• Toxicological Research
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• 제14권2호
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• pp.123-127
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• 1998

BRCA1 is a tumor suppresser gene in familial cases of breast cancer. It has been controversial whether the subcellular localization of BRCA1 is located in nuclei or cytoplasm in normal human breast cells. We found that a p220 protein was expressed in Type II Normal human breast epithelial cells (NHBEC) but not in Type I NHBEC in Western blot analysis using the 17F8 (3A2) antibody. Immunostaining using the same antibody revealed positive staining in nuclei, cytoplasm and perinuclei of Type II cells and negative staining in Type I NHBEC. The p220 protein, however, was expressed in SV40 immortalized Type I NHBEC and tumorigenic cells derived from them after x-ray and neu oncogene treatment. The subcelluar localization was mostly cytoplasmic and punctate in the nuclei. The breast carcinoma cell lines, MCF-7 and T47D, also expressed the p220 protein. Using RT-PCR, we observed the expression of BRCA1 mRNA in both Type I and Type II NHBEC. This result indicated that there might be mechanisms involved in post-translational or translational regulation of BRCA1 gene. It is speculated that the absence of BRCA1 protein expression in Type I NHBEC might playa role in their susceptibility to neoplastic transformation.

• Toxicological Research
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• 제32권3호
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• pp.245-250
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• 2016

3-Methylpentane ($C_6H_{14}$, CAS No. 96-14-0), isomer of hexane, is a colorless liquid originating naturally from petroleum or natural gas liquids. 3-Methylpentane has been used as a solvent in organic synthesis, as a lubricant, and as a raw material for producing carbon black. There is limited information available on the inhalation toxicity of 3-methylpentane, and the aim of this study was to determine its subacute inhalation toxicity. According to OECD Test Guideline 412 (subacute inhalation toxicity: 28-day study), Sprague Dawley rats were exposed to 0, 284, 1,135, and 4,540 ppm of 3-methylpentane for 6 hr/day, 5 days/week for 4 weeks via whole-body inhalation. Mortality, clinical signs, body weights, food consumption, hematology, serum chemistry, organ weights, and gross and histopathological findings were compared between control and all exposure groups. No mortality or remarkable clinical signs were observed during the study. No gross or histopathological lesions, or adverse effects on body weight, food consumption, hematology, serum chemistry, and organ weights were observed in any male or female rats in all exposure groups, although some statistically significant changes were observed in food consumption, serum chemistry, and organ weights. In conclusion, the results of this study indicate that no observable adverse effect level (NOAEL) for 3-methylpentane above 4,540 ppm/6 hr/day, 5 days/week for rats.

• 생명과학회지
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• 제14권6호
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• pp.925-930
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• 2004

양파 열수 추출물의 항산화능 및 인공소화 전과후의 항돌연변이 효과를 BHT와 ascorbic acid와 비교하여 조사하였다. 총 페놀 및 플라보노이드의 함량은 노란색 양파 추출물이 횐색 양파 추출물보다 많았으며, 양파 추출물의 과산화수소 소거능은 농도가 증가함에 따라 비례적으로 증가하였다. $\beta-carotene-linoleate\;system$에서 항산화능과 reducing power는 증가되었으나, BHT와 ascorbic acid보다는 낮았다. 양파열수 추출물의 인공소화 후에 IQ와 MNNG로 처리된 Salmonella typhimurium TA80과 TA100에 대하여 항돌연변이 효과가 나타났으며, 노란색 양파가 횐색 양파보다 높게 나타났다. 결론적으로 양파 추출물을 소화시키면 항산화 및 항돌연변이의 효과는 양파의 페놀과 플라보노이드의 성분 변화에 의한 것으로 판단된다.

• Toxicological Research
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• 제21권1호
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• pp.1-14
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• 2005

Transgenic mouse models have been introduced and accepted by regulatory bodies as an alternative to carcinogenicity assay models to predict and evaluate chemical carcinogens. The recent research outcomes in transgenic mouse models have made progressive advances in the understanding of chemical carcinogenesis and the evaluation of potential human carcinogens. However, these models still remain to be insufficient assay systems although the insufficiencies have been recognised and are being resolved. Based on up to date information from literature, this review article intends to understand currently accepted transgenic mouse models, issues arising from study design, interpretation of the study, results of validation project and their cancer prediction rate, and further perspectives of cancer assay models from the regulatory view point.

• 한국환경성돌연변이발암원학회지
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• 제22권4호
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• pp.259-265
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• 2002

Phthalate analogues are a plasticizer and solvent used in industry. Phthalates were reported to be a potential carcinogen classified in the category of suspected endocrine disruptors. Most common human exposure to these compounds may occur with contaminated food. They may migrate into food from plastic wrap or may enter food from general environmental contamination. Since these substances are not limited to the original products, and enter the environment, they have become widespread environmental pollutants, thus leading to a variety of phthalates that possibly threaten the public health. Concern about their use has been mounting. To screen and elucidate the endocrine disrupting activity and their mechanism of phthalate analogues, first of all, E-screen assay was performed in MCF7 human breast cancer cells with seven phthalate analogues. In this cell proliferation assay, only dibutyl phthalate (DBP) showed weak estrogenic activity. Also the yeast-based transcription assay to assess the interactions of DBP with the estrogen, androgen, and progesterone receptors was conducted. DBP in the concentration ranges from 10$^{-16}$ to 10$^{-11}$ M was active in the estrogen transcriptional assay, but it did not show the effect on $\beta$-galactosidase activity in the progesterone and androgen transcriptional assays. These data indicate that DBP shows estrogenic potential and can be classified as weak and/or suspected endocrine disrupting chemicals.

• Toxicological Research
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• 제31권4호
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• pp.363-369
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• 2015

We evaluated the antioxidant activity and anti-wrinkle effects of Aceriphyllum rossii leaf ethanol extract (ARLEE) in vitro using human dermal fibroblasts. The total polyphenol and flavonoid contents of ARLEE were 578.6 and 206.3 mg/g, respectively. At a concentration of $250{\mu}g/mL$, the electron-donating ability of ARLEE was 87.1%. In comparison with the vehicle, ARLEE treatment at $100{\mu}g/mL$ significantly increased type I procollagen synthesis (p < 0.01) by 50.7%. In vitro ARLEE treatment (10 mg/mL) inhibited collagenase and elastase activity by 97.1% and 99.2%, respectively. Compared with the control, ascorbic acid treatment at $100{\mu}g/mL$ significantly decreased matrix metalloproteinase (MMP)-1 protein expression (p < 0.01) by 37.0%. ARLEE treatment at $50{\mu}g/mL$ significantly decreased MMP-1 protein expression (p < 0.01) by 46.1%. Ascorbic acid and ARLEE treatments at $100{\mu}g/mL$ significantly decreased MMP-1 mRNA expression (p < 0.01) by 26.1% and 36.1%, respectively. From these results, we conclude that ARLEE has excellent antioxidant activity and even better anti-wrinkle effects than ascorbic acid in human dermal fibroblasts. These results suggest that ARLEE could be used in functional cosmetics for the prevention or alleviation of skin wrinkles induced by ultraviolet rays.

• Toxicological Research
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• 제11권2호
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• pp.215-221
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• 1995

This paper examines the effects of dietary polyunsaturated fatty acid/saturated fatty acid (p/s) ratios and butylated hydroxytoluene (BHT) on the hepatic microsomaI mixed-function oxidase sy. stem in 2~acetylaminofiuorene (2-AAF) treated rats. Sprague-Dawley male rats were fed the diet of beef tallow (p/s 0.08), beef tallow plus soybean oil (p/s 1.0), and soybean oil (p/s 4.0) at the level of 15%fat and with or without 0.3% BHT. After 2-AAF was injected twice at the ages of 23 and 27 weeks, cholesterol/phospholipid molar ratio, thiobarbituric acid reactive substances (TBARS) level, cytochrome P450, cytochrome $b_5$, NADPH-cytochrome $b_5$, and NADPH-cytochrome c reductase activity were measured from isolated hepatic microsomal fractions. In the beef tallow (p/s 0.08) and beef tallow plus soybean oil (p/s 1.0) groups, cholesterol/phospholipid molar ratio showed decreasing tendency by 2-AAF and BHT. Cytochrome P-450 content was decreased in the group of soybean oil (p/s 4.0) and NADPH-cytochrome c reductase activity was increased by 2-AAF and BHT in all the dietary groups. While TBARS levels were increased by 2-AAF in all the dietary groups, they were reduced by BHT in the soybean oil (p/s 4.0) group. These results suggest that long term intake of soybean oil (p/s 4.0) diet induced changes in the nature of microsomal membrane and induced less cytochrome P-450, low level feeding of BHT increased cytochrome c reductase activity and lowered microsomal lipid peroxidation levels, which were increased by 2-AAF treatment.

• Toxicological Research
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• 제34권3호
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• pp.241-247
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• 2018

Lactobacillus (LAB) have been reported to exert both harmful and beneficial effects on human and animal health. Recently, it has been reported that dysbiosis and bacterial translocation contribute to liver fibrosis. However, the role of Gram-positive LAB in the situation of chronic liver diseases has not been yet elucidated. Liver injury was induced by bile duct ligation (BDL) in LAB or control-administered mice. Liver fibrosis was enhanced in LAB-administered mice compared with control-treated mice as demonstrated by quantification of Sirius-red positive area, hydroxyproline contents and fibrosis-related genes ($Col1{\alpha}1$, Acta2, Timp1, Tgfb1). Moreover, LAB-administered mice were more susceptible to BDL-induced liver injury as shown by increased ALT and AST level of LAB group compared with control group at 5 days post BDL. Consistent with serum level, inflammatory cytokines ($TNF-{\alpha}$, IL-6 and $IL-1{\beta}$) were also significantly increased in LAB-treated mice. Of note, LAB-treated liver showed increased lipoteichoic acid (LTA) expression compared with control-treated liver, indicating that LAB-derived LTA may translocate from intestine to liver via portal vein. Indeed, responsible receptor or inflammatory factor (PAFR and iNOS) for LTA were upregulated in LAB-administered group. The present findings demonstrate that administration of LAB increases LTA translocation to liver and induces profibrogenic inflammatory milieu, leading to aggravation of liver fibrosis. The current study provides new cautious information of LAB for liver fibrosis patients to prevent the detrimental effect of LAB supplements.

• 한국식품저장유통학회지
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• 제9권1호
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• pp.92-96
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• 2002

비파 부위별 추출물의 아질산염 소거능 및 항돌연변이 효과를 조사한 결과는 다음과 같다. 추출용매 중 활성이 높게 나타난 메탄올 추출물을 비극성∼극성 용매별로 계통분획한 에칠아세테이트 분획물에서 잎은 80%, 씨를 제거한 과실 81%, 과피 73% 및 종자 63%로 아질산염 소거 효과가 가장 높게 나타났다. 메탄올 추출물의 분획하여 Salmonella typhimurium TA 100에 대한 항돌연변이 효과를 측정한 결과, 잎과 씨를 제거한 과실의 에칠아세테이트 분획물에서 각각 53.1%, 48.3%로 높게 나타났다. 에틸아세테이트 분획물을 농도별로 첨가하여 항돌연변이 효과를 확인한 결과, 잎과 씨를 제거한 과실의 경우 에틸아세테이트 분획물 2.5 mg과 5.0 mg 첨가시 각각 65.5%, 71.2%와 63.4%, 69.2%로 분획물의 농도가 높을수록 항돌연변이 효과가 높게 나타났다.

• Toxicological Research
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• 제27권4호
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• pp.225-229
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• 2011

Extract of Taraxacum platycarpum (AF-343) has been reported to have several biological properties such as skin hydration and anti-inflammatory effects. Although clinical evidences of skin hydration and antiinflammatory effect were proven in clinical trial, precise mechanism of skin hydration was not fully understood yet. In this study, we have focused skin hydration mechanism related filaggrin, collagen, and matrix metalloproteinase (MMP) in vitro and animal study. Herein, skin hydration mechanism of AF-343 is due to recovery of filaggrin in mice model and increased production of collagen with suppression of matrix MMP in vitro fibroblast cell line.