• Environmental Analysis Health and Toxicology
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• 제7권1_2호
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• pp.17-34
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• 1992

The object of this study is to investigate the toxicity of S-biol (d-allethron-d-transchrysanthemate) and the mode of action between other synthetic pyrethroid insecticides and S-biol in rats. Rats were treated daily with S-biol (25 mg/kg, 50 mg/kg, 100mg/kg) by oral administration for 5 weeks. The experimental results were summerized as follows: Biochemical parameters such as LDH and Glucose in serum were much more increased in control groups. No significant hematological change excepts for MCHC in rats treated with S-biol 100 mg/kg were observed in all groups compared to control groups. In animals treated with S-biol for 4∼5 weeks, the levels of cytochrome P-450 in the liver were significantly increased. In renal microsomal fractions, however, no significant changes of cytochrome P-450 contents were observed. The activitis of ATPase in groups treated with S-biol (50 mg/kg, 100 mg/kg) were decreased compared to those in other groups. TBA values and activities of glucose-6-phosphatase in the liver were increased a little in the groups treated with S-biol (100 mg/kg) for 5 weeks. The activities of cholinesterase in hepatic and serum were not significantly changed in all groups but slightly decreased in animals treated with high dose of S-biol (100 mg/kg). The activities of carboxylesterase in serum and in the liver were slightly increased but not significantly changed.

• 대한한의학회지
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• 제38권2호
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• pp.15-30
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• 2017

Objectives: Hwangryunhaedok-tang (HHT; Huanglianjiedu-tang, Orengedoku-to), a traditional herbal formula, is used for treating inflammation, hypertension, gastritis, liver dysfunction, cerebrovascular diseases, dermatitis and dementia. The objective of this study was to assess the sub-acute toxicity of HHT in Sprague-Dawley (SD) rats, and its effect on the activities of human microsomal cytochrome P450s (CYP450s) and UDP-glucuronosyltransferases (UGTs). Methods: Male and female SD rats were orally administered HHT once daily at doses of 0, 500, 1000 and 2000 mg/kg for 4 weeks. We analyzed mortality, clinical observations, body weight, food consumption, organ weights, urinalysis, hematology, serum biochemistry, and histopathology. The activities of major human CYP450s (CYP1A2, CYP3A4, CYP2B6, CYP2C9, CYP2C19, CYP2D6, and CYP2E1) and UGTs (UGT1A1, UGT1A4, and UGT2B7) were assessed using in vitro fluorescence- and luminescence-based enzyme assays, respectively. Results: No toxicologically significant changes related to the repeated administration of HHT were observed in both male and female SD rats. The no observed adverse effect level (NOAEL) value was more than 2000 mg/kg/day for both sexes. HHT inhibited the activities of human microsomal CYP1A2, CYP2C19, CYP2D6, and CYP2E1, whereas it weakly inhibited the activities of CYP2B6, CYP2C9, CYP3A4, and UGT1A1. In addition, HHT negligibly inhibited the activities of human microsomal UGT1A4 and UGT2B7 with $IC_{50}$ values in excess of $1000{\mu}g/mL$. Conclusions: Our findings indicate that HHT may be safe for repeated administration up to 4 weeks. In addition, these findings provide information on the safety and effectiveness of HHT when co-administered with conventional drugs.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제22권4호
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• pp.373-382
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• 2000

Individual genetic susceptibilities to cancers may result from several factors including differences in xenobiotics metabolism to chemical carcinogens, DNA repair, altered oncogenes and suppressor genes, and environmental carcinogen exposures. Among them, genetic polymorphisms of metabolizing enzymes to chemical carcinogens have been recognized as a major important host factors in human cancers. They have two main types of enzymes: the phase I cytochrome P-450 mediating enzymes (CYPs) and phase II conjugating enzymes. The purpose of this study is to determine the frequencies of genotypes of phase I (CYP1A1 and CYP2E1) and phase II (NAT2) metabolizing enzymes in healthy control and head and neck cancer patients of Korean and to identify the relative high risk genotypes of these metabolizing enzymes to head and neck cancer in Korean. The author has analyzed 132 head and neck cancer patients and 113 healthy controls using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The results were as following; 1. The frequencies of genotypes of CYP1A1, CYP2E1 and NAT2 in healthy control were as following; CYP1A1 exon 7 polymorphism; Ile/Ile: Ile/Val: Val/Val = 59.3%: 36.3%: 4.4% CYP2E1 Pst I polymorphism, C1/C1: C1/C2: C2/C2 = 61.1%: 32.1%: 6.2% NAT2 polymorphism; F/F: F/S: S/S = 43.4%: 48.7%: 8.0% 2. In analysis of phase I enzyme, Val/Val genotype in CYP1A1 exon 7 polymorphism and C2/C2 genotype in CYP2E1 Pst I polymorphism were associated with relative high risks to head and neck cancers (Odds' ratio: 2.09 and 1.37, respectively). 3. Among the genotypes of NAT2 enzyme polymorphism, S/S genotype of NAT2 enzyme had 1.03 times of relative risk to head and neck cancers. 4. In combined genotyping of CYP1A1, CYP2E1, and NAT2 enzymes polymorphisms, the patients with Val/Val and C1/C1, C2/C2 and fast acetylator, and Val/Val and fast acetylator had higher relative risks than the patients with each baseline of combined genotypes (Odds' ratio: 2.82, 1.98 and 2.1, respectively). These results suggest the combined genotypes of Val/Val and C1/C1, C2/C2 and fast acetylator, and Val/Val and fast acetylator were more susceptible to head and neck cancers in Korean. And genotyping of metabolizing enzymes could be useful for predicting individual susceptibility to head and neck cancer.

• Nutrition Research and Practice
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• 제2권2호
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• pp.80-84
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• 2008

Beneficial effects of dehydroepiandrosterone (DHEA) supplement on age-associated chronic diseases such as cancer, cardiovascular disease, insulin resistance and diabetes, have been reported. However, its mechanism of action in hepatocellular carcinoma in vivo has not been investigated in detail. We have previously shown that during hepatocellular carcinogenesis, DHEA treatment decreases formation of preneoplastic glutathione S-transferase placental form-positive foci in the liver and has antioxidant effects. Here we aimed to determine the mechanism of actions of DHEA, in comparison to vitamin E, in a chemically-induced hepatocellular carcinoma model in rats. Sprague-Dawley rats were administered with control diet without a carcinogen, diets with 1.5% vitamin E, 0.5% DHEA and both of the compounds with a carcinogen for 6 weeks. The doses were previously reported to have anti-cancer effects in animals without known toxicities. With DHEA treatment, cytosolic malate dehydrogenase activities were significantly increased by ${\sim}5$ fold and glucose 6-phosphate dehydrogenase activities were decreased by ${\sim}25%$ compared to carcinogen treated group. Activities of Se-glutathione peroxidase in the cytotol was decreased siguificantly with DHEA treatment, confirming its antioxidative effect. However, liver microsomal cytochrome P-450 content and NADPH-dependent cytochrome P-450 reductase activities were not altered with DHEA treatment. Vitamin E treatment decreased cytosolic Se-glutathione peroxidase activities in accordance with our previous reports. However, vitamin E did not alter glucose 6-phosphate dehydrogenase or malate dehydrogenase activities. Our results suggest that DHEA may have decreased tumor nodule formation and reduced lipid peroxidation as previously reported, possibly by increasing the production of NADPH, a reducing equivalent for NADPH-dependent antioxidant enzymes. DHEA treatment tended to reduce glucose 6-phosphate dehydrogenase activities, which may have resulted in limited supply for de novo synthesis of DNA via inhibiting the hexose monophophaste pathway. Although both DHEA and vitamin E effectively reduced preneoplastic foci in this model, they seemed to fimction in different mechanisms. In conclusion, DHEA may be used to reduce hepatocellular carcinoma growth by targeting NADPH synthesis, cell proliferation and anti-oxidant enzyme activities during tumor growth.

• Applied Microscopy
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• 제36권4호
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• pp.291-297
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• 2006

주류의 섭취가 산업화학물질의 생체 내 독성유발에 어떠한 영향을 미치는지를 검토하기 위해 흰쥐를 이용하여 15%에탄올을 6주간 섭취시킨 후, cyclohexane(CH)을 2일 간격으로 4회 복강 투여하고 24시간 후 다음과 같은 결과를 얻었다. CH의 투여로 인해 정상군과 비교하여 간 무게와 헐청내 xanthine oxidase활성은 증가되었고, 간 내 glucose-6-phosphatase활성은 감소되었다. 그리고 CH 대사효소인 cytochrome P450 dependent aniline hydroxylase와 alcohol dehydrogenase의 활성은 CH투여 후 유의적으로 증가되었으며, 알코올 전처치 후 CH투여군이 가장 높은 활성을 보였다. 미세구조적으로도 알코올 섭취군과 CH투여군 모두에서 조면소포체로부터 활면소포체로의 전환이 일어났으며, 전 실험군 중 알코올 전처치 후 CH투여군이 가장 높은 전환율을 보였다. 이러한 결과들로 볼 때, 병변을 초래하지 않는 수준의 알코올의 섭취는 CH대사활성을 증대시키는 것으로 판단되었다.

• Toxicological Research
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• 제9권2호
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• pp.253-262
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• 1993

The effects of dichloromethane (DCM) on carbon tetrachloride (CT) toxicity were examined in adult male rats. A concomitant treatment of rats with DCM (0.3, 0.6, 1.2 g/kg, po) significantly potentiated the hepatotoxicity of CT (1.0 g/kg, po) as determined by increase in serum GPT (glutamic pyruvic transaminase), GOT (glutamic oxaloacetic transaminase), and SDH (sorbitol dehydrogenase) activity 24 hr following the treatments. Serum LDH (lactate dehydrogenase) activity was increased by either DCM or CT treatment.

• Biomolecules & Therapeutics
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• 제21권6호
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• pp.487-492
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• 2013

Cytochrome P450 4A11 (CYP4A11) is a fatty acid hydroxylase enzyme expressed in human liver. It catalyzes not only the hydroxylation of saturated and unsaturated fatty acids, but the conversion of arachidonic acid to 20-hydroxyeicosatetraenoic acid (20-HETE), a regulator of blood pressure. In this study, we performed a directed evolution analysis of CYP4A11 using the luminogenic assay system. A random mutant library of CYP4A11, in which mutations were made throughout the entire coding region, was screened with luciferase activity to detect the demethylation of luciferin-4A (2-[6-methoxyquinolin-2-yl]-4,5-dihydrothiazole-4-carboxylic acid) of CYP4A11 mutants in Escherichia coli. Consecutive rounds of random mutagenesis and screening yielded three improved CYP4A11 mutants, CP2600 (A24T/T263A), CP2601 (T263A), and CP2616 (A24T/T263A/V430E) with ~3-fold increase in whole cells and >10-fold increase in purified proteins on the luminescence assay. However, the steady state kinetic analysis for lauric acid hydroxylation showed the significant reductions in enzymatic activities in all three mutants. A mutant, CP2600, showed a 51% decrease in catalytic efficiency ($k_{cat}/K_m$) for lauric acid hydroxylation mainly due to an increase in $K_m$. CP2601 and CP2616 showed much greater reductions (>75%) in the catalytic efficiency due to both a decrease in $k_{cat}$ and an increase in Km. These decreased catalytic activities of CP2601 and CP2616 can be partially attributed to the changes in substrate affinities. These results suggest that the enzymatic activities of CYP4A11 mutants selected from directed evolution using a luminogenic P450 substrate may not demonstrate a direct correlation with the hydroxylation activities of lauric acid.

• Molecular & Cellular Toxicology
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• 제5권4호
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• pp.346-353
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• 2009

Drug metabolism is a critical determinant of the therapeutic and adverse effects of many psychotropic drugs. The metabolism depends on the pharmacokinetics of a drug, which includes its absorption, distribution, and elimination. Psychotropic drugs are metabolized mainly by cytochrome P450 (CYP) enzymes; about 20 of these enzymes exist and they are often responsible for the rate-limiting step of drug metabolism. CYP2D6 is the best-characterized P450 enzyme that exhibits polymorphism in humans. This study determined the relationship between the CYP2D6*10 (P34S) polymorphism and the response to mirtazapine in 153 Koreans with major depressive disorder (MDD). The genotype frequencies were compared using logistic regression analysis, and between-genotype differences in the decrease in the 21-item Hamilton Depression (HAMD21) score over the 12-week treatment period were analyzed using a linear regression analysis. The proportion of remitters was lower in patients with MDD possessing the S allele than in P allele carriers after 2 weeks of mirtazapine treatment. Similarly, the reductions in the HAMD21 and Clinical Global Impression (CGI) scores in S allele carriers were smaller than those in patients with the P allele after 2 weeks of mirtazapine treatment. In the analysis of depression symptoms, the sleep and delusion scores had smaller reductions in S allele carriers. Based on the Liverpool University Neuroleptic Side Effect Rating Scale (LUNSERS), the psychic adverse effects of mirtazapine were associated with CYP2D6 P34S, while weight gain was not. These results suggest that CYP2D6 P34S affects the outcome of mirtazapine treatment in patients with MDD, and that this polymorphism may be a good genetic marker for predicting the clinical outcome of mirtazapine treatment.

• 대한임상약리학회:학술대회논문집
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• 대한임상약리학회 2003년도 제12차 추계학술대회
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• pp.13-13
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• 2003

• 한국환경성돌연변이발암원학회:학술대회논문집
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• 한국환경성돌연변이발암원학회 2004년도 춘계학술대회
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• pp.31-32
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• 2004