• 한국축산식품학회지
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• 제34권4호
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• pp.525-532
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• 2014

This study was designed to elucidate the effect of ozone exposure on the bacteria counts and oxidative properties of ground Hanwoo beef contaminated with Escherichia coli O157:H7 at refrigeration temperature. Ground beef was inoculated with 7 Log CFU/g of E. coli O157:H7 isolated from domestic pigs and was then subjected to ozone exposure ($10{\times}10^{-6}kg\;O_3h^{-1}$) at $4^{\circ}C$ for 3 d. E. coli O157:H7, total aerobic and anaerobic bacterial growth and oxidative properties including instrumental color changes, TBARS, catalase (CAT) and glutathione peroxidase (GPx) activity were evaluated. Ozone exposure significantly prohibited (p<0.05) the growths of E. coli O157:H7, total aerobic and anaerobic bacteria in ground beef samples during storage. Ozone exposure reduced (p<0.05) the CIE $a^*$ value of samples over storage time. The CIE $L^*$ and CIE $b^*$ values of the samples fluctuated over storage time, and ozone had no clear effect. Ozone exposure increased the TBARS values during 1 to 3 d of storage (p<0.05). The CAT and GPx enzyme activities were not affected by ozone exposure until 2 and 3 d of storage, respectively. This study provides information about the use of ozone exposure as an antimicrobial agent for meat under refrigerated storage. The results of this study provide a foundation for the further application of ozone exposure by integrating an ozone generator inside a refrigerator. Further studies regarding the ozone concentrations and exposure times are needed.

• 한방비만학회지
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• 제15권2호
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• pp.93-103
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• 2015

Objectives: It was investigated the cytoprotective efficacies of isorhamnetin, a flavonoid originally derived from Hippophae rhamnoides L., against oxidative stress-induced apoptosis in C2C12 myoblasts. Methods: The effects of isorhamnetin on cell growth, apoptosis and reactive oxygen species (ROS) generation were evaluated by trypan blue dye exclusion assay, 4',6-diamidino-2-phenylindole staining and flow cytometry. The levels of apoptosis-regulatory and nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway-related proteins, and caspase activities (caspase-3 and -9) were determined by Western blot analysis and colorimetric assay, respectively. Results: Our results revealed that treatment with isorhamnetin prior to hydrogen peroxide ($H_2O_2$) exposure significantly increased the C2C12 cell viability and, indicating that the exposure of C2C12 cells to isorhamnetin conferred a protective effect against oxidative stress. Isorhamnetin also effectively attenuated $H_2O_2$-induced apoptosis and ROS generation, which was associated with the restoration of the upregulation of Bax and downregulation of Bcl-2 induced by $H_2O_2$. In addition, $H_2O_2$ enhanced the activation of caspase-9 and -3, and degradation of poly (ADP-ribose)-polymerase, a typical substrate protein of activated caspase-3; however, these events were almost totally reversed by pretreatment with isorhamnetin. Moreover, isorhamnetin increased the levels of heme oxygenase-1, a potent antioxidant enzyme, associated with the induction of Nrf2. Conclusions: Our data indicated that isorhamnetin may potentially serve as an agent for the treatment and prevention of muscle disorders caused by oxidative stress.

• 대한약침학회지
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• 제22권2호
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• pp.83-89
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• 2019

Introduction: Oxidative stress (OS) during uncontrolled hyperglycemia has a pivotal role in pancreatic dysfunction. Our study aimed to demonstrate that crocin can potentiate anti-oxidant defense systems of pancreatic cells to improve oxidative stress. Methods: Male Wistar rats were divided randomly into four groups: a normal group, a normal-treated group, a diabetic group and a diabetic-treated group (n = 6 rats per group). Diabetes was induced by a single dose of streptozotocin (45 mg/kg/IV). The treated groups received crocin daily for 8 weeks (40 mg/kg/IP). At the end of the experiment, rats were sacrificed and pancreas tissue was obtained. Subsequently, the concentrations of malondialdehyde (MDA), nitrate and glutathione as well as the enzymatic activities of catalase and superoxide dismutase (SOD) were determined in all animals. Data were analyzed by two-way ANOVA with appropriate post hoc testing and a probability value of P < 0.05 was considered to represent a statistically significant difference in mean values. Results: Uncontrolled hyperglycemia weakened the anti-oxidant system by decreasing SOD and catalase enzyme activity in pancreatic tissues and induced OS by increasing the MDA content in diabetic non-treated animals. Crocin potentiated the anti-oxidant defense system by increasing the activity of both SOD and catalase, and improved OS by diminishing MDA production in pancreatic cells of rats contained in the diabetic-treated group. Conclusion: Based on our results, it is concluded that uncontrolled hyperglycemia can weaken the anti-oxidant defense system and cause the development of OS. Also, crocin can improve OS in pancreatic cells by potentiating the anti-oxidant defense system.

• 농업과학연구
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• 제42권4호
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• pp.407-414
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• 2015

본 실험에서는 청국장의 항산화 기능성 증진을 위해 녹차를 첨가한 서리태 청국장을 제조한 후 LLC-$PK_1$ 세포를 이용하여 SIN-1유도 세포 독성에 대한 보호효과를 검토하였다. 항산화능이 대두보다 우수한 서리태를 주재료로, 부재료로 녹차를 농도별(0.5%, 2.0%, 5.0%)로 달리하여 청국장을 각각 제조한 후 $ONOO^-$에 의해 유도된 산화적 스트레스에 대해 서리태 청국장과 녹차첨가 서리태 청국장의 산화스트레스에 대한 개선효과를 비교한 결과, 녹차첨가 서리태청국장 추출물은 SOD, GSH-Px와 같은 항산화효소의 활성을 증가시키고, 지질과산화를 억제하여 세포생존율을 증가시킴으로써 산화적 스트레스에 대한 보호효과를 나타냈었으며, 특히 녹차를 5.0% 첨가했을 때의 효과가 가장 높은 것으로 나타났다. 따라서, 녹차 첨가 서리태 청국장은$ONOO^-$에 의해 유발된 산화적 스트레스를 개선함으로써 이로 인한 질병을 예방하는 항산화제로서 역할을 할 것으로 생각된다

• Journal of Nutrition and Health
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• 제44권5호
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• pp.366-377
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• 2011

Glutathione S-transferase (GST) is a multigene family of phase II detoxifying enzymes that metabolize a wide range of exogenous and endogenous electrophilic compounds. GSTM1 and GSTT1 gene polymorphisms may account for inter-individual variability in coping with oxidative stress. We investigated the relationships between the level of lymphocyte DNA and antioxidative parameters and the effect on GST genotypes. GSTM1 and GSTT1 were characterized in 301 young healthy Korean adults and compared with oxidative stress parameters such as the level of lymphocyte DNA, plasma antioxidant vitamins, and erythrocyte antioxidant enzymes in smokers and non smokers. GST genotype, degree of DNA damage in lymphocytes, erythrocyte activities of superoxide dismutase, catalase, and glutathione peroxidase (GSH-Px), and plasma concentrations of total radical-trapping antioxidant potential (TRAP), vitamin C, ${\alpha}$- and ${\gamma}$-tocopherol, ${\alpha}$- and ${\beta}$-carotene, and cryptoxanthin were analyzed. Lymphocyte DNA damage assessed by the comet assay was higher in smokers than that in non-smokers, but the levels of plasma vitamin C, ${\beta}$-carotene, TRAP, erythrocyte catalase, and GSH-Px were lower than those of non-smokers (p < 0.05). Lymphocyte DNA damage was higher in subjects with the GSTM1- or GSTT1-present genotype than those with the GSTM1-present or GSTT1- genotype. No difference in erythrocyte antioxidant enzyme activities, plasma TRAP, or vitamin levels was observed in subjects with the GSTM1 or GSTT1 genotypes, except ${\beta}$-carotene. Significant negative correlations were observed between lymphocyte DNA damage and plasma levels of TRAP and erythrocyte activities of catalase and GSH-Px after adjusting for smoking pack-years. Negative correlations were observed between plasma vitamin C and lymphocyte DNA damage only in individuals with the GSTM1-present or GSTT1- genotype. The interesting finding was the significant positive correlations between lymphocyte DNA damage and plasma levels of ${\alpha}$-carotene, ${\beta}$-carotene, and cryptoxanthin. In conclusion, the GSTM1- and GSTT1-present genotypes as well as smoking aggravated antioxidant status through lymphocyte DNA damage. This finding confirms that GST polymorphisms could be important determinants of antioxidant status in young smoking and non-smoking adults. Consequently, the protective effect of supplemental antioxidants on DNA damage in individuals carrying the GSTM1- or GSTT1-present genotypes might show significantly higher values than expected.

• Nutritional Sciences
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• 제7권3호
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• pp.138-143
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• 2004

Conjugated linoleic acid (CLA) has been shown to have a range of biological activities, including anti-carcinogenic, anti-atherosclerotic, anti-adipogenic and anti-diabetogenic effects. Recent reports also showed that CLA has free radical scavenging capacity, which may have health benefits for human beings. The current study was performed to investigate the effect of structured lipid (SL)-containing CLA on plasma lipids and hepatic antioxidant enzyme activity. Sprague-Dawley mts were fed 5% and 10% SL-containing normal diet for 6 wks and these groups were compared to rats fed 5% and 10% corn oil. In plasma lipids, total-cholesterol was not affected by fat source or dietary fat level while triglyceride level decreased significantly in groups fed 10% fat diet compared to the other groups. Plasma thiobarbituric acid reactive substances (TBARS) level decreased significantly in the S5 and S10 groups compared to the C5 and C10 groups, although hepatic TBARS level was not altered by fat source. On the other hand, in terms of hepatic antioxidant enzyme activity, superoxide dismutase activity increased in the S10 group, whereas catalase activity decreased in the S10 group. Glutathione peroxidase activity decreased significantly in the SL groups compared to the C5 group. Glutathione reductase activity increased and glucose-6-phosphate dehydrogenase activity decreased in the C10 group compared to the C5 and C5 groups. In conclusion, the free radical scavenging activity of CLA seemed to suppress oxidative stress, which reduced lipid peroxidation resulting in lower hepatic antioxidant enzyme activity.

• Journal of Microbiology and Biotechnology
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• 제17권8호
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• pp.1344-1352
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• 2007

An opportunistic human pathogen, Pseudomonas aeruginosa, contains the major catalase KatA, which is required to cope with oxidative and osmotic stresses. As an attempt to uncover the $H_2O_2$-dependent regulatory mechanism delineating katA gene expression, four prototrophic $H_2O_2$-sensitive mutants were isolated from about 1,500 TnphoA mutant clones of P. aeruginosa strain PA14. Arbitrary PCR and direct cloning of the transposon insertion sites revealed that one insertion is located within the katA coding region and two are within the coding region of oxyR, which is responsible for transcriptional activation of several antioxidant enzyme genes in response to oxidative challenges. The fourth insertion was within PA3815 (IscR), which encodes a homolog of the Escherichia coli iron-sulfur assembly regulator, IscR. The levels of catalase and SOD activities were significantly reduced in the iscR mutant, but not in the oxyR mutant, during the normal planktonic culture conditions. These results suggest that both IscR and OxyR are required for the optimal resistance to $H_2O_2$, which involves the expression of multiple antioxidant enzymes including KatA.

• Journal of Microbiology and Biotechnology
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• 제19권11호
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• pp.1319-1327
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• 2009

Marine red algae of genus Laurencia are becoming the most important resources to produce unique natural metabolites with wide bioactivities. However, reports related to Laurencia undulata, an edible species used as folk herb, are rarely found to date. In this research, 5-hydroxymethyl-2-furfural (5-HMF) was isolated and characterized by nuclear magnetic resonance (NMR) from Laurencia undulata as well as other marine algae. The following characteristics of 5-HMF were systematically evaluated: its antioxidant activities, such as typical free-radicals scavenging in vitro by electron spin resonance spectrometry (ESR) and intracellular reactive oxygen species (ROS) scavenging; membrane protein oxidation; oxidative enzyme myeloperoxidase (MPO) inhibition; as well as expressions of antioxidative enzymes glutathione (GSH) and superoxide dismutase (SOD) on the gene level using the polymerase chain reaction (PCR) method. The results demonstrated that 5-HMF could be developed as a novel marine natural antioxidant or potential precursor for practical applications in the food, cosmetic, and pharmaceutical fields.

• IMMUNE NETWORK
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• 제11권1호
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• pp.42-49
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• 2011

Background: In this study, we have investigated the effect of Korean red ginseng (KRG) extracts on the production of TNF-${\alpha}$ and IL-8 in human keratinocytes. Also, to examine the antioxidative effect of red ginseng extracts, free radical scavenging activity and superoxide dismutase (SOD) activity in human dermal fibroblasts was measured. Methods: To investigate the effect of KRG in atopic dermatitis, we measured the level of TNF-${\alpha}$ and IL-8 secretion in LPS-stimulated human keratinocytes after the treatment of KRG extracts using enzyme-linked immunosorbent assay. Anti-oxidative activity was investigated by measuring 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging and SOD activity. Results: The stimulation of human keratinocytes with KRG extracts shifted the LPS-induced cytokine secretion toward a more immunosuppressive response. KRG dose-dependently decreased TNF-${\alpha}$ and IL-8 production in HaCaT cells and a significant inhibition of TNF-${\alpha}$ was shown when cells were treated with 500 and $1,000{\mu}g/ml$ of KRG extracts. Additionally, KRG extracts showed DPPH radical scavenging and SOD activity in a dose-dependent manner. Particularly, SOD activities of concentrations higher than $60{\mu}g/ml$ of KRG extracts were significantly different in human dermal fibroblast cells. Conclusion: Based on this study, KRG extracts may be a useful immunosuppressive agent in the treatment of atopic dermatitis.

• 환경생물
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• 제26권2호
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• pp.94-101
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• 2008

공장 폐수로 인한 오염이 심한 경기 시화호에서 오염정도가 다른 두 지역으로부터 풀망둑을 채집하여 이들의 해독효소계 또는 항산화효소계의 반응을 비교하였다. 해독효소계에서 I상효소로는 CYP, P450R, b5R, EROD를, II상효소로는 GST를 조사하였다. 그리고 항산화효소계로는 CAT, GR, CPx의 활성 그리고 GSH및 CSSG농도를 조사하였다. 그 결과, 오염정도가 심한 지역에서 잡은 어류가 간장 중 P450R, b5R, GST의 활성이 높았으나 EROD활성은 오히려 낮았고 CYP농도는 차이가 없었다. 그리고 이지역에서 잡은 어류는 CAT와 GR의 활성, 비효소적인 항산화계인 CSH와 GSSC농도도 더 높았으나 GTx활성은 오히려 낮았다. 이들 결과는 시화호의 오염된 곳에서 서식하는 풀망둑 Acanthogobius hasta은 상당히 해독효소계가 항진되어 있으며 산화 스트레스도 크게 받고 있음을 보여준다.