• Asian Pacific Journal of Cancer Prevention
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• 제13권10호
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• pp.5273-5279
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• 2012

The aim of the present study was to investigate the chemopreventive effect of coumarin against 7, 12-dimethylbenz[a]anthracene (DMBA)-induced hamster buccal pouch carcinogenesis by monitoring tumor incidence and histopathological changes as well as by analyzing the status of biochemical markers (lipid peroxidation, enzymatic and non-enzymatic antioxidants, phase I and phase II detoxification enzymes). Oral squamous cell carcinomas were induced in the buccal pouch of Syrian golden hamsters by painting with 0.5% DMBA in liquid paraffin three times a week for 14 weeks. We noted 100% tumor formation with marked abnormalities in the biomarkers status in hamsters treated with DMBA alone. Oral administration of coumarin at a dose of 100 mg/kg body weight (bw) to DMBA treated hamsters completely prevented the tumor formation as well as restored the staus of biochemical variables. The results of the present study thus suggest that the chemopreventive effect of coumarin is probably due to its anti-lipid peroxidative potential and modulating effect on carcinogen detoxification agents in favor of the excretion of ultimate carcinogenic metabolites of DMBA during DMBA-induced hamster buccal pouch carcinogenesis.

• Toxicological Research
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• 제22권4호
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• pp.423-429
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• 2006

Recent reports on the photocarcinogenicity and photogerotoxicity of many compounds led to an increasing awareness for the need of a standard approach to test for photogenotoxicity. The comet assay has been recently validated as a sensitive and specific test system for the quantification of DNA damage. Thus, the objectives of this study are to investigate the utility of photo-comet assay for detecting photo-mutagens, and to evaluate its ability to predict rodent photo-carcinogenicity. Photo-comet assays were performed using L5178Y $Tk^{+/-}$ mouse lymphoma cells on five test substances (8-methoxypsoralen, chlorpromazine, lomefloxacin, anthracene and retinoic acid) that demonstrated positive results in photocarcinogenicity tests. For the best discrimination between the test substance-mediated DNA damage and the undesirable DNA damage caused by direct UV absorption, a UV dose-response of the cells in the absence of the test substances was firstly fnalized. Out of 5 test substances, positive comet results were obtained for chlorpromazine, lomefloxacin, anthracene and retinoic acid while 8-methoxypsoralen found negative. An investigation into the predictive value of this photo-comet assay for determining the photocarcinogenicity showed that photo-comet assay has relatively high sensitivity. Therefore, the photo-comet assay with mammalian cells seems to be a good and sensitive predictor of the photocarcinogenic potential of new substances.

• 한국독성학회:학술대회논문집
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• 한국독성학회 2001년도 International Symposium on Dietary and Medicinal Antimutgens and Anticarcinogens
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• pp.85-86
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• 2001

Indole-3-carbinol (I3C), one component of cruciferous vegetables (the Family of Cruciferae), has been shown to exert chemopreventive effects in liver, colon and mammary tissue, but there has been substantial evidence that consumption of I3C induces tumor promotion in some tissues. Our studies were investigated to examine the modifying effects of I3C in the 7, 12-dimethylbenz［a］anthracene (DMBA) induced rat mammary tumor model.(omitted)

• 환경생물
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• 제34권3호
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• pp.201-207
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• 2016

The hazards associated with the polycyclic aromatic hydrocarbons (PAHs) are known to be recalcitrant by their structure, but white rot fungi are capable of degrading recalcitrant organic compounds. Phlebia brevispora KUC9045 isolated from Korea was investigated its efficiency of degradation of four PAHs, such as phenanthrene, anthracne, fluoranthene, and pyrene. And the species secreted extracellular laccase and MnP (Manganese dependent peroxidase) during degradation. P. brevispora KUC9045 demonstrated effective degradation rates of phenanthrene (66.3%), anthracene (67.4%), fluoranthene (61.6%), and pyrene (63.3%), respectively. For enhancement of degradation rates of PAHs by the species, Remazol Brilliant Blue R (RBBR) was preferentially supplemented to induce ligninolytic enzymes. The biodegradation rates of the three PAHs including phenanthrene, fluoranthene, and pyrene were improved as higher concentration of Remazol Brilliant Blue R was supplemented. However, anthracene was degraded with the highest rate among four PAHs after two weeks of the incubation without RBBR addition. According to the previous study, RBBR can be clearly decolorized by P. brevispora KUC9045. Hence, the present study demonstrates simultaneous degradation of dye and PAHs by the white rot fungus. And it is considered that the ligninolytic enzymes are closely related with the degradation. In addition, it indicated that dye waste water might be used to induce ligninolytic enzymes for effective degradation of PAHs.

• Archives of Pharmacal Research
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• 제23권2호
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• pp.139-146
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• 2000

7- Bromomethylbenz[a]anthracene is a known mutagen and carcinogen. The two major DNA adducts produced by this carcinogen, i.e., $N^2$-(benz[a]anthracen-7-yl methyl)-2'-deoxyguanosine (2, b[a]$a^2$G) and $N^6$-(benz[a]anthracen-7-ylmethyl)-2'-deoxyadenosine (4, b[a]$a^6$/A), as wel 1 as the simpler benzylated analogs,$N^2$-benzyl-2'deoxyguanosine (1, $bn^2$G) and $N^6$-benzyl-2'-deoxyadenosine (3, $bn^6$/A), were prepared by direct aralkylation of 2'-deoxyguanosine and 2'-deoxyadenosine. To determine the site-specific mutagenicity of these bulky exocyclic amino-substituted adducts, the suitably protected nucleosides were incorporated into 16-base oligodeoxyribonucleotides in place of a normal guanine or adenine residues which respectively are part of the ATG initiation codon for the lac Z' \alpha-complementation gene by using an in situ activation approach and automated phosphite triester synthetic methods. The base composition and the incorporation of the bulky adducts into synthetic oligonucleotides were characterized after purification of the modified oligonucleotides by enzymatic digestion and HPLC analysis.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
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• pp.150-150
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• 2013

Organic Light Emitting Diode (OLED)에 사용되는 유기발광재료 9,10-di(2-naphthyl)anthracene (ADN)의 상평형 특성을 저진공에서 고진공 조건에 따라 연구하였다. ADN재료의 지속적인 가열과 압력제어가 가능한 진공시스템에서 진공도를 변화시키면서 ADN재료의 온도변화에 따른 상전이 현상을 확인하였다. 본 연구장비의 신뢰성평가를 위하여 상압에서 기존의 Differential Scanning Calorimetry (DSC) 열분석으로 측정한 ADN의 melting point와 비교하였고 각각의 진공조건에서 3회 반복 측정하여 장비신뢰성을 검증하였다. 연구결과, 0.1 Torr에서부터는 상압의 경우와 달리 ADN이 승화하는 것을 확인하였고, 예상대로 진공도가 높아질수록 상전이가 시작되는 온도가 낮아지는 것을 알 수 있었다. 이러한 결과는 기존의 DSC열분석으로는 확인할 수 없었던 고진공에서의 유기재료의 상전이 현상을 관측하였다는데 큰 의미가 있다. 향후, 이러한 방법을 활용한 고진공에서의 유기재료의 상전이 특성 관측은 유기재료를 이용한 진공 증착공정방법의 최적화와, 다양한 유기재료의 열안정성 특성 파악에 도움이 될 것으로 기대가 된다.

• 한국축산식품학회지
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• 제18권1호
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• pp.42-49
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• 1998

The contents of holocellulose, one of the main components of the wood, were 83.9% in oak wood and 76.9% in apple wood, respectively. Those of hemicellulose were 16.41 and 20.33%, and in lignin 23.0 and 19.7%, respectively. Six species of domestic oak wood and apple wood were considered to be suitable for smoking materials due to the low content of lignin. Benzo(a)pyrene contents in smoke flavoring prepared with oak wood at 150, 400 and 500$^{\circ}C$ were 0. 4, 3. 7 and 5.6$\mu\textrm{g}$,/kg, respectively. The amounts of phenanthrene were 112.7, 131.4 and 255.9$\mu\textrm{g}$/kg, respectively, in each temperature. The amounts of polycyclic aromatic hydrocarbons(PAH) in smoke flavory were in the order of phenanthrene＞anthracene＞pyrene＞benzo(a)anthracene＞chrysene＞benzo(b)fluoranthens＞benzo(a)pyrene Benzo(a)pyrene contents in smoking extracts prepared with apple wood at 150, 400 and 500$^{\circ}C$ were 0.4, 3.3 and 5.5$\mu\textrm{g}$/kg, respectively. Phenanthrene contents in those samples were 72.7, 100.2 and 220.5$\mu\textrm{g}$/kg, respectively. Contents of each PAH showed the same order as in oak wood.

• Archives of Pharmacal Research
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• 제26권5호
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• pp.394-404
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• 2003

Certain polycyclic aromatic hydrocarbons (PAHs) have been reported to induce cytochrome P450 (CYP) 1A1 and 1A2. In the present study, the effects of six well-known PAHs, such as benzo[a]pyrene, benz[a]anthracene, dibenz[a,h]anthracene, chrysene, benzo[k]fluorancene and benzo[b]fluorancene, on the activities of hepatic and pulmonary CYP enzymes were investigated in male ICR mice. When mice were treated intraperitoneally with 3, 10 and 30 mg/kg of individual PAHs for 3 consecutive days, the activities of ethoxyresorufin- and methoxyresorufin-Ο-dealkylases were significantly and differentially induced in both liver and lung. Moreover, other CYP isozyme-associated monooxygenase activities were also induced significantly in liver and lung with characteristic induction profiles. Our present results suggest that individual PAHs might have inductive effects on CYP isozymes, and that the characteristic inductive effects of individual PAHs on certain CYP isozymes would be developed as a marker for determining exposure to certain PAHs.

• 한국환경과학회지
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• 제12권11호
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• pp.1145-1157
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• 2003

The surface sediments inside Hallim Harbor, one of the major harbors of Jeju Island, were sampled three times (June, September and December, 2001) and analyzed for 16 polycyclic aromatic hydrocarbons (PAHs), recommended by US-EPA as priority pollutants, to assess their distribution levels and to suggest their possible origins. The concentrations of PAHs ranged from 19 to 496 ng/g on a dry weight basis with a mean value of 245 ng/g, and the levels were low to moderate in comparison with other areas in the world. Based on comparisons of individual and total PAH concentrations with effects-based and equilibrium partitioning-based on sediment quality guidelines, the potential for the biological effects were expected to be low. The sedimentary PAHs may be correlated with organic carbon and mud contents to some extent. From the examinations of the four PAH origin indices, such as LMW/HMW (low molecular weight 2-3 ring PAHs over high molecular weight 4-6 ring PAHs), phenanthrene/anthracene ratio, fluoranthene/pyrene ratio, chrysene/benzo〔a〕anthracene ratio, it can be concluded that the sediment PAH contaminations were ascribed to both pyrolytic and petrogenic origins.

• Food Science and Biotechnology
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• 제17권6호
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• pp.1341-1344
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• 2008

The present study was conducted to investigate the effects of flowers ethanol extract of Elsholtzia splendens (ESE) on the antioxidant defence system in mice with 7,12-dimethylbenz(a)anthracene (DMBA)-induced oxidative stress. The ESE was pre-administered orally to 2 groups of mice at 10 and 50mg/kg body weight (BW) for 5 weeks. Subsequently, mice with pretreatment of ESE received DMBA intragastrically at a dose of 34 mg/kg BW twice a week for 2 weeks. In DMBA alone group, biomarkers of oxidative stress (TBARS value, carbonyl content, and serum 8-OH-dG) were significantly increased. Also, the antioxidant enzymes were down-regulated. ESE significantly restored the TBARS value and carbonyl content at both doses, while a decrease in the elevated serum 8-OH-dG content was observed only at the higher dose. The DMBA-induced decreases in catalase and superoxide dismutase (SOD) activities were restored to nearly control levels by ESE. Glutathione peroxidase (GSH-px) and glutathione reductase (GR) activities, as well as the reduced glutathione (GSH)/oxidized GSH (GSSG) ratio, were significantly affected by ESE at the higher dose. These results suggest that ESE possesses antioxidant activity, which plays a protective role against DMBA-induced oxidative stress.