• Archives of Pharmacal Research
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• v.22 no.5
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• pp.474-478
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• 1999

Modulation of unscheduled DNA synthesis by dehydroepiandrosterone (DHEA) after exposure to various chemical carcinogens was investigated in the primary rat hepatocytes. Unscheduled DNA synthesis was induced by treatment of such direct acting carcinogens as methly methanesulfonate (MMS) and ethyl methanesulfonate (EMS) or procarcinogens including benzo(a)pyrene (BaP) and 7, 12-dimethylbenz(a)anthracene (DMBA). Unscheduled DNA synthesis was determined by measuring [methyl-3H]thymidine radioactivity incorporated into nuclear DNA of hepatocytes treated with carcinogens in the presence or absence of DHEA. Hydroxyurea $(5{\times}10^{-3} M)$was added to growth medium to selectively suppress normal replication. DHEA at concentrations ranging from $(1{\times}10^{-6} M)$ to$(5{\times}10^{-4} M)$ did not significantly inhibit unscheduled DNA synthesis induced by either MMS $(1{\times}10^{-4} M)$ or EMS $(1{\times}10^{-2} M)$. In contrast, DHEA-significantly inhibited unscheduled DNA synthesis induced by BaP $(6.5{\times}10^{-5} M)$ and DMBA.$(2{\times}10^{-5} M)$. DHEA-induced hepatotoxicity in rats was examined using lactate dehydrogenase (LDH) release as an indicator of cytotoxicity. DHEA exhibit no significant increase in LDH release compared with the control at 18 h. These data suggest that nontoxic concentration of DHEA does not affect the DNA excision repair process, but it probably influence the enzymatic system responsible for the metabolic activation of procarcinogens and thereby decreases the amount of the effective DNA adducts formed by the ultimate reactive carcinogenic species.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.4
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• pp.755-764
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• 2000

Fate and transport of hydrophobic organic contaminants can be influenced by naturally-existing humic substances and surfactants applied to wash polluted soils in the subsurface environment. The objective of this paper is to study the solubility enhancement of four PAHs (polycyclic aromatic hydrocarbon) and p,p'-DDT in humic acid and surfactant solutions. As the number of aromatic ring is increased, the extent of solubility enhancement of PAHs by humic acid increased. Although the hydrophobicity of p,p'-DDT was the largest among five organic compounds used, the extent of solubility enhancement of p,p'-DDT by humic acid was lower than that of pyrene. In case of anionic surfactants, the extent of the increased solubility of five organic compounds by SDS and SDDBS was increased linearly, but the extent of the increased solubility of p,p'-DDT by MADS-12 was lower than that of perylene.

• Environmental Analysis Health and Toxicology
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• v.13 no.1_2
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• pp.43-53
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• 1998

Ambient air levels of polycyclic aromatic hydrocarbons(PAHs) are of concern because of their potential for adverse health effects including transformation of some of these substances to mutagens and carcinogens by mammalian microsomal enzyme system. Airbone particulate samples were collected by a conventional high-volume sampler and by an Anderson cascade impactor on 2 to 3 days in each month over a period of 1 year at a representative site of the heavy traffic area of Seoul from beptember 1994 to August 1995. Ten individual PAHs in sizable air particulates of each stage of two months were separated and analyzed by gas chromatography/mass spectrometry. As a results of analysis, the gross concentrations of PAHs in the fine and coarse particles were higher in the winter month than in the spring, followed in descending order by in the fall and summer. In a study of dependency of 10 PAHs compounds on size distribution of particles at heavy traffic area found that about 85% of the total PAHs content was associated with particles less than 2.0um (fine particles) in diameter of winter sampling period. while 79% were associated with this size fraction during summer period. In according to the mean concentrations of the 10 PAHs in 7 size classification from < 0.38 to> 10.1, the 'size was the smaller, PAHs concentration was the higher. Thus it was found that PAHs concentration was greatly affected by air particle size. Annual mean benzo(a)pyrene equivalents was 5.88ng/m$^3$ and obtained by applying, toxic equivalency factor developed by Nisbet and Lagoy.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.6
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• pp.1287-1292
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• 2001

The effect of Herricium erinaceus on the mutagenicity in salmonella assay and quinone reductase activity in hapalclc7 cells were studied. Antimutagenic as evaluated by Ames test, the extract and fractions of JHerricium erinaceus had no effects on the mutagenicity by themselves. However, methanol extract and fractions from Hericium erinaceus showed strong inhibitory effect on the mutagenesis induced by N-methyl -N'-nitor-N- nitroso-guanidine (MNNG) and benzo(a)pyrene (B(a)P). Among the solvent fractions of methanol extract, the hexane fraction, the chloroform fraction and the ethylacetate fraction exhibited stronger inhibitory activity against MNNG and B(a)P induced mutagenesis than butanol and water fractions. The methanol extract, the extract, the chloroform and the ethylacetate fractions of Hericium erinaceus induced the activity of quinone reductase, an anticarcinogenic marker enzyme, in murine hepalclc7 cells while the others did have little effect on the enzyme activity.

• YAKHAK HOEJI
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• v.51 no.6
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• pp.415-423
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• 2007

This study was to evaluate the genotoxic effects of airborne particulate matters using single cell gell elec trophoresis (comet assay) in A549 human lung carcinoma cells. The total suspended particulate (TSP) was collected on back-up filter in Chuncheon, Kangwon Do, South Korea from April, 2003 to February, 2005. The concentrations of TSP, B(a)p and most of heavy metals seemed to be higher in spring and winter, and lower in summer. And they showed higher concentration in the commercial areas and the residential area having more traffics than in the rural area. It was found that A549 cells interacting with the organic extract of TSP showed more DNA single-strand breaks compare to untreated cells. The genotoxicity of the organic extract of TSP was increased with the pre-treatment of S-9 mixture during the culture or with the treatment of endonuclease after cell lysis. The DNA damage by the organic extract of TSP was higher in winter and the commercial area than in summer and the rural area. This study suggests that TSP, heavy metals and B(a)P analyzed showed significant variation depend on the seasons and the areas which are correlated with the DNA damage evaluated by Comet assay, indicating that genotoxic biomarker is useful for toxicological evaluation of air quality.

• Archives of Pharmacal Research
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• v.29 no.8
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• pp.712-719
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• 2006

In this study, we prepared core-shell type nanoparticles of a poly(DL-lactide-co-glycolide) (PLGA) grafted-dextran (DexLG) copolymer with varying graft ratio of PLGA. The synthesis of the DexLG copolymer was confirmed by $^1H$ nuclear magnetic resonance (NMR) spectroscopy. The DexLG copolymer was able to form nanoparticles in water by self-aggregating process, and their particle size was around $50\;nm{\sim}300\;nm$ according to the graft ratio of PLGA. Morphological observations using a transmission electron microscope (TEM) showed that the nanoparticles of the DexLG copolymer have uniformly spherical shapes. From fluorescence probe study using pyrene as a hydrophobic probe, critical association concentration (CAC) values determined from the fluorescence excitation spectra were increased as increase of DS of PLGA. $^1H-NMR$ spectroscopy using $D_2O$ and DMSO approved that DexLG nanoparticles have core-shell structure, i.e. hydrophobic block PLGA consisted inner-core as a drug-incorporating domain and dextran consisted as a hydrated outershell. Drug release rate from DexLG nano-particles became faster in the presence of dextranase in spite of the release rate not being significantly changed at high graft ratio of PLGA. Core-shell type nanoparticles of DexLG copolymer can be used as a colonic drug carrier. In conclusion, size, morphology, and molecular structure of DexLG nanoparticles are available to consider as an oral drug targeting nanoparticles.

• Journal of Ginseng Research
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• v.18 no.3
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• pp.160-164
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• 1994

In this study, we investigeated the anticarcinogenicity of various types and ages of ginseng extracts as an extended study using Yun's anticarcinogenicity test. Fresh ginseng at 1.5, 3, 4, 5 and 6 years was dried and powdered. And white ginseng was processed in the same way that of fresh ginseng after removal fo the ginseng cortex and fine root. For red ginsneg, fresh ginseng was steamed and dried. Each ginseng powder was extracted and extracts was freeze dried. Newborn N:GP(S) mice were given a single subcutaneous injection of 0.5 mg of benzo(a)pyrene(BP). Various types and ages of ginseng extracts at 2.5mg/ml were orally administered. All the mice were sacrificed at the 9th week. The following results were obtained. In the dried fresh ginseng extract treated group, the incidence of lung adenoma induced by BP was 63.9% and its incidence was reduced to 48.3%, 52.5%, 51.8%, 47.5% and 44.1% after co-treatment with 1.5, 3, 4, 5 and 6 year-dried fresh ginseng, respectively. The incidence of lung adenoma induced by BP on the white ginseng extract treated group was 41.3% and decreased to 31.0%, 46.0%, 44.0% and 26.5% after co-treatment with 3, 4, 5 and 6 year-white ginseng, respectively. In the red ginseng extract treated group, the incidence of lung adenoma induced by BP was 47.5% and its incidence diminished to 40.7%, 35.0%, 30.1%, 30.0% and 26.3% after co-treatment with 1.5, 3, 4, 5 and 6 year-red ginseng, respectively. From the above results, we concluded that a statistically significant anticarcinogenic effect was observed in extracts of 6 year-dried fresh ginseng, 6 year-white ginseng, and 4, 5 and 6 year-red ginseng and it is suggested that the anticarcinogenicity of ginseng varies according to the types and ages Key words Ginseng extract, types and ages. anticarcinogenic, newborn mice, lung tumor.

• Transactions of the Korean hydrogen and new energy society
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• v.27 no.2
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• pp.192-200
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• 2016

A characteristics of microwave drying-gasification was analyzed for converting a dewatered sewage sludge generated a wastewater treatment plant. Gas (60%) was the largest component of the product of microwave gasification, followed by sludge char (33%) and tar (2%). The main components of the producer gas were hydrogen (33%) and carbon monoxide (40%), and there was some methane and hydrocarbons ($C_2H_4$, $C_2H_6$, $C_3H_8$). Larger nitrogen and smaller oxygen amounts were generated. Gravimetric tar generated $414g/m^3$. This means a total tar which is a heavy hydrocarbons from the volatile organic substance in the sewage sludge. Selected light tars were benzene, anthracene, naphthalene, pyrene, showing lower concentrations as 2.62, 0.37, 0.49, $0.28g/m^3$, respectively. Sludge char has larger meso pores which is a mean pore size of $50.85{\AA}$ and has high adsorptivity. An amount of adsorption was $228.71cm^3/g$, showing higher quantity than acommercial adsorbers. This indicates that the gas obtained from the microwave gasification of wet sewage sludge can be used as fuel, but the heavy tar in the gas must be treated. Sludge char can be used as a tar reduction adsorbent in the process, and then burns as a solid fuel.

• Journal of Environmental Science International
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• v.16 no.3
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• pp.323-331
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• 2007

Polycyclic aromatic hydrocarbons (PAHs) are well known for strong carcinogen. However, the human exposure analysis of PAHs is quite difficult and unreliable because of hard for estimation of actual expose dose. Then urinary 1-hydroxypyrene (1-OHP) has been a biological marker of exposure to PAHs. The purpose of this study was to investigate total amount from exposure to PAHs soused by indoor occupational exposure, and residence at Seoul metropolitan area and Kyeonggi province in Korea. Thirty-five housewives were included in this study from April 2003 through February 2004. Dietary habit and general characteristics such as age, type of building, existence of passive smoking, period of residence, fuel type for heating and ventilation type were obtained by self administered questionnaire. Urine samples were collected at morning and freeze quickly. Urinary creatinine was measured for converting into 24 hr urine. Concentration of the indoor PAHs was examined by NIOSH method number 5506. Urinary 1-OHP and PAHs were analysed by HPLC. Correlation coefficient between urinary 1-OHP levels and pyrene concentration of indoor air was 0.66 and statistically significant(P<0.01). The difference of urinary 1-OHP level due to dietary habits were not significant. Urinary 1-OHP level of Spring, Summer, Autumn, and Winter were $0.21{\pm}0.12,\;0.10{\pm}0.17,\;0.16{\pm}0.12,\;0.17{\pm}0.14{\mu}g/g$ cr, respectively. The arithmetic means of urinary 1-OHP for four season tee $0.16{\pm}0.14 {\mu}g/g$ cr. There was a trend that urinary 1-OHP level of residents who dwelling in apartment were higher compared with detached home, Comparison of 1-OHP level between heating by kerosene and LPG, Much higher gas heating type than kerosene type (P<0.05). This result implies that the urinary 1-OHP can be applied as the PAHs exposure indices.

• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.3
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• pp.599-606
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• 1999

Water extracts of persimmon leaf tea(PLTE), green tea(GTE) and oolong tea(OTE), at the con centration used for human consumption, were examined for inhibitory effects on the mutagenicity of major classes of dietary and environmental mutagens including indirect acting mutagens, B[ ]P (benzo[ ]pyrene), IQ(2 amino 3 methylimidazo[4,5 f]quinoline), 2 AA(2 aminoanthracene) in the presence of S9 mix and direct acting mutagen, 4 NQO(4 nitroquinoline 1 oxide) without S9 mix, using the modified Ames Salmonella/microsome assay. PLTE, GTE and OTE showed very potent and concentration dependent antimutagenic effects against indirect acting mutagens B[ ]P and IQ. At the maximum concentration(16,200 g/plate) of each tea extract, number of colonies decreased in a dose dependent manner up to 82~100%. Similar inhibition of PLTE, GTE and OTE were seen at higher concentration in the mutagenicity of the 2 AA following an initial increase in the activity at lower concentration. However, the mutagenicity of the direct acting mutagen 4 NQO were not suppressed at lower concentration of the three tea extracts, and higher concentration of the tea extracts enhanced mutagenic activity of the mutagen. There were no differences in the mode of antimutagenesis between PLTE, GTE, and OTE, in both Salmonella typhimurium TA98 and TA100 strains against the same mutagen. In conclusion, the water extracts of persimmon leaf tea, green tea and oolong tea possess marked antimutagenic potential against a variety of important dietary and environmental indirect acting mutagens, but the activity was not observed against the direct acting mutagens. These results suggest that the mode of inhibitory action may not have resulted from direct interaction between tea extracts and the mutagens, but rather from indirect metabolic inactivation of mutagens by tea extracts.