• Proceedings of the Korea Environmental Mutagen Society Conference
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• 2004.11a
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• pp.102-102
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• 2004

• Proceedings of the Korean Society of Environment and Ecology Conference
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• 2011.04a
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• pp.61-62
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• 2011

• Proceedings of the Korean Society of Toxicology Conference
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• 2001.10a
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• pp.33-34
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• 2001

Cancer chemoprevention Chemoprevention with strategies using food phytochemicals is currently regarded ascompose one of the noticeable most visible and promising scientific fields for cancer control. A large body of data from both epidemiologic and rodent studies has demonstrated that the ingestion of various vegetables and fruits is occasionally beneficial for cancer risk reduction of cancer risks in humans.(omitted)

• Proceedings of the Korean Society of Toxicology Conference
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• 2005.05a
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• pp.114-114
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• 2005

• Proceedings of the Korean Society of Embryo Transfer Conference
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• 2004.10a
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• pp.78-78
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• 2004

• Proceedings of the Korean Society of Toxicology Conference
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• 2003.10b
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• pp.23-23
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• 2003

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) and other aryl hydrocarbon (AhR) ligands suppress 17${\beta}$-estradiol (E)-induced responses in the rodent uterus and mammary tumors and in human breast cancer cells. Treatment of ZR-75, T47D and MCF-7 human breast cancer cells with TCDD induces proteasome-dependent degradation of endogenous estrogen receptor ${\alpha}$ (ER${\alpha}$).(omitted)

• Toxicological Research
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• v.32 no.3
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• pp.231-237
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• 2016

Eryngium foetidum Linn. leaves (EF) are widely used in Thailand and many countries throughout Asia as a culinary seasoning and a traditional medicine. However, adverse effect of high dose consumption in long duration has not been evaluated. The aim of this study was to investigate chronic toxicity of EF in mice. Thirty-two ICR male mice were divided into 4 groups of 8 mice each. The mice were fed AIN-76 rodent diet, or AIN-76 rodent diet supplemented with ground freeze-dried EF at 0.8%, 1.6% and 3.2% that is equivalent to approximately 35, 73 and 155 times that of human consumption, respectively, at 97.5 percentile for a period of 24 weeks. At the end of experiment, the mice were euthanized and blood samples were collected for hematological and biochemical evaluations. Necropsy was performed while visceral organs such as lung, liver, kidneys, spleen etc. were collected, weighed and histopathologically examined. Blood urea nitrogen (BUN) results of mice in 1.6% and 3.2% EF diet groups were significantly higher than the BUN of control group. No significant difference was noted in other biochemical and hematological properties between the treatment groups and control; all results were within normal range. Histopathology of almost all visceral organs showed no significant changes. However, tubulonephrosis and chronic interstitial nephritis were observed in the groups treated with 1.6% and 3.2% EF diet. Body weight was reduced significantly at week 12 to week 20 when compared to the control group while relative kidney weights were significantly increased. In conclusion, the consumption of EF in diet at high doses illustrated the adverse effect on some biochemical parameters and histopathology in mice. Our findings suggested that EF daily consumption for 24 weeks, at higher doses than the 0.8% EF diet (35 times of human consumption), might cause adverse effect on kidney function in mice.

• Environmental Mutagens and Carcinogens
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• v.23 no.3
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• pp.99-102
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• 2003

IARC classified areca quid as a human carcinogen. Areca quid chewed in Taiwan includes Piper betle inflorescence, which contains high concentrations of safrole (15 mg/fresh weight). Safrole is a documented rodent hepatocarcinogen, and chewing areca quid may contribute to human exposure (420 $\mu$m in saliva). The carcinogenicity of safrole is mediated through 1'-hydroxysafrole formation, followed by sulfonation to an unstable sulfate that reacts to form DNA adducts. Using human liver microsomes and Escherichia coli membranes expressing bicistronic human P450s, CYP2E1 and CYP2C9 were identified as the main P450s involved in the activation of safrole. We have demonstrated the presence of stable safrole-dGMP adducts in human oral tissues following areca quid chewing using $^{32}$ P-postlabeling and HPLC mass spectrometry methods. By studying 88 subjects with a known AQ chewing history and 161 matched controls, we have demonstrated that the presence of safrole-DNA adducts in peripheral blood cells was correlated to AQ chewing, and CYP2E1 seemed to play an important role in the modulation of safrole-DNA adduct formation. We have also shown that safrole can form stable safrole-DNA adducts as well as oxidative damages in rodent liver. However, the stable safrole-DNA adducts may represent a more significant initial lesion as compared to the rapidly repaired safrole-induced 8-hydroxy-2'-deoxyguanosine. This oxidative DNA damage is mediated through the formation of hydoryxchavicol, the major safrole metabolite in human urine. Hydroxychavicol may have gone through two-electron oxidation to the o-quinone; then via one-electron reduction to semiquinone radicals to generate oxidative DNA damage. However, these reactive metabolites can be efficiently conjugated by GSH. These data suggest that safrole may contribute to the initiation of oral carcinogenesis through safrole-DNA adduct and not oxidative DNA damage. In addition, CYP2E1 may modulate this adduct formation.

• Nutrition Research and Practice
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• v.5 no.3
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• pp.205-213
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• 2011

Exercise training (ET) and selenium (SEL) were evaluated either individually or in combination (COMBI) for their effects on expression of glucose (AMPK, PGC- $1{\alpha}$, GLUT-4) and lactate metabolic proteins (LDH, MCT-1, MCT-4, COX-IV) in heart and skeletal muscles in a rodent model (Goto-Kakisaki, GK) of diabetes. Forty GK rats either remained sedentary (SED), performed ET, received SEL, ($5\;{\mu}mol{\cdot}kg$ body $wt^{-1}{\cdot}day^{-1}$) or underwent both ET and SEL treatment for 6 wk. ET alone, SEL alone, or COMBI resulted in a significant lowering of lactate, glucose, and insulin levels as well as a reduction in HOMA-IR and AUC for glucose relative to SED. Additionally, ET alone, SEL alone, or COMBI increased glycogen content and citrate synthase (CS) activities in liver and muscles. However, their effects on glycogen content and CS activity were tissue-specific. In particular, ET alone, SEL alone, or COMBI induced upregulation of glucose (AMPK, PGC-la, GLUT-4) and lactate (LDH, MCT-1, MCT-4, COX-IV) metabolic proteins relative to SED. However, their effects on glucose and lactate metabolic proteins also appeared to be tissue-specific. It seemed that glucose and lactate metabolic protein expression was not further enhanced with COMBI compared to that of ET alone or SEL alone. These data suggest that ET alone or SEL alone or COMBI represent a practical strategy for ameliorating aberrant expression of glucose and lactate metabolic proteins in diabetic GK rats.

• Toxicological Research
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• v.17
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• pp.293-297
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• 2001

The international pharmaceutical and regulatory communities had been recognizing the limited utility of conventional rodent carcinogenicity study particularly on the second species, mouse, after intense investigation of carcinogenicity data base worldwide, and a new scheme for carcinogenicity testing for pharmaceuticals was proposed at the Expert Working Group on Safety in the International Conference on Harmonization (ICH) in 1996. CB6F 1-Tg rasH2 mouse carrying human prototype c-Ha-ras gene with its own promoter/enhancer is one oj the new carcinogenicity assay model for human cancer risk assessment. Studies have been conducted since 1992 to validate the transgenic (Tg) mice for rapid carcinogenicity test-ing, short term (26 weeks) studies with genotoxic (by Salmonella), non-genotoxic carcinogens, genotoxic non-carcinogens, non-genotoxic non-carcinogens revealed relatively high concordance oj the response of the Tg mouse with classical bioassay across classes of carcinogenic agents. Mechanistic basis for carcinogensis in the model are being elucidated in terms of the role of overexpression and/or point mutation of the transgene. This report review the initial studies of validation of the model and preliminary results of on-going ILSI HESI ACT project will be presented.