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Frontiers in Pharmacology 2023Pharmacogenetics-informed drug prescribing is increasingly applied in clinical practice. Typically, drug metabolizing phenotypes are determined based on genetic test...
Pharmacogenetics-informed drug prescribing is increasingly applied in clinical practice. Typically, drug metabolizing phenotypes are determined based on genetic test results, whereupon dosage or drugs are adjusted. Drug-drug-interactions (DDIs) caused by concomitant medication can however cause mismatches between predicted and observed phenotypes (phenoconversion). Here we investigated the impact of genotype on the outcome of CYP2C19-dependent DDIs in human liver microsomes. Liver samples from 40 patients were included, and genotyped for *2, *3 and *17 variants. S-mephenytoin metabolism in microsomal fractions was used as proxy for CYP2C19 activity, and concordance between genotype-predicted and observed CYP2C19 phenotype was examined. Individual microsomes were subsequently co-exposed to fluvoxamine, voriconazole, omeprazole or pantoprazole to simulate DDIs. Maximal CYP2C19 activity (V) in genotype-predicted intermediate metabolizers (IMs; *1/*2 or *2/*17), rapid metabolizers (RMs; *1/*17) and ultrarapid metabolizers (UMs; *17/*17) was not different from V of predicted normal metabolizers (NMs; *1/*1). Conversely, *2/*2 genotyped-donors exhibited V rates ∼9% of NMs, confirming the genotype-predicted poor metabolizer (PM) phenotype. Categorizing CYP2C19 activity, we found a 40% concordance between genetically-predicted CYP2C19 phenotypes and measured phenotypes, indicating substantial phenoconversion. Eight patients (20%) exhibited CYP2C19 IM/PM phenotypes that were not predicted by their CYP2C19 genotype, of which six could be linked to the presence of diabetes or liver disease. In subsequent DDI experiments, CYP2C19 activity was inhibited by omeprazole (-37% ± 8%), voriconazole (-59% ± 4%) and fluvoxamine (-85% ± 2%), but not by pantoprazole (-2 ± 4%). The strength of CYP2C19 inhibitors remained unaffected by genotype, as similar percental declines in CYP2C19 activity and comparable metabolism-dependent inhibitory constants (K/K) of omeprazole were observed between CYP2C19 genotypes. However, the consequences of CYP2C19 inhibitor-mediated phenoconversion were different between genotypes. In example, voriconazole converted 50% of *1/*1 donors to a IM/PM phenotype, but only 14% of *1/*17 donors. Fluvoxamine converted all donors to phenotypic IMs/PMs, but *1/*17 (14%) were less likely to become PMs than *1/*1 (50%) or *1/*2 and *2/*17 (57%). This study suggests that the differential outcome of CYP2C19-mediated DDIs between genotypes are primarily dictated by basal CYP2C19 activity, that may in part be predicted by genotype but likely also depends on disease-related factors.
PubMed: 37361233
DOI: 10.3389/fphar.2023.1201906 -
Scientific Reports Feb 2022Human CYP2B6 enzyme although constitutes relatively low proportion (1-4%) of hepatic cytochrome P450 content, it is the major catalyst of metabolism of several...
Human CYP2B6 enzyme although constitutes relatively low proportion (1-4%) of hepatic cytochrome P450 content, it is the major catalyst of metabolism of several clinically important drugs (efavirenz, cyclophosphamide, bupropion, methadone). High interindividual variability in CYP2B6 function, contributing to impaired drug-response and/or adverse reactions, is partly elucidated by genetic polymorphisms, whereas non-genetic factors can significantly modify the CYP2B6 phenotype. The influence of genetic and phenoconverting non-genetic factors on CYP2B6-selective activity and CYP2B6 expression was investigated in liver tissues from Caucasian subjects (N = 119). Strong association was observed between hepatic S-mephenytoin N-demethylase activity and CYP2B6 mRNA expression (P < 0.0001). In less than one third of the tissue donors, the CYP2B6 phenotype characterized by S-mephenytoin N-demethylase activity and/or CYP2B6 expression was concordant with CYP2B6 genotype, whereas in more than 35% of the subjects, an altered CYP2B6 phenotype was attributed to phenoconverting non-genetic factors (to CYP2B6-specific inhibitors and inducers, non-specific amoxicillin + clavulanic acid treatment and chronic alcohol consumption, but not to the gender). Furthermore, CYP2B6 genotype-phenotype mismatch still existed in one third of tissue donors. In conclusion, identifying potential sources of CYP2B6 variability and considering both genetic variations and non-genetic factors is a pressing requirement for appropriate elucidation of CYP2B6 genotype-phenotype mismatch.
Topics: Alleles; Cytochrome P-450 CYP2B6; Gene Expression; Genotype; Humans; Liver; Phenotype; Polymorphism, Genetic; RNA, Messenger; White People
PubMed: 35194103
DOI: 10.1038/s41598-022-07022-9 -
Toxins Jul 2022Beauvericin (BEA) is a well-known mycotoxin produced by many fungi, including Beaveria bassiana. The purpose of this study was to evaluate the in vitro distribution and...
Beauvericin (BEA) is a well-known mycotoxin produced by many fungi, including Beaveria bassiana. The purpose of this study was to evaluate the in vitro distribution and metabolism characteristics as well as the in vivo pharmacokinetic (PK) profile of BEA. The in vitro metabolism studies of BEA were performed using rat, dog, mouse, monkey and human liver microsomes, cryopreserved hepatocytes and plasma under conditions of linear kinetics to estimate the respective elimination rates. Additionally, LC-UV-MSn (n = 1~2) was used to identify metabolites in human, rat, mouse, dog and monkey liver microsomes. Furthermore, cytochrome P450 (CYP) reaction phenotyping was carried out. Finally, the absolute bioavailability of BEA was evaluated by intravenous and oral administration in rats. BEA was metabolically stable in the liver microsomes and hepatocytes of humans and rats; however, it was a strong inhibitor of midazolam 1′-hydroxylase (CYP3A4) and mephenytoin 4′-hydroxylase (CYP2C19) activities in human liver microsomes. The protein binding fraction values of BEA were >90% and the half-life (T1/2) values of BEA were approximately 5 h in the plasma of the five species. The absolute bioavailability was calculated to be 29.5%. Altogether, these data indicate that BEA has great potential for further development as a drug candidate. Metabolic studies of different species can provide important reference values for further safety evaluation.
Topics: Animals; Biological Availability; Cytochrome P-450 Enzyme System; Depsipeptides; Dogs; Humans; Mice; Microsomes, Liver; Pharmaceutical Preparations; Rats
PubMed: 35878215
DOI: 10.3390/toxins14070477 -
Frontiers in Pharmacology 2023Vortioxetine is a novel anti-major depression disorder drug with a high safety profile compared with other similar drugs. However, little research has been done on...
Vortioxetine is a novel anti-major depression disorder drug with a high safety profile compared with other similar drugs. However, little research has been done on drug-drug interactions (DDI) about vortioxetine. In this paper, the inhibitory effect of vortioxetine on cytochrome P450 (CYP450) and the type of inhibitory mechanism were investigated in human and rat liver microsomes. We set up an incubation system of 200 μL to measure the metabolism of probe substrates at the present of vortioxetine at 37°C. The concentrations of the metabolites of probe substrates were all measured by ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method. It was found no time-dependent inhibition (TDI) of vortioxetine through determination of half-maximal inhibitory concentration (IC) shift values. The enzymes and metabolites involved in this experiment in human and rats were as follows: CYP3A4/CYP3A (midazolam); CYP2B6/CYP2B (bupropion); CYP2D6/CYP2D (dextromethorphan); CYP2C8/CYP2C-1 (amodiaquine); CYP2C9/CYP2C-2 (losartan); and CYP2C19/CYP2C-3 (mephenytoin). We found that vortioxetine competitively inhibited CYP2C19 and CYP2D6 in human liver microsomes (HLMs) with inhibition constant (K) values of 2.17 μM and 9.37 μM, respectively. It was noncompetitive inhibition for CYP3A4 and CYP2C8, and its K values were 7.26 μM and 6.96 μM, respectively. For CYP2B6 and CYP2C9, vortioxetine exhibited the mixed inhibition with K values were 8.55 μM and 4.17 μM, respectively. In RLMs, the type of vortioxetine inhibition was uncompetitive for CYP3A and CYP2D (K = 4.41 and 100.9 μM). The inhibition type was competitive inhibition, including CYP2B and CYP2C-2 (K = 2.87 and 0.12 μM). The inhibition types of CYP2C-1 and CYP2C-3 (K = 39.91 and 4.23 μM) were mixed inhibition and noncompetitive inhibition, respectively. The study of the above mechanism will provide guidance for the safe clinical use of vortioxetine so that the occurrence of DDI can be avoided.
PubMed: 37790811
DOI: 10.3389/fphar.2023.1199548 -
Basic & Clinical Pharmacology &... May 2020There is evidence that the antipsychotic drug perazine is an inhibitor of CYP2D6. This study aimed at evaluating its effect on CYP2D6 and CYP2C19 activities in...
There is evidence that the antipsychotic drug perazine is an inhibitor of CYP2D6. This study aimed at evaluating its effect on CYP2D6 and CYP2C19 activities in submitting psychiatric patients to phenotyping with dextromethorphan and mephenytoin, respectively, substrates of these enzymes, before and during a treatment with perazine. A total of 31 patients were phenotyped with dextromethorphan (CYP2D6) and mephenytoin (CYP2C19) before and after a 2-week treatment with 450 ± 51 mg/day (mean ± sd) perazine. At baseline, five patients appeared to be poor metabolizers (PM) of dextromethorphan and two patients of mephenytoin. The metabolic ratio (MR) of dextromethorphan/dextrorphan as determined in collected urine increased significantly (Wilcoxon; P < .0001) from baseline (0.39 ± 1.38 [mean ± sd]) till day 14 (1.46 ± 2.22). In 19 out of 26 extensive metabolizers (EM) of dextromethorphan, the phenotype changed from EM to PM. This suggests an almost complete inhibition of CYP2D6 by perazine and/or its metabolites. On the other hand, perazine (or some of its metabolites) did seemingly not inhibit CYP2C19. In conclusion, this study suggests that in patients treated with perazine and co-medicated with CYP2D6 substrates, there could be an increased risk of adverse effects as a consequence of a pharmacokinetic interaction.
Topics: Adult; Antipsychotic Agents; Cytochrome P-450 CYP2C19; Cytochrome P-450 CYP2D6; Cytochrome P-450 CYP2D6 Inhibitors; Dextromethorphan; Drug Interactions; Female; Humans; Male; Mephenytoin; Middle Aged; Perazine; Phenotype; Schizophrenia; Young Adult
PubMed: 31814297
DOI: 10.1111/bcpt.13373 -
Toxins Mar 2017Developing drugs to treat the toxic effects of lethal toxin (LT) and edema toxin (ET) produced by is of global interest We utilized a computational approach to score...
Developing drugs to treat the toxic effects of lethal toxin (LT) and edema toxin (ET) produced by is of global interest We utilized a computational approach to score 474 drugs/compounds for their ability to reverse the toxic effects of anthrax toxins. For each toxin or drug/compound, we constructed an activity network by using its differentially expressed genes, molecular targets, and protein interactions. Gene expression profiles of drugs were obtained from the Connectivity Map and those of anthrax toxins in human alveolar macrophages were obtained from the Gene Expression Omnibus. Drug rankings were based on the ability of a drug/compound's mode of action in the form of a signaling network to reverse the effects of anthrax toxins; literature reports were used to verify the top 10 and bottom 10 drugs/compounds identified. Simvastatin and bepridil with reported in vitro potency for protecting cells from LT and ET toxicities were computationally ranked fourth and eighth. The other top 10 drugs were fenofibrate, dihydroergotamine, cotinine, amantadine, mephenytoin, sotalol, ifosfamide, and mefloquine; literature mining revealed their potential protective effects from LT and ET toxicities. These drugs are worthy of investigation for their therapeutic benefits and might be used in combination with antibiotics for treating infection.
Topics: Anthrax; Antidotes; Antigens, Bacterial; Bacterial Toxins; Computational Biology; Drug Repositioning; Humans; Macrophages, Alveolar; Transcriptome
PubMed: 28287432
DOI: 10.3390/toxins9030099 -
Pharmaceutics Dec 2020Physiologically-based pharmacokinetic (PBPK) modeling is a well-recognized method for quantitatively predicting the effect of intrinsic/extrinsic factors on drug...
A Physiologically-Based Pharmacokinetic (PBPK) Model Network for the Prediction of CYP1A2 and CYP2C19 Drug-Drug-Gene Interactions with Fluvoxamine, Omeprazole, S-mephenytoin, Moclobemide, Tizanidine, Mexiletine, Ethinylestradiol, and Caffeine.
Physiologically-based pharmacokinetic (PBPK) modeling is a well-recognized method for quantitatively predicting the effect of intrinsic/extrinsic factors on drug exposure. However, there are only few verified, freely accessible, modifiable, and comprehensive drug-drug interaction (DDI) PBPK models. We developed a qualified whole-body PBPK DDI network for cytochrome P450 (CYP) CYP2C19 and CYP1A2 interactions. Template PBPK models were developed for interactions between fluvoxamine, S-mephenytoin, moclobemide, omeprazole, mexiletine, tizanidine, and ethinylestradiol as the perpetrators or victims. Predicted concentration-time profiles accurately described a validation dataset, including data from patients with genetic polymorphisms, demonstrating that the models characterized the CYP2C19 and CYP1A2 network over the whole range of DDI studies investigated. The models are provided on GitHub (GitHub Inc., San Francisco, CA, USA), expanding the library of publicly available qualified whole-body PBPK models for DDI predictions, and they are thereby available to support potential recommendations for dose adaptations, support labeling, inform the design of clinical DDI trials, and potentially waive those.
PubMed: 33302490
DOI: 10.3390/pharmaceutics12121191 -
BMC Complementary Medicine and Therapies Feb 2022Echinacoside (ECH) possesses a wide range of biological activity. This present study analyzes the effect of ECH on cytochrome P450 isozymes (CYPs) activities of human...
BACKGROUND
Echinacoside (ECH) possesses a wide range of biological activity. This present study analyzes the effect of ECH on cytochrome P450 isozymes (CYPs) activities of human liver microsomes.
METHODS
The effect of ECH on CYPs enzyme activities were studied using the enzyme-selective substrates phenacetin (1A2), chlorzoxazone (2E1), S-mephenytoin (2C19), testosterone (3A4), coumarin (2A6), diclofenac (2C9), paclitaxel (2C8), and dextromethorphan (2D6). The IC50 values for CYP1A2, CYP2E1, CYP2C19, and CYP3A4 isoforms were examined to express the strength of inhibition. Further, the inhibition of CYPs was checked for time-dependent or not, and then fitted with competitive or non-competitive inhibition models. The corresponding parameters were also obtained.
RESULTS
ECH caused inhibitions on CYP1A2, CYP2E1, CYP2C19 and CYP3A4 enzyme activities in HLMs with IC50 of 21.23, 19.15, 8.70 and 55.42 μM, respectively. The obtained results showed that the inhibition of ECH on CYP3A4 was time-dependent with the KI/K value of 6.63/0.066 min·μM. Moreover, ECH inhibited the activity of CYP1A2 and CYP2E1 via non-competitive manners (K = 10.90 μM and K = 14.40 μM, respectively), while ECH attenuated the CYP2C19 activity via a competitive manner (K = 4.41 μM).
CONCLUSIONS
The results of this study indicate that ECH inhibits CYP1A2, CYP2E1, CYP2C19 and CYP3A4 activities in vitro. In vivo and clinical studies are warranted to verify the relevance of these interactions.
Topics: Cytochrome P-450 Enzyme Inhibitors; Cytochrome P-450 Enzyme System; Glycosides; Humans; Isoenzymes
PubMed: 35180866
DOI: 10.1186/s12906-022-03517-0 -
Drug Metabolism and Disposition: the... Apr 2019and are highly polymorphic pharmacogenes; however, clinically actionable genetic variability in drug metabolism due to these genes has been limited to a few common...
and are highly polymorphic pharmacogenes; however, clinically actionable genetic variability in drug metabolism due to these genes has been limited to a few common alleles. The identification and functional characterization of less-common open reading frame sequence variation might help to individualize therapy with drugs that are substrates for the enzymes encoded by these genes. The present study identified seven uncharacterized variants each in and using next-generation sequence data for 1013 subjects, and functionally characterized the encoded proteins. Constructs were created and transiently expressed in COS-1 cells for the assay of protein concentration and enzyme activities using fluorometric substrates and liquid chromatography- tandem mass spectrometry with tolbutamide () and (S)-mephenytoin () as prototypic substrates. The results were compared with the SIFT, Polyphen, and Provean functional prediction software programs. Cytochrome P450 oxidoreductase (CPR) activities were also determined. Positive correlations were observed between protein content and fluorometric enzyme activity for variants of ( < 0.05) and ( < 0.0005). However, 709G>C and 65A>G activities were much lower than predicted based on protein content. Substrate intrinsic clearance values for 218C>T, 343A>C, and 337G>A, 518C>T, 556C>T, and 557G>A were less than 25% of wild-type allozymes. CPR activity levels were similar for all variants. In summary, sequencing of and in 1013 subjects identified low-frequency variants that had not previously been functionally characterized. In silico predictions were not always consistent with functional assay results. These observations emphasize the need for high-throughput methods for pharmacogene variant mutagenesis and functional characterization.
PubMed: 30745309
DOI: 10.1124/dmd.118.084269 -
Molecules (Basel, Switzerland) Oct 2020AB-FUBINACA, a synthetic indazole carboxamide cannabinoid, has been used worldwide as a new psychoactive substance. Because drug abusers take various drugs...
AB-FUBINACA, a synthetic indazole carboxamide cannabinoid, has been used worldwide as a new psychoactive substance. Because drug abusers take various drugs concomitantly, it is necessary to explore potential AB-FUBINACA-induced drug-drug interactions caused by modulation of drug-metabolizing enzymes and transporters. In this study, the inhibitory effects of AB-FUBINACA on eight major human cytochrome P450s (CYPs) and six uridine 5'-diphospho-glucuronosyltransferases (UGTs) of human liver microsomes, and on eight clinically important transport activities including organic cation transporters (OCT)1 and OCT2, organic anion transporters (OAT)1 and OAT3, organic anion transporting polypeptide transporters (OATP)1B1 and OATP1B3, P-glycoprotein, and breast cancer resistance protein (BCRP) in transporter-overexpressing cells were investigated. AB-FUBINACA inhibited CYP2B6-mediated bupropion hydroxylation via mixed inhibition with value of 15.0 µM and competitively inhibited CYP2C8-catalyzed amodiaquine -de-ethylation, CYP2C9-catalyzed diclofenac 4'-hydroxylation, CYP2C19-catalyzed []-mephenytoin 4'-hydroxylation, and CYP2D6-catalyzed bufuralol 1'-hydroxylation with values of 19.9, 13.1, 6.3, and 20.8 µM, respectively. AB-FUBINACA inhibited OCT2-mediated MPP uptake via mixed inhibition (, 54.2 µM) and competitively inhibited OATP1B1-mediated estrone-3-sulfate uptake (, 94.4 µM). However, AB-FUBINACA did not significantly inhibit CYP1A2, CYP2A6, CYP3A4, UGT1A1, UGT1A3, UGT1A4, UGT1A6, or UGT2B7 enzyme activities at concentrations up to 100 µM. AB-FUBINACA did not significantly inhibit the transport activities of OCT1, OAT1/3, OATP1B3, P-glycoprotein, or BCRP at concentrations up to 250 μM. As the pharmacokinetics of AB-FUBINACA in humans and animals remain unknown, it is necessary to clinically evaluate potential in vivo pharmacokinetic drug-drug interactions induced by AB-FUBINACA-mediated inhibition of CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, OCT2, and OATP1B1 activities.
Topics: Cannabinoids; Cell Line; Cytochrome P-450 Enzyme Inhibitors; Cytochrome P-450 Enzyme System; Drug Interactions; Glucuronosyltransferase; HEK293 Cells; Humans; Indazoles; Membrane Transport Proteins; Microsomes, Liver; Uridine Diphosphate
PubMed: 33050066
DOI: 10.3390/molecules25194589