• Journal of Ginseng Research
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• v.16 no.3
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• pp.210-216
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• 1992

The effect of saponin extracted from Panax grneng CA Meyer on DNA repair and replicative DNA synthesis were examined in CHO-Kl cells cotreated with benzo(a)pyrene and rat liver S-15 fraction. The DNA strand breaks inititated by benzo(a)pyrene metabolites were measured by alkaline election technique. The addition of ginseng saponin to the culture media resulted in decrease of benzo(a)pyrene-induced DNA strand breaks, and restored the suppressed-semiconservative-DNA-synthesis by the carcinogen. DNA repair synthesis in the damaged cells was also elevated by the ginseng treatment when the repairing activites were measured for the (3H)-thymidine incorporation into the carcinogen damaged cellular DNk Comparative analysis of DNA-adduces of benzo(a)pyrene metabortes in microsomes suggested that ginseng saponin treatment in rats reduced the formation of electrophilic metabolites of benzo (a)-pyrene in the rat liver microsomes.

• Journal of Aquaculture
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• v.16 no.3
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• pp.196-201
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• 2003

Sessile organisms such as the oyster Crassostrea gigas have been given much attention as a potential biomonitoring indicator to assess the impact of toxicants on aquatic organism. In this study, we exposed cells isolated from gill of oyster (Crassostrea gigas) to hydrogen peroxide in vitro. In addition oysters were in vivo exposed to pyrene and benzo(a)pyrene at various concentrations for 2 weeks. Comet assay was used to detect DNA single strand breaks and to investigate the application of this technique as a tool for aquatic biomonitoring. Hydrogen peroxide increased DNA single strand break with increasing concentration after 30 minutes exposure in vitro. Pyrene and benzo(a)pyrene caused DNA damage only at very high concentration (100 $\mu\textrm{g}$/L or 1000 $\mu\textrm{g}$/L) at two week exposure in vivo. DNA damage was relatively higher at hemocyte than at gill. It suggested that metabolized PAHs are transferred to hemolymph from digestive gland which have a relatively high enzyme activity, and attacked the DNA of hemocyte, while gill accumulated PAHs without degrading them to their metabolites due to low enzyme activity at gill. Both in vitro and in vivo exposure experiments showed that the comet assay is an effective tool on screening whether the organism are exposed to genotoxic contaminants.

• BMB Reports
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• v.28 no.1
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• pp.1-5
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• 1995

The effect of 6-sulfooxymethyl benzo(a)pyrene (SMBP) on conformational changes of calf thymus DNA was investigated. As SMBP is a strong electrophile, the covalent binding of SMBP to DNA should distort three dimensional conformation of DNA at the binding sites. A formaldehyde-unwinding methods were used to determine the rate of DNA denaturation. The increase in absorbance at 251nm was detected by addition of formaldehyde following treatment with SMBP. SMBP changed supercoiled DNA to relaxed and linear DNA as determined by electrophoresis, which was similar to the change in DNA due to in vitro treatment with benzo(a) pyrene diol epoxide. Treatment with SMBP completely denatured DNA under alkaline conditions. However, DNA was nicked or partially denatured under neutral condition. The absorption band of DNA was increased by the treatment with SMBP in V79 cells, which may be explained by the formation of stabilized SMBP-DNA adduct.

• Molecular & Cellular Toxicology
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• v.2 no.2
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• pp.114-119
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• 2006

Benzo[a]pyrene is a representative ecotoxicant in marine environment and a model compound of polycyclic aromatic hydrocarbons, which has an ability to bioaccumulate in aquatic organisms. This study aimed to identify molecular biomarkers suitable for assessing environmental pollution using a microarray technique. We examined the effects of benzo[a]pyrene on gene expressions in the rockfish, Sebastes schlegeli. We constructed the subtractive cDNA library with hepatic RNA from benzo[a]pyrene-exposed and non-exposed control fish. From the library 10,000 candidate clones were selected randomly and cDNA microarray was constructed. We determined benzo[a]pyrene-responsive genes using a high-density microarray. Statistical analysis showed that approximately 400 genes are significantly induced or reduced by benzo[a]pyrene treatment ($2\;{\mu}m$). Especially gene expression changes of 4 candidate clones among the up- or down-regulated genes were investigated in 6, 12 and 24 hr BaP-exposed fish groups. Many methods have been developed to monitor marine environmental status, which depend on quantifying the levels of the toxic components in polluted seawater or on ecological accessing, such as species diversity or richness. However, those methods could not provide information on physiological or genetic changes induced by such environmental stresses. Comparing with the conventional methods, these data will propose that benzo[a]pyrene-responsive genes can be useful for biological risk assessment of polycyclic aromatic hydrocarbons on marine organism at molecular level.

• Journal of Ginseng Research
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• v.13 no.1
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• pp.37-41
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• 1989

Reactive metabolites generated by benzo(a)pyrene(BP) monooxygenase(AHH) interact with nucleophiles in DNA and cause mutation and carcinogenesis. We studied the effect of Panax ginseng C.A. Meyer, which induce epoxide hydratase(EH) activity without concomitant induction of AHH activity, on the binding of BP metabolites to DNA in uitro in Sprague Dawley rats. DNA-BP metabolite adducts can be resolved into at least five distinct peaks by elution of a Sephadex LH-20 column with a water methanol gradieNt. These peaks are arbitrarily designated A(most polar) through I(least polar). Of the 5 peaks tentatively assigned to 7,8 biol-9,10-oxide(A),7,8·oxide(B),4,5-oxide(C), and further metabolites of 9-OH-BP(D & E), peaks A, C, D, and I were reduced to 70, 85, 80, and 30% of controls, respectively, and there was no significant change in peak B. In connection with this DNA binding study, BP metabolizing enzymes including AHH, EH, demethylase(DM) activity and cyt. P-450 contents were also investigated in order to compare the BP treated control with ginseng and BP treated test groups. The results showed that the EH activity was increased by 139% over the BP control, the Cyt. P-450 content was increased by 180% over the control value, and DM and AHH activities were also increased to some degree for the BP test group, but there was no significant effect of the ginseng treatment.

• Journal of Life Science
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• v.8 no.4
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• pp.400-409
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• 1998

Formation of adduct was studied in benzo(a)pyrene(BP)- and doxorubicin(Dx)-treated human NC-37 cells and isolated nuclei. Major adducts formed were determined by fluorescence absorption spectrophotometery and DNA-lin-ked protein assay. When isolated nuclei were exposed to carcinogens BP and DMBA, and anticancer drugs m-AMSA, ellipticine and Dx, varying degrees of adduct formation occured between DNA-protein complex and these drugs. When the mixture was centrifuged 1.7 M sucrose solution, binding BP and DMBA appeared to be similar between the sediment and the supernatant. When the sediment was centrifuged again with 0.35% polymin-P, the amount of BP bound was 2-fold greater in the protein(1077$\pm$55cpm) than in DNA fraction (470$\pm$20cpm), whereas that of DMBA was 1.6-fold greater in the DNA than in protein fraction. In the case of m-AMSA, ellipticine and Dx, the amount of binding was slightly greater in supernatant than in sediment in centrifugation with 1.7 M sucrose, and more than 3 times greater in the DNA- than in protein- fraction in centrifugation with 0.35% polymin P. DNA fractions which associated with a subset of nonhistone chromosomal protein were isolated from NC-37 cells exposed to $^{3}$H-BP and $^{14}$C-Dx. They were separated into two distince components DNA-S and DNA-P by centrifugation with 2M Nacl chromatin extraction. The results indicated that the amount of $^{3}$H-BP bound was 6.0-fold greater in DNA-P as compared with DNA-S, while that of $^{14}$C-Dx binding appreaed to be 6.2-fold greater in DNA-S than in DNA-P fraction. When $^{3}$H-BP binding wasdetermined in the presence of cold Dx, the amount of binding was reduced only in the DNA-P fraction, indicating that the interaction between DNA and protein is decreased. Gene expression by these drugs, BP treated cells were increased to compare with nomal cells but reduced by treatment with BP-Dx. These results suggest that the protein moiety which tightly bound to DNA-P fraction may play an important role in the regulation of gene expression.

• Bulletin of the Korean Chemical Society
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• v.35 no.10
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• pp.3015-3020
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• 2014

The behavior of benzo[a]pyrene-7,8-dione (BPQ) in aqueous solution and its interaction with native DNA was investigated using conventional absorption and linear dichroism (LD) spectroscopy. The appearance of a broad absorption maximum at long wavelengths and its proportional relationship to solvent polarizability suggested that BPQ adopts a aggregated state for all solutions examined. Disappearance of this absorption band at higher temperatures in aqueous solution also supported BPQ aggregation. When associated with DNA absorption spectral properties were essentially the same as that in aqueous solution. However, two isosbestic wavelengths were found in the concentration-dependent absorption spectrum of the BPQ-DNA complex, suggesting the presence of at least two or more DNA-bound BPQ species. Both species produced $LD^r$ spectra whose magnitude in BPQ absorption region is larger or comparable to that in the DNA absorption region, suggesting that the molecular BPQ plane is near perpendicular relative to the local DNA helical axis. Therefore, BPQ molecules are aligned along the DNA stem in both DNA-aggregated BPQ species.

• Environmental Mutagens and Carcinogens
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• v.18 no.2
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• pp.71-76
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• 1998

Exposure to environmental toxicants can cause cellular problems including the interference of DNA repair processes which may lead to the development of cancer. The existence of toxicant-induced DNA repair abnormality was investigated using mice exposed in vivo to genotoxic chemicals and then challenging their exposed lymphocytes in vitro with bleomycin. The repair of bleomycin-induced DNA damage as estimated by the frequency of chromosome aberrations was determined. Our data indicates that the observed aberration frequencies after in vivo exposure to N-methyl-N'-nitro-N-nitnsoguanidine (MNNG) and in vitro challenge with bleomycin are consistently higher than expected. The enhanced response is not due to the induction of chromosome damage by 25 or 50 mg/kg MNNG since the chemical did not cause chromosome aberrations in lymphocytes of these mice. The observed response after the combined exposure to benzo[a]pyrene (BP) and bleomycin was significantly lower than expected with low in vivo doses of BP (50 mg/kg) and then significantly higher than expected with the high doses (200 mg/kg). We interpret our data to indicate that in vivo exposure to genotoxic agents can cause abnormal DNA repair activities. The response is, however, independent of the clastogenic activities of the inducing chemicals, but dependent upon the inducing agents and on the exposure doses.

• Journal of Environmental Health Sciences
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• v.40 no.1
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• pp.55-62
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• 2014

Objectives: $^{32}P$-postlabeling assay is the most sensitive method of detecting DNA adduct formation. However, it is limited by a low sample throughput and use of radioisotopes (RI). In this study, we modified it to minimize these limitations and applied it to Z. platypus exposed to Benzo(a)pyrene (BaP) in order to investigate DNA adduct formation (effect biomarker for pollutants) in Z. platypus for assessing risk of waterborne BaP exposure. Methods: DNA hydrolysis was performed only with Micrococcal nuclease (MNase), RI reduction test was performed and the overlapping steps between thin layer chromatography (TLC) and radioisotope high-performance liquid chromatography (RI-HPLC) were omitted. The application of a modified method to Z. platypus exposed to BaP was performed. Results: The results revealed that the amount of RIs used can be reduced roughly 10-fold. Because the analysis time was shortened by 8.5 hours, the sample throughput per hour was increased compared with the previous method. The results of applying modified $^{32}P$-postlabeling assay to Z. platypus, DNA adduct formation in Z. platypus showed dose-dependency with the BaP concentration. Only BPDE-dGMP was detected as a DNA adduct. Conclusion: These results demonstrate that the modified $^{32}P$-postlabeling assay is a suitable method for detecting DNA adduct formation in Z. platypus exposed to waterborne BaP and will be useful in risk assessment of carcinogenic effect in aquatic environment due to BaP.

• Korean Journal of Acupuncture
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• v.19 no.1
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• pp.7-13
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• 2002

The effects of Cnidium officinale Makino aqua-acupuncture solution (COMAS) and Cnidium officinale Makino water-extraced solution (COMWS) on the CYP1A1 activity and benzo[a]pyrene(B[a]P)-DNA adduct formation were examined. There were 6.8%, 12.1%, 15.1%, 18.3% and 22.6% inhibition in the activity of cytochrome 4501A1 enzyme with the treatment of $0.1{\times},\;0.5{\times},\;1{\times},\;3{\times},\;and\;5{\times}$ COMAS, respectively. At concentration of $0.1{\times}$ COMAS, the binding of $[^3H]B[a]P$ metabolites to DNA of NCTC-clone 1469 cell was significantly inhibited by 56.9%. These results suggest that COMAS has chemopreventive potential by inhibiting cytochrome P4501A1 activity and benzo[a]pyrene-DNA adduct formation.