• Asian Pacific Journal of Cancer Prevention
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• v.14 no.6
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• pp.3761-3768
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• 2013

Background: The Saudi population has experienced a sharp increase in colorectal and gastric cancer incidences within the last few years. The relationship between gene polymorphisms of xenobiotic metabolizing enzymes and colorectal cancer (CRC) incidence has not previously investigated among the Saudi population. The aim of the present study was to investigate contributions of CYP1A1, CYP2E1, and GSTM1 gene polymorphisms. Materials and Methods: Blood samples were collected from CRC patients and healthy controls and genotypes were determined by polymerase chain reaction restriction fragment length polymorphism and sequencing. Results and Conclusions: $CYP2E1^*6$ was not significantly associated with CRC development (odd ratio=1.29; confidence interval 0.68-2.45). A remarkable and statistically significant association was observed among patients with $CYP1Awt/^*2A$ (odd ratio=3.65; 95% confidence interval 1.39-9.57). The $GSTM1^*0/^*0$ genotype was found in 2% of CRC patients under investigation. The levels of CYP1A1, CYP2E1 and GSTM1 mRNA gene expression were found to be 4, 4.2 and 4.8 fold, respectively, by quantitative real time PCR. The results of the present case-control study show that the studied Saudi population resembles Caucasians with respect to the considered polymorphisms. Investigation of genetic risk factors and susceptibility gene polymorphisms in our Saudi population should be helpful for better understanding of CRC etiology.

• BMB Reports
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• v.32 no.3
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• pp.232-238
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• 1999

Sex differences in the induction of microsomal cytochrome P-450 (CYP) and the activities of several related enzymes of Sprague-Dawley rats treated with 1-bromopropane (1-BrP) were investigated. Male and female rats were exposed to 50, 300, and 1800 ppm of 1-BrP per kg body weight (6 h a day,S days a week, 8 weeks) by inhalation. The mean body weight of 1-BrP treated groups increased according to the day elapsed, but four and five weeks respectively after the start of the exposure, the mean body weight of male and female rats had significantly reduced in the group treated with 1800 ppm 1-BrP compared with the control group (p<0.01). While the relative weights of liver increased in both sexes, statistical significance in both sexes was found only in the group receiving 1800 ppm/kg of 1-BrP (p<0.01). The total contents of CYP, $b_5$, NADPH-P-450 reductase, NADH $b_5$ reductase, ethoxyresorufin-O-deethylase (EROD), pentoxyresorufin-O-dealkylase (PROD), and p-nitrophenol hydroxylase (pNPH) activities were examined for the possible effects of 1-BrP. No significant changes in the CYP and $b_5$ contents, NADPH-P-450 reuctase, NADH $b_5$ reductase, ethoxyresorufin-O-deethylase (EROD), and pentoxyresorufin- O-dealkylase (PROD) were observed between the control and treated groups. The activity of pNPH increased steadily with the increase in the concentration of 1-BrP in both sexes, but was significantly increased only in the 1800 ppm-treated group of male rats (p<0.05). When Western blottings were carried out with three monoclonal antibodies (MAb 1-7-1, MAb 2-66-3, and MAb 1-98-1) which were specific against CYP1A1/2, CYP2B1/2, and CYP2E1, respectively, a strong signal corresponding to CYP2E1 was observed in microsomes obtained from rats treated with 1-BrP. Glutathione S-transferase (GST) activity and the content of lipid peroxide significantly increased in the treated groups compared with the control group (p<0.05). These results suggest that 1-BrP can primarily induce CYP2E1 as the major form and that GST phase II enzymes play important roles in 1-BrP metabolism, showing sex-dependence in the metabolic mechanism of 1-BrP in the rat liver.

• Experimental and Molecular Medicine
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• v.50 no.11
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• pp.8.1-8.14
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• 2018

We previously demonstrated that the direct transplantation of human umbilical cord blood-derived mesenchymal stem cells (hUCB-MSCs) into the dentate gyrus ameliorated the neurological symptoms of Niemann-Pick type C1 (NPC1)-mutant mice. However, the clinical presentation of NPC1-mutant mice was not fully understood with a molecular mechanism. Here, we found 14,15-epoxyeicosatrienoic acid (14,15-EET), a cytochrome P450 (CYP) metabolite, from hUCB-MSCs and the cerebella of NPC1-mutant mice and investigated the functional consequence of this metabolite. Our screening of the CYP2J family indicated a dysregulation in the CYP system in a cerebellar-specific manner. Moreover, in Purkinje cells, CYP2J6 showed an elevated expression level compared to that of astrocytes, granule cells, and microglia. In this regard, we found that one CYP metabolite, 14,15-EET, acts as a key mediator in ameliorating cholesterol accumulation. In confirming this hypothesis, 14,15-EET treatment reduced the accumulation of cholesterol in human NPC1 patient-derived fibroblasts in vitro by suppressing cholesterol synthesis and ameliorating the impaired autophagic flux. We show that the reduced activity within the CYP system in the cerebellum could cause the neurological symptoms of NPC1 patients, as 14,15-EET treatment significantly rescued cholesterol accumulation and impaired autophagy. We also provide evidence that the intranasal administration of hUCB-MSCs is a highly promising alternative to traumatic surgical transplantation for NPC1 patients.

• Archives of Pharmacal Research
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• v.27 no.5
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• pp.547-553
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• 2004

The pyrrolizidine alkaloids (PAs), contained in a number of traditional remedies in Africa and Asia, show wide variations in metabolism between animal species but little work has been done to investigate differences between animal strains. The metabolism of the PA senecionine (SN) in Fischer 344 (F344) rats has been studied in order to compare to that found in the previously investigated Sprague-Dawley (SO) rats (Drug Metab. Dispos. 17: 387, 1989). There was no difference in the formation of ($\pm$) 6,7-dihydro-7-hydroxy-1-hydroxymethyl-5H-pyrrolizine (DHP, bioactivation) by hepatic microsomes from either sex of SO and F344 rats. However, hepatic microsomes from male and female F344 rats had greater activity in the Noxidation (detoxication) of SN by 88% and 180%, respectively, when compared to that of male and female SD rats. Experiments conducted at various pH showed an optimum pH of 8.5, the optimal pH for flavin-containing monooxygenase (FMO), for SN N-oxidation by hepatic microsomes from F344 females. In F344 males, however, a bimodal pattern was obtained with activity peaks at pH 7.6 and 8.5 reflecting the possible involvement of both cytochrome P450 (CYP) and FMO. Use of specific inhibitors (SKF525A, 1-benzylimidazole and methimazole) showed that the N-oxide of SN was primarily produced by FMO in both sexes of F344 rats. In contrast, SN N-oxide formation is known to be catalyzed mainly by CYP2C11 rather than FMO in SD rats. This study, therefore, demonstrated that there were substantial differences in the formation of SN N-oxide by hepatic microsomes from F344 and SD rats and that this detoxification is catalyzed primarily by two different enzymes in the two rat strains. These findings suggest that significant variations in PA biotransformation can exist between different animal strains.

• Biomedical Science Letters
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• v.18 no.1
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• pp.1-9
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• 2012

Differentially expressed genes by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) were identified in order to evaluate them as dioxin-sensitive markers and crucial signaling molecules to understand dioxin-induced toxic mechanisms in human bronchial cells. Gene expression profiling was analyzed by cDNA microarray and ten genes were selected for further study. They were cytochrome P450, family 1, subfamily B, polypeptide 1 (CYP1B1), S100 calcium binding protein A8 (calgranulin A), S100 calcium binding protein A9 (calgranulin B), aldehyde dehydrogenase 1 family, member A3 (ALDH6) and peroxiredoxin 5 (PRDX5) in up-regulated group. Among them, CYP1B1 was used as a hallmark for dioxin and sharply increased by TCDD exposure. Down-regulated genes were IK cytokine, interferon-induced protein with tetratricopeptide repeats 1 (IFIT1), nuclease sensitive element binding protein 1 (NSEP1), protein tyrosine phosphatase type VI A, member 1 (PTP4A1), ras oncogene family 32 (RAB32). Although up-regulated 4 genes in microarray were coincided with northern hybridization, down-regulated 5 genes showed U-shaped expression pattern which is sharply decreased at lower doses and gradually increased at higher doses. These results introduce some of TCDD-responsive genes can be sensitive markers against TCDD exposure and used as signaling cues to understand toxicity initiated by TCDD inhalation in pulmonary tissues.

• Korean Journal of Clinical Pharmacy
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• v.18 no.1
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• pp.6-10
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• 2008

This study investigated the effect of long-term administration of pioglitazone on the pharmacokinetics of verapamil in rats. Pharmacokinetic parameters of verapamil were determined after oral administration of verapamil (9 mg/kg) in rats coadministered pioglitazone (0.5 mg/kg) or pretreated with pioglitazone (0.5 mg/kg) for 3 and 9 days. Compared to oral control group, the presence of pioglitazone significantly (p<0.05) increased the area under the plasma concentration-time curve (AUC) of verapamil by 48.6% (coad), 61.1% (3 days) and 56.5% (9 days), and the peak concentration($C_{max}$) by 65.1% (coad), 76.8% (3 days) and 66.4% (9 days). The absolute bioavailability (AB%) of verapamil was significantly (p<0.05) higher by 6.2% (coad), 6.7% (3 days), 6.5% (9 days) compared to control (4.2%), and presence of pioglitazone was no significant change in the terminal half-life ($t_{1/2}$) and the time to reach the peak concentration($T_{max}$) of verapamil. Our results indicate that pioglitazone significantly enhanced oral bioavailability of verapamil in rats, implying that presence of pioglitazone could be effective to inhibit the CYP3A4-mediated metabolism of verapamil in the intestine. Drug interactions should be considered in the clinical setting when verapamil is coadministrated with pioglitazone.

• Korean Journal of Food Science and Technology
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• v.33 no.6
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• pp.656-663
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• 2001

The most representative nitrosamine derived from nicotine, nitrosamine-4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone(NNK), has been reported to cause lung cancer in A/J mice. It has been also demonstrated that NNK-induced lung tumorigenesis involves $O^6-methylguanine(O^6MeG)$ formation, leading to $GC\;{\rightarrow}\;AT$ transitional mispairing during DNA replication. Our in vitro experiment, modified from the method of DBA assay, examined the ability of phyto-extract mixture to inhibit the metabolism of nicotine to nitrosamines. The production of nitromorpholine from morpholine was inhibited about 75% at the concentration of 20 mg/mL of phyto-extract mixture, which was lower than vitamine C and green tea powder. NNK, which is a pro-carcinogen in laboratory animals, is hydroxylated primarily in liver and lung by CYP 1A2, 2A6 and 3A4. A critical phase. of NNK activation is its change to an unstable metabolite methyl-diazohydroxide via CYP-mediated ${\alpha}-hydroxylation$; and then it provides a methyl group to the DNA to form DNA adducts which can easily induce mutations. $Aroclor^R$ 1254 was used to induce CYPs in the liver of a Sprague-Dawley rat. The ability of various test samples to inhibit CYPs that participate in NNK activation was evaluated, following the removal of the liver from the rat. Microsomal CYPlA2 catalyzing the conversion of NNK into strong carcinogenic chemicals was inhibited more efficiently by phyto-extract mixture than green tea powder. These results indicate that phyto-extract mixture can be used to reduce $O^6MeG$ DNA adducts for chemoprevention.

• Tuberculosis and Respiratory Diseases
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• v.78 no.2
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• pp.99-105
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• 2015

Background: Aryl hydrocarbon receptor (AhR), a ligand-dependent transcription factor, binds to a wide variety of synthetic and naturally occurring compounds. AhR is involved in the regulation of inflammatory response during acute and chronic respiratory diseases. We investigated whether nuclear receptor coactivator 7 (NCOA7) could regulate transcriptional levels of AhR target genes and inflammatory cytokines in 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-treated human bronchial epithelial cells. This study was based on our previous study that NCOA7 was differentially expressed between normal and chronic obstructive pulmonary disease lung tissues. Methods: BEAS-2B and A549 cells grown under serum-free conditions were treated with or without TCDD (0.15 nM and 6.5 nM) for 24 hours after transfection of pCMV-NCOA7 isoform 4. Expression levels of cytochrome P4501A1 (CYP1A1), IL-6, and IL-8 were measured by quantitative real-time polymerase chain reaction. Results: The transcriptional activities of CYP1A1 and inflammatory cytokines were strongly induced by TCDD treatment in both BEAS-2B and A549 cell lines. The NCOA7 isoform 4 oppositely regulated the transcriptional activities of CYP1A1 and inflammatory cytokines between BEAS-2B and A549 cell lines. Conclusion: Our results suggest that NCOA7 could act as a regulator in the TCDD-AhR signaling pathway with dual roles in normal and abnormal physiological conditions.

• Journal of Plant Biotechnology
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• v.46 no.3
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• pp.189-204
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• 2019

In this study, we analyzed the changes in glucosinolate content and gene expression in TO1000DH3 and Early big seedling upon methyl jasmonate (MeJA) treatment. Analysis of glucosinolate contents after MeJA treatment at $200{\mu}M$ concentration showed that the total glucosinolate content increased by 1.3-1.5 fold in TO1000DH3 and 1.3-3.8 fold in Early big compared to those before treatment. Aliphatic glucosinolates, progoitrin and gluconapin, were detected only in TO1000DH3, and the changes in the content of neoglucobrassicin were the greatest at 48 hours after MeJA treatment in TO1000DH3 and Early big. The transcriptomic analysis showed that transcripts involved in stress or defense reactions, or those related to growth were specifically expressed in TO1000DH3, while transcripts related to nucleosides or ATP biosynthesis were specifically expressed in Early big. GO analysis on transcripts with more than two-fold change in expression upon MeJA treatment, corresponding to 12,020 transcripts in TO1000DH3 and 13,510 transcripts in Early big, showed that the expression of transcripts that react to stimulus and chemical increased in TO1000DH3 and Early big, while those related to single-organism and ribosome synthesis decreased. In particular, the expression increased for all transcripts related to indole glucosinolate biosynthesis, which is associated with increase in glucobrassicin and neoglucobrassicin contents. Upon MeJA treatment, the expression of AOP3 (Bo9g006220, Bo9g006240), TGG1 (Bo14804s010) increased only in TO1000DH3, while the expression of Dof1.1 (Bo5g008360), UGT74C1 (Bo4g177540), and GSL-OH (Bo4g173560, Bo4g173550, Bo4g173530) increased specifically in Early big.

• Journal of Pharmaceutical Investigation
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• v.37 no.2
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• pp.107-111
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• 2007

Epigallocatechin gallate (EGCC), a flavonoid, is the main component of green tea extracts. EGCG has been reported to be an inhibitor of P-glycoprotein (P-gp) and cytochrom P450 3A(CYP3A4). This study investigated the effect of long-term administration of EGCG on the pharmacokinetics of verapamil in rats. Pharmacokinetic parameters of verapamil were determined after oral administration of verapamil (9 mg/kg) in rats pretreated with EGCG (7.5 mg/hg) for 3 and 9 days. Compared to oral control group, the presence of EGCG significantly (p<0.01) increased the area under the plasma concentration-time curve (AUC) of verapamil by 102% (coad), 83.2% (3 days) and 52.3% (9 days), and the peak concentration $(C_{max})$ by 134% (coad), 120% (3 days) and 66.1% (9 days). The absolute bioavailability (A.B.%) of verapamil was significantly (p<0.01) higher by 8.4% (coad), 7.7% (3 days), 6.4% (9 days) compared to control (4.2%), and presence of EGCG was no significant change in the terminal half-life $(t_{1/2})$ and the time to reach the peak concentration $(T_{max})$ of verapamil. Our results indicate that EGCG significantly enhanced oral bioavailability of verapamil in rats, implying that presence of EGCG could be effective to inhibit the CYP3A4-mediated metabolism and P-gp efflux of verapamil in the intestine. Drug interactions should be considered in the clinical setting when verapamil is coadministrated with EGCG or EGCG-containing dietary.