Inhibitory effect of isavuconazole,ketoconazole, and voriconazole on the pharmacokinetics of methadone in vivo and in vitro

The aim of this study was to investigate the possible effect of orally administered isavuconazole, ketoconazole, or voriconazole on the pharmacokinetics of methadone in rats. Twenty Sprague–Dawley (SD) rats were divided randomly into four groups: Group A (control), group B (5 mg/kg isavuconazole), group C (5 mg/kg ketoconazole), and group D (5 mg/kg voriconazole). A single dose of methadone was administrated half an hour later. Methadone in plasma concentrations and its metabolite EDDP in microsomes were determined by ultra‐high‐performance liquid chromatography–tandem mass spectrometry method (UPLC–MS/MS), and pharmacokinetic parameters were calculated by DAS version 3.0. The C_max of methadone in groups C and D increased to 2.7‐fold and 5‐fold, respectively. While AUC increased in three groups and group D increased the most. Also, isavuconazole, ketoconazole, and voriconazole showed inhibitory effect on human and rat microsomes. The inhibition ratios of isavuconazole, ketoconazole, and voriconazole in rat liver microsome were 97.87%, 96.74% and 78.9%, respectively (p < 0.01), while in human liver microsome, inhibition ratios were 86.97%, 96.46%, and 53.11%, respectively. And the IC₅₀ for inhibition activity of isavuconazole, ketoconazole, and voriconazole in rat microsomes were 7.76 μM, 8.33 μM, and 4.45 μM, respectively. Our study indicated that taking methadone combine with ketoconazole, isavuconazole, or voriconazole could reduce the metabolism rate of methadone and prolong the pharmacological effects in vivo and in vitro.     

异鼠李素对人肝微粒体CYPs活性及大鼠原代肝细胞毒性作用研究

目的 研究异鼠李素对肝脏6种CYPs的体外抑制作用,以及对大鼠原代肝细胞的毒性作用。方法 采用人肝微粒体（HLMs）体外温孵法研究异鼠李素对6种细胞色素P450酶（CYPs）——CYP2C19、CYP2D6、CYP3A4、CYP2E1、CYP1A2和CYP2C9的体外抑制作用;使用HPLC-MS/MS法检测异鼠李素和HLMs共同孵育后的代谢产物;利用体外培养的低CYPs活性的大鼠原代肝细胞,考察不同剂量异鼠李素对细胞培养液中乳酸脱氢酶（LDH）、丙氨酸氨基转移酶（ALT）、天门冬氨酸氨基转移酶（AST）的影响。结果 50 μmol/L的异鼠李素对CYP2E1和CYP1A2有一定的抑制作用,抑制率分别为59.48%和39.91%;异鼠李素和HLMs共同孵育后,产生去甲基化代谢产物3,3'',4'',5,7-五羟基黄酮,转化为极性和水溶性较高的代谢物;30、100、300 μmol/L的异鼠李素会使大鼠原代肝细胞培养液中的ALT和LDH显著上升（P＜0.01）,100、300 μmol/L异鼠李素使AST显著上升（P＜0.05、0.01）,呈浓度相关性。结论 异鼠李素在体外主要经HLMs代谢,同时对CYP2E1和CYP1A2有一定的抑制作用,可能会使CYP2E1和CYP1A2的底物药物在体内的浓度产生变化,导致一系列药物的相互作用;大量使用异鼠李素可能会造成一定程度的肝细胞损伤,且呈现浓度相关性。临床应用应合理设置剂量,并注意潜在的药物之间的相互作用。     

In vitro metabolism of alectinib,a novel potent ALK inhibitor,in human: contribution of CYP3A enzymes

1.?The in vitro metabolism of alectinib, a potent and highly selective oral anaplastic lymphoma kinase inhibitor, was investigated.

2.?The main metabolite (M4) in primary human hepatocytes was identified, which is produced by deethylation at the morpholine ring. Three minor metabolites (M6, M1a, and M1b) were also identified, and a minor peak of hydroxylated alectinib (M5) was detected as a possible precursor of M4, M1a, and M1b.

3.?M4, an important active major metabolite, was produced and further metabolized to M6 by CYP3A, indicating that CYP3A enzymes were the principal contributors to this route. M5 is possibly produced by CYP3A and other isoforms as the primary step in metabolism, followed by oxidation to M4 mainly by CYP3A. Alternatively, M5 could be oxidized to M1a and M1b via an NAD-dependent process. None of the non-CYP3A-mediated metabolism appeared to be major.

4.?In conclusion, this study suggests that involvement of multiple enzymes in the metabolism of alectinib reduces its potential for drug–drug interactions.     

Metabolism studies on hydroxygenkwanin and genkwanin in human liver microsomes by UHPLC-Q-TOF-MS

Hydroxygenkwanin (HYGN) and genkwanin (GN) are major constituents of Genkwa Flos for the treatment of edema, ascites, cough, asthma and cancer. This is a report about the investigation of the metabolic fate of HYGN and GN in human liver microsomes and the recombinant UDP-glucuronosyltransferase (UGT) enzymes by using ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry (UHPLC-Q-TOF-MS). An on-line data acquisition method multiple mass defect filter (MMDF) combined with dynamic background subtraction (DBS) was developed to trace all probable metabolites. Based on this analytical strategy, three phase I metabolites and seven glucuronide conjugation metabolites of HYGN, seven phase I metabolites and 12 glucuronide conjugation metabolites of GN were identified in the incubation samples of human liver microsomes. The results indicated that demethylation, hydroxylation and o-glucuronidation were main metabolic pathways of HYGN and GN. The specific UGT enzymes responsible for HYGN and GN glucuronidation metabolites were identified using recombinant UGT enzymes. The results indicated that UGT1A1, UGT1A3, UGT1A9, UGT1A10 and UGT2B7 might play major roles in the glucuronidation reactions. Overall, this study may be useful for the investigation of metabolic mechanism of HYGN and GN, and it can provide reference and evidence for further experiments.     

瓜蒌皮注射液对人肝微粒体CYP450酶4种亚型的影响

目的研究瓜蒌皮注射液对人肝细胞色素P450(CYP450)酶4种亚型CYP1A2、CYP2B6、CYP2C9和CYP2D6的体外抑制作用。方法瓜蒌皮注射液8个不同浓度(2%、1%、0.2%、0.05%、0.01%、0.005%、0.002%、0.000 5%)的工作液分别与4种CYP450酶亚型的探针底物混合,即非那西丁(CYP1A2)、安非他酮(CYP2B6)、双氯芬酸(CYP2C9)、右美沙芬(CYP2D6),用维拉帕米作为内标,在人肝微粒体中孵育,采用高效液相色谱法检测4种探针底物的剩余浓度,计算半数抑制浓度(IC_(50))。结果瓜蒌皮注射液对CYP1A2、CYP2B6、CYP2C9和CYP2D6的IC_(50)值均大于临床常用量。结论正常用量下,瓜蒌皮注射液对人CYP450酶的4亚型无明显影响。     

Detection of metabolites of the new synthetic cannabinoid CUMYL‐4CN‐BINACA in authentic urine samples and human liver microsomes using high‐resolution mass spectrometry

CUMYL‐4CN‐BINACA(1‐(4‐cyanobutyl)‐N‐(2‐phenylpropan‐2‐yl)‐1H–indazole‐3‐carboxamide) is a recently introduced indazole‐3‐carboxamide‐type synthetic cannabinoid (SC) that was detected in herbal incense seized by of the Council of Forensic Medicine, Istanbul Narcotics Department, in May 2016 in Turkey. Recently introduced SCs are not detected in routine toxicological analysis; therefore, analytical methods to measure these compounds are in demand. The present study aims to identify urinary marker metabolites of CUMYL‐4CN‐BINACA by investigating its metabolism in human liver microsomes and to confirm the results in authentic urine samples (n = 80). In this study, 5 μM CUMYL‐4CN‐BINACA was incubated with human liver microsomes (HLMs) for up to 3 hours, and metabolites were identified using liquid chromatography–high‐resolution mass spectrometry (LC–HRMS). Less than 21% of the CUMYL‐4CN‐BINACA parent compound remained after 3 hours of incubation. We identified 18 metabolites that were formed via monohydroxylation, dealkylation, oxidative decyanation to aldehyde, alcohol, and carboxylic acid formation, glucuronidation or reaction combinations. CUMYL‐4CN‐BINACA N‐butanoic acid (M16) was found to be major metabolite in HLMs. In urine samples CUMYL‐4CN‐BINACA was not detected; CUMYL‐4CN‐BINACA N‐butanoic acid (M16) was major metabolite after β‐glucuronidase hydrolysis. Based on these findings, we recommend using M16 (CUMYL‐4CN‐BINACA N‐butanoic acid), M8 and M11 (hydroxylcumyl CUMYL‐4CN‐BINACA) as urinary marker metabolites to confirm CUMYL‐4CN‐BINACA intake.     

常用中药单体及其制剂对CYP3A活性的体外抑制作用研究

摘 要 目的:研究常用中药单体及其制剂对CYP3A活性的抑制作用。方法: 在体外肝微粒体孵育体系中加入底物睾酮和不同浓度的中药单体或其制剂,以高效液相色谱法检测6β羟基睾酮的生成量,计算CYP3A酶活性。用GraphPad Prism v5.0软件,按照非线性回归计算出药物对CYP3A抑制作用的IC₅₀值。结果:不同中药单体及其制剂对CYP3A抑制作用的IC₅₀值如下：大黄酸IC₅₀值为36.74 μmol·L^-1;大黄素IC₅₀值为23.09 μmol·L^-1、芦荟大黄素IC₅₀值为23.91 μmol·L^-1,蜂胶IC₅₀值为60.3 μg·mL^-1;水飞蓟素胶囊IC₅₀值为24.5μg·mL^-1;丹参酮ⅡA磺酸钠注射液IC₅₀值为0.14%(v/v);五味子酯甲IC₅₀值为0.56 μmol·L^-1。结论: 大黄中的蒽醌、五味子酯甲、蜂胶、水飞蓟胶囊以及丹参酮ⅡA磺酸钠注射液在体外对鼠或人肝CYP3A酶具有抑制作用,临床上使用相关制剂时应密切关注其可能引起的药物相互作用。     

In vitro metabolism of cis- and trans-permethrin by rat liver microsomes,and its effect on estrogenic and anti-androgenic activities

Permethrin is a widely applied broad-spectrum pyrethroid insecticide that consists of a mixture of cis- and trans-isomers. We examined the changes of estrogenic and anti-androgenic activities resulting from metabolism of the isomers. Both cis- and trans-permethrin were hydrolyzed to 3-phenoxybenzyl alcohol (PBAlc) by rat liver microsomes, but the extent of hydrolysis of trans-permethrin was much greater than that of the cis-isomer. In the presence of NADPH, PBAlc was further transformed to 4′-hydroxylated PBAlc (4′-OH PBAlc), 3-phenoxybenzaldehyde (PBAld) and 3-phenoxybenzoic acid (PBAcid). cis-Permethrin, but not trans-permethrin, also afforded its 4′-hydroxylated derivative (4′-OH cis-permethrin). trans-Permethrin was an anti-androgen, but also showed weak estrogenic activity, while cis-permethrin was a weak estrogen and a weak anti-androgen. After incubation with rat liver microsomes in the presence of NADPH, cis-permethrin but not trans-permethrin was metabolically activated for estrogenic activity. On the other hand, estrogenic activity of trans-permethrin was not changed, but its anti-androgenic activity was enhanced after incubation. 4′-OH PBAlc and PBAlc showed estrogenic activity, while PBAld and PBAlc showed anti-androgenic activity. PBAcid showed neither activity. 4′-OH cis-permethrin showed both estrogenic and anti-androgenic activities. Overall, our results indicate that permethrin is metabolically activated for estrogenic and anti-androgen activities, and the microsomal transformation of permethrin to 4′-OH cis-permethrin, 4′-OH PBAlc and PBAlc contributes to the both metabolic activations.     

Transesterification of a series of 12 parabens by liver and small-intestinal microsomes of rats and humans

Hydrolytic transformation of parabens (4-hydroxybenzoic acid esters; used as antibacterial agents) to 4-hydroxybenzoic acid and alcohols by tissue microsomes is well-known both in vitro and in vivo. Here, we investigated transesterification reactions of parabens catalyzed by rat and human microsomes, using a series of 12 parabens with C1–C12 alcohol side chains. Transesterification of parabens by rat liver and small-intestinal microsomes occurred in the presence of alcohols in the microsomal incubation mixture. Among the 12 parabens, propylparaben was most effectively transesterified by rat liver microsomes with methanol or ethanol, followed by butylparaben. Relatively low activity was observed with longer-side-chain parabens. In contrast, small-intestinal microsomes exhibited higher activity towards moderately long side-chain parabens, and showed the highest activity toward octylparaben. When parabens were incubated with liver or small-intestinal microsomes in the presence of C1–C12 alcohols, ethanol and decanol were most effectively transferred to parabens by rat liver microsomes and small-intestinal microsomes, respectively. Human liver and small-intestinal microsomes also exhibited significant transesterification activities with different substrate specificities, like rat microsomes. Carboxylesterase isoforms, CES1b and CES1c, and CES2, exhibited significant transesterification activity toward parabens, and showed similar substrate specificity to human liver and small-intestinal microsomes, respectively.     

In vitro metabolism of the lignan (−)‐grandisin,an anticancer drug candidate,by human liver microsomes

(?)‐grandisin is a tetrahydrofuran lignan that displays important biological properties, such as trypanocidal, anti‐inflammatory, cytotoxic, and antitumor activities, suggesting its utility as a potential drug candidate. One important step in drug development is metabolic characterization and metabolite identification. To perform a biotransformation study of (?)‐grandisin and to determine its kinetic properties in humans, a high performance liquid chromatography (HPLC) method was developed and validated. After HPLC method validation, the kinetic properties of (?)‐grandisin were determined. (?)‐grandisin metabolism obeyed Michaelis‐Menten kinetics. The maximal reaction rate (V_max) was 3.96 ± 0.18 µmol/mg protein/h, and the Michaelis‐Menten constant (K_m) was 8.23 ± 0.99 μM. In addition, the structures of the metabolites derived from (?)‐grandisin were characterized via gas chromatography‐mass spectrometry (GC‐MS) and liquid chromatography‐mass spectrometry (LC‐MS) analysis. Four metabolites, 4‐O‐demethylgrandisin, 3‐O‐demethylgrandisin, 4,4′‐di‐O‐demethylgrandisin, and a metabolite that may correspond to either 3,4‐di‐O‐demethylgrandisin or 3,5‐di‐O‐demethylgrandisin, were detected. CYP2C9 isoform was the main responsible for the formation of the metabolites. These metabolites have not been previously described, demonstrating the necessity of assessing (?)‐grandisin metabolism using human‐derived materials. Copyright © 2015 John Wiley & Sons, Ltd.