• Proceedings of the Korean Society of Toxicology Conference
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• 2001.10a
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• pp.195-195
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• 2001

The inhibitory potentials of TCAs (imipramine, desipramine, amitriptyline, and nortriptyline) on phenytoin p-hydroxylation and probe metabolic pathways of each CYP isoforms were evaluated from incubation studies of human liver microsomes and cDNA-expressed cytochrome P450s in vitro in order to understand the mechanism of drug interaction between TCAs and phenytoin, a substrate of CYP2C9 and CYP2C19. (omitted)

• Biomolecules & Therapeutics
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• v.19 no.2
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• pp.255-260
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• 2011

The purpose of this study was to investigate the effect of ticlopidine on the pharmacokinetics of diltiazem and its active metabolite, desacetyldiltiazem, in rats. Pharmacokinetic parameters of diltiazem and desacetyldiltiazem were determined in rats after oral administration of diltiazem (15 $mg{\cdot}kg^{-1}$) with ticlopidine (3 or 9 $mg{\cdot}kg^{-1}$). The effects of ticlopidine on P-glycoprotein (P-gp) and cytochrome P450 (CYP) 3A4 activities were also evaluated. Ticlopidine inhibited CYP3A4 enzyme activity in a concentrationdependent manner with a 50% inhibition concentration ($IC_{50}$) of 35 ${\mu}M$. In addition, ticlopidine did not significantly enhance the cellular accumulation of rhodamine-123 in NCI/ADR-RES cells overexpressing P-gp. Compared with the control (given diltiazem alone), ticlopidine significantly altered the pharmacokinetic parameters of diltiazem. The peak concentration ($C_{max}$) and the area under the plasma concentration-time curve (AUC) of diltiazem were significantly (9 $mg{\cdot}kg^{-1}$, p<0.05) increased in the presence of ticlopidine. The AUC of diltiazem was increased by 1.44-fold in rats in the presence of ticlopidine (9 $mg{\cdot}kg^{-1}$). Consequently, the absolute bioavailability (A.B.) of diltiazem in the presence of ticlopidine (9.3-11.5%) was signifi cantly higher (9 $mg{\cdot}kg^{-1}$, p<0.05) than that in the control group (8.0%). Although ticlopidine significantly (p<0.05) increased the AUC of desacetyldiltiazem, the metabolite-parent AUC ratio (M.R.) in the presence of ticlopidine (9 $mg{\cdot}kg^{-1}$) was significantly decreased compared to that in the control group, implying that ticlopidine could effectively inhibit the metabolism of diltiazem. In conclusion, the concomitant use of ticlopidine significantly enhanced the oral bioavailability of diltiazem in rats by inhibiting CYP3A4-mediated metabolism in the intestine and/or liver rather than by inhibiting intestinal P-gp activity or renal elimination of diltiazem.

• Preventive Nutrition and Food Science
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• v.19 no.4
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• pp.268-273
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• 2014

The induction of detoxification enzymes by benzyl isothiocyanate (BITC) and its synthetic N-acetyl-L-cysteine (NAC) conjugate (NAC-BITC) was examined in Hepa1c1c7 murine hepatoma cells. BITC and NAC-BITC inhibited Hepa1c1c7 cell growth in a dose-dependent manner. Cell growth was 4.5~57.2% lower in Hepa1c1c7 cells treated with $0.1{\sim}1.0{\mu}M$ BITC than in control-treated Hepa1c1c7 cells. The NAC-BITC treatment had a similar inhibitory pattern on Hepa1c1c7 cell growth; $0.5{\mu}M$ and $10{\mu}M$ NAC-BITC decreased cell growth by 13.6% and 47.4%, respectively. Treatment of Hepa1c1c7 cells with $0.1{\sim}2.0{\mu}M$ BITC also elicited a dose-response effect on the induction of quinone reductase quinone reductase (QR) activity and QR mRNA expression. Treatment with $1{\mu}M$ and $2{\mu}M$ BITC caused 1.8- and 2.8-fold inductions of QR mRNA, respectively. By comparison, treatment with $1{\mu}M$ and $2{\mu}M$ NAC-BITC caused 1.6-and 1.9-fold inductions of QR mRNA, respectively. Cytochrome P450 (CYP) 1A1 and CYP2E1 induction were lower in $0.1{\sim}2{\mu}M$ BITC-treated cells than in control-treated cells. CYP2E1 activity was 1.2-fold greater in $0.1{\mu}M$ NAC-BITC-treated cells than in control-treated cells. However, the CYP2E1 activity of cells treated with higher concentrations (i.e., $1{\sim}2{\mu}M$) of NAC-BITC was similar to the activity of control-treated cells. Considering the potential of isothiocyanatesto prevent cancer, these results provide support for the use of BITC and NAC-BITC conjugates as chemopreventive agents.

• Biomolecules & Therapeutics
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• v.19 no.4
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• pp.498-503
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• 2011

The purpose of this study was to investigate the effects of nisoldipine on the pharmacokinetics of repaglinide in rats. The effect of nisoldipine on cytochrome P450 (CYP) 3A4 activity and P-glycoprotein (P-gp) were evaluated. The pharmacokinetic parameters of repaglinide were also determined in rats after oral (0.5 $mg{\cdot}kg^{-1}$) and intravenous (0.2 $mg{\cdot}kg^{-1}$) administration of repaglinide to rats without or with nisoldipine (0.3 and 1.0 $mg{\cdot}kg^{-1}$). Nisoldipine inhibited CYP3A4 enzyme activity with a 50% inhibition concentration of 5.5 ${\mu}M$. In addition, nisoldipine significantly enhanced the cellular accumulation of rhodamine-123 in MCF-7/ADR cells overexpressing P-gp. Compared to the oral control group, nisoldipine significantly increased the $AUC_{0-{\infty}}$ and the $C_{max}$ of repaglinide by 46.9% and 24.9%, respectively. Nisoldipine also increased the absolute bioavailability (A.B.) of repaglinide by 47.0% compared to the oral control group. Moreover, the relative bioavailability (R.B.) of repaglinide was 1.16- to 1.47-fold greater than that of the control group. Nisoldipine enhanced the oral bioavailability of repaglinide, which may be attributable to the inhibition of the CYP3A4-mediated metabolism in the small intestine and/or in the liver and to inhibition of P-gp in the small intestine rather than to reduction of renal elimination of repaglinide by nisoldipine. The increase in the oral bioavailability of repaglinide should be taken into consideration of potential drug interactions when co-administering repaglinide and nisoldipine.

• Biomolecules & Therapeutics
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• v.19 no.4
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• pp.493-497
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• 2011

The aim of this study was to investigate the effect of amlodipine on the pharmacokinetics of warfarin after oral and intravenous administration of warfarin in rats. Warfarin was administered orally (0.2 mg/kg) or intravenously (0.05 mg/kg) without or with oral administration of amlodipine (0.1 or 0.4 mg/kg) in rats. The effect of amlodipine on the P-glycoprotein (P-gp) as well as cytochrome P450 (CYP) 3A4 activity was also evaluated. Amlodipine inhibited CYP3A4 enzyme activity with 50% inhibition concentration ($IC_{50}$) of 9.1 ${\mu}M$. Compared to those animals in the oral control group (warfarin without amlodipine), the area under the plasma concentration-time curve (AUC) of warfarin was significantly greater (0.1 mg/kg, p<0.05; 0.4 mg/kg, p<0.01) by 26.5-53.5%, and the peak plasma concentration ($C_{max}$) was significantly higher (0.4 mg/kg, p<0.05) by 26.2% after oral administration of warfarin with amlodipine, respectively. Consequently, the relative bioavailability of warfarin increased by 1.26- to 1.53-fold and the absolute bioavailability of warfarin with amlodipine was significantly greater by 61.7-72.5% compared to that in the control group (47.4%). In contrast, amlodipine had no effect on any pharmacokinetic parameters of warfarin given intravenously. Therefore, the enhanced oral bioavailability of warfarin may be due to inhibition of CYP 3A4-mediated metabolism in the intestine and/or liver rather than renal elimination and P-gp by amlodipine.

• Journal of Life Science
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• v.22 no.8
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• pp.991-998
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• 2012

Ginseng is one of the most commonly used herbal medicines and health foods. Korean red ginseng (KRG; Panax ginseng C.A. Meyer) extract is known to have potential therapeutic activities, such as anti-viral effects, the amelioration of food allergies, anti-oxidant effects, and obesity reduction. Nevertheless, no reports have been issued the modulatory effects of KRG extract on the activity of cytochrome P450 (CYP). In the present study, we investigated the modulatory effect of KRG extract in vitro and in vivo by using pooled human liver microsomes and male ICR mice. When human liver microsomes were incubated with KRG extract at 0.01-10 mg/ml, CYP1A2, 2B6, 2C19, 2D6, and 3A were not significantly inhibited by KRG extract, although CYP2B6 was slightly inhibited. Mice were orally administered KRG extract at 50, 250, or 500 mg/kg daily for 3, 7, or 14 days. However, the activities of CYPs in mouse livers were not significantly different from those of vehicle-treated controls. In conclusion, no significant ginseng-drug interaction was observed. KRG extract did not significantly modulate the activities of CYPs in vitro or in vivo.

• 대한임상약리학회:학술대회논문집
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• 2001.12a
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• pp.50-50
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• 2001

• Proceedings of the Korean Society of Embryo Transfer Conference
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• 2006.10a
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• pp.74-75
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• 2006

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.3
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• pp.1145-1150
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• 2015

Associations of GSTT1, GSTM1 and CYP1A1 gene variants with risk of developing oral cancer were evaluated in this study. A case-control study was conducted in Pashtun population of Khyber Pakhtunkhwa province of Pakistan in which 200 hospital based oral cancer cases and 151 population based healthy controls exposed to similar environmental conditions were included. Sociodemographic data were obtained and blood samples were collected with informed consent for analysis. GSTM1 and GSTT1 were analysed through conventional PCR method while specific RT-PCR method was used to detect CYP1A1 polymorphisms. Results were analyzed for conditional logistic regression model by SPSS version 20. The study shows that patients with either GSTM1 or GSTT1 null genotypes have significantly higher risk of oral cancer (adjusted odds (OR): (3.019 (1.861-4.898) and 3.011(1.865-4.862), respectively), which further increased when either one or both null genes were present in combination (adjusted odds (OR): (3.627 (1.981-6.642 and 9.261 (4.495-19.079), respectively). CYP1A1 rs4646903 gene variants individually showed weak association OR: 1.121 (0.717-1.752); however, in the presence of GSTM1 and/or GSTT1 null genotypes further increasing the association (adjusted odds (ORs): 4.576 (2.038-10.273), 5.593 (2.530-12.362) and 16.10 (3.854-67.260 for GSTM/GSTT null and CYP1A1 wild type, GSTM/GSTT either null and CYP1A1 variant alleles, and all 3 gene polymorphisms combinations, respectively). Our findings suggest that presence of GSTM1 and/or GSTT1 null genotypes along with variant alleles of CYP1A1 may be the risk alleles for oral cancer susceptibility in Pashtun population.

• The Journal of Korean Medicine
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• v.42 no.4
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• pp.10-24
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• 2021

Objectives: Yongdamsagan-tang (YST) and Paljung-san (PJS) in traditional medicine and finasteride in modern medicine are used to treat benign prostatic hyperplasia (BPH). In recent, the use of combination herbal remedies with conventional drugs has been increasing. Therefore, we investigated the anti-inflammatory effects of these drugs to treat BPH and the influence of herbal formulas on finasteride metabolism. Methods: The inhibitory effects of the herbal formulas and finasteride on the production of inflammatory mediators and cytokines were determined in lipopolysaccharide (LPS)-treated RAW 264.7 cells. Additionally, the influence of herbal formulas on activities of human drug metabolizing enzymes (DMEs) was assessed using human microsomal enzymes. Results: We observed that YST, PJS and finasteride inhibited the production of nitric oxide (NO), prostaglandin E₂ (PGE₂) and interleukin-6 (IL-6) in RAW 264.7 cells. The half maximal inhibitory concentration (IC₅₀) of YST on PGE₂ production was calculated to be below 25 ㎍/mL. YST inhibited the activity of uridine diphosphate-glucuronosyltransterase (UGT) 1A4 with an IC₅₀ value of 49.35 ㎍/mL. The activities of cytochrome P450 (CYP) 1A2, CYP2B6, CYP2C19, CYP3A4, and UGT1A1 were inhibited by PJS (IC₅₀ < 100 ㎍/mL, each). Although PJS and YST inhibited the activities of CYP3A4 and UGT1A4, respectively, these formulas may not influence the metabolism of finasteride because the IC₅₀ values of herbal formulas on DMEs are too high to affect metabolism. Conclusions: Our results suggest that the combination of finasteride and YST or PJS might not influence their drug metabolism and that the drugs may have synergistic effects against BPH.