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Cytochrome P450s (CYP450) is a superfamily of phase I metabolic enzymes, which participates in more than 90% of drug oxidation. The induction or inhibition of CYP450s is the main mechanism of drug-drug interaction. In recent years, in vitro metabolism studies conducted through isolated organs, cells, or enzyme systems have developed rapidly, due to their precision and simplicity. Therefore, profiles of the in vitro metabolism studies of traditional Chinese medicines can infer the possible metabolic pathways of drugs, predict the potential drug interactions, and may enhance the rational use of drugs in clinic. This article reviews the in vitro inhibitory effects of traditional Chinese medicine, ingredients, and extracts on the activities of CYP450 enzymes in the liver microsomes, which can provide a reference for further researches on the interaction between Chinese medicine and chemical medicine.
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Synthetic cathinones are new psychoactive substances that represent a health risk worldwide. For most of the 130 reported compounds, information about toxicology and/or metabolism is not available, which hampers their detection (and subsequent medical treatment) in intoxication cases. The principles of forensic analytical chemistry and the use of powerful analytical techniques are indispensable for stab-lishing the most appropriate biomarkers for these substances. Human metabolic fate of synthetic cathinones can be assessed by the analysis of urine and blood obtained from authentic consumers;however, this type of samples is limited and difficult to access. In this work, the metabolic behaviour of three synthetic cathinones (4-CEC, 4-CPrC and 5-PPDi) and one amphetamine (3-FEA) has been evalu-ated by incubation with pooled human hepatocytes and metabolite identification has been performed by high-resolution mass spectrometry. This in vitro approach has previously shown its feasibility for obtaining excretory human metabolites. 4-CEC and 3-FEA were not metabolised, and for 4-CPrC only two minor metabolites were obtained. On the contrary, for the recently reported 5-PPDi, twelve phase I metabolites were elucidated. Up to our knowledge, this is the first metabolic study of an indanyl-cathinone. Data reported in this paper will allow the detection of these synthetic stimulants in intoxi-cation cases, and will facilitate future research on the metabolic behaviour of other indanyl-based cathinones.
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Objective::To investigate in vivo and in vitro metabolites of coptisine and their metabolic pathways. Method::SD rats were given coptisine by single gavage (dose of 25 mg·kg-1). Urine and feces from 0 h to 48 h, bile from 0 h to 24 h, and plasma and brain tissue samples at 0.25, 1, 2 h after administration were collected.In vitro metabolism was incubated with rat liver microsomes and intestinal flora.The metabolites were analyzed and identified by the high-resolution HPLC-MS/MS technique.The liquid chromatography separation was carried out on ZORBAX SB-C18 column (4.6 mm×150 mm, 5 μm) with acetonitrile-0.1% formic acid solution as the mobile phase for gradient elution, the flow rate was 1.0 mL·min-1, and column temperature was 25 ℃.The mass spectra were obtained in positive and negative ion mode with electrospray ionization (ESI), the scanning range was m/z 50-1 200.The relative molecular weight was determined according to the quasi-molecular ion peaks.The structures of metabolites were elucidated by comparing the data with literature data, including main ion peaks, UV spectrum and HPLC retention time information. Result::A total of 17 metabolites were identified in each sample, including 11 phase Ⅰ metabolites and 6 phase Ⅱ metabolites.The pathways to these metabolites were hydroxylation, demethylation, dehydrogenation, sulfation and glucuronide conjugation. Conclusion::Coptisine can produce metabolic reaction of phase Ⅰ and phase Ⅱ in rat, and metabolites are predominantly present in urine, and the main metabolic site is liver.Coptisine is poorly absorbed and rarely metabolized in gastrointestinal tract, so it is mostly excreted through feces by prototype.This experiment can provide material basis for the pharmacodynamics and pharmacology of coptisine.
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CAT3 is a promising anti-brain tumor agent that has significant anti-tumor activity on Daoy or U87MG orthotopic xenograft in nude mice. This study was carried out to investigate the metabolic profiles of CAT3 in mouse/dog/human blood and microsome as well as in humanized recombinant enzymes. All animal care and experimental procedures were reviewed and approved by the Animal Ethics Committee of Chinese Academy of Medical Sciences. Our findings showed that CAT3 could be hydrolyzed to active metabolite PF403 by carboxylesterase, butyrylcholinesterase and serine hydrolase in mouse/dog/ human blood. PF403 could be further metabolized to M1 oxidative dehydration product, M2 double oxidation dehydration product, M3 methylation oxidative dehydration product, M4 oxidation product and M5 demethylation product, which were mainly catalyzed by CYP1A2, 1A1, 2C9 and 3A4, and slightly by CYP2B6, 2C8, 2C19 and 2D6. Besides oxidative metabolism, PF403 also was transformed into glucuronylation metabolites GLU-PF403 by Phase II enzymes UGT1A1, 1A3 and 1A9. Taken together, the metabolism of CAT3 was a multiple enzyme catalytic reaction. These results could provide valuable information for potential enzyme-mediated DDI in clinic studies.
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The mass spectrometry-based metabolomics method was used to systematically investigate the formation of celastrol metabolites,and the effect of celastrol on endogenous metabolites. The mice plasma,urine and feces samples were collected after oral administration of celastrol. Ultra-high performance liquid chromatography with quadrupole time-of-flight mass spectrometry( UPLC-QTOF-MS) was applied to analyze the exogenous metabolites of celastrol and its altered endogenous metabolites. Mass defect filtering was adopted to screen for the exogenous metabolites of celastrol. Multivariate statistical analysis was used to identify the endogenous metabolites affected by celastrol. Celastrol and its eight metabolites were detected in urine and feces of mice,and 5 metabolites of them were reported for the first time. The hydroxylated metabolites were observed in the metabolism of both human liver microsomes and mouse liver microsomes. Further recombinant enzyme experiments revealed CYP3 A4 was the major metabolic enzyme involved in the formation of hydroxylated metabolites. Urinary metabolomics revealed that celastrol can affect the excretion of intestinal bacteria-related endogenous metabolites,including hippuric acid,phenylacetylglycine,5-hydroxyindoleacetic acid,urocanic acid,cinnamoylglycine,phenylproplonylglycine and xanthurenic acid. These results are helpful to elucidate the metabolism and disposition of celastrol in vivo,and its mechanism of action.
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Animals , Humans , Mice , Chromatography, High Pressure Liquid , Mass Spectrometry , Metabolomics , Microsomes, Liver , Metabolism , Triterpenes , Metabolism , PharmacokineticsABSTRACT
IG-105, N-(2,6-dimethoxypyridine-3-yl)-9-methylcarbazole-3-sulfonamide, a novel antimicrotubule agent, showed potent anticancer activity in a variety of human tumor cells in vitro and in vivo. In order to characterize the metabolism and the possible drug-drug interaction of IG-105, we carried out a series of experiments. Drug metabolizing enzymes involved in IG-105 metabolism were investigated by using pooled human liver microsomes (HLMs) and recombinant cytochrome P450 isoforms (rP450s) respectively. The possible metabolites were analyzed by liquid chromatography-orbitrap-mass spectrometry (LC-Orbitrap-MS). The inhibitory effect of IG-105 on main P450 enzymes was also evaluated. The results showed that IG-105 can be metabolized by a series of rP450s, including CYP1A2, CYP2B6, CYP2C9, CYP2C19, CYP2D6, CYP3A4 and CYP3A5, with the major contribution enzymes being CYP1A2, CYP2B6, CYP2C19, and CYP3A. Three metabolites (M1-M3) were identified and demethylation was the major phase I metabolic reaction for IG-105. IG-105 moderately inhibited CYP1A2, CYP2C9, CYP2C19, CYP2D6, and CYP3A enzyme activities with IC50 values of 6.42, 23.64, 0.39, 1.4, and 3.14 μmol·L-1, respectively. Since the biotransformation of IG-105 involves multiple enzymatic pathways, the compound is less likely to be a victim of a concomitantly used medicine which inhibits activity of one of the CYPs. However, as IG-105 showed medium to strong inhibition on CYP1A2, CYP2D6, CYP3A, and CYP2C19, caution is particularly needed when IG-105 is co-administrated with other anticancer drugs which are mainly metabolized by the above enzymes.
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OBJECTIVE: To establish a UPLC-Q-TOF-MS method to characterize the metabolites of phillygenin in human liver microsomal incubation system for the first time. METHODS: The chromatography separation was performed on a C18 reversed phase LC column (Phenomenex Kinetex C18, 2.1 mm×100 mm, 2.6 μm). The mobile phase consisted of water-formic acid (100:0.1, V/V) and acetonitrile and a gradient elution program was adopted at the flow rate of 400 μL·min-1. The mass spectral analysis was performed in a positive electrospray ionization mode, and the turbo spray temperature was 550℃. The full MS experiment was run with a scan range from m/z100 to m/z 1 000. RESULTS: The possible fragmentation pathways of phillygein were speculated in a positive electrospray ionization mode, and eight metabolites was identified in human liver microsomal incubation system. CONCLUSION: The UPLC-Q-TOF-MS method is very convenient and efficient for detecting phillygein in human liver mirosomes. The developed method is suitable for the metabolism research of phillygein in human liver microsomes, which providing valuable reference for pharmacokinetic study of phillygenin.
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OBJECTIVE: To study the in vitro metabolism and enzyme kinetics of di-n-butyl-(4-chlorobenzohydroxamato) tin(IV) chloride in rat liver microsomes, and to identify the major cytochrome P450 isozymes involved in the metabolism of di-n-butyl-(4-chlorobenzohydroxamato) tin(IV) chloride in rat liver microsomes. METHODS: By optimizing the incubation conditions of di-n-butyl-(4-chlorobenzohydroxamato) tin(IV) chloride in rat liver microsomes, the enzyme kinetics in different enzyme sources was researched; the cytochrome P450 isozymes involved in metabolism of di-n-butyl-(4-chlorobenzohydroxamato) tin(IV) chloride were preliminarily explored through in vitro inhibition experiments. RESULTS: Different enzyme source metabolism experiments showed that between phenobarbital(PB) and desamethasone(Dex) induction groups and blank control group there had significant differences, but between the BNF group and blank control group there had no significant difference; the inhibition experiments revealed that ketoconazole had strong inhibition effect on di-n-butyl-(4-chlorobenzohydroxamato) tin(IV) chloride metabolism. CONCLUSION: CYP3A plays a leading role in di-n-butyl-(4-chlorobenzohydroxamato) tin(IV) chloride metabolism, and CYP2C9 may be partly involved. CYP1A has no catalysis action on metabolism of di-n-butyl-(4-chlorobenzohydroxamato) tin(IV) chloride. The Results suggest that attention should be paid to the possibility of drug interactions when di-n-butyl-(4-chlorobenzohydroxamato) tin(IV) chloride is combined with the drugs metabolized by above-mentioned isozymes.
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Gender-related differences in drug pharmacokinetics have frequently been considered as potentially important determinants for the clinical effectiveness of drug therapy. Major molecular factors involved in drug disposition include drug-metabolising enzymes and drug transporters. Oxidative drug metabolism by cytochrome P450 (CYP) enzymes is a major pathway for drug elimination. CYP3A4,the major human drug-metabolizing CYP enzymes,has repeatedly been suggested higher metabolic activity in women than that in men,which sex-dependent secretory patterns of growth hormone that may be responsible for.
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Objective:To investigate in vitro metabolism method and HPLC method for the dextromethorphan.Methods:Total protein of normal liver specimens metabolismed dextromethorphan in vitro.An HPLC method with fluorescence was developed to study the contents of dextromethorphan and metabolites by joining an internal standard(Adriamycin).Methanol-10mmol/l,sodium dihydrogen phosphate solution(50:50,contain 0.01% sodium heptanesulfonate,5% triethylamine,pH 3.5)was used to the mobile phase.Results:Total protein of normal liver specimens metabolismed dextromethorphan in vitro efficiently with coenzyme,Mg~(2+), suitable temperature and pH value.Dextromethorphan and metabolites were analyed by HPLC method with fluorescence.The metabolic rate of dextromethorphan was 16.09%.Conclusion:It is suggested that the metabolism method of dextromethorphan in vitro is simple,convenient and accurate.It can be used for the determination of metabolism dextromethorphan in vitro.