scholarly journals Inhibition and Induction by Poziotinib of Different Rat Cytochrome P450 Enzymes In Vivo and in an In Vitro Cocktail Method

2021 ◽  
Vol 11 ◽  
Author(s):  
Jinhui Wang ◽  
Feifei Chen ◽  
Hui Jiang ◽  
Jia Xu ◽  
Deru Meng ◽  
...  
Keyword(s):  
Cytochrome P450 ◽  
Rat Liver ◽  
Clinical Investigation ◽  
Liver Microsomes ◽  
Pharmacokinetic Parameters ◽  
Rat Liver Microsomes ◽  
Cytochrome P450 Enzymes ◽  
Significant Difference

Poziotinib is an orally active, irreversible, pan-HER tyrosine kinase inhibitor used to treat non-small cell lung cancer, breast cancer, and gastric cancer. Poziotinib is currently under clinical investigation, and understanding its drug-drug interactions is extremely important for its future development and clinical application. The cocktail method is most suitable for evaluating the activity of cytochrome P450 enzymes (CYPs). As poziotinib is partially metabolized by CYPs, cocktail probes are used to study the interaction between drugs metabolized by each CYP subtype. Midazolam, bupropion, dextromethorphan, tolbutamide, chlorzoxazone, phenacetin, and their metabolites were used to examine the effects of poziotinib on the activity of cyp1a2, 2b1, 2d1, 2c11, 2e1, and 3a1/2, respectively. The in vitro experiment was carried out by using rat liver microsomes (RLMs), whereas the in vivo experiment involved the comparison of the pharmacokinetic parameters of the probes after co-administration with poziotinib to rats to those of control rats treated with only probes. UPLC-MS/MS was used to detect the probes and their metabolites in rat plasma and rat liver microsomes. The in vitro results revealed that the half-maximal inhibitory concentration values of bupropion and tolbutamide in RLMs were 8.79 and 20.17 μM, respectively, indicating that poziotinib showed varying degrees of inhibition toward cyp2b1 and cyp2c11. Poziotinib was a competitive inhibitor of cyp2b1 and cyp2c11, with Ki values of 16.18 and 17.66 μM, respectively. No time- or concentration-dependence of inhibition by poziotinib was observed toward cyp2b1 and cyp2c11 in RLMs. Additionally, no obvious inhibitory effects were observed on the activity of cyp1a2, cyp2d1, cyp2e1, and cyp3a1/2. In vivo analysis revealed that bupropion, tolbutamide, phenacetin, and chlorzoxazone showed significantly different pharmacokinetic parameters after administration (p < 0.05); there was no significant difference in the pharmacokinetic parameters of dextromethorphan and midazolam. These results show that poziotinib inhibited cyp2b1 and cyp2c11, but induced cyp1a2 and cyp2e1 in rats. Thus, poziotinib inhibited cyp2b1 and cyp2c11 activity in rats, suggesting the possibility of interactions between poziotinib and these CYP substrates and the need for caution when combining them in clinical settings.

Biopharmaceutical and pharmacokinetic activities of oxymatrine determined by a sensitive UHPLC-MS/MS method

2021 ◽  
Vol 22 ◽  
Author(s):  
Hai-Qiao Wang ◽  
Feng-Hua Chen ◽  
Liang Wang ◽  
Li-Qun Chi ◽  
Guang-Hua Wang
Keyword(s):  
Rat Liver ◽  
Liver Microsomes ◽  
Passive Diffusion ◽  
Pharmacokinetic Parameters ◽  
Rat Liver Microsomes ◽  
Absorption Model ◽  
Absolute Oral Bioavailability ◽  
Rat Liver Microsome

Background: Oxymatrine is one of the most promising alkaloids from Sophora flavescens for its excellent pharmacological effects. Objective: The aim of this research is to assess the biopharmaceutical and pharmacokinetic activities of oxymatrine, and clarify its mechanisms of absorption and metabolism. Methods: The biological characteristics of oxymatrine were systematically investigated by UHPLC-MS/MS. The mechanisms of absorption and metabolism of oxymatrine were further clarified through incubation in rat liver microsomes and transport across Caco-2 monolayer cell absorption model. Results: It was found that the absolute oral bioavailability of oxymatrine was 26.43% and the pharmacokinetic parameters Cmax, Tmax, and t1/2 were 605.5 ng/mL, 0.75 h, and 4.181 h after oral administration, indicating that oxymatrine can be absorbed quickly. The tissue distribution tests showed that oxymatrine distributed throughout all the organs, with the small intestine accumulating the highest level followed by kidney, stomach and spleen. The Papp in Caco-2 cell line absorption model was over 1 × 10-5 and PDR 1.064, t1/2 of oxymatrine in rat liver microsome in vitro was 1.042 h, indicating that oxymatrine can be absorbed easily through passive diffusion and CYP450 enzymes could be involved in its metabolism. The plasma protein binding rate of oxymatrine was 2.78 ± 0.85%. Conclusion: Oxymatrine can be absorbed into blood easily through passive diffusion, mainly distributed in the intestine, stomach, liver and spleen in vivo, and CYP450 enzymes in liver could be involved in its metabolism.

Inhibitory effects of the medicinal herb, Thonningia san gunea, on liver drug metabolizing enzymes of rats

2000 ◽  
Vol 19 (11) ◽  
pp. 623-631 ◽  
Author(s):  
M A Gyamfi ◽  
N Hokama ◽  
K Oppong-Boachie ◽  
Y Aniya
Keyword(s):  
Rat Liver ◽  
Liver Microsomes ◽  
Rat Liver Microsomes ◽  
Glutathione S Transferase ◽  
P450 Monooxygenase ◽  
Significant Difference ◽  
Cytosolic Glutathione ◽  
Thonningia Sanguinea

In this study we examined the effect of the aqueous extract of Thonningia sanguinea (T.S.) on 7-ethoxyresorufin 0- deethylase (EROD, CYPlAl), 7-pentoxyresorufin-dealkylase (PROD, CYP2B1/2), 7-methoxyresorufin 0- demethylase (MROD, CYP1A2), aniline hydroxylase (aniline, CYP2E1), p-nitrophenol hydroxylase (PNPH, CYP2E1) and erythromycin N-demethylase (ERDM, CYP3A1) in rat liver in vitro and in vivo. Although T.S. extract increased ERDM activity in induced rat liver microsomes, it showed a dose-dependent inhibitory effectin vitro on other P450 monooxygenase activities particularly EROD and PROD, which are mediated primarily by CYPlAl and CYP2B1/2, respectively. PROD, EROD and MROD activities were also decreased by 18%, 19% and 40%, respectively, in hepatic microsomes prepared from rats treated with T.S. extract for 3 days. Kinetic analysis of CYP activity of 3-methylchloranthrene-induced microsomes demonstrated that T.S. inhibited EROD and MROD activities by a noncompetitive and competitive mechanism, respectively. The analysis of alterations produced by T.S. on PROD kinetic parameters in phenobarbital-induced microsomes suggested that the inhibition is noncompetitive. Pretreatment of rats with T.S. prolonged pentobarbital and phenobarbital sleeping time; however, plasma phenobarbital concentration determined on awakening showed no significant difference between control and T.S.-treated rats. T.S. was also found to be a potent inhibitor of the liver cytosolic glutathione S-transferase. These data suggest that selective modulation of CYP isoenzymes by T.S. might con-tribute to protection of the liver from xenobiotic-induced intoxication or to alteration of the action of drug (s) conco-mitantly administered besides its antioxidative properties.

In Vitro Metabolism of E2, G2: Novel Bile Acid-Coupling Camptothecin Analogues, in Rat Liver Microsomes

2021 ◽  
Vol 16 ◽  
Author(s):  
Xiangli Zhang ◽  
Qin Shen ◽  
Yi Wang ◽  
Leilei Zhou ◽  
Qi Weng ◽  
...  
Keyword(s):  
Bile Acid ◽  
Phase I ◽  
Rat Liver ◽  
Deoxycholic Acid ◽  
Liver Microsomes ◽  
Intrinsic Clearance ◽  
Rat Liver Microsomes ◽  
Camptothecin Analogues

Background: E2 (Camptothecin - 20 (S) - O- glycine - deoxycholic acid), and G2 (Camptothecin - 20 (S) - O - acetate - deoxycholic acid) are two novel bile acid-derived camptothecin analogues by introducing deoxycholic acid in 20-position of CPT(camptothecin) with greater anticancer activity and lower systematic toxicity in vivo. Objective: We aimed to investigate the metabolism of E2 and G2 by Rat Liver Microsomes (RLM). Methods: Phase Ⅰ and Phase Ⅱ metabolism of E2 and G2 in rat liver microsomes were performed respectively, and the mixed incubation of phase I and phase Ⅱ metabolism of E2 and G2 was also processed. Metabolites were identified by liquid chromatographic/mass spectrometry. Results: The results showed that phase I metabolism was the major biotransformation route for both E2 and G2. The isoenzyme involved in their metabolism had some difference. The intrinsic clearance of G2 was 174.7mL/min. mg protein, more than three times of that of E2 (51.3 mL/min . mg protein), indicating a greater metabolism stability of E2. 10 metabolites of E2 and 14 metabolites of G2 were detected, including phase I metabolites (mainly via hydroxylations and hydrolysis) and their further glucuronidation products. Conclusion: These findings suggested that E2 and G2 have similar biotransformation pathways except some difference in the hydrolysis ability of the ester bond and amino bond from the parent compounds, which may result in the diversity of their metabolism stability and responsible CYPs(Cytochrome P450 proteins).

scholarly journals Enzymatic activity in turkey, duck, quail and chicken liver microsomes against four human cytochrome P450 prototype substrates and aflatoxin B1

2011 ◽  
Vol 1 (1) ◽  
pp. 4 ◽  
Author(s):  
Hansen W. Murcia ◽  
Gonzalo J. Díaz ◽  
Sandra Milena Cepeda
Keyword(s):  
Cytochrome P450 ◽  
Aflatoxin B1 ◽  
Enzyme Activities ◽  
High Performance ◽  
Biochemical Characterization ◽  
Liver Microsomes ◽  
Cytochrome P450 Enzymes ◽  
Catalytic Rate

Cytochrome P450 enzymes (CYP) are a group of monooxygenases able to biotransform several kinds of xenobiotics including aflatoxin B1 (AFB1), a highly toxic mycotoxin. These enzymes have been widely studied in humans and others mammals, but there is not enough information in commercial poultry species about their biochemical characteristics or substrate specificity. The aim of the present study was to identify CYPs from avian liver microsomes with the use of prototype substrates specific for human CYP enzymes and AFB1. Biochemical characterization was carried out in vitro and biotransformation products were detected by high-performance liquid chromatography (HPLC). Enzymatic constants were calculated and comparisons between turkey, duck, quail and chicken activities were done. The results demonstrate the presence of four avian ortholog enzyme activities possibly related with a CYP1A1, CYP1A2, CYP2A6 (activity not previously identified) and CYP3A4 poultry orthologs, respectively. Large differences in enzyme kinetics specific for prototype substrates were found among the poultry species studied. Turkey liver microsomes had the highest affinity and catalytic rate for AFB1 whereas chicken enzymes had the lowest affinity and catalytic rate for the same substrate. Quail and duck microsomes showed intermediate values. These results correlate well with the known in vivo sensitivity for AFB1 except for the duck. A high correlation coefficient between 7-ethoxyresorufin-Odeethylase (EROD) and 7-methoxyresorufin- O-deethylase (MROD) activities was found in the four poultry species, suggesting that these two enzymatic activities might be carried out by the same enzyme. The results of the present study indicate that four prototype enzyme activities are present in poultry liver microsomes, possibly related with the presence of three CYP avian orthologs. More studies are needed in order to further characterize these enzymes.

Inhibitory Effect of Resveratrol on the Pharmacokinetics of Ticagrelor in Vivo and Vitro

2021 ◽  
Author(s):  
Peng Wang ◽  
Xiao-Xia Hu ◽  
Ying-hui Li ◽  
Nan-Yong Gao ◽  
Guo-quan Chen ◽  
...  
Keyword(s):  
Rat Liver ◽  
Liver Microsomes ◽  
In Vitro Study ◽  
Inhibitory Effect ◽  
Control Group ◽  
Rat Liver Microsomes ◽  
Sprague Dawley ◽  
Group B

This study was to evaluate the effect of resveratrol on the pharmacokinetics of ticagrelor in rats and the metabolism of ticagrelor in human CYP3A4 and liver microsomes. Eighteen Sprague-Dawley rats were randomly divided into three groups: group A (control group), group B (50mg/kg resveratrol), and group C (150mg/kg resveratrol ). After 30 minutes administration of resveratrol, a single dose of ticagrelor (18mg/kg) was administered orally. The vitro experiment was performed to examine the influence of resveratrol on ticagrelor metabolism in CYP3A4*1, human, and rat liver microsomes. Serial biological samples were assayed by validated UHPLC-MS/MS methods. In vivo study, the AUC and Cmax of ticagrelor in group B and C appeared to be significantly higher than the control group, while Vz/F and CLz/F of ticagrelor in group B and C were significantly decreased. In vitro study, resveratrol exhibited an inhibitory effect on CYP3A4*1, human and rat liver microsomes. The IC50 values of resveratrol were 56.75μM，69.07μM and 14.22μM, respectively. Our results indicated that resveratrol had a inhibitory effect on the metabolism of ticagrelor in vitro and vivo. It should be paid more attention to the clinical combination of resveratrol with ticagrelor and ticagrelor plasma concentration should be monitored to avoid the occurrence of adverse reaction.

scholarly journals Assessment of inhibitory effects on major human cytochrome P450 enzymes by spasmolytics used in the treatment of overactive bladder syndrome

2017 ◽  
Vol 9 (7) ◽  
pp. 163-177
Author(s):  
Dominik Dahlinger ◽  
Sevinc Aslan ◽  
Markus Pietsch ◽  
Sebastian Frechen ◽  
Uwe Fuhr
Keyword(s):  
Cytochrome P450 ◽  
Liver Microsomes ◽  
Fold Increase ◽  
Pharmacokinetic Data ◽  
Cytochrome P450 Enzymes ◽  
Trospium Chloride ◽  
Screening Experiments ◽  
Human Cytochrome

Background: The objective of this study was to examine the inhibitory potential of darifenacin, fesoterodine, oxybutynin, propiverine, solifenacin, tolterodine and trospium chloride on the seven major human cytochrome P450 enzymes (CYP) by using a standardized and validated seven-in-one cytochrome P450 cocktail inhibition assay. Methods: An in vitro cocktail of seven highly selective probe substrates was incubated with human liver microsomes and varying concentrations of the seven test compounds. The major metabolites of the probe substrates were simultaneously analysed using a validated liquid chromatography tandem mass spectrometry (LC-MS/MS) method. Enzyme kinetics were estimated by determining IC50 and Ki values via nonlinear regression. Obtained Ki values were used for predictions of potential clinical impact of the inhibition using a static mechanistic prediction model. Results: In this study, 49 IC50 experiments were conducted. In six cases, IC50 values lower than the calculated threshold for drug–drug interactions (DDIs) in the gut wall were observed. In these cases, no increase in inhibition was determined after a 30 min preincubation. Considering a typical dosing regimen and applying the obtained Ki values of 0.72 µM (darifenacin, 15 mg daily) and 7.2 µM [propiverine, 30 mg daily, immediate release (IR)] for the inhibition of CYP2D6 yielded a predicted 1.9-fold and 1.4-fold increase in the area under the curve (AUC) of debrisoquine (CYP2D6 substrate), respectively. Due to the inhibition of the particular intestinal CYP3A4, the obtained Ki values of 14 µM of propiverine (30 mg daily, IR) resulted in a predicted doubling of the AUC for midazolam (CYP3A4 substrate). Conclusions: In vitro/ in vivo extrapolation based on pharmacokinetic data and the conducted screening experiments yielded similar effects of darifenacin on CYP2D6 and propiverine on CYP3A4 as obtained in separately conducted in vivo DDI studies. As a novel finding, propiverine was identified to potentially inhibit CYP2D6 at clinically occurring concentrations.

scholarly journals Prediction of cytochrome P450-mediated drug clearance in humans based on the measured activities of selected CYPs

2017 ◽  
Vol 37 (6) ◽  
Author(s):  
Jie Gao ◽  
Jie Wang ◽  
Na Gao ◽  
Xin Tian ◽  
Jun Zhou ◽  
...  
Keyword(s):  
Cytochrome P450 ◽  
Liver Microsomes ◽  
Normal Liver ◽  
Drug Clearance ◽  
Cytochrome P450 Enzymes ◽  
Simple Method ◽  
Drug Metabolizing Enzyme ◽  
Descriptive Models

Determining drug-metabolizing enzyme activities on an individual basis is an important component of personalized medicine, and cytochrome P450 enzymes (CYPs) play a principal role in hepatic drug metabolism. Herein, a simple method for predicting the major CYP-mediated drug clearance in vitro and in vivo is presented. Ten CYP-mediated drug metabolic activities in human liver microsomes (HLMs) from 105 normal liver samples were determined. The descriptive models for predicting the activities of these CYPs in HLMs were developed solely on the basis of the measured activities of a smaller number of more readily assayed CYPs. The descriptive models then were combined with the Conventional Bias Corrected in vitro–in vivo extrapolation method to extrapolate drug clearance in vivo. The Vmax, Km, and CLint of six CYPs (CYP2A6, 2C8, 2D6, 2E1, and 3A4/5) could be predicted by measuring the activities of four CYPs (CYP1A2, 2B6, 2C9, and 2C19) in HLMs. Based on the predicted CLint, the values of CYP2A6-, 2C8-, 2D6-, 2E1-, and 3A4/5-mediated drug clearance in vivo were extrapolated and found that the values for all five drugs were close to the observed clearance in vivo. The percentage of extrapolated values of clearance in vivo which fell within 2-fold of the observed clearance ranged from 75.2% to 98.1%. These findings suggest that measuring the activity of CYP1A2, 2B6, 2C9, and 2C19 allowed us to accurately predict CYP2A6-, 2C8-, 2D6-, 2E1-, and 3A4/5-mediated activities in vitro and in vivo and may possibly be helpful for the assessment of an individual’s drug metabolic profile.

Inhibitory effect of silybin on pharmacokinetics of imatinib in vivo and in vitro

2014 ◽  
Vol 92 (11) ◽  
pp. 961-964 ◽  
Author(s):  
Li Wang ◽  
Zhe Wang ◽  
Meng-ming Xia ◽  
Ying-ying Wang ◽  
Hai-yun Wang ◽  
...  
Keyword(s):  
Single Dose ◽  
Rat Liver ◽  
Liver Microsome ◽  
Liver Microsomes ◽  
Inhibitory Effect ◽  
Pharmacokinetic Parameters ◽  
Control Group ◽  
Rat Liver Microsomes ◽  
Multiple Doses

The objective of this work was to investigate the effect of orally administered silybin on the pharmacokinetics of imatinib in rats and the metabolism of imatinib in human liver microsome and rat liver microsomes. Eighteen healthy male SD rats were randomly divided into 3 groups: group A (control group), group B (received multiple doses of 50 mg·kg−1 silybin for 15 consecutive days), and group C (received a single dose of 50 mg·kg−1 silybin). A single dose of imatinib was administered orally 30 min after administration of silybin (50 mg·kg−1). Imatinib plasma levels were measured by UPLC-MS/MS, and pharmacokinetic parameters were calculated by DAS 3.0 software (Bontz Inc., Beijing, China). In addition, human and rat liver microsome were performed to determine the effects of silybin metabolism of imatinib in vitro. The multiple doses or single dose of 50 mg·kg−1 silybin significantly decreased the area under the curve (0-t) of imatinib (p < 0.01). And the half-life (t1/2) of imatinib is significantly increased (p < 0.05 and p < 0.01, respectively). Also, silybin showed inhibitory effect on human and rat microsomes, the IC50 of silybin were 26.42 μmol·L−1 and 49.12 μmol·L−1 in human and rat liver microsomes, respectively. These results indicate that more attention should be paid to when imatinib is administrated combined with silybin.

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