Identification of Carboxylesterase-Dependent Dabigatran Etexilate Hydrolysis
Identification of Carboxylesterase-Dependent Dabigatran Etexilate Hydrolysis
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DOI：
10.1124/dmd.113.054353
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发表时间：
2014-02-01
影响因子：
3.9
通讯作者：
Hu, Zhe-Yi
中科院分区：
文献类型：
--
作者：
Laizure, S. Casey;Parker, Robert B.;Hu, Zhe-Yi
达比加群酯 (DABE) 是一种口服前药，可通过丝氨酸酯酶迅速转化为活性凝血酶抑制剂达比加群 (DAB)。本研究的目的是研究人羧酸酯酶水解 DABE 的体外动力学和途径，以及酒精对这些转化的影响。测定了两种人重组羧酸酯酶（CES1 和 CES2）以及人肠微粒体和人肝脏 S9 级分中 DABE 水解的动力学。还检查了酒精（一种已知的 CES1 抑制剂）对羧酸酯酶和人肝脏 S9 组分中 DABE 代谢物形成的影响。研究了双（4-硝基苯基）磷酸酯对羧酸酯酶介导的 DABE 代谢的抑制作用以及酒精对经典羧酸酯酶底物（可卡因）水解的影响，以验证体外模型。 DABE 的乙酯仅被 CES1 水解为 M1（K-m 24.9 +/- 2.9 μM，V-max 676 +/- 26 pmol/min 每毫克蛋白质），DABE 的氨基甲酸酯仅被 CES2 水解为 M2（K-m 5.5 +/- 0.8 μM；V-max 71.1 +/- 2.4） pmol/分钟每毫克蛋白质）。 DABE 在人肠微粒体中依次水解，然后在人肝脏 S9 级分中水解，导致完全转化为 DAB。这些结果表明，人类口服 DABE 后，DABE 被肠道 CES2 水解为中间代谢物 M2，随后在肝脏中被 CES1 水解为 DAB。羧酸酯酶介导的 DABE 水解不受酒精抑制。
Dabigatran etexilate (DABE) is an oral prodrug that is rapidly converted to the active thrombin inhibitor, dabigatran (DAB), by serine esterases. The aims of the present study were to investigate the in vitro kinetics and pathway of DABE hydrolysis by human carboxylesterase enzymes, and the effect of alcohol on these transformations. The kinetics of DABE hydrolysis in two human recombinant carboxylesterase enzymes (CES1 and CES2) and in human intestinal microsomes and human liver S9 fractions were determined. The effects of alcohol (a known CES1 inhibitor) on the formation of DABE metabolites in carboxylesterase enzymes and human liver S9 fractions were also examined. The inhibitory effect of bis(4-nitrophenyl) phosphate on the carboxylesterase-mediated metabolism of DABE and the effect of alcohol on the hydrolysis of a classic carboxylesterase substrate (cocaine) were studied to validate the in vitro model. The ethyl ester of DABE was hydrolyzed exclusively by CES1 to M1 (K-m 24.9 +/- 2.9 mu M, V-max 676 +/- 26 pmol/min per milligram protein) and the carbamate ester of DABE was exclusively hydrolyzed by CES2 to M2 (K-m 5.5 +/- 0.8 mu M; V-max 71.1 +/- 2.4 pmol/min per milligram protein). Sequential hydrolysis of DABE in human intestinal microsomes followed by hydrolysis in human liver S9 fractions resulted in complete conversion to DAB. These results suggest that after oral administration of DABE to humans, DABE is hydrolyzed by intestinal CES2 to the intermediate M2 metabolite followed by hydrolysis of M2 to DAB in the liver by CES1. Carboxylesterase-mediated hydrolysis of DABE was not inhibited by alcohol.