• YAKHAK HOEJI
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• v.59 no.2
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• pp.49-54
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• 2015

In the present study we evaluated comparative herb-drug interaction potential of red ginseng total powder, ginsenoside Rg1, and Rb1 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, red ginseng total powder inhibited significantly activities of CYP1A2, CYP2A6, CYP2B6, CYP2C9, CYP2C19, CYP2D6, CYP2E1 and testosterone 6-beta hydroxylation by CYP3A4, but the $IC_{50}$ values were higher than $556{\mu}g/ml$. Activities of CYP2B6, CYP2C9, CYP2D6 and CYP3A4 were inhibited by ginsenoside Rb1. Also, activities of CYP1A2, CYP2A6, CYP2B6, CYP2C9, CYP2C19, CYP2D6 and testosterone 6-beta hydroxylation by CYP3A4 were inhibited by ginsenoside Rg1. The $IC_{50}$ values of ginsenoside Rb1 and Rg1 were higher than $200{\mu}g/ml$. Based on $IC_{50}$ values against CYP isoforms, ginsenosides-drug interactions by CYP inhibition may be very low in clinical situations.

• Journal of Life Science
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• v.26 no.1
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• pp.42-49
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• 2016

The retinoic acid (RA) plays an important role in the growth and development of many cells, and bioactive RA concentration is regulated by several enzymes, including CYP26A1. The expression of the CYP26A1 gene is regulated by RA, and the CYP26A1 gene is one of the candidates for RA-responsive genes. Although CYP26A1 genes are cloned from several animals, cloning of the CYP26A1 gene from cows has not been reported yet. The promoter region of CYP26A1 from cows was cloned by PCR and analyzed by sequence alignment with human and mouse CYP26A1. The RA-responsive element (RARE), DR-5 (ttggg), was located in this region and was perfectly conserved. The promoter region of bovine CYP26A1, which contains DR-5, was ligated to the luciferase reporter gene on transient transfection assays. The expression of CYP26A1-Luc promoter was activated by ATRA treatment in lung-derived mtCC cells. Co-transfection with RAR-α or -β with ATRA significantly activates the expression of CYP26A1-Luc promoter; however, it was less effective with either RAR-γ or RXR-γ. In addition, the endogenous gene expressions measured by Q-RT-PCR in mtCC cells were not significantly affected by ATRA treatment for 2 days; however, the expression of the endogenous CYP26A1 gene was diminished sharply at day 3 with ATRA treatment. In conclusion, the promoter region of bovine CYP26A1 contains conserved DR-5 RARE, which functions as a binding site for RAR-α or -β, and it is involved in the regulation of CYP26A1 gene expression and the control of RA signaling in mtCC cells.

• Molecular & Cellular Toxicology
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• v.3 no.4
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• pp.314-319
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• 2007

The effects of common variants of CYP1A2 gene (CYP1A2$^*$1C and CYP1A2$^*$1F) on the CYP1A2 activity and inducibility were controversial. The aim of the present study is to investigate the effects of CYP1A2$^*$1C and CYP1A2$^*$1F on the activity of CYP1A2 determined by urinary caffeine metabolite ratio in Koreans. As might be expected, there was large inter-individual variation (16-folds) of CYP1A2 activity ranged from 2.41 to 39.58. The mean CYP1A2 activity of smokers was significantly higher than that of non-smokers. The frequencies of CYP1A2$^*$1C (-3858A) and $^*$1F (-164A) alleles were 0.219 and 0.646, respectively. The effect of CYP1A2$^*$1C on the CYP1A2 activity was not significant. However, the CYP1A2 activity of subjects with AA genotype for CYP1A2$^*$1F allele was significantly lower than that of non-AA genotypes (CC, or CA). Interestingly, the significant effect of CYP1A2$^*$1F allele on CYP1A2 activity was not observed in nonsmokers. Our results suggest that CYP1A2$^*$1F allele rather than CYP1A2$^*$1C allele significantly influences on the inducibility of CYP1A2 in Koreans. Owing to small sample size of our study, further studies should be conducted to reveal the inter-ethnic difference or the gene-environmental interaction.

• Archives of Pharmacal Research
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• v.28 no.10
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• pp.1114-1121
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• 2005

Flavonoids are polyphenols composed of two aromatic rings (A, B) and a heterocyclic ring (C). In order to determine the effects of the number of hydroxyl groups in the B-ring of the flavonoids on human cytochrome P450 (CYP) 1 family enzymes, we evaluated the inhibition of CYP1A-dependent 7-ethoxyresorufin O-deethylation activity by chrysin, apigenin and luteolin, using bacterial membranes that co-express human CYP1A1, CYP1A2, or CYP1B1 with human NADPH-cytochrome P450 reductase. Chrysin, which possesses no hydroxyl groups in its B-ring, exhibited the most pronounced inhibitory effects on CYP1A2-dependent EROD activity, followed by apigenin and luteolin. On the contrary, CYP1A1-mediated EROD activity was most potently inhibited by luteolin, which is characterized by two hydroxyl groups in its B-ring, followed by apigenin and chrysin. However, all of the 5,7-dihydroxyflavones were determined to similarly inhibit CYP1B1 activity. Chrysin, apigenin, and luteolin exhibited a mixed-type mode of inhibition with regard to CYP1A2, CYP1B1, and CYP1A1, with apparent Ki values of 2.4, 0.5, and 2.0 ${\mu}M$, respectively. These findings suggested that the number of hydroxyl groups in the B-ring of 5,7-dihydroxyflavone might have some influence on the degree to which CYP1A enzymes were inhibited, but not on the degree to which CYP1B1 enzymes were inhibited.

• Biomolecules & Therapeutics
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• v.16 no.4
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• pp.336-342
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• 2008

The resveratrol analogue piceatannol (3,5,3',4'-tetrahydroxy-trans-stilbene) is a polyphenol present in grapes and wine and reported to have anti-carcinogenic activities. To investigate the mechanism of anticarcinogenic activities of piceatannol, the effects on CYP 1 enzymes were determined in Escherichia coli membranes coexpressing recombinant human CYP1A1, CYP1A2 or CYP1B1 with human NADPH-P450 reductase. Piceatannol showed a strong inhibition of CYP1A1 and CYP1B1 in a concentration-dependent manner, and $IC_{50}$ of human CYP1A1 and CYP1B1 was 5.8 ${\mu}M$ and 16.6 ${\mu}M$, respectively. However, piceatannol did not inhibit CYP1A2 activity in the concentration of up to 100 ${\mu}M$. Piceatannol exhibited 3-fold selectivity for CYP1B1 over CYP1A1. The mode of inhibition of piceatannol was non-competitive for CYP1A1 and CYP1B1. The result that piceatannol did not inhibit CYP1B1-mediated $\alpha$-naphthoflavone ($\alpha$-NF) metabolism suggests piceatannol may act as a non-competitive inhibitor as well. In human prostate carcinoma PC-3 cells, piceatannol induces apoptosis and prevents Aktmediated signal pathway. Taken together, abilities of piceatannol to induce apoptotic cell death as well as CYP1 enzyme inhibition make this compound a useful tool for cancer chemoprevention.

• 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.

• The Journal of Korean Medicine
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• v.24 no.2
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• pp.40-46
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• 2003

Objectives : Achyranthes bidentata radix (Usul) has been used as anti-arthritic, antiallergic, antidiuretic, and so on. Recently extracts of Achyranthes bidentata radix have shown anti-inflammatory and cancer preventive effects in vitro and in vivo. Methods : We therefore evaluated the inhibitory potential of ethanol extracts of Achyranthes bidentata radix on cytochrome P450 (CYP) isoforms-catalyzed reactions, which relate to causes of cancer and inflammation, including CYP1A2, CYP2C9, CYP2C19, CYP2E1, CYP2D6, CYP2C8, and CYP3A4, using human liver microsomal preparations. Results : The extracts showed weak or negligible inhibitory effects on CYP2C9-catalyzed (S)-warfarin 7-hydroxylation, CYP2C19-catalyzed S-mephenytoin 4-hydroxylation, and CYP2D6-catalyzed dextromethorphan O-demethylation with each IC50 over 1750 g/ml, respectively. However, it showed relatively significant inhibitory effect on CYP1A2-catalyzed phenacetin O-deethylation and CYP2E1-catalyzed chlorzoxazone 6-hydroxylation with IC50s of 970.5 g/ml and 821.4 g/ml, respectively. Conclusions : These results suggest that extracts of Achyranthes bidentata radix have inhibitory effects on CYP-catalyzed reactions, especiallyCYP1A2 and CYP2E1, in human liver microsomes. These effects appear to relate to anti-inflammatory and cancer prevention following decrease of reactive oxygen species formed by CYP, especially CYP1A2 and CYP2E1, by Achyranthes bidentata radix. However, further evaluation is necessary to demonstrate and to confirm its effects in human.

• The Journal of Korean Medicine
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• v.35 no.2
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• pp.47-59
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• 2014

Objectives: Most drug interactions are attributed to the inhibition or induction of the activity of cytochrome P450s (CYP450). Although the regulation of CYP450s by drugs has been widely reported, there have been few studies on influence of traditional herbal formulas on the drug-metabolizing enzymes. Because herbal formulas have been used traditionally to treat various diseases and because herb-drug interactions are crucial factors determining therapeutic efficacies, a systematic evaluation of the effects of herbal formulas is important. Methods: The effects of Galgeun-tang (GGT, gegen tang), Gumiganghwal-tang (GMGHT, jiuweiqianghuo tang), Insampaedok-san (ISPDS, renshenbaidu powder), Samsoeum (SSE, shensu drink), Socheongryong-tang (SCRT, xiaoqinglong-tang) and Sosiho-tang (SSHT, xiaochaihu tang) that are traditional herbal formulas used to treat common cold, on drug-metabolizing enzymes were evaluated through an in vitro CYP3A4, CYP2D6, CYP2C19 and CYP2E1 inhibition assay to assess its interaction potential with synthetic drugs. The inhibitory effects of herbal formulas were characterized with $IC_{50}$ values. Results: These six herbal formulas inhibited the activities of CYP3A4, 2C19, 2D6 and 2E1, in a concentration-dependent manner. Among the six herbal formulas, GGT critically inhibited CYP2C19, CYP2D6 and CYP2E1. GMGHT also inhibited CYP2D6 and CYP2E1 to a greater extent than the other CYP450 isozymes. Additionally, SSE and SSHT may change the effects of medicines that depend primarily on the CYP2C19 and CYP2E1 pathways. On the other hand, ISPDS and SCRT were not inhibited CYP3A4, CYP2C19, CYP2D6 and CYP2E1-mediated metabolism. Conclusions: These findings provide useful information regarding the safety and effectiveness of herbal formulas.

• Environmental Mutagens and Carcinogens
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• v.26 no.3
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• pp.86-88
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• 2006

Cytochrome P450 1A2 (CYP1A2) is a xenobiotic metabolizing enzyme that is tissue-specifically expressed in the mammalian liver. In this study, the extent of CYP1A2 promoter methylation was analyzed to determine its potential role in the regulation of CYP1A2 in diethylnitrosamine (DEN)-induced mouse liver tumors. CYP1A2 mRNA was under-expressed about three fold in DEN-induced liver tumors compared to age-matched control livers. The CYP1A2 promoter was hypermethylated in DEN-induced liver tumors compared to controls, especially in a promoter domain close to the coding region. These results suggest that promoter methylation is involved in the regulation of CYP1A2 in mouse liver tumors.

• Toxicological Research
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• v.33 no.3
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• pp.211-218
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• 2017

Cytochrome P450 1B1 (CYP1B1) acts as a hydroxylase for estrogen and activates potential carcinogens. Moreover, its expression in tumor tissues is much higher than that in normal tissues. Despite this association between CYP1B1 and cancer, the detailed molecular mechanism of CYP1B1 on cancer progression in HeLa cells remains unknown. Previous reports indicated that the mRNA expression level of Herc5, an E3 ligase for ISGylation, is promoted by CYP1B1 suppression using specific small interfering RNA, and that ISGylation may be involved in ubiquitination related to ${\beta}-catenin$ degradation. With this background, we investigated the relationships among CYP1B1, Herc5, and ${\beta}-catenin$. RT-PCR and western blot analyses showed that CYP1B1 overexpression induced and CYP1B1 inhibition reduced, respectively, the expression of $Wnt/{\beta}-catenin$ signaling target genes including ${\beta}-catenin$ and cyclin D1. Moreover, HeLa cells were treated with the CYP1B1 inducer $7,12-dimethylbenz[{\alpha}]anthracene$ (DMBA) or the CYP1B1 specific inhibitor, tetramethoxystilbene (TMS) and consequently DMBA increased and TMS decreased ${\beta}-catenin$ and cyclin D1 expression, respectively. To determine the correlation between CYP1B1 expression and ISGylation, the expression of ISG15, a ubiquitin-like protein, was detected following CYP1B1 regulation, which revealed that CYP1B1 may inhibit ISGylation through suppression of ISG15 expression. In addition, the mRNA and protein expression levels of Herc5 were strongly suppressed by CYP1B1. Finally, an immunoprecipitation assay revealed a direct physical interaction between Herc5 and ${\beta}-catenin$ in HeLa cells. In conclusion, these data suggest that CYP1B1 may activate $Wnt/{\beta}-catenin$ signaling through stabilization of ${\beta}-catenin$ protein from Herc5-mediated ISGylation for proteosomal degradation.