Faculty of Pharmacy, Drug Research Program, University of Helsinki, Viikinkaari 5E, 00790 Helsinki, Finland; Helsinki Institute of Sustainability Science, University of Helsinki, Yliopistonkatu 3, 00100 Helsinki, Finland.
Faculty of Pharmacy, Drug Research Program, University of Helsinki, Viikinkaari 5E, 00790 Helsinki, Finland.
Aquat Toxicol. 2024 Sep;274:107048. doi: 10.1016/j.aquatox.2024.107048. Epub 2024 Aug 11.
Residues of human pharmaceuticals are widely detected in surface waters and can be taken up by and bioaccumulate in aquatic organisms, especially fish. One of the key challenges in assessing the bioaccumulation potential of ionizable organic compounds, such as the pharmaceuticals, is the lack of empirical data for biotransformation. In the present study, we assessed the in vitro intrinsic clearances (CL) of twelve pharmaceuticals, individually and some additionally as mixtures, in rainbow trout (Oncorhynchus mykiss) liver S9 fractions (RT-S9) adhering to the OECD test guidance 319B. The test substances included four anti-inflammatory agents (diclofenac, ibuprofen, ketoprofen, naproxen), seven antidepressants/antipsychotics (citalopram, haloperidol, levomepromazine, mirtazapine, risperidone, sertraline, venlafaxine) and the O-desmethyl metabolite of venlafaxine. Quantifiable intrinsic clearances were detected for diclofenac, ibuprofen, naproxen, levomepromazine, and sertraline. Apart from diclofenac, the in vitro clearances of the other four pharmaceuticals were shown to be critically dependent on the cytochrome P450 (CYP) metabolism. Therefore, we also determined the half-maximal inhibitory concentrations (IC) of the same twelve pharmaceuticals toward CYP1A-like (7-ethoxyresorufin-O-deethylation, EROD) and CYP3A-like (benzyloxy-4-trifluoromethylcoumarin-O-debenzyloxylation, BFCOD) activities in RT-S9 using IC shift assay. As a result, levomepromazine and sertraline were identified as the most potent inhibitors of both EROD and BFCOD activity (unbound IC < 10 µM each), followed by citalopram and haloperidol (10 µM < IC < 100 µM). Additionally, mirtazapine was a selective EROD inhibitor (IC ∼ 30 µM). The inhibitory impacts of haloperidol and sertraline were indicatively time dependent. Finally, we carried out intrinsic clearance assays with mixtures of diclofenac, ibuprofen, naproxen, levomepromazine, and sertraline to examine the impacts of EROD and BFCOD inhibitions on their in vitro CL in RT-S9. Our in vitro data suggests that the intrinsic clearances of ibuprofen, levomepromazine, and sertraline in rainbow trout can be significantly reduced as the result of P450 inhibition by pharmaceutical mixtures, whereas the clearances of diclofenac and naproxen are less impacted.
人用药物的残留广泛存在于地表水，并且可以被水生生物吸收和生物累积，尤其是鱼类。评估可电离有机化合物（如药物）的生物累积潜力的一个关键挑战是缺乏生物转化的经验数据。在本研究中，我们根据 OECD 测试指南 319B，评估了 12 种药物在虹鳟鱼肝脏 S9 级分（RT-S9）中的单独和一些混合物的体外固有清除率（CL）。测试物质包括四种抗炎剂（双氯芬酸、布洛芬、酮洛芬、萘普生）、七种抗抑郁药/抗精神病药（西酞普兰、氟哌啶醇、左美丙嗪、米氮平、利培酮、舍曲林、文拉法辛）和文拉法辛的 O-去甲基代谢物。可量化的固有清除率被检测到双氯芬酸、布洛芬、萘普生、左美丙嗪和舍曲林。除双氯芬酸外，其他四种药物的体外清除率被证明严重依赖细胞色素 P450（CYP）代谢。因此，我们还使用 IC 移位测定法测定了相同的 12 种药物对 RT-S9 中 CYP1A 样（7-乙氧基resorufin-O-去乙基化，EROD）和 CYP3A 样（苄氧基-4-三氟甲基香豆素-O-脱苄氧基化，BFCOD）活性的半最大抑制浓度（IC）。结果表明，左美丙嗪和舍曲林是两种 EROD 和 BFCOD 活性的最强抑制剂（未结合的 IC 均 < 10µM），其次是西酞普兰和氟哌啶醇（10µM < IC < 100µM）。此外，米氮平是一种选择性 EROD 抑制剂（IC∼30µM）。氟哌啶醇和舍曲林的抑制作用具有时间依赖性。最后，我们用混合物进行了固有清除率测定双氯芬酸、布洛芬、萘普生、左美丙嗪和舍曲林，以检查 EROD 和 BFCOD 抑制对它们在 RT-S9 中的体外 CL 的影响。我们的体外数据表明，由于药物混合物对细胞色素 P450 的抑制，虹鳟鱼中布洛芬、左美丙嗪和舍曲林的固有清除率可能会显著降低，而双氯芬酸和萘普生的清除率则受影响较小。
