Department of Chemistry, University of Bergen, Bergen 5007, Norway.
Marine Toxicology, Institute of Marine Research, Bergen 5817, Norway.
Environ Sci Technol. 2024 Aug 20;58(33):14855-14863. doi: 10.1021/acs.est.4c05112. Epub 2024 Aug 5.
Fish exposed to xenobiotics like petroleum-derived polycyclic aromatic hydrocarbons (PAHs) will immediately initiate detoxification systems through effective biotransformation reactions. Yet, there is a discrepancy between recognized metabolic pathways and the actual metabolites detected in fish following PAH exposure like oil pollution. To deepen our understanding of PAH detoxification, we conducted experiments exposing Atlantic haddock () to individual PAHs or complex oil mixtures. Bile extracts, analyzed by using an ion mobility quadrupole time-of-flight mass spectrometer, revealed novel metabolites associated with the mercapturic acid pathway. A dominant spectral feature recognized as PAH thiols set the basis for a screening strategy targeting (i) glutathione-, (ii) cysteinylglycine-, (iii) cysteine-, and (iv) mercapturic acid S-conjugates. Based on controlled single-exposure experiments, we constructed an interactive library of 33 metabolites originating from 8 PAHs (anthracene, phenanthrene, 1-methylphenanthrene, 1,4-dimethylphenanthrene, chrysene, benz[]anthracene, benzo[]pyrene, and dibenz[,]anthracene). By incorporation of the library in the analysis of samples from crude oil exposed fish, PAHs conjugated with glutathione and cysteinylglycine were uncovered. This qualitative study offers an exclusive glimpse into the rarely acknowledged mercapturic acid detoxification pathway in fish. Furthermore, this furnishes evidence that this metabolic pathway also succeeds for PAHs in complex pollution sources, a notable discovery not previously reported.
鱼类暴露于像石油衍生的多环芳烃（PAHs）这样的外来生物时，会立即通过有效的生物转化反应启动解毒系统。然而，在 PAH 暴露（如石油污染）后，鱼类中识别出的代谢途径与实际检测到的代谢物之间存在差异。为了更深入地了解 PAH 的解毒作用，我们进行了实验，将大西洋鳕鱼（）暴露于单一 PAHs 或复杂的石油混合物中。使用离子淌度四极杆飞行时间质谱仪分析胆汁提取物，揭示了与硫醚尿酸途径相关的新型代谢物。一种被识别为 PAH 硫醇的主要光谱特征为筛选策略提供了基础，该策略旨在针对 (i) 谷胱甘肽-、(ii) 半胱氨酸甘氨酸-、(iii) 半胱氨酸-和 (iv) 硫醚尿酸 S-缀合物。基于受控的单一暴露实验，我们构建了一个 33 种代谢物的交互式文库，这些代谢物源自 8 种 PAHs（蒽、菲、1-甲基菲、1,4-二甲基菲、荧蒽、苯并[a]蒽、苯并[b]荧蒽和二苯并[a,h]蒽）。通过将文库纳入暴露于原油的鱼类样本分析中，揭示了与谷胱甘肽和半胱氨酸甘氨酸结合的 PAHs。这项定性研究提供了鱼类中很少被承认的硫醚尿酸解毒途径的独特视角。此外，这为该代谢途径也适用于复杂污染源中的 PAHs 提供了证据，这是一个以前没有报道过的显著发现。
