• Archives of Pharmacal Research
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• v.21 no.1
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• pp.35-40
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• 1998

Human cytochrome P450 4F2 shows high regioselectivity in hydroxylation of stearic acid and leukotriene $ B_4.$ As a first step of its regulation study, human cytochrome P450 4F2 genomic DNA was isolated from liver of a person who was administered clofibrate for 10 years. From Southern hybridization, restriction enzyme digestion and sequencing experiments, isolated genomic DNA fragment was found to contain around 32 Kb DNA and more than 20 Kb of $5^I$ end regulatory region. Sequences of the structural gene region revealed exon 1 and exon 2. Further regulation studies would elucidate the feedback mechanisms of the oxidative degradation of fatty acids, inflammatory response and the clearance of leukotriene B4 in the liver. Furthermore, regulation study of this gene could explain the species difference in responses to peroxisome proliferator and help in the safety evaluation of peroxisome proliferating chemicals to human being.

• Journal of Oral Medicine and Pain
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• v.20 no.2
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• pp.461-475
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• 1995

The purpose of this study was to investigate the effect of alcohol and stress on liver and buccal mucosa in guinea pig by immunological methods. Especially, Cytochrome P450 (CYP) which in oxidase during alcohol metabolism and bioactivator to carcinogen was used as an indicator in this study. 48 guinea pigs were used in this study. The experimental guinea pig were divided into three groups: The first was a group with giving alcohol-15%(v/v) ethyl alcohol, the second group was a with giving stress in the $0^{\circ}C$ water and the third was a control group. Every 4 guinea pigs of each group were sacrificed weekly-first, second, third, fourth week after experiment and extracted liver tissues and buccal mucosa. The liver tissues were observed by using immunoblotting technique (Western blot) and buccal mucosa were observed by immunofluorescence technique. The results were as follows: 1. By the alcohol and stress, Cytochrome P450 was amplified positive in the liver tissues at third week. 2. By the alcohol and stress, Cytochrome P450 was not detected in the buccal mucosa at any period.

• Mass Spectrometry Letters
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• v.8 no.4
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• pp.98-104
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• 2017

Ginseng (Panax ginseng Meyer) is a well-known health functional food used as a traditional herbal drug in Asian countries owing to its diverse pharmacological effects. Herb-drug interactions may cause unexpected side effects of co-administered drugs by the alteration of pharmacokinetics through effects on cytochrome P450 activity. In this study, we investigated the herb-drug interactions between Korean red ginseng extract (KRG) and five CYP-specific probes in mice. The pharmacokinetics of KRG extract induced-drug interactions were studied by cassette dosing of five CYP substrates for CYP1A, 2B, 2C, 2D, and 3A and the LC-MS/MS analysis of the blood concentration of metabolites of each of the five probes. The linearity, precision, and accuracy of the quantification method of the five metabolites were successfully confirmed. The plasma concentrations of five metabolites after co-administration of different doses of the KRG extract (0, 0.5, 1, and 2 g/kg) were quantified by LC-MS/MS and dose-dependent pharmacokinetic parameters were determined. The pharmacokinetic parameters of the five metabolites were not significantly altered by the dose of the KRG extract. In conclusion, the single co-administration of KRG extract up to 2 g/kg in vivo did not cause any significant herb-drug interactions linked to the modulation of CYP activity.

• Journal of Pharmaceutical Investigation
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• v.41 no.5
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• pp.301-307
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• 2011

The aim of this study was to investigate the effects of kaempferol on the pharmacokinetics of nimodipine in rats. Nimodipine and kaempferol interact with cytochrome P450 (CYP) enzymes and P-glycoprotein (P-gp), and the increase in the use of health supplements may result in kaempferol being taken concomitantly with nimodipine as a combination therapy to treat orprevent cardiovascular disease. The effect of kaempferol on P-gp and CYP3A4 activity was evaluated and Pharmacokinetic parameters of nimodipine were determined in rats after an oral (12 mg/kg) and intravenous (3 mg/kg) administration of nimodipine to rats in the presence and absence of kaempferol (0.5, 2.5, and 10 mg/kg). Kaempferol inhibited CYP3A4 enzyme activity in a concentration-dependent manner with 50% inhibition concentration ($IC_{50}$) of $17.1{\mu}M$. In addition, kaempferol significantly enhanced the cellular accumulation of rhodamine-123 in MCF-7/ADR cells overexpressing P-gp. Compared to the oral control group, the area under the plasma concentration-time curve ($AUC_{0-\infty}$) and the peak plasma concentration ($C_{max}$) of nimodipine significantly increased, respectively. Consequently, the absolute bioavailability of nimodipine in the presence of kaempferol (2.5 and 10 mg/kg) was 29.1-33.3%, which was significantly enhanced compared to the oral control group (22.3%). Moreover, the relative bioavailability of nimodipine was 1.30- to 1.49-fold greater than that of the control group. The pharmacokinetics of intravenous nimodipine was not affected by kaempferol in contrast to those of oral nimodipine. Kaempferol significantly enhanced the oral bioavailability of nimodipine, which might be mainly due to inhibition of the CYP3A4-mediated metabolism of nimodipine in the small intestine and /or in the liver and to inhibition of the P-gp efflux transporter in the small intestine by kaempferol. The increase in oral bioavailability of nimodipine in the presence of kaempferol should be taken into consideration of potential drug interactions between nimodipine and kaempferol.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.12
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• pp.4927-4935
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• 2015

Northeastern India is a major nasopharyngeal carcinoma (NPC) high risk-area although the rest of the country has very low incidence. A case-control study of 105 NPC cases and 115 controls was conducted to identify the potential risk factors for NPC development in this region. Information was collected by interviewer about socio-demographic characteristics, cigarette smoking, alcohol consumption, dietary history, occupational history, and a family history of cancer. Epstein-Barr viral load was assayed from the blood DNA by real time PCR. Associations between GSTs genotypes, cytochrome P450 family including CYP1A1, CYP2E1 and CYP2A6 polymorphisms and susceptibility to relationship between the diseases were studied using PCR-RFLP assay. Results indicate that Epstein-Barr virus load was significantly higher in patients compared to controls (p<0.0001). Furthermore, concentration of blood EBV-DNA was significantly higher in advanced stage disease (Stage III and IV) than in early stage disease (Stage I and II) (p<0.05). Presence of CYP2A6 variants that reduced the enzyme activity was significantly less frequent in cases than controls. Smoked meat consumption, exposure to smoke, living in poorly ventilated house and alcohol consumption were associated with NPC development among the population of Northeastern India. Thus, overall our study revealed that EBV viral load and genetic polymorphism of CYP2A6 along with living practices which include smoked meat consumption, exposure to smoke, living in poorly ventilated houses and alcohol consumption are the potential risk factors of NPC in north eastern region of India. Understanding of the risk factors and their role in the etiology of NPC are helpful forpreventive measures and screening.

• Journal of Preventive Medicine and Public Health
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• v.37 no.4
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• pp.321-328
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• 2004

Objectives : The purpose of this study was to investigate the effect of genetic polymorphism of cytochrome P450 2E1 (CYP2E1) and aldehyde dehydrogenase 2 (ALDH2) on the xylene metabolism. Methods : Among 247 workers, 116 were occupationally exposed to xylene and 131 were not. Workers exposed to xylene had different work such as spray, touch-up, mix & assist, and pre-treat. Questionnaire variables were age, sex, use of personal protective equipment, smoking, previous night's drinking and work duration. The urinary methylhippuric acid was measured in the urine collected in the afternoon and corrected by urinary creatinine concentration. The genotypes of CYP2E1 and ALDH2 were investigated by using PCR-RFLP (polymerase chain reaction-restriction fragment length polymorphism) methods with DNA extracted from venous blood. Results : 1. The urinary concentrations of o-, m-, and p-methylhippuric acid and total methylhippuric acid in the exposed group were significantly higher than those in the non-exposed group (p<0.001). 2. In multiple regression analysis, the urinary methylhippuric acid concentration was significantly influenced by exposure grade (Job-exposure matrixes), smoking, drug use and kind of protective equipment (p<0.1). 3. Genetic polymorphism of CYP2E1 and ALDH2 did not affect urinary methylhippuric acid level in the exposed group (p>0.05). Conclusions : Exposure grade, smoking, drug use and kind of protective equipment affected urinary methylhippuric acid level, whereas genetic polymorphism of CYP2E1 and ALDH2 did not. However, further investigation for the effect of genetic polymorphism on the metabolism of xylene with a larger sample size is needed.

• Korean Journal of Clinical Pharmacy
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• v.23 no.3
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• pp.206-212
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• 2013

Purpose: The aim of this study was to investigate the effect of nimodipine on the pharmacokinetics of warfarin after oral and intravenous administration of warfarin in rats. Methods: Warfarin was administered orally (0.2 mg/kg) or intravenously (0.05 mg/kg) without or with oral administration of nimodipine (0.5 or 2 mg/kg) in rats. The effect of nimodipine on the P-glycoprotein as well as cytochrome P450 (CYP) 3A4 activity was also evaluated. Results: Nimodipine inhibited CYP3A4 enzyme activity with 50% inhibition concentration ($IC_{50}$) of $10.2{\mu}M$. Compared to those animals in the oral control group (warfarin without nimodipine), the area under the plasma concentration-time curve (AUC) of warfarin was significantly greater (0.5 mg/kg, P<0.05; 2 mg/kg, P<0.01) by 31.3-57.6%, and the peak plasma concentration ($C_{max}$) was significantly higher (2 mg/kg, P<0.05) by 29.4% after oral administration of warfarin with nimodipine, respectively. Consequently, the relative bioavailability of warfarin increased by 1.31- to 1.58-fold and the absolute bioavailability of warfarin with nimodipine was significantly greater by 64.1-76.9% compared to that in the control group (48.7%). In contrast, nimodipine had no effect on any pharmacokinetic parameters of warfarin given intravenously. Conclusion: Therefore, the enhanced oral bioavailability of warfarin may be due to inhibition of CYP 3A4-mediated metabolism rather than P-glycoprotein-mediated efflux by nimodipine.

• Archives of Pharmacal Research
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• v.29 no.7
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• pp.570-576
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• 2006

Phytoestrogen biochanin A is an isoflavone derivative isolated from red clover Trifolium pratense with anticarcinogenic properties. This study examined the action of biochanin A with the carcinogen activation pathway that is mediated by the aryl hydrocarbon receptor (AhR) in MCF-7 breast carcinoma cells. Treating the cells with biochanin A alone caused the accumulation of CYP1A1 mRNA and an increase in CYP1A1-specific 7-ethoxyresorufin O-deethylase (EROD) activity in a dose dependent manner. A concomitant treatment with 7,12-dimethylbenz[a]anthracene (DMBA) and biochanin A markedly reduced the DMBA-inducible EROD activity and CYP1A1 mRNA level. In addition, the biochanin A treatment alone activated the DNA-binding capacity of the AhR for the dioxin-response element (DRE) of CYP1A1, as measured by the electrophoretic-mobility shift assay (EMSA). EMSA revealed that biochanin A reduced the level of the DMBA-inducible AhR-DRE binding complex. Furthermore, biochanin A competed with the prototypical AhR ligand, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), for binding to the AhR in an isolated rat cytosol. The biochanin A competitively inhibited the metabolic activation of DMBA, as measured by the formation of the DMBA-DNA adducts. These results suggest that biochanin A may thus be a natural ligand to bind on AhR. Therefore, biochanin A may be due to act an antagonist/agonist of the AhR pathway.

• 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.

• Biomolecules & Therapeutics
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• v.32 no.5
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• pp.601-610
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• 2024

Tofacitinib, a Janus kinase (JAK) inhibitor used to treat rheumatoid arthritis, is metabolized through hepatic cytochrome P450 (CYP), specifically CYP3A1/2 and CYP2C11. Prolonged administration of rheumatoid arthritis medications is generally associated with an increased risk of renal toxicity. Loganin (LGN), an iridoid glycoside, has hepatorenal regenerative properties. This study investigates the potential of LGN to mitigate acute kidney injury (AKI) and its effects on the pharmacokinetics of tofacitinib in rats with cisplatin-induced AKI. Both intravenous and oral administration of tofacitinib to AKI rats significantly increased the area under the plasma concentration-time curve from time 0 to infinity (AUC) compared with control (CON) rats, an increase attributed to the decelerated non-renal clearance (CL_NR) and renal clearance (CL_R) of tofacitinib. Administration of LGN to AKI rats, however, protected kidneys from severe impairment, restoring the pharmacokinetic parameters (AUC, CL_NR, and CL_R) of tofacitinib to those observed in untreated CON rats, with partial recovery of kidney function, as evidenced by an increase in creatinine clearance. Possible interactions between drugs and natural components should be considered, especially when co-administering both a drug and a natural extract containing LGN or iridoid glycosides to patients with kidney injury.