• Korean Journal of Veterinary Research
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• v.44 no.1
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• pp.41-47
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• 2004

The alkaline single-cell gel electrophoresis (SCGE) assay, called the comet assay, has been applied to detect DNA damage induced by a number of chemicals and biological factors in vivo and in vitro. The DNA damage was analysed by tail moment (TM) and tail length (TL), which were markers of DNA strand breaks in SCGE. Human, mouse and rat peripheral blood lymphocytes (PBLs) were irradiated with different doses of $^{60}Co$ ${\gamma}$-rays, e.g. 1, 2, 4, and 8 Gy at a dose rate of 1 Gy/min. A dose-dependent increase in TM (p<0.01) and TL (p<0.01) was obtained at all the radiation doses (1-8 Gy) in human, mouse and rat PBLs. Mouse PBLs were more sensitive than human PBLs which were in turn more sensitive than rat PBLs when the treated dosages were 1 and 2 Gy. However, human PBLs were more sensitive than mouse PBLs which were in turn more sensitive than rat PBLs when the irradiation dosages were 4 and 8 Gy. Data from all three species could be fitted to a linear-quadratic model. These results indicated that there may be inherent differences in the radio-sensitivity among PBLs of mammalian species.

• Nutrition Research and Practice
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• v.3 no.2
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• pp.114-121
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• 2009

The effect of diet supplemented with red beet (Beta vulgaris L.) leaf on antioxidant status of plasma and tissue was investigated in C57BL/6J mice. The mice were randomly divided into two groups after one-week acclimation, and fed a high fat (20%) and high cholesterol (1%) diet without (control group) or with 8% freeze-dried red beet leaf (RBL group) for 4 weeks. In RBL mice, lipid peroxidation determined as 2-thiobarbituric acid-reactive substances (TBARS value) was significantly reduced in the plasma and selected organs (liver, heart, and kidney). Levels of antioxidants (glutathione and $\beta$-carotene) and the activities of antioxidant enzyme (glutathione peroxidase) in plasma and liver were considerably increased, suggesting that antioxidant defenses were improved by RBL diet. Comet parameters such as tail DNA (%), tail extent moment, olive tail moment and tail length were significantly reduced by 25.1%, 49.4%, 35.4%, and 23.7%, respectively, in plasma lymphocyte DNA of RBL mice compared with control mice, and indicated the increased resistance of lymphocyte DNA to oxidative damage. In addition, the RBL diet controlled body weight together with a significant reduction of fat pad (retroperitoneal, epididymal, inguinal fat, and total fat). Therefore, the present study suggested that the supplementation of 8% red beet leaf in high fat high cholesterol diet could prevent lipid peroxidation and improve antioxidant defense system in the plasma and tissue of C57BL/6J mice.

• Journal of Nutrition and Health
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• v.50 no.1
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• pp.10-24
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• 2017

Purpose: GST (glutathione S-transferase) M1 and T1 gene polymorphisms are known to affect antioxidant levels. This study was carried out to evaluate genetic susceptibility by measuring the effect of DNA damage reduction in the Korean diet by vegetable food according to GST gene polymorphisms using the ex vivo method with human lymphocytes. Methods: Vegetable foods in the Korean diet based the results of the KNHANES V-2 (2011) were classified into 10 food groups. A total of 84 foods, which constituted more than 1% of the total intake in each food group, were finally designated as a vegetable food in the Korean diet. The Korean diet applied in this study is the standard one-week meals for Koreans (2,000 Kcal/day) suggested by the 2010 Dietary Reference Intakes for Koreans. Ex vivo DNA damage in human lymphocytes was assessed using comet assay. Results: In the Korean food group, the DNA damage protective effect of GSTM1 and GSTT1 was found to be greater in mutant type and wild-type, respectively. and the DNA damage protective effect according to the combined genotype of GSTM1 and GSTT1 was different depending on the food group. On the other hand, in Korean Diet, the DNA damage protective effect appeared to be larger in GSTM1 wild-type than in mutant type and was found to not be affected by GSTT1 genotype. Conclusion: These results can be used as basic data to demonstrate the superiority of the antioxidant function of Korean dietary patterns and food groups. Furthermore, it may be a starting point to begin research on customized antioxidant nutrition according to individual genes.

• Radiation Oncology Journal
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• v.33 no.3
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• pp.256-260
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• 2015

Purpose: Mefenamic acid (MEF) as a non-steroidal anti-inflammatory drug is used as a medication for relieving of pain and inflammation. Radiation-induced inflammation process is involved in DNA damage and cell death. In this study, the radioprotective effect of MEF was investigated against genotoxicity induced by ionizing radiation in human blood lymphocytes. Materials and Methods: Peripheral blood samples were collected from human volunteers and incubated with MEF at different concentrations (5, 10, 50, or $100{\mu}M$) for two hours. The whole blood was exposed to ionizing radiation at a dose 1.5 Gy. Lymphocytes were cultured with mitogenic stimulation to determine the micronuclei in cytokinesis blocked binucleated lymphocyte. Results: A significant decreasing in the frequency of micronuclei was observed in human lymphocytes irradiated with MEF as compared to irradiated lymphocytes without MEF. The maximum decreasing in frequency of micronuclei was observed at $100{\mu}M$ of MEF (38% decrease), providing maximal protection against ionizing radiation. Conclusion: The radioprotective effect of MEF is probably related to anti-inflammatory property of MEF on human lymphocytes.

• Korean Journal of Poultry Science
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• v.47 no.1
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• pp.29-37
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• 2020

This study was performed to investigate the effect of mixed rearing of male and female chickens on the stress response in Korean native chickens. To identify the degree of the stress response, heterophil-lymphocyte ratio (H/L ratio), heat shock protein genes (HSPs) expression, and intracellular nuclear DNA damage rate were analyzed before and after the mixed rearing of male and female chickens. The results showed that the H/L ratio of chickens after mixing males and females was more than thrice as higher than before mixing (P<0.001), but the differences between males and females were not significant. HSP-70, HSP90-α, and HSP90-β expression levels were 2.5 to 3.4 times higher after mixing male and female chickens, compared to before mixing (P<0.01). In the mixed rearing of male and female chickens, the increase in HSPs expression in females was higher than in males. Comet indicators in intracellular DNA damage rate analysis showed a significant increase after mixing male and female chickens compared to before mixing (P<0.001). However, there was no significant difference between males and females with respect to DNA damage rate. Taken together, these results suggest that male and female mixed rearing acts as a strong external stressor in both male and female chickens.

• Journal of Nutrition and Health
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• v.27 no.3
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• pp.253-262
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• 1994

This study was intended to investigate the anticarcinogenic effect of ginseng previously elucidated by other researches in animal studies. The sister chromatid exchange(SCE) method of human lymphocytes was used as a biomarker. Based on the literature search and the results of our laboratory, smoking was used as a parameter elevating the SCE frequency of general human population. To evaluate the smoking and ginseng effect on SCE frequency, 98 male healthy factory workers aged 23 to 58 years were divided into 4 groups : smoker with ginseng (SG), smoker control(SC), non-smoker with ginseng(NSG), and non-smoker control(NSC) groups, according to their smoking habits and ginseng intake. The mean sponteneous SCE per cell for the SG(10.8$\pm$0.3) and SC(10.4$\pm$0.3) groups were significantly higher than the NSG(9.1$\pm$0.2) and NSC(9.3$\pm$0.3) groups(p<0.05). High frequency cells (HFCs, cells with 15 SCEs) in SG and SC groups were also greater than those in NSG and NSC groups. However, the SCE levels of the SG and SC groups were not associated with the personal smoking history and the number of cigaretts smoked per day. Ginseng intake did not show any effect on the increased SCE caused by smoking. There were no correlations of the elevated SCE among smoking and ginseng types, history of ginseng intake, and consumption frequencies of ginseng intake. These results does not support the findings of other researchers that ginseng could be a protective agent to DNA damage.

• Journal of Nutrition and Health
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• v.49 no.5
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• pp.277-287
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• 2016

Purpose: This study was performed to compare total phenolic contents, in vitro antioxidant capacity, and reduction effect of Korean food groups on ex vivo DNA damage in human cells and analyze correlations between each indicator. Methods: Vegetable foods in the Korean diet based the results of the KNHANES V-2 (2011) were classified into 10 food groups: cereals, fruits, vegetables, nuts, kimchi, seaweeds, potatoes, mushrooms, legumes, and oils. Eighty-four foods constituted more than 1% of the total intake in each food group and finally designated as vegetable foods in the Korean diet. Total phenolic content of each food group was measured. Further, in vitro antioxidant capacity was measured based on DPPH radical scavenging assay, TEAC assay, and $ORAC_{ROO{\cdot}}$ assay. Ex vivo DNA damage in human lymphocytes was assessed using comet assay. Results: Total phenolic contents of food groups of the Korean diet increased in the order of mushrooms, fruits, vegetables, seaweeds, and kimchi. Meanwhile, antioxidant rankings of food groups as mean values from the three in vitro test methods increased in the order of mushrooms, seaweeds, vegetables, kimchi, and fruits. Protection against ex vivo DNA damage in human lymphocytes was highest in mushrooms, followed by vegetables, fruits, seaweeds, and kimchi. The rankings of the food groups for total phenolic content, in vitro DAC, and ex vivo DNA protection activity were similar, and correlations between each indicator were significantly high. Conclusion: Mushrooms, fruits, vegetables, and seaweeds among the tested food groups in the Korean diet showed high total phenolic contents, in vitro antioxidant capacities, and protection against DNA damage. Correlations between each indicator in terms of total phenolic content, in vitro antioxidant capacity, and ex vivo DNA protection between each food group were found to be particularly high.

• Journal of Nutrition and Health
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• v.50 no.1
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• pp.1-9
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• 2017

Purpose: Fruit and vegetable juices are known to be rich sources of antioxidants, which have beneficial effects on diseases caused by oxidative stress. The purpose of this study was to directly compare the antioxidant activities of fruit and vegetable juices marketed in Korea. Methods: We analyzed four fruit juices, two vegetable juices, two yellow-green juices, and six mixed vegetable juices. Antioxidant activities were analyzed using 2,2-diphenyl-1-picrylhydrazyl (DPPH) test, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonate) (ABTS) test, and oxygen radical absorbance capacity (ORAC) assay. Protective effects against DNA damage were determined using an ex vivo comet assay with human lymphocytes. Results: DPPH radical scavenging activities were in the following order: blueberry juice > mixed vegetable C juice > kale juice > mixed vegetable P juice > grape juice. ABTS radical scavenging activities were in the following order: blueberry juice > mixed vegetable C juice > grape juice > mixed vegetable P juice > kale juice. Peroxyl radical scavenging activities as assessed by ORAC assay were in the following order: blueberry juice > kale juice > mixed vegetable C juice > grape juice. Grape or blueberry juice showed strong abilities to prevent DNA damage in lymphocytes, and the difference between them was not significant according to the GSTM1/GSTT1 genotype. Conclusion: Antioxidant activities of fruit and vegetable juices and ex vivo DNA protective activity increased in the order of blueberry juice, grape juice, and kale juice, although the rankings were slightly different. Therefore, these juices rich in polyphenols and flavonoids deserve more attention for their high antioxidant capacity.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.2
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• pp.154-161
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• 2008

Phellinus linteus (PL) has been known to exhibit potent biological activity. The present study was designed to investigate lipase-inhibitory and anti-oxidative activity of the methanol extract and the powder of PL fruiting body. The methanol extract of PL appeared to have the inhibitory activity against pancreatic lipase with an $IC_{50}$ value of $36.3\;{\mu}g/mL$, and the scavenging activity of DPPH radical with an $IC_{50}$ value of $20.1\;{\mu}g/mL$, which was similar to that of vitamin C ($IC_{50}\;18.3\;{\mu}g/mL$). To investigate the lipase-inhibitory and anti-oxidative effect of PL on animal, Sprague-Dawley rats were fed with high-fat diet supplemented with either 2% or 5% PL powder for 8 weeks. Total food intake was significantly increased, but body weight was not changed by PL powder supplementation. However, fecal fat excretion of the experimental groups fed with the PL powder were higher than that of the control group. PL powder showed a decrease in the plasma total cholesterol, LDL-cholesterol, and the hepatic total cholesterol levels. The anti-oxidative enzyme activities were also affected by PL supplementation. Glutathione peroxidase (GSH-Px) in the plasma and liver were significantly increased by 98% and 46% in the 2% PL group, and 99% and 32% in the 5% PL group, respectively. Total superoxide dismutase (T-SOD) activity was not affected by PL supplementation. DNA damage was measured by the comet assay in the lymphocytes collected after 2 weeks, 4 weeks, and 8 weeks of feeding PL supplemented diet. Lymphocyte DNA damage was decreased in the PL supplemented group. Furthermore, PL feeding enhanced the resistance to lymphocyte DNA damage caused by an oxidant challenge with $H_2O_2$.

• Journal of Radiation Protection and Research
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• v.26 no.4
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• pp.385-392
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• 2001

Environmental risk factors such as ionizing radiations, heavy metals, and pesticides can cause environmental disasters when they exist in excess. The increases in use of ionizing radiation and agricultural pesticide are somewhat related to the possibility of the disaster. The risk of radiation and pesticide was evaluated by means of the single cell gel electrophoresis (SCGE) assay on the human blood lymphocytes. The lymphocytes were irradiated with $0{\sim}2.0Gy$ of $^{60}Co$ gamma ray. Another groups of lymphocytes were exposed to various concentrations of parathion. Significantly increased tail moment, which was a marker of DNA strand breaks in SCGE assay, showed a clear dose- or concentration-response relationship. Parathion of a recommended concentration for agricultural use ($1mg {\ell}^{-1}$ ) has a strong cytotoxic effect on lymphocytes, which is equivalent to damage induced by 0.1 Gy of ${\gamma}$-ray. Furthermore, $2mg{\ell}^{-1}$ of parathion can give rise to DNA damage equivalent to that induced by 0.25 Gy at which the radiation-induced damage can start to develop into clinical symptoms. The comparative results of this study can provide an experimental basis and biological information for the prevention of environmental disaster.