• Journal of fish pathology
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• v.33 no.2
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• pp.153-161
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• 2020

Cytochrome P450(CYP) gene is involved in the biotransformation of drugs and environmental pollutants. In this study, we analyzed the nucleotide sequence of the Anguilla japonica CYP1(AjCYP1) family gene and examined the relative expression of AjCYP1A, AjCYP1B and AjCYP1C1 in response to the exposure to environmental pollutants. After exposure to B[a]P 20mg/kg bw, the expression of AjCYP1 family gene increased over time. Among four tissues examined (liver, spleen, gill and kidney), AjCYP1 family gene was expressed significantly in the kidney. Compared with the control group, AjCYP1A was expressed about 5-fold at 48 hr, AjCYP1B about 6-fold at 24 hr, and AjCYP1C1 about 4-fold at 24 hr. However, after exposure to B[a]P 200mg/kg bw, AjCYP1A did not change in all tissues. On the other hand, AjCYP1B was expressed at about 4-fold at 24 hr in the spleen and 4-fold at 48 hr in the gill. Finally AjCYP1C1 was expressed 3.7-fold and 4.3-fold in the spleen and kidneys at 48 hr, respectively. Taken together, our results suggest that the expression of AjCYP1 gene in eel tissues might be used as a useful tool to assess the exposure to environmental pollutants in aquaculture system.

• Biomolecules & Therapeutics
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• v.20 no.6
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• pp.562-568
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• 2012

Cytochrome P450 BM3 (CYP102A1) from Bacillus megaterium is a self-sufficient monooxygenase that consists of a heme domain and FAD/FMN-containing reductase domain (BMR). In this report, the reduction of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and 5-cyano-2,3-ditolyl tetrazolium chloride (CTC) by BMR was evaluated as a method for monitoring BMR activity. The electron transfer proceeds from NADPH to BMR and then to BMR substrates, MTT and CTC. MTT and CTC are monotetrazolium salts that form formazans upon reduction. The reduction of MTT and CTC followed classical Michaelis-Menten kinetics ($k_{cat}=4120\;min^{-1}$, $K_m=77{\mu}M$ for MTT and $k_{cat}=6580\;min^{-1}$, $K_m=51{\mu}M$ for CTC). Our continuous assay using MTT and CTC allows the simple, rapid measurement of BMR activity. The BMR was able to metabolize mitomycin C and doxorubicin, which are anticancer drug substrates for CPR, producing the same metabolites as those produced by CPR. Moreover, the BMR was able to interact with CYP1A2 and transfer electrons to promote the oxidation reactions of substrates by CYP1A2 and CYP2E1 in humans. The results of this study suggest the possibility of the utilization of BMR as a surrogate for mammalian CPR.

• Journal of Microbiology and Biotechnology
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• v.22 no.12
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• pp.1659-1664
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• 2012

TSAHC [4'-(p-toluenesulfonylamido)-4-hydroxychalcone] is a promising antitumorigenic chalcone compound, especially against TM4SF5 (four-transmembrane L6 family member 5)-mediated hepatocarcinoma. We evaluated the potential of TSAHC to inhibit the catalytic activities of nine cytochrome P450 isoforms and of P-glycoprotein (P-gp). The abilities of TSAHC to inhibit phenacetin O-deethylation (CYP1A2), coumarin 6-hydroxylation (CYP2A6), bupropion hydroxylation (CYP2B6), amodiaquine N-deethylation (CYP2C8), diclofenac 4-hydroxylation (CYP2C9), omeprazole 5-hydroxylation (CYP2C19), dextromethorphan O-demethylation (CYP2D6), chlorzoxazone 6-hydroxylation (CYP2E1), and midazolam 1'-hydroxylation (CYP3A) were tested using human liver microsomes. The P-gp inhibitory effect of TSAHC was assessed by [$^3H$]digoxin accumulation in the LLCPK1-MDR1 cell system. TSAHC strongly inhibited CYP2C8, CYP2C9, and CYP2C19 isoform activities with $K_i$ values of 0.81, 0.076, and $3.45{\mu}M$, respectively. It also enhanced digoxin accumulation in a dose-dependent manner in the LLCPK1-MDR1 cells. These findings indicate that TSAHC has the potential to inhibit CYP2C isoforms and P-gp activities in vitro. TSAHC might be used as a nonspecific inhibitor of CYP2C isoforms based on its negligible inhibitory effect on other P450 isoforms such as CYP1A2, CYP2A6, CYP2B6, CYP2D6, CYP2E1, and CYP3A.

• Development and Reproduction
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• v.10 no.2
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• pp.127-133
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• 2006

[ $17\;{\alpha}-hydroxylase/17,20-lyase(P450_{C17})$ ] is the key enzyme mediating the conversion of progesterone to $17\;{\alpha}-hydroxyprogesterone$, ultimately to androstenedione during steroidogenesis. R. dybowskii's ovarian $P450_{C17}$ cDNA was cloned to understand the regulatory mechanism of ovarian steroidogenic pathway at the molecular level in amphibian. A 2.5kb cDNA clone encoding a single open-reading frame with a 519 deduced amino acid was isolated with the screening of ovarian cDNA library. This sequence contained the three highly conserved domains as seen in $P450_{C17}$ of other species. The comparison of amino acid sequence of Rana $P450_{C17}$ with other animal's $P450_{C17}$ showed relatively high identity with 76% in Xenopus, 63% in chicken, 60% in rainbow trout, and 45% in human. Phylogenic analysis also indicated that Rana $P450_{C17}$ gene was evolutionary well conserved among vertebrate. Northern analysis indicated that the two different sizes of $P450_{C17}$ transcripts with approximately 2.5 and 3.6kb were detected in ovary tissue, but not in other tissues. The expression vector of Rana $P450_{C17}$ clearly showed the $17\;{\alpha}-hydroxylase$ activity converting the exogenous progesterone into $17\;{\alpha}-hydroxyprogesterone$ in the nonsteroidogenic COS-1 cells. Therefore, Rana $P450_{C17}$ cDNA is very useful to investigate the molecular mechanism of the ovarian steroidogenesis in amphibian.

• Environmental Mutagens and Carcinogens
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• v.9 no.2
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• pp.87-96
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• 1989

Studies on the biodisposition of beta-nicotyrine by lung and liver microsomes was examined in order to provide a better understanding of its fate in this tissue. beta-nicotyrine (100$\mu$M) was incubated with microsomes (1 mg/ml) prepared from New Zealand White rabbits. The rate of oxidation observed in lung microsomal incubations was 1.7 nmoles $\beta$-nicotyrine oxidized mg$^{-1}$ min$^{-1}$ compared with 2.7 nmoles $\beta$-nicotyrine oxidized mg$^{-1}$ min$^{-1}$ by the liver microsomal preparation. However, when these rates were expressed as a function of cytochrome P-450 content, the specific activity of the metabolic oxidation catalyzed by lung (8.3 nmoles $\beta$-nicotyrine oxidized nmole cytochrome P-450$^{-1}$ min$^{-1}$) was approxiamtely 4 times greater than liver microsomes (2.3 nmoles $\beta$-nicotyrine oxidized nmole cytochrome P-450$^{-1}$ min$^{-1}$). Isozyme studies on the oxidation of $\beta$-nicotyrine employed several methods of altering activities of specific isozymes present in pulmonary microsomes, including the use of the isozyme 2 and 6 specific inhibitor $\alpa$-methyl ABT, metabolic inhibitor(MI) complex formation. The results of this inhibition study would appear to indicate the $\beta$-nicotyrine is metabolized predominantly by pulmonary isozyme 5.

• Journal of Physiology & Pathology in Korean Medicine
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• v.21 no.6
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• pp.1415-1423
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• 2007

Carbon tetrachloride ($CCl_4$)-induced liver injury depends on a toxic agent that has to be metabolized by the liver NAPDH-cytochrome P450 enzyme system to a highly reactive intermediate. Alternations in the activity of cytochrome P450 enzymes affect the susceptibility to hepatic injury from $CCl_4$. In this study, we evaluated the potential protective activity of the traditional Korean medicinal herb, Corni fructus (CF), against an experimental model of hepatotoxicity induced by $CCl_4$. The CF exhibited a hepatoprotective activity against $CCl_4-induced$ liver damage in Sprague-Dawley (SD) rats, as measured by GOT, GPT, ALP and histological observation. The CF also showed significant decrease of malodialdehyde (MDA) and increase of glutathion (GSH), catalase activity in rat liver homogenate. In addition, the expression of CYP2E1, as measured by reverse transcriptase-polymerase chain reaction (RT-PCR) and Western blot analysis, was significantly decreased in the liver of CF treated SD rats. But $CCl_4$ and CF has no significant effect on 1A1 and 3A1 isoform of cytochrome P450. Based on these findings, it is suggested that hepatoprotective effects of CF possibly related to antioxidative effects and regulation of CYP2E1 expression.

• The Korean Journal of Physiology and Pharmacology
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• v.1 no.5
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• pp.597-602
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• 1997

Cytochrome P450 2E1 (CYP2E1) is involved in the toxicity and carcinogenicity of a number of solvents and xenobiotics. Like the various types of oxidation pharmacogenetics, the activity of the enzyme shows a discernible interindividual and interethnic variation. However, no pharmacogenetic information on CYP2E1 polymorphism has been available from a Korean population. The aim of this study was to explore the pharmacogenetics of CYP2E1 polymorphism in a native Koreans after an oral 400 mg dose of chlorzoxazone administered to 128 subjects. Urine samples were collected during the subsequent 8-hour period and urinary concentrations of chlorzoxazone and 6-hydroxychlorzoxazone were determined by a high performance liquid chromatography with an ultraviolet detector. The limit of detection in the samples was found to be $0.5\;{\mu}g/ml$. The mean value of the 6-hydroxychlorzoxazone excreted in 8 hr urine expressed as the percentage was 48.2 13.8%. The frequency distribution of percentage of the administered dose excreted as the 6-hydroxy metabolite was unimodally distributed in the subjects studied. However, the values showed wide (7-fold) interindividual difference, ranged from 11.6% to 79.8% of the dose of chlorzoxazone. Thus, it was considered that the pharmacogenetic characteristics of CYP2E1 in a Korean population did not represent multimodal distribution in the 6-hydroxychlorzoxazone excreted in 8-hr urine expressed as the percentage. And the activity of the CYP2E1 in a Korean population seemed to be less compared with that of the Caucasian subjects.

• 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.

• Mass Spectrometry Letters
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• v.3 no.4
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• pp.104-107
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• 2012

Mollugin isolated from Rubia cordifolia is known to have anti-inflammatory, anti-cancer, and anti-viral activities. In the present study, a cocktail probe assay and LC-MS/MS were used to investigate the modulating effect of mollugin on cytochrome P450 (CYP) enzymes in male ICR mice. After mollugin was orally administrated to mice at the 20, 40, or 80 mg/kg for 3 days, the activities of CYP in hepatic S-9 fractions were investigated. Unlike the selective inhibitory effect of mollugin on CYP1A2-catalyzed phenacetin O-deethylation in vitro, mollugin only significantly inhibited the activity of CYP2E1-catalyzed chlorzoxazone 6-hydroxylase in vivo. The activities of other CYPs were only slightly altered by mollugin. The results of this study suggest that mollugin might cause herb-drug interactions via the selective inhibition of CYP2E1 in vivo.

• Journal of Nutrition and Health
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• v.25 no.2
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• pp.116-122
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• 1992

This study determined hepatic microsomal lipid peroxide values glucose 6-phosphatase NA-DPH-cytochrome P450 reductase and cytosolic glutathione S-transferase activites to examine the effects of methyl group deficiency on hepatic lipid peroxidation in rats treated with diethylni-trosamine(DEN) and 2-acetylamionfluorene(AAF) Weanling sprague Dawley male rats were fed the diet with methyl group supplemented or deficient. Two weeks after feeding rate were injected with a single of 200mg/kg body weight DEN intraperitoneally and after four weeks 0.02% AAF containing diets were fed for two weeks. Animals were sacrificed at 6th week. Microsomal lipid peroxide values were tended to increase in methyl group deficiency(MD). Especially in case of carcinogen tratments lipid peroxide values were increased significantly in MD. Microsomal glucose 6-phophatase activities were decreased by MD and carcinogens and in MD with carcinogen group (MD+C) the enzyme activites were the lowest Glucose 6-phosphatase activities were negatively correlated with lipid peroxidation. Microsomal NADPH-cytochrome P450 reductase activities were the highest in MD+C and correlated positively with lipid peroxidation. Cytosolic glutathione S-transferase activities were the highest in MD+C Methyl group deficiency induces lipid peroxidation especially in case of being exposed to carcinogens. Therefore the results suggest that lipid peroxidation may be one of the meachanisms of carcinogensis by methyl group deficiency.