• Journal of Nutrition and Health
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• v.37 no.6
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• pp.440-447
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• 2004

In this study the in vitro protective effects of several antioxidant vitamins (vitamin C, $\alpha$-tocopherol, $\beta$-carotene), fruits and vegetables (strawberry, tangerine, orange and 100％ orange juice, carrot juice), on the levels of isolated human lymphocyte DNA damage was measured using Comet assay. Comet assay has been used widely to assess the level of the DNA damage in the individual cells. Lymphocytes were pre-treated for 30 minutes with antioxidant vitamins (10, 50, 100, 500 $\mu$M) or fruits$.$vegetables (10, 100, 500, 1000 $\mu$g/ml), an4 then oxidatively challenged with 100 $\mu$M $H_2O$$_2$ for 5 min at 4$^{\circ}C$. The protective effect of antioxidant vitamins against DNA damage at a concentration of 50 $\mu$M were 50％ in vitamin C, 32％ in $\alpha$-tocopherol, whereas, fJ-carotene showed a 55％ protection at a dose as low as 10 $\mu$M. The inhibitory effects of DNA damage by strawberry, tangerine, orange, orange juices, carrot juices were 50 - 60％ with wide ranges of doses. The results of the present study indicate that most the antioxidant vitamins and fruits$.$vegetables juices produced a significant reduction in oxidative DNA damage.

• Applied Biological Chemistry
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• v.48 no.2
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• pp.155-160
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• 2005

Electrolyzed reduced water (ERW), showing extremely negative oxidation-reduction potential, was used to investigate the effects of paraquat-induced damages on DNA from human lymphocyte. The effect of ERW on paraquat-induced oxidative DNA damage in human lymphocytes was evaluated by Comet assay (single-cell gel electrophoresis) quantified as percentage fluorescence in tail. Comet assay has been used widely to assess the level of the DNA damage in individual cells. Lymphocytes were oxidatively challenged with various concentrations of paraquat for 30 min at $37^{\circ}C$, and were then treated with electrolyzed reduced water for 30 min. The oxidative DNA damage by paraquat, as indicated by the fluorescent tail in DNA, increased in a dose-dependent manner. However, oxidative damage of the DNA was almost completely prevented upon treatment with electrolyzed reduced water.

• Environmental Analysis Health and Toxicology
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• v.19 no.1
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• pp.101-107
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• 2004

To ascertain the effects of hair dyeing application on the DNA damage in human lymphocytes, a mixture of permanent black colored hair dye with the same amount of oxidant containing 6% hydrogen peroxide was used. A hair dyeing with contacting the scalp (conventional dyeing) and a hair dyeing with 3 to 4mm away from the scalp (alternative dyeing) were applied to each If young healthy women. Blood was taken from the brachial vein at two sampling times, just before and 6 hours after the hair dyeing, and tail extent moment(TEM) and tail length (TL) were measured by using a comet assay. After dyeing, TL was significantly increased in both conventional dyeing group and alternative dyeing group compared with before dyeing as an average of 47% and 28%, respectively, and TL for conventional dyeing group was higher than alternative dyeing group as an average of 1.2 fold. After dyeing, TEM was significantly increased in both conventional dyeing group and alternative dyeing group compared with before dyeing as an average of 192% and 76%, respectively, and TEM for conventional dyeing group was significantly higher than alternative dyeing group as an average of 1.7 fold. Therefore, alternative dyeing application was induced to lower lymphocyte DNA damage than conventional dyeing application, and TEM was appeared to be a more sensitive tool for the measurement of lymphocyte DNA damage than TL in this study.

• Restorative Dentistry and Endodontics
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• v.18 no.2
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• pp.317-340
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• 1993

This study was designed 1) to compare the distributions of periapical inflammatory cells and 2) to identify lymphocytes and compare the lymphocyte distribution with T lymphocyte subpopulation and then 3) to examine the distribution of cycling cell in human dental periapical lesions. From each of the twenty-five human dental periapical lesions observed one small portion was fixed, embeded in paraffin, sectioned serially and stained with HE. The periapical inflammatory cells were counted to obtain the relative concentration of lymphocyte, plasma cell, macrophage and neutrophil. The large part of each lesion was analysed using Flow cytometer and monoclonal antibodies to obtain the relative concentration of T lymphocyte, B lymphocyte, T'helper cell and T suppressor/cytotoxic cell. In addition to that, seven human dental periapical lesions were examined with DNA analysis to observe the distribution of cycling cell. Following results were obtained: 1. 24 cases of the 32 periapical lesions examined were diagnosed as periapical granuloma and the remaining 8 cases as periapical cyst. Lymphocytes comprised 42.1% of total inflammatory cells in periapical granuloma and 41.8% in periapical cyst. Corresponding percentages for macrophages were 33.8% and 30.3%; for plasma cells, 15.9% and 19.0%; for neutrophils, 8.2% and 8.8%. 2. All of the periapical lesions examined had T lymphocyte, B lymphocyte, T helper cell, T suppressor/cytotoxic cell. And in all cases, T lymphocytes were observed predominantly more than B lymphocytes. 3. In 2 cases of the control group only T lymphocytes were found, and in the remaining 2 cases T lymphocytes were observed predominantly. 4. T helper cells were observed predominantly more than T suppressor/cytotoxic cells in all cases of perapical granulomas. 5. T suppressor/cytotoxic cells were observed predominantly more than T helper cells in 4 cases of periapical cysts (total 5 cases were examined) and only in one case T helper cells were more than T suppressor/cytotoxic cells. 6. In control group, T helper cells were predominant in 2 cases and T helper cells were equivalent to T suppressor/cytotoxic cells in one case. In remaining one case T suppressor/cytotoxic cells were predominant. 7. As the result of DNA analysis, the average proliferating indices of the various groups examined were measured as follows: in the control group 5.45%, in periapical granuloma 6.64%, in periapical cyst 10.1%. The highest index was observed in periapical cyst.

• Proceedings of the Korean Nutrition Society Conference
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• 2002.05a
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• pp.167-167
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• 2002

• Molecular & Cellular Toxicology
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• v.5 no.3
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• pp.243-249
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• 2009

Melamine, which is used to produce melamine resin for various industrial applications, has a high nitrogen content by mass. For this reason, it has been illegally added to foods to increase their apparent protein content. In the present investigation, melamine-induced oxidative damage of human lymphocyte DNA was evaluated by Comet assay. The in vitro oxidative DNA damage caused by melamine increased in a dose-dependent manner. This DNA damage was significantly inhibited by treatment with ascorbate. Moreover, the traditional Korean medicinal herb, named Acanthopanax, red ginseng and green tea markedly reduced the DNA damage. Various edible plant extracts also inhibited melamine-induced oxidative DNA damage in vitro. Melamine enhanced intracellular ROS generation, and this effect was suppressed by treatment with various antioxidants.

• Nutrition Research and Practice
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• v.11 no.1
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• pp.33-42
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• 2017

BACKGROUND/OBJECTIVE: This study aims to measure the in vitro antioxidant capacity of Korean diet (KD) with American diet (AD) as a control group and to examine the ex vivo DNA damage reduction effect on human lymphocytes. MATERIALS/METHODS: The KD applied in this study is the standard one-week meals for Koreans (2,000 kcal/day) suggested by 2010 Dietary Reference Intakes for Koreans. The AD, which is the control group, is a one-week menu (2,000 kcal/day) that consists of foods that Americans would commonly take in according to the National Health and Nutrition Examination Survey. The antioxidant capacity of each menu was measured by means of the total phenolic assay and 3 in vitro antioxidant activity assays (2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, trolox equivalent antioxidant capacity (TEAC), Oxygen radical absorbance capacity ($ORAC_{ROO{\cdot}}$)), while the extent of ex vivo lymphocyte DNA damage was measured by means of the comet assay. RESULTS: When measured by means of TEAC assay, the in vitro antioxidant capacity of the KD of the day was higher than that of the AD (P < 0.05) while there was no significant difference in total phenolic contents and DPPH and ORAC assays. The ex vivo lymphocyte DNA damage protective effect of the KD was significantly higher than that of the AD (P < 0.01). As for the one-week menu combining the menus for 7 days, the total phenolic assay (P < 0.05) and in vitro antioxidant capacity (P < 0.001, DPPH; P < 0.01, TEAC) of the KD menu were significantly higher than those of the AD menu. Likewise, the ex vivo DNA damage reduction rate of the Korean seven-day menu was significantly higher than that of the American menu (P < 0.01). CONCLUSION: This study demonstrates that the high antioxidant capacity and DNA damage protective effect of KD, which consists generally of various plant foods, are higher than those of typical AD.

• Journal of Radiation Protection and Research
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• v.25 no.4
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• pp.223-232
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• 2000

Comparative study was performed for the assessment of DNA damage and Chromosomal aberration in human lymphocyte exposed to low dose radiation using fluorescence in situ hybridization(FISH) and single cell gel electrophoresis(SCGE). Chromosomal aberrations in human lymphocytes exposed to radiation at doses of 5, 10, 30 and 50cGy were analysed with whole chromosome-specific probes by human chromosome 1, 2 and 4 according to PAINT system. FISH with chromosome-specific probe has been used to be a valid and rapid method fer detection of chromosome rearrangements induced by low dose radiation. The frequencies of stable translocation per cell equivalents were 0.0116, 0.0375, 0.040f, 0.0727 and 0.0814 for 0, 5, 10, 30 and 50cGy, respectively, and those of dicentric were 0.00, 0.0125, 0.174, 0.0291 and 0.0407 respectively. Radiation induced DNA damage in human lymphocyte in a dose-dependent manner at low doses from 5cGy to 50cGy, which were analysed by single tell gel electrophoresis(SCGE). From above results, FISH seemed to be useful for radiation biodosimetry by which the frequencies of stable aberrations in human lymphocyte can be observed more easily than by conventional method and SCGE also seemed to be sensitive method f9r detecting DNA damage by low dose radiation exposure, so that those methods will improve our technique to perform meaningful biodosimetry for radiation at low doses.

• Journal of Nutrition and Health
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• v.35 no.2
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• pp.213-222
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• 2002

The alkaline comet assay has been used with increasing popularity to investigate the level of DNA damage in biomonitoring studies within the last decade in Western countries. The purpose of this study was to evaluate the usefulness of the alkaline comet assay as a biomarker of oxidative DNA damage for monitoring in the Korean population, and also to evaluate the effect of nutritional status and lifestyle factors on H2O2 induced oxidative DNA damage measured by the alkaline comet assay in human lymphocytes. The study population consisted of 61 healthy Korean male volunteers, aged 20-28. Epidemiological background data including dietary habits, smoking habits and anthropometrical measurements were collected through personal interviews. After blood collection, the comet assay in peripheral lymphocytes and plasma lipids analysis was carried out and the results analyzed. Tail moment (TM) and tail length (TL) of the comet assay were use\ulcorner to measure DNA damage in the lymphocytes of the subjects. Statistically significant (p < 0.05) positive correlations were observed between DNA damage (TM or TL) and smoking habits expressed as cigarettes smoked per day and pack years (r = 0.311 and 0.382 for TM, r = 0.294 and 0.350 for TL, respectively). There were also significant positive correlations between DNA damage parameter and waist-hip ratio. Higher plasma triglyceride levels were associated with increased damage to DNA. There were no correlations between the consumption frequencies of vegetables and DNA damage to the subjects. However, consumption frequencies of fruit and fruit juice intake were inversely associated with the TM and TL. The results indicate that die comet assay is a simple, rapid and sensitive method for detecting lymphocyte DNA damage induced by cigarette smoking. Consumption of fruit or fruit juices could potentiall modify the damaged DNA in the human peripheral lymphocytes of young Korean men.

• Journal of Microbiology and Biotechnology
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• v.18 no.3
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• pp.600-610
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• 2008

A cancer-associated antigen gene (CAGE) was identified by serological analysis of a recombinant cDNA expression library (SEREX). The gene was identified by screening cDNA expression libraries of human testis and gastric cancer cell lines with sera from patients with gastric cancer. CAGE was found to contain a D-E-A-D box domain and encodes a putative protein of 630 amino acids with possible helicase activity. The CAGE gene is widely expressed in various cancer tissues and cancer cell lines. Demethylation plays a role in the activation of CAGE in certain cancer cell lines where the gene is not expressed. The functional roles of CAGE in tumorigenesis, the molecular mechanisms of CAGE expression, and cell motility are also discussed.