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• pp.7-13
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• 2012

Objectives : Reactive oxygen species (ROS) have been associated with pathogenic processes including carcinogenesis through direct effect on DNA directly and by acting as a tumor promoter. Therefore, it has been regarded that ROS may be a major target for cancer prevention. The root of Paeonia lactiflora pall (PL), a traditional Chinese herb, has been a component of effective prescriptions for treatment of liver disease. Also, there are some reports about the antioxidant activities of the extracts from PL. However, little has been known about the effects of PL against oxidative damage. This work aimed to elucidate the anti-oxidant effects of Paeonia lactiflora pall (PL) in the non-cellular system and cellular system. Methods : Antioxidant activities of PL were evaluated by hydroxyl radical scavenging assay and $Fe^{2+}$ chelating assay. Anti-oxidative effect of PL was evaluated by ${\varphi}X$-174 RF I plasmid DNA cleavage assay in non-cellular system. In addition, DNA migration assay, expression level of phospho-H2AX, MTT assay and lipid peroxidation assay were performed for evaluate the anti-oxidative effect of PL in cellular system. Results : PL had a dose-dependent hydroxyl radical scavenging and $Fe^{2+}$ chelating capacity. In addition, PL inhibited oxidative DNA and cell damage induced by hydroxyl radical in non-cellular system and cellular system. Conclusion : Taken together, P. lactiflora pall may be possible for the application to a potential drug for treating the oxidative diseases such as cancer.

• Korean Journal of Agricultural Science
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• v.39 no.1
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• pp.81-86
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• 2012

In this study, the antioxidative effect and protective potential against oxidative damage of extract and fractions from broccoli were investigated under in vitro and cellular system. The methanol (MeOH) extracts of broccoli flowers and sprouts were partitioned as dichloromethane, n-butanol (BuOH) and aqueous fractions. The comparison of antioxidative effect of broccoli flowers and sprouts showed that broccoli sprouts exerted the more effective protective activity from 2,2'-azobis (2-aminopropane) dihydrochloride (AAPH)-induced oxidative stress in LLC-$PK_1$ porcine renal epithelial cell. In addition, the extract and fractions from broccoli sprouts showed strong scavenging effect of 1,1-diphenyl-2-picrylhydrazyl radical and the BuOH fraction exerted the strongest activity. Therefore, the BuOH fraction was evaluated as the most active fraction with strong radical scavenging activity among the fractions of broccoli flowers and sprouts. The present study suggests the antioxidative potential against free radical-induced oxidative damage of flowers and sprouts of broccoli. In addition, the BuOH fraction of broccoli is considered as the active fraction with antioxidative effect.

• Journal of Environmental Health Sciences
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• v.23 no.4
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• pp.9-15
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• 1997

This experiment was carried out to examine the roles of selenium in arsenic- and chromium-induced oxidative stress, which results in chromosomal damage, such as sister chromatid exchange (SCE) and chromosomal aberration (CA). For this purpose, the frequency of CA and SCE related to the level of 0xidative stress were analyzed. Selenium decreased the frequency of CA induced by As. In order to evaluate the effect of selenium on clastogenic factors, media from As- and Cr-treated cells were ultrafiltered and added again to cells in the presence or absence of selenium. Selenium decreased the frequency of SCE by As and Cr. This observation indicates the possibility of presence of clastogenic factor. In addition, the clastogenic factor would be involed in oxidative stress since selenium decreased the level of oxidative stress. Thus, it is suggested that selenium may play a role as an anti-clastogenic effector by preventing the oxidative stress, thereby decreasing the frequency of Asand Cr-induced chromosomal damage.

• Journal of Yeungnam Medical Science
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• v.38 no.2
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• pp.83-94
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• 2021

The global obesity epidemic and the growing elderly population largely contribute to the increasing incidence of type 2 diabetes. Insulin resistance acts as a critical link between the present obesity pandemic and type 2 diabetes. Naturally occurring reactive oxygen species (ROS) regulate intracellular signaling and are kept in balance by the antioxidant system. However, the imbalance between ROS production and antioxidant capacity causes ROS accumulation and induces oxidative stress. Oxidative stress interrupts insulin-mediated intracellular signaling pathways, as supported by studies involving genetic modification of antioxidant enzymes in experimental rodents. In addition, a close association between oxidative stress and insulin resistance has been reported in numerous human studies. However, the controversial results with the use of antioxidants in type 2 diabetes raise the question of whether oxidative stress plays a critical role in insulin resistance. In this review article, we discuss the relevance of oxidative stress to insulin resistance based on genetically modified animal models and human trials.

• Biomolecules & Therapeutics
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• v.20 no.5
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• pp.492-498
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• 2012

Phytochemicals have been known to exhibit potent antioxidant activity. This study examined cytoprotective effects of phytochemicals including quercetin, catechin, caffeic acid, and phytic acid against oxidative damage in SK-Hep-1 cells induced by the oxidative and non-oxidative metabolism of ethanol. Exposure of the cells to excess ethanol resulted in a significant increase in cytotoxicity, reactive oxygen species (ROS) production, lipid hydroperoxide (LPO), and antioxidant enzyme activity. Excess ethanol also caused a reduction in mitochondrial membrane potential (MMP) and the quantity of reduced glutathione (GSH). Co-treatment of cells with ethanol and quercetin, catechin, caffeic acid and phytic acid significantly inhibited oxidative ethanol metabolism-induced cytotoxicity by blocking ROS production. When the cells were treated with ethanol after pretreatment of 4-methylpyrazole (4-MP), increased cytotoxicity, ROS production, antioxidant enzyme activity, and loss of MMP were observed. The addition of quercetin, catechin, caffeic acid and phytic acid to these cells showed suppression of non-oxidative ethanol metabolism-induced cytotoxicity, similar to oxidative ethanol metabolism. These results suggest that quercetin, catechin, caffeic acid and phytic acid have protective effects against ethanol metabolism-induced oxidative insult in SK-Hep-1 cells by blocking ROS production and elevating antioxidant potentials.