• Journal of Nutrition and Health
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• 제27권4호
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• pp.347-355
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• 1994

Indolo[3,2-b]carbazole(ICZ) is a potent Ah receptor agonist with biological activities similar in several respects to those of the potent environmental toxin, TCDD. ICZ is produced during the oilgomerization of indole-3-carbinol(I3C), a breakdown product of the glucobrassicin present in food plants of the Brassica genus. In the present study we examined ICZ levels in tissues and excreta of rats treated with I3C or dietary cabbage of established glucobrasicin content, and in feces of conventional and germfree rats fed on a basal diet, and of humans. We also examined the levels of cytochrome P4501A1 induction, as determined by the ethoxyresorufin ο-deethylase assay, in tissues of animals that received cabbage-supplemented diets, or which were treated with purified I3C or ICZ. Our findings indicated that incorporation of either homogenized or whole freeze-dried cabbage in the feed led to large increases(16-60 fold) in the levels of ICZ in the feces and lower gastrointestinal tract of rats. We observed that whereas ICZ is readily detectable at about the same levels(2.00$\pm$0.50 ppb) in the feces of conventional rats fed on a purified diet and in human feces, levels of ICZ in the feces of germfree animals fed on the basal diet were at the limits of detection(0.40$\pm$0.20 ppb), indication that gut bacteria are important for the production of ICZ from essential dietary constituents in the basal diet. We showed that in contrast to the near 7000-fold difference in CYP1A1 inducing potencies of ICZ and TCDD in cells in culture, their inducing potencies differ by only about an order of magnitude in rats. Nonetheless, the levels of ICZ remaining in livers twenty hours after I3C treatment appear too low to account for the induced activity. This result indicates that ICZ may be rapidly cleared from the liver or that substances other than, or in addition to, ICZ be responsible for the enzyme-inducing activity of orally administered I3C or its precursors.

• 한국환경성돌연변이발암원학회지
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• 제24권4호
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• pp.180-188
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• 2004

CYP1A1 is known to be inducible by xenobiotic compouds such as polyciclic aromatic hydrocarbons(PAHs) and 2,3,7,8-tetrachloro-dibenzo-p-dioxin(TCDD). These chemicals have been identified worldwide and can have a significant impact on the human health and well being of human and wildlife. Given these issues, the detection and quantification of these chemicals in biological, environmental and food samples is important. We investigated the effect of dietaty flavonoid, such as CYP1A1 promoter activity, 7-ethoxyresorufin-O-deethylase(EROD) activity and CYP1A1 mRNA expression induced by benzo(k)fluoranthene(B(k)F) in MCF-7 cells. Based on the three criteria of frequency of occurrence in the environment, toxicity and potential exposure to humans, B(k)F is one of the top-listed PAHs. We found that B(k)F significantly up-regulates the level of CYP1A1 promoter activity, EROD and CYP1A1 mRNA. when cells were treated with daidzein inhibited the B(k)-induced CYP1A1 prompter activity and mRNA level at high concentration. But daidzein exhibited stimulatory effects B(k)F-induced CYP1A1 promoter activity and mRNA level at low concentration. Overall, results from these studies demonstrate flavonoids might interfere the action of B(k) with AhR system to stimulate CYP1A1 gene expression.

• 한국환경성돌연변이발암원학회지
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• 제24권4호
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• pp.189-197
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• 2004

We investigated the effect of dietaty flavonoid, such as CYP1A1 promoter activity, 7-ethoxyresorufin-O-deethylase(EROD) activity and CYP1A1 mRNA expression induced by benzo(k)fluoranthene(B(k)F) in MCF-7 cells. Based on the three criteria of frequency of occurrence in the environment, toxicity and potential exposure to humans, B(k)F is one of the top-listed PAHs. We found that B(k)F significantly up-regulates the level of CYP1A1 promoter activity, EROD and CYP1A1 mRNA. When cells were treated with morin alonem, it was not changed that EROD and CYP1A1 mRNA, compared to that of control. However, morin inhibited the B(k)-induced CYP1A1 prompter activity and mRNA level at high concentration. But morin exhibited stimulatory effects B(k)F-induced CYP1A1 promoter activity and mRNA level at low concentration. Overall, results from these studies demonstrate morin might interfere the action of B(k) with AhR system to stimulate CYP1A1 gene expression. CYP1A1 is known to be inducible by xenobiotic compouds such as polyciclic aromatic hydrocarbons(PAHs) and 2,3,7,8-tetrachloro-dibenzo-p-dioxin(TCDD). These chemicals have been identified worldwide and can have a significant impact on the human health and well being of human and wildlife. Given these issues, the detection and quantification of these chemicals in biological, environmental and food samples is important.

• Genomics & Informatics
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• 제2권2호
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• pp.75-80
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• 2004

In a variety of animal species, the perinatal exposure of experimental animals to the 2,3,7,8-tetrachlorodibenzo­p-dioxin (TCDD) leads to the immune dysfunction, which is more severe and persistent than that caused by adult exposure. We report here the changes of gene expression and the identification of the marker-genes representing the dioxin exposure. The expressions of the transcripts were analyzed using the 11 K oligonucleotide­microarray from the bone marrow cells of male C57BL/6J mice after an intraperitoneal injection of $1{\mu}g$ TCDD/kg body weight at various time intervals: gestational 6.5 day(G6.5), 13.5 day(G13.5), 18.5 day(G18.5), and postnatal 3 (P3W)and 6 week (P6W). The type of self-organizing maps(SOM) representing the specific exposure dioxin could be identified as follows; G6.5D(C14), G13.5D(C0, C5, C10, C18), G18.5D(7): P3W(C2, C21), and P6W(C4, C15, C20). The candidate marker-genes were restricted to the transcripts, which could be consistently expressed greater than $\pm$2-fold in three experiments. The resulting candidates were 85 genes, the characteristics of that were involved in cell physiology and cell functions such as cell proliferation and immune function. We identified the biomarker-genes for dioxin exposure: smc -like 2 from SOM C14 for the dioxin exposure at G6.5D, focal adhesion kinase and 6 other genes from C0, and protein tyrosine phosphatase 4a2 and 3 other genes from C5 for G13.5D, platelet factor 4 from C7 for G18.5D, fos from C2 for P3W.

• 한국환경성돌연변이발암원학회:학술대회논문집
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• 한국환경성돌연변이발암원학회 2003년도 추계학술대회
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• pp.178-178
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• 2003

• 한국환경성돌연변이발암원학회:학술대회논문집
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• 한국환경성돌연변이발암원학회 2003년도 추계학술대회
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• pp.179-179
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• 2003

• 한국환경성돌연변이발암원학회:학술대회논문집
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• 한국환경성돌연변이발암원학회 2003년도 추계학술대회
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• pp.190-191
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• 2003

• 한국환경성돌연변이발암원학회:학술대회논문집
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• 한국환경성돌연변이발암원학회 2002년도 Molecular and Cellular Response to Toxic Substances
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• pp.145-145
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• 2002

• Environmental Analysis Health and Toxicology
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• 제11권3_4호
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• pp.75-87
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• 1996

There are numerous and evidential findings that TCDD (2, 3, 7, 8-tetrachlorodibenzo-Pdioxin, or dioxin) is a potential carcinogen and general toxin in rodents. flowever, human risk assessment for dioxin exposure has been a topic of debate, owing in part to the large animal interspecies differences in its toxicity. We review dioxin-related reports indicating its toxicity, toxic effects in animal, and human epidemiologic findings. The intent of this paper does not provide a causal inference about chronic human diseases related to dioxin exposure. This summary would give a valuable clue for a researcher to conduct or design a further dioxin-related study.

• Toxicological Research
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• 제21권4호
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• pp.333-338
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• 2005

Many of thyroid hormones disrupting chemicals induce effects via interaction with thyroid hormone and retinoic acid receptors and responsive elements intrinsic in target cells. We studied thyroid hormones disrupting effects of food additives and contaminants including BHA, BHT, ethoxyquin, propionic acid, sorbic acid, benzoic acid, CPM, aflatoxin B1, cadmium chloride, genistein, TCDD, PCBs and TDBE in recombinant HeLa cells containing plasmid construct for thyroxin responsive elements. The limit of response of the recombinant cells to T3 and T4 was $1\times10^{-12}\;M$. BHA. genistein, cadmium and TBDE were interacted with thyroid receptors with dose-responsive pattern. In addition, BHA, BHT, ethoxyquin, propionic acid, benzoic acid, sorbic acid, and TBDE showed synergism while cadmium chloride antagonism for T3-induced activity. This study elucidates that recombinant HeLa cell is sensitive and high-throughput system for the detection of chemicals that induce thyroid hormonal disruption via thyroid hormone receptors and responsive elements. Also this study raised suspect of BHA. BHT, ethoxyquin, propionic acid, benzoic acid, sorbic acid, TBDE, genisteine and cadmium chloride as thyroid hormonal system disruptors.