Department of Surgery and Cancer, Faculty of Medicine, Imperial College London, Exhibition Road, South Kensington, London, SW7 2AZ, UK.
Cyprotex, Alderley Park, Nether Alderley, Cheshire, SK10 4TG, UK.
Sci Rep. 2018 Feb 5;8(1):2405. doi: 10.1038/s41598-018-20464-4.
The release of aromatic amines from drugs and other xenobiotics resulting from the hydrolysis of metabolically labile amide bonds presents a safety risk through several mechanisms, including geno-, hepato- and nephrotoxicity. Whilst multiple in vitro systems used for studying metabolic stability display serine hydrolase activity, responsible for the hydrolysis of amide bonds, they vary in their efficiency and selectivity. Using a range of amide-containing probe compounds (0.5-10 µM), we have investigated the hydrolytic activity of several rat, minipig and human-derived in vitro systems - including Supersomes, microsomes, S9 fractions and hepatocytes - with respect to their previously observed human in vivo metabolism. In our hands, human carboxylesterase Supersomes and rat S9 fractions systems showed relatively poor prediction of human in vivo metabolism. Rat S9 fractions, which are commonly utilised in the Ames test to assess mutagenicity, may be limited in the detection of genotoxic metabolites from aromatic amides due to their poor concordance with human in vivo amide hydrolysis. In this study, human liver microsomes and minipig subcellular fractions provided more representative models of human in vivo hydrolytic metabolism of the aromatic amide compounds tested.
药物和其他外来化合物中代谢不稳定酰胺键的水解会释放出芳香胺，通过多种机制（包括遗传毒性、肝毒性和肾毒性）带来安全风险。虽然用于研究代谢稳定性的多种体外系统显示出丝氨酸水解酶活性，负责酰胺键的水解，但它们的效率和选择性存在差异。我们使用一系列含酰胺的探针化合物（0.5-10μM），研究了几种大鼠、小型猪和人源体外系统（包括 Supersomes、微粒体、S9 级分和肝细胞）的水解活性，以及它们之前观察到的人体体内代谢情况。在我们的实验中，人源羧酸酯酶 Supersomes 和大鼠 S9 级分系统对人体体内代谢的预测能力相对较差。大鼠 S9 级分常用于 Ames 试验评估致突变性，但由于与人体体内酰胺水解的一致性较差，可能会限制对芳香胺类遗传毒性代谢物的检测。在这项研究中，人肝微粒体和小型猪亚细胞级分提供了更具代表性的芳香胺类化合物体内水解代谢模型。
