• Environmental Analysis Health and Toxicology
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• 제28권
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• pp.3.1-3.8
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• 2013

Objectives We investigated the genotoxic effects of 40-59 nm silver nanoparticles (Ag-NPs) by bacterial reverse mutation assay (Ames test), in vitro comet assay and micronucleus (MN) assay. In particular, we directly compared the effect of cytochalasin B (cytoB) and rat liver homogenate (S9 mix) in the formation of MN by Ag-NPs. Methods Before testing, we confirmed that Ag-NPs were completely dispersed in the experimental medium by sonication (three times in 1 minute) and filtration ($0.2{\mu}m$ pore size filter), and then we measured their size in a zeta potential analyzer. After that the genotoxicity were measured and especially, S9 mix and with and without cytoB were compared one another in MN assay. Results Ames test using Salmonella typhimurium TA98, TA100, TA1535 and TA1537 strains revealed that Ag-NPs with or without S9 mix did not display a mutagenic effect. The genotoxicity of Ag-NPs was also evaluated in a mammalian cell system using Chinese hamster ovary cells. The results revealed that Ag-NPs stimulated DNA breakage and MN formation with or without S9 mix in a dose-dependent manner (from $0.01{\mu}g/mL$ to $10{\mu}g/mL$). In particular, MN induction was affected by cytoB. Conclusions All of our findings, with the exception of the Ames test results, indicate that Ag-NPs show genotoxic effects in mammalian cell system. In addition, present study suggests the potential error due to use of cytoB in genotoxic test of nanoparticles.

• Environmental Analysis Health and Toxicology
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• 제19권4호
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• pp.335-344
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• 2004

Diesel exhaust particle (<2.5 ${\mu}{\textrm}{m}$, DEP$_{2.5}$) is known to be probarbly carcinogenic (IARC group 2A). DEP$_{2.5}$ contains organic compounds such as polycyclicaromatic hydrocarbon (PAH), heterocyclic compounds, phenols, and nitroarenes. Reactive oxygen species (ROS) are generated by DEP$_{2.5}$ without any biological activation system. Therefore, an alternative mechanism by which DEP$_{2.5}$ could be carcinogenic is known by the generation of oxidative DNA damage. The aim of this study was to investigate genotoxic effects of DEP$_{2.5}$ using single cell gel electrophoresis. In order to evaluate the mechanisms of DEP$_{2.5}$ genotoxicity, the rat micro-some mediated and DNA repair enzyme treated comet assays together with routine comet assay were performed. DEP$_{2.5}$ was collected from diesel engine bus and dichloromethane extract was obtained. The organic extract of DEP$_{2.5}$ revealed DNA damage itself in NIH/3T3 cells. And it showed both oxidative and microsome mediated DNA damages. Vitamin C as an model antioxidant reduced DNA damage in endonuclase III treated comet assay. One of flavonoid, galangin as a CYP1A1 inhibitor reduced DNA damage in the presence of S-9 mixture. Our results show that DEP$_{2.5}$ are genotoxic and a great source of oxidative stress, but antioxidants can significantly reduce oxidative DNA damages. And DEP$_{2.5}$ may contain indirect mutagens which can be inhibited by CYP inhibitors.d by CYP inhibitors.

• 한국식품영양과학회지
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• 제32권7호
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• pp.1071-1075
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• 2003

차가버섯 분획물의 항산화활성과 유전독성 억제효과를 규명하기 위하여 차가버섯으로부터 조다당, 불용성 조다당 I과 II를 각각 추출하였으며 그 여액에서 저분자 물질과 에틸 아세테이트, 물 분획물을 얻었다. 얻어진 시료들은 DPPH free radical 소거능으로 항산화 활성을 측정하였으며, 마우스를 이용한 소핵실험으로 유전독성 억제효과를 검토하였다. 실험결과, 에틸 아세테이트 분획물의 RC$_{50}$ 이 46.5 $\mu\textrm{g}$으로 월등히 높았으며, 물 분획물과 수용성 다당도 각각 78.3$\mu\textrm{g}$과 77.4$\mu\textrm{g}$으로 다른 분획물에 비해 높은 항산화 효과를 나타내었다. 그리고 유전독성 억제효과에서는 양성대조군에 비하여 최고 농도인 80 mg/mg에서 저분자 물질과 에틸 아세테이트 분획물, 물 분획물, 수용성 다당 그리고 불용성 다당 I 및 II에서 각각 63.9%, 72.2%, 63.9%, 88.9%, 80.6% 그리고 81.5%의 소핵생성 억제효과를 나타내었으며 다당 분획물들이 80% 이상의 높은 억제율을 나타내었다.

• 한국한의학연구원논문집
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• 제18권2호
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• pp.151-157
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• 2012

In this research, the genotoxic effect of Bupleuri Radix (BR), the dried roots of Bupleurum falcatum Linne has been traditionally used as anti-inflammatory agent, was evaluated using the mouse micronucleus test. BR aqueous extract (yield = 16.52%) was administered once a day for 2 continuous days by oral gavage to male ICR mice at doses of 2,000, 1,000 and 500 mg/kg. Cyclophosphamide (CPA) 70 mg/kg was used as a known genotoxic agent in a positive control. The appearance of a micronucleus (MN) in polychromatic erythrocyte (PCE) is used as an index for genotoxic potential, and PCE ratio is used as an index of cytotoxicity. Although significant (p<0.01) increase of the number of PCE with one or more nuclei (MNPCE) was detected in CPA treated groups, no significant increases of MNPCE numbers were observed in all three different dosages of BR extracts treated mice with over 0.30 of the individual polychromatic erythrocyte ratio in all mice used in this study. The results obtained indicated that BR extract shows no genotoxicity effects up to 2,000 mg/kg dosing levels the limit dosage in rodents.

• 대한예방한의학회지
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• 제16권1호
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• pp.81-89
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• 2012

Objectives : In this research, the genotoxic effect of $Scutellariae$ $Radix$(SR), the dried roots of $Scutellaria$ $baicalensis$ Georgi has been traditionally used as antipyretic agent, was evaluated using the mouse micronucleus test. Methods : SR aqueous extract(yield = 27.2%) was administered once a day for 2 continuous days by oral gavage to male ICR mice at doses of 2,000, 1,000 and 500 mg/kg. Cyclophosphamide(CPA) 70 mg/kg was used as a known genotoxic agent in a positive control. The appearance of a micronucleus(MN) in polychromatic erythrocyte(PCE) is used as an index for genotoxic potential, and PCE ratio is used as an index of cytotoxicity. Results and Conclusions : Although significant(p<0.01) increase of the number of PCE with one or more nuclei(MNPCE) was detected in CPA treated groups, no significant increases of MNPCE numbers were observed in all three different dosages of SR extracts treated mice with over 0.33 of the individual polychromatic erythrocyte ratio in all mice used in this study. The results obtained indicated that SR extract shows no genotoxicity effects up to 2,000 mg/kg dosing levels - the limit dosage in rodents.

• Archives of Pharmacal Research
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• 제21권4호
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• pp.363-369
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• 1998

Glutathione S-transferase placental form (GST-P) positive foci development and its expression in liver exposed by nongenotoxic carcinogens phenobarbital (PB) and clofibrate (CF), and genotoxic carcinogen 2-amino-3-methylimidazo[4,5-f] quinoline (IQ) were investigated as a measure of carcinogenic potential of these chemicals. Male F344 rats were initially given a single intraperitioneal injection of diethyinitrosamine (200 mg/kg), and 2 weeks later, animals were fed diets containing 0.03% IQ or 0.5% CF or 0.05% PB or basal diet as a control for 6 weeks. All rats were subjected to two-thirds partial hepatectomy (PH) at week 3. Sequential sacrifice of rats was performed at 8 weeks or 52 weeks, and liver tissues were examined for immunohistochemical staining of GST-P positive foci. The numbers (No./$cm^2$) and areas ($mm^2$/ $cm^2$) of GST-P positive foci were increased by IQ or PB, but were decreased by CF compare to the control. Consistent with the development of GST-P positive foci, a time-related increase in the expression of GST-P mRNA was found in the rats treated with IQ, whereas CF decreased it. The incidence of hepatocellular carcinoma at 52 weeks was increased by all three chemicals. These results show that PB and IQ induced GST-P positive foci, but the peroxisome proliferator CF did not, which suggest that the prediction of carcinogenic potency based on the development of prenoplastic foci may cause false negative in a particular category compounds like peroxisome proliferators.

• 한국식품위생안전성학회지
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• 제11권1호
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• pp.41-50
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• 1996

The yields of solvent fraction of irradiated red ginseng powder were increased in the order of petroleum ether(PE)

• Toxicological Research
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• 제34권2호
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• pp.111-125
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• 2018

Solvents can be used in the manufacture of medicinal products provided their residual levels in the final product comply with the acceptable limits based on safety data. At worldwide level, these limits are set by the "Guideline Q3C (R6) on impurities: guideline for residual solvents" issued by the ICH. Diisopropyl ether (DIPE) is a widely used solvent but the possibility of using it in the pharmaceutical manufacture is uncertain because the ICH Q3C guideline includes it in the group of solvents for which "no adequate toxicological data on which to base a Permitted Daily Exposure (PDE) was found". We performed a risk assessment of DIPE based on available toxicological data, after carefully assessing their reliability using the Klimisch score approach. We found sufficiently reliable studies investigating subchronic, developmental, neurological toxicity and carcinogenicity in rats and genotoxicity in vitro. Recent studies also investigated a wide array of toxic effects of gasoline/DIPE mixtures as compared to gasoline alone, thus allowing identifying the effects of DIPE itself. These data allowed a comprehensive toxicological evaluation of DIPE. The main target organs of DIPE toxicity were liver and kidney. DIPE was not teratogen and had no genotoxic effects, either in vitro or in vivo. However, it appeared to increase the number of malignant tumors in rats. Therefore, DIPE could be considered as a non-genotoxic animal carcinogen and a PDE of 0.98 mg/day was calculated based on the lowest No Observed Effect Level (NOEL) value of $356mg/m^3$ (corresponding to 49 mg/kg/day) for maternal toxicity in developmental rat toxicity study. In a worst-case scenario, using an exceedingly high daily dose of 10 g/day, allowed DIPE concentration in pharmaceutical substances would be 98 ppm, which is in the range of concentration limits for ICH Q3C guideline class 2 solvents. This result might be considered for regulatory decisions.

• 한국환경독성학회:학술대회논문집
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• 한국환경독성학회 2003년도 춘계학술대회
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• pp.194-194
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• 2003

The International Agency for Research on Cancer (IARC, 1989) has classified whole diesel exhaust as probably carcinogenic to humans. Diesel exhaust particulate matter (DPM) adsorbs different chemical substances including PAHs and nitroarenes. DPM is emphasized because it is a major component of diesel exhaust, it is suspected of contributing to a health hazard. Diesel exhaust is a complex mixture of carbon particles and associated organics and inorganics, and it is not known what fraction or combination of fractions cause the health effects [cancer effects, noncancer effects (respiratory tract irritation/inflammation and changes in lung function)] that have been observed with exposure to diesel exhaust. In order to identify which chemical classes are responsible for the majority of the observed biological activities, we performed a particular biological/chemical analysis. Respirable particulate matter (PM2.5: <2.5mm) was collected from diesel engine exhaust using a high-volume sampler equipped with a cascade impactor. Particulate oganic matter was extracted by the dichloromethane/sonication method and the crude extract was fractionated according to EPA recommended procedure into seven fractions by acid-base partitioning and silica gel column chromatography. We examined genotoxic potentials of diesel exhaust particulate matter using novel genotoxicity tests, which are rapid, simple and sensitive methods for assessing DNA-damage at the DNA and chromosomal level (comet assay, in vitro MN test and Ames test). Higher genotoxic potency was observed in non polar fractions and several PAHs were detected by GC-MS, such as 1,2,5,6 dibenzanthracene, chrysene, 1,2-benzanthracene, phenanthrene and fluoranthene.

• Molecular & Cellular Toxicology
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• 제2권3호
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• pp.151-158
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• 2006

Khal was a synthetic congener of halocidin, a heterodimeric peptide consisting of 19 and 15 amino acid residues detected in Halocynthia aurantium. This compound was considered a candidate for the development of a novel peptide antibiotic. The genotoxicity of Khal was subjected to high throughput toxicity screening (HTTS) because they revealed strong antibacterial effects. Mouse lymphoma thymidine kinase ($tk^{+/-}$) gene assay (MOLY), single cell gel electrophoresis (Comet) assay and 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. These compounds are not mutagenic in S. typhimurium TA98 and TA100 strains both in the presence and absence of metabolic activation. Before performing the comet assay, $IC_{20}$ of Khal was determined the concentration of $25.51\;{\mu}/mL\;and\;21.99\;{\mu}g/mL$ with and without S-9, respectively. In the comet assay, Khal was not induced DNA damage in mouse lymphoma cell line. Also, the mutation frequencies in the Khal-treated cultures were similar to the vehicle controls. It is suggests that Khal is non-mutagenic in MOLY assay. And no clastogenicity was observed in Khal-treated Chinese hamster lung cells. The results of this battery of assays indicate that Khal has no genotoxic potential in bacterial or mammalian cell systems. Therefore, we suggest that Khal, as the optimal candidates with both no genotoxic potential and antibacterial effects must be chosen.