• Journal of Preventive Medicine and Public Health
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• v.37 no.4
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• pp.373-380
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• 2004

Objectives : There has been gradually increasing concern about the adverse health effects of electromagnetic radiation originating from cell phones which are widely used in modern life. Cell phone radiation may affect human health by increasing free radicals of human blood cells. This study has been designed to identify DNA damage of blood cells by electromagnetic radiation caused by cell phone use. Methods : This study investigated the health effect of acute exposure to commercially available cell phones on certain parameters such as an indicator of DNA damage for 14 healthy adult volunteers. Each volunteer during the experiment talked over the cell phone with the keypad facing the right side of the face for 4 hours. The single cell gel electrophoresis assay (Comet assay), which is very sensitive in detecting the presence of DNA strand-breaks and alkali-labile damage in individual cells, was used to assess peripheral blood cells (T-cells, B-cells, granulocytes) from volunteers before and after exposure to cell phone radiation. The parameters of Comet assay measured were Olive Tail Moment and Tail DNA %. Results : The Olive Tail Moment of B-cells and granulocytes and Tail DNA % of B-cells and granulocytes were increased by a statistically significant extent after 4-hour use of a cell phone compared with controls. Conclusion : It is concluded that cell phone radiation caused the DNA damage during the 4 hours of experimental condition. Nonetheless, this study suggested that cell phone use may increase DNA damage by electromagnetic radiation and other contributing factors.

• YAKHAK HOEJI
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• v.51 no.4
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• pp.239-245
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• 2007

In order to evaluate the genotoxicity of airborne particulate matter extracted with dichloromethane (APE), the rat microsome mediated (S-9) or DNA repair enzyme treated Comet assays were performed using the single cell gel electrophoresis in A549 human lung carcinoma cells. It was found that the cells interacting with APE showed more DNA single-strand breaks relative to untreated cells. The genotoxicity of APE was increased with the treatment of S-9 mixture. Microsome mediated DNA damage was inhibited by CYP1Al inhibitor, quercetin. The APE also showed oxidative DNA damage evaluated by endonuclease III treatment. Oxidative DNA damage of APE was inhibited by antioxidants such as vita- min C and Trolox. We also found that the vegetables or fruits extract may reduce APE-induced genotoxicity by their anti- oxidant activity and CYP1A1 inhibition.

• Molecular & Cellular Toxicology
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• v.4 no.4
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• pp.285-292
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• 2008

Crocin is one of the major components of gardenia fruit and saffron which are widely used as natural food colorants and as traditional Chinese medicines. However, the genotoxicity data on crocin are not sufficient for safety evaluation. The purpose of this study was the examination of the genotoxicity on crocin from gardenia yellow in bacterial and mammalian cells, using various genotoxic battery testing assays and the influence of crocin on methyl methanesulfonate (MMS) and ${H_2}{O_2}$-induced DNA damage in vitro, using single cell gel electrophoresis (comet) assay. From results, no considerable mutagenicity and clastogenicity were seen in bacteria and mammalian cells treated with crocin, by Ames test, chromosomal aberration assay, ${tk}^{+/-}$ gene forward mutation assay and comet assay. And, post-treatment with crocin significantly suppressed ${H_2}{O_2}$-induced DNA damage in a dose-dependent manner. In conclusion, the findings of the present study and other previous observations indicate that crocin has no genotoxic potential. And it showed that crocin clearly repressed the genotoxic potency of ${H_2}{O_2}$. These results suggest that anti-oxidative effects of crocin may be involved in the protective effects of DNA damage.

• Korean Journal of Ecology and Environment
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• v.41 no.4
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• pp.466-471
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• 2008

Little is known about DNA-level and physiological levels for health assessments of stream or river environments. Recently, comet assay, so called Single Cell Gel Electrophoresis (SCGE) is introduced for assessments of DNA damage in the medical science, food science and mammal toxicology. The comet assay is known as a biomarker which is one of the best barometers in assessing the DNA damage by oxidative stress. In this study, we conducted the comet assay using sentinel species, Zacco platypus, as one of the pre-warning alarm systems for the aquatic ecosystem health assessments and also applied it to Gap Stream as a model system. Tail extent moments in the S1 and S2 were 5.20 and 9.90 respectively and the moment was 19.89 in the S3. Statistical ANOVA in the tail moments showed a significant difference (n=75, p<0.05) between S1 and S3. Also, the proportions of DNA in the tail were 14.47, 23.64, and $30.04{\mu}m$ in the upstream (control site), midstream, downstream sites, respectively. Our results in the downstream were accord with previous studies of individual-level, population-level, and community-level in Gap Stream. Our results suggest that the comet assay may be used as an important tool for diagnosing ecological health of aquatic ecosystems in the level of DNA.

• Molecular & Cellular Toxicology
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• v.1 no.4
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• pp.230-236
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• 2005

Formaldehyde is a common environmental contaminant found in tobacco smoke, paint, garments, diesel and exhaust, and medical and industrial products. Formaldehyde has been considered to be potentially carcinogenic, making it a subject of major environmental concern. However, only a little information on the mechanism of immunological sensitization and asthma by this compound has been known. So, we performed with Jurkat cell line, a human T lymphocyte, to assess the induction of DNA damage and to identify the DEGs related to immune response or toxicity by formaldehyde. In this study, we investigated the induction of DNA single strand breaks by formaldehyde using single cell gel electrophoresis assay (comet assay). And we compared gene expression between control and formaldehyde treatment to identify genes that are specifically or predominantly expressed by employing annealing control primer (ACP)-based $GeneFishing^{TM}$ method. The cytotoxicity ($IC_{30}$) of formaldehyde was determined above the 0.65 mM in Jurkat cell in 48 h treatment. Based on the $IC_{30}$ value from cytotoxicity test, we performed the comet assay in this concentration. From these results, 0.65 mM of formaldehyde was not revealed significant DNA damages in the absence of S-9 metabolic activation system. And the one differentially expressed gene (DEG) of formaldehyde was identified to zinc finger protein 292 using $GeneFishing^{TM}$ method. Through further investigation, we will identify more meaningful and useful DEGs on formaldehyde, and then can get the information on the associated mechanism and pathway with immune response or other toxicity by formaldehyde exposure.

• YAKHAK HOEJI
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• v.54 no.1
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• pp.32-38
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• 2010

The aim of this study was to evaluate the effect of galangin towards hydrogen peroxide-induced DNA damage. The calf thymus DNA and Chinese Hamster Lung (CHL) cells were used to measure 8-hydroxy-2'-deoxyguanosine(8-OH2'dG) as an indicator of DNA oxidative damage using high performance liquid chromatography with electrochemical detection. Hydrogen peroxide in the presence of Fe(II) ion induced the formation of 8-OH2'dG in both calf thymus DNA and CHL cells. The DNA damage effects were enhanced by increasing the concentration of Fe(II) ion and inhibited by galangin. In the single cell gel electrophoresis (Comet assay), galangin and dl-a-tocopherol showed an inhibitory effect in CHL on hydrogen peroxide induced DNA single strand breaks. Galangin showed more potent activity than dl-$\alpha$-tocopherol under our experimental conditions. These results indicate that galangin can modify the action mechanisms of the oxidative DNA damage and may act as chemopreventive agents against oxidative stress.

• Molecular & Cellular Toxicology
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• v.1 no.3
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• pp.179-188
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• 2005

To develop the novel anti-allergic drug, many sophoricoside derivatives were synthesized. Among these derivatives, JSH-II-3, VI-3, VII-3, VIII-3, VII-20 and VII-20 (sodium salt) were selected and subjected to high throughput toxicity screening (HTTS) because they revealed strong IL-5 inhibitory activity and limitation of quantity. Single cell gel electrophoresis (Comet) assay, mouse lymphoma thymidine kinase ($tk^{+/-}$) gene assay (MOLY), chromosomal aberration assay in mammalian cells and Ames reverse mutation assay in bacterial system were used as simplified, inexpensive, short-term in vitro screening tests in our laboratory. Through the primary screening using the comet assay, we could choose the first candidates of sophoricoside derivatives with no genotoxic potentials as JSH-VI-3, VII-3, VII-20 and VII-20 (sodium salt). Also JSH-VII-3, VII-20 and VII-20 (sodium salt) are non-mutagenic in MOLY assay, while JSH-II-3 is mutagenic at high concentration with the presence of metabolic activation system in both comet assay and MOLY assay. The selected derivatives (JSH-VI-3, VII-3, VII-20 and VII-20 (sodium salt) are not mutagenic in S. typhimurium TA98 and TA100 strains both in the presence and absence of metabolic activation. From results of chromosomal aberration assay, 6 h treatment of JSH-VI-3, VII-3 and VII-20 (sodium salt) were not revealed clastogenicity both in the presence and absence of S-9 mixture. Therefore, we suggests that JSH-VI-3, VII-3, VII-20 and VII-20 (sodium salt), as the optimal candidates with both no genotoxic potential and IL-5 inhibitory effects must be chosen. To process the development into new anti-inflammatory drug of these derivatives, further investigation will need.

• Proceedings of the Korean Society of Toxicology Conference
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• 2001.10a
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• pp.182-182
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• 2001

Sophoricoside was isolated as the inhibitor of IL-5 bioactivity from Sophora japonica (Leguminosae). It has been reported to have an anti-inflammatory effect on rat paw edema model. To develope as an anti-allergic drug, genotoxicity of sophoricoside was investigated in bacterial and mammalian cell system such as Ames bacterial test, chromosomal aberration assay and single cell gel electrophoresis (Comet) assay.(omitted)

• Proceedings of the Korea Society of Environmental Toocicology Conference
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• 1996.12a
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• pp.61-61
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• 1996

Taxol is used as cancer therapeutic agent. It has been known as weak posotive of chromosome aberration assay in vitro in our previous results (Ryu et al., 1996) and potent clastogens in the mouse bone marrow micronucleus (Tinwell and Ashby, 1994). We performed microgel electrophoresis to determine the effect of taxol and it's precursor 10-deacetyl baccatin III(DAB) on DNA. Microgel electrophoresis is useful, rapid, simple, visual, and sensitive technique for measuring DNA breakage and repair mechanisms in mammalian 근ells. The range of concentration used for taxol were 854, 427, 213.5, 106.8, 53.4 Ug/ml, for DAB 910 ,455, 227.5 U9/ml, Cell viability always exceed 85%. We analyzed the results by using the special software of image analyzer for this comet assay (Komet 3.0). By using this image analyzer software , we can get the result as the tail moment ((mean of tail length - mean of head lengh) x tail%DNA/100). A slight increase in DNA migration was observed for taxol at the concentration of 854 Ug/m4 in the absence of S9 mixture. No increased DNA migration was observed after treatment with DAB.

• Journal of Nutrition and Health
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• v.36 no.3
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• pp.255-261
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• 2003

Food irradiation has been steadily increasing in many countries in line with increasing international trade and concerns about naturally occurring harmful contaminants in food. Although irradiation provides an excellent safeguard for the consumer by destroying almost 100% of harmful bacteria, it is necessary to ensure the safety of irradiated foods. This study was performed to investigate the effect of an irradiated diet on lipid peroxidation in the plasma, liver, small intestinal mucosa, and lymphocyte DNA damage in mice. Eight-week old ICR mice were assigned to two groups to receive either non-irradiated or irradiated (10 kGy) diets containing 20.38% fish powder and 6.06% sesame seeds for 4 weeks. The resulting changes in the degrees of lipid peroxidation were evaluated based on the level of plasma and liver thiobarbituric acid reactive substance (TBARS), transmission electron micrograph of jejunal mucosa, and free radical-induced oxidative DNA damage in lymphocytes, as measured by alkaline comet assay (single cell gel electrophoresis). The peroxide values of the gamma irradiated diet were measured every week, and the sample for comet assay was taken at the end of the four week experimental period. There was no significant difference in food efficiency ratio between the two groups. The peroxide values of the diet were immediately increased to 35.5% after gamma irradiation and kept on increasing during storage. After 4 weeks, no differences in tissue or plasma TBARS value were observed between the two groups, but epithelial cells of jejumum showed osmiophillic laminated membranous structures, considered as myelin figures,. The oxidative DNA damage expressed as tail moment (TM) increased 30% in the blood lymphocytes of the mice fed the irradiated diet. In conclusion, the comet assay sensitively detected differences in lymphocyte DNA damage after feeding with the irradiated diet for 4 weeks. However, in order to ensure the safety of irradiated foods, it would be more useful to conduct a long-term feeding regimen using an irradiated diet and examine the level of lipid peroxidation and the state of oxidative stress in a greater range of organs.