• YAKHAK HOEJI
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• v.41 no.4
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• pp.492-497
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• 1997

A difference in ethanol metabolism between premature and young adult rats was examined. Female SD rats, either 4wk or 12wk old, were injected with a single dose of ethanol (1.5g /kg) through jugular vein and the blood ethanol level was monitored for 300 min using a gas chromatographic method. Reduction of blood ethanol level per unit of time was less and the area under the blood concentration-time curve (AUC) was significantly greater in young adults compared to premature rats. Activity of hepatic alcohol dehydrogenase was not influenced by the age increase. Total cytochrome P-450, cytochrome $b_5$. or aminopyrine N-demethylation was not different between premature rats and young adult rats. However, p-nitrophenol hydroxylation and p-nitroanisole O-demethylation activities were significantly higher in premature rats. The relative liver weight was 45% greater in premature rats leading to an overall increase in ethanol metabolizing activity in these animals. The results indicate that the reduction in ethanol elimination in young adult rats appears to be mostly associated with the decrease in relative liver weight as the age of animals increases.

• Archives of Pharmacal Research
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• v.23 no.4
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• pp.267-282
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• 2000

Cytochrome P45O (CYP) 2E1 catalyzes the metabolism of a wide variety of therapeutic agents, procarcinogens, and low molecular weight solvents. CYP2E1-catalyzed metabolism may cause toxicity or DNA damage through the production of toxic metabolites, oxygen radicals, and lipid peroxidation. CYP2E1 also plays a role in the metabolism of endogenous compounds including fatty acids and ketone bodies. The regulation of CYP2E1 expression is complex, and involves transcriptional, post-transcriptional, translational, and post-translational mechanisms. CYP2E1 is transcriptionally activated in the first few hours after birth. Xenobiotic inducers elevate CYP2E1 protein levels through both increased translational efficiency and stabilization of the protein from degradation, which appears to occur primarily through ubiquitination and proteasomal degradation. CYP2E1 mRNA and protein levels are altered in response to pathophysiologic conditions by hormones including insulin, glucagon, growth hormone, and leptin, and growth factors including epidermal growth factor and hepatocyte growth factor, providing evidence that CYP2E1 expression is under tight homeostatic control.

• Journal of Microbiology and Biotechnology
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• v.15 no.6
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• pp.1310-1316
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• 2005

To evaluate the toxicological properties of human cytochrome P450 2E1 (CYP2E1) induced by ethanol and possible protective effects of various green tea catechins on alcohol-induced toxicity, transfected HepG2 cells that stably and constitutively express human CYP2E1 were established using the recombinant retroviral expression vector. Exposure of the CYP2E1-expressing HepG2 cells to high concentration of ethanol (200 mM) for 5 days resulted in a more than $50\%$ increase of cytotoxicity, assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) reduction, lactate dehydrogenase (LDH) release, and reactive oxygen species (ROS) production, and loss of normal morphology, in comparison with HepG2 cells containing control vector. Treatment of the cells with various catechins increased cell viability by more than 2-fold. (-)-Epicatechin gallate and(-)-catechin gallate at the lowest concentration ($5\;{\mu}M$) attenuated cell death induced CYP2E1 by $60-65\%$. Therefore, the results showed that the catechins, including epimerized catechins, have strong protective effects against alcohol-induced CYP2E1 toxicity, and it is correlated with antioxidant effect.

• Biomedical Science Letters
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• v.4 no.2
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• pp.129-135
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• 1998

We have carried out polymerase chain reaction (PCR) to investigate if retropseudogene for CYP2El is present in human genome. PCR primers were designed based on the structure of functional CYP2El gene and used to amplify both functional gene and retropseudogene in one reaction. From the repeated experiments we were able to amplify a previously unidentified CYP2El retropseudogene that was present in human genome. Its detailed structure was confirmed by Southern blotting and DNA sequencing. Nucleotide sequence of this retropseudogene was completely matched up to human liver CYP2El mRNA suggesting that the development of this retropseudogene might be a relatively recent event.

• Biomolecules & Therapeutics
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• v.22 no.2
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• pp.155-160
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• 2014

Thelephoric acid is an antioxidant produced by the hydrolysis of polyozellin, which is isolated from Polyozellus multiplex. In the present study, the inhibitory effects of polyozellin and thelephoric acid on 9 cytochrome P450 (CYP) family members (CYP1A2, CYP2A6, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, CYP2E1, and CYP3A4) were examined in pooled human liver microsomes (HLMs) using a cocktail probe assay. Polyozellin exhibited weak inhibitory effects on the activities of all 9 CYPs examined, whereas thelephoric acid exhibited dose- and time-dependent inhibition of all 9 CYP isoforms ($IC_{50}$ values, $3.2-33.7{\mu}M$). Dixon plots of CYP inhibition indicated that thelephoric acid was a competitive inhibitor of CYP1A2 and CYP3A4. In contrast, thelephoric acid was a noncompetitive inhibitor of CYP2D6. Our findings indicate that thelephoric acid may be a novel, non-specific CYP inhibitor, suggesting that it could replace SKF-525A in inhibitory studies designed to investigate the effects of CYP enzymes on the metabolism of given compounds.

• Proceedings of the PSK Conference
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• 2003.04a
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• pp.185.2-185.2
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• 2003

Effects of diallyl sulfide (DAS), a component of garlic, on thioacetamide-induced hepatotoxicity were investigated in male ICR mice. When mice treated subcutaneously with 100, 200 and 400 mg/kg of DAS in corn oil for three consecutive days, the activity of cytochrome P450 (P450) 2E1-selective p-nitrophenol hydroxylase was dose-dependently suppressed. In addition, the activities of P450 2B-selective benzyloxyresorufin O-debenzylase and pentoxyresorufin O-depentylase were dose-dependently induced by the treatment with DAS. (omitted)

• Biomolecules & Therapeutics
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• v.22 no.2
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• pp.149-154
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• 2014

Effects of diallyl sulfide (DAS) on thioacetamide-induced hepatotoxicity and immunotoxicity were investigated. When male Sprague-Dawley rats were treated orally with 100, 200 and 400 mg/kg of DAS in corn oil for three consecutive days, the activity of cytochrome P450 (CYP) 2E1-selective p-nitrophenol hydroxylase was dose-dependently suppressed. In addition, the activities of CYP 2B-selective benzyloxyresorufin O-debenzylase and pentoxyresorufin O-depentylase were significantly induced by the treatment with DAS. Western immunoblotting analyses also indicated the suppression of CYP 2E1 protein and/or the induction of CYP 2B protein by DAS. To investigate a possible role of metabolic activation by CYP enzymes in thioacetamide-induced hepatotoxicity, rats were pre-treated with 400 mg/kg of DAS for 3 days, followed by a single intraperitoneal treatment with 100 and 200 mg/kg of thioacetamide in saline for 24 hr. The activities of serum alanine aminotransferase and aspartate aminotransferase significantly elevated by thioacetamide were protected in DAS-pretreated animals. Likewise, the suppressed antibody response to sheep erythrocytes by thioacetamide was protected by DAS pretreatment in female BALB/c mice. Taken together, our present results indicated that thioacetamide might be activated to its toxic metabolite(s) by CYP 2E1, not by CYP 2B, in rats and mice.

• YAKHAK HOEJI
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• v.57 no.3
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• pp.194-198
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• 2013

In the present study we evaluated drug-drug interaction potential of ambroxol and cetirizine mediated by inhibition of CYP isoforms including CYP1A2, CYP2A6, CYP2B6, CYP2C9, CYP2C19, CYP2D6, CYP2E1 and CYP3A4 using pooled human liver microsomes (HLMs). As measured by liquid chromatography-electrospray ionization tandem mass spectrometry, cetirizine and ambroxol inhibited significantly CYP2E1 but the maximal inhibition was approximately 36% at 10 ${\mu}M$ cetirizine and 28% at 3 ${\mu}M$ ambroxol. In addition, CYP2D6 activity was decreased to approximately 83% of control activity in pooled HLM incubated with 3 ${\mu}M$ ambroxol. Activities of CYP1A2, CYP2A6, CYP2B6, CYP2C9, CYP2C19, and CYP3A4 were not significantly inhibited by cetirizine and ambroxol. Considering their maximal plasma concentration in human ($C_{max}$ of cetirizine is approximately 0.67 ${\mu}M$ and $C_{max}$ of ambroxol is 0.044 ${\mu}M$), these two drugs have very low possibility in drug-drug interaction by CYP inhibition in clinical situations.

• Journal of Environmental Science International
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• v.14 no.5
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• pp.499-511
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• 2005

This study was performed to determine the effects of genetic polymorphisms, such as glutathione S-transferase ${\mu}1(GSTM1)$, glutathione S-transferase ${\Theta}1\;(GSTM1)$, glutathione S-transferase ${\pi}l (GSTP1)$, aryl hydrocarbon N-acetyltransferase 2 (NAT2), cytochrome P450 2E1 (CYP2E1), cytochrome P450 1A1 (CYP1A1) on the concentrations of urinary 1-hydroxypyrene (1-OHP) and 2-naphthol in general population with no occupational exposure to polycyclic aromatic hydrocarbons (PAHs). Study subjects were 257 men who visited a health promotion center in Susan. A questionnaire was used to obtain detailed data about age, smoking, drinking, body fat mass, intake of fat etc. Urinary l-OHP and 2-naphthol concentration were analyzed by HPLC system with a fluorescence detector. A multiplex PCR method was used to identify the genotypes for GSTM1 and GSTT1. The polymorphisms of GSTP1, NAT2, CYP1A1 and CYP2E1 were determined by the polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) method. Urinary 1-OHP concentration was higher in deleted genotype of GSTM1, increased as smoking and alcohol drinking increased. Urinary 2-naphthol concentration was also rely on the age and smoking. Neither genetic polymorphism nor drinking-related factors were significantly related to urinary 2-naphthol concentration. No significant relation was found between physical characteristics and concentrations of urinary PAHs metabolites in the subjects, but the geometric mean of urinary 1-OHP and 2-naphthol was higher in the group with higher value compared to median value. These data suggest that in general population occupationally not exposed to PAHs, urinary concentration of PAHs metabolites is influenced by smoking, alcohol drinking and deleted genotype of GSTM1 in 1-OHP and smoking in 2-naphthol.

• Toxicological Research
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• v.29 no.3
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• pp.187-193
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• 2013

The effects of toluene in dimethylformamide (DMF)-induced hepatotoxicity were investigated with respect to the induction of cytochrome P-450 (CYP) and the activities of related enzymes. The rats were treated intraperitoneally with the organic solvents in olive oil (Single treatment groups: 450 [D1], 900 [D2], 1,800 [D3] mg DMF, and 346 mg toluene [T] per kg of body weight; Combined treatment groups: D1+T, D2+T, and D3+T) once a day for three days, while the control group received just the olive oil. Each group consisted of 4 rats. The activities of the xenobiotic metabolic enzymes and the hepatic morphology were assessed. The immunoblots indicated that the expression of CYP2E1 was considerably enhanced depending on the dosage of DMF and the CYP2E1 blot densities were significantly increased after treatment with both DMF and toluene, compared to treatment with DMF alone. The activities of glutathione-S-transferase and glutathione peroxidase were either decreased or remained unaltered after treatment with DMF and toluene, whereas the lipid peroxide levels were increased with increasing dosage of DMF and toluene. The liver tissue in the D3 group (1,800 mg/kg of DMF) showed signs of microvacuolation in the central vein region and a large necrotic zone around the central vein, in rats treated with both DMF (1,800 mg/kg) and toluene (D3T). These results suggest that the expression of CYP2E1 is induced by DMF and enhanced by toluene. These changes may have facilitated the accelerated formation of N-methylformamide (NMF) from toluene, and the generated NMF may directly induce liver damage.