Research Group in Community Nutrition and Oxidative Stress, University of Balearic Islands, E-07122, Palma de Mallorca, Balearic Islands, Spain; Interdisciplinary Ecology Group, Department of Biology, University of the Balearic Islands, E-07122, Palma de Mallorca, Balearic Islands, Spain.
Instituto Español de Oceanografía, Centro Oceanográfico de Baleares, Muelle de Poniente s/n, 07015, Palma de Mallorca, Balearic Islands, Spain.
Environ Pollut. 2020 Nov;266(Pt 1):115295. doi: 10.1016/j.envpol.2020.115295. Epub 2020 Jul 31.
Environmental pollution from plastic debris is a major global concern, being a potential threat to marine organisms and ecosystems. The accumulation of microplastics (MPs) in the oceans has notable ecological implications due to their long persistence, their potential ecotoxicity, and their ability to adsorb other pollutants and act as vectors of pathogens. Nevertheless, whereas the number of investigations documenting the presence of MPs in wild fish has increased, less studies have addressed the toxicological effects associated with the ingestion of MPs in long-term laboratory conditions. The aim of the present study was to assess the physiological response of gilthead seabream (Sparus aurata) exposed to low-density polyethylene (LDPE) MPs during a 90-day exposure followed by an extra 30 days of depuration through the application of oxidative stress biomarkers in the gut. No changes were observed in the Fulton condition factor of fish associated with MP intake. The activities of antioxidant enzymes and glutathione s-transferase and the levels of reduced glutathione progressively increased throughout the study in the MPs-fed group compared to the control group, reaching the highest values at 90 days. Similarly, the activity of the pro-inflammatory enzyme, myeloperoxidase, and the levels of oxidative damage markers -malondialdehyde and protein carbonyls-also increased after 90 days of exposure to an enriched diet with MPs. During the 30-day depuration period, all the biomarkers analysed tended to normalize, with the majority recovering values similar to those of the control group. In conclusion, MPs exposure during 90 days to S. aurata induced oxidative stress and a pro-inflammatory response in gut, and were able to recover after the exposure to MPs was removed.
塑料碎片造成的环境污染是一个全球性的主要关注点，因为它对海洋生物和生态系统构成了潜在威胁。海洋中的微塑料（MPs）由于其长期存在、潜在的生态毒性以及吸附其他污染物和作为病原体载体的能力，对生态系统具有显著影响。然而，尽管越来越多的研究调查了海洋鱼类中 MPs 的存在，但在长期实验室条件下，与 MPs 摄入相关的毒理学效应的研究较少。本研究的目的是评估在 90 天暴露于低密度聚乙烯（LDPE）MPs 后，通过在肠道中应用氧化应激生物标志物进行 30 天的净化，斜带石斑鱼（Sparus aurata）的生理反应。与摄入 MPs 相关的鱼的富尔顿状况系数没有变化。与对照组相比，在整个研究过程中，MPs 喂养组的抗氧化酶和谷胱甘肽 S-转移酶的活性以及还原型谷胱甘肽的水平逐渐增加，在 90 天时达到最高值。同样，在 90 天的富含 MPs 的饮食暴露后，促炎酶髓过氧化物酶的活性和氧化损伤标志物丙二醛和蛋白质羰基的水平也增加。在 30 天的净化期内，所有分析的生物标志物均趋于正常化，大多数恢复到与对照组相似的值。总之，在 90 天内暴露于 S. aurata 的 MPs 诱导了肠道中的氧化应激和促炎反应，并且在去除 MPs 暴露后能够恢复。
