Abstract：
The present study aims to compare and assess the toxicity induced by aged (irradiated with ultraviolet radiation for 120 days) polyethylene microplastics (PE-MPs) in comparison to virgin (non-irradiated) ones, after feeding the freshwater fish Perca fluviatilis. To this end, MPs mediated genotoxicity was assessed by the investigation of micronucleus nuclear abnormalities frequency in fish blood, and the degree of DNA damage in the liver and muscle tissues, while metabolic alterations were also recorded in both tissues. Results showed that both virgin and aged PE-MPs induced signaling pathways leading to DNA damage and nuclear abnormalities, as well as metabolites changes in all tissues studied. Metabolic changes revealed that the metabolism of nucleic acids, energy, amino acids, and neurotransmitters was more disrupted in the liver and by aged PE-MPs compared to muscles. Fish fed with aged PE-MPs exhibited greater DNA damage, while blood cells of fish fed with virgin PE-MPs seemed to be more vulnerable to nuclear abnormalities in relation to those fed with aged PE-MPs. Moreover, aged PE-MPs induced more acute overall effects on the metabolic profiles of fish tissues, and initiated stronger stress responses, inflammation, and cellular damages in fish tissues in relation to virgin ones. Characterization of both virgin and aged MPs revealed that the latter exhibited lower crystallinity and melting point, more irregular shapes and higher moiety of oxygen and carbonyl groups, which could be attributed for their observed higher toxicity. The research outcomes provide significant insights for advancing toxicological investigations in this field.
摘要：
本研究旨在比较和评估老化（紫外线照射120天）聚乙烯微塑料（PE-MPs）与原始（未照射）聚乙烯微塑料引起的毒性，喂食淡水鱼Percafluviatilis后。为此,通过调查鱼血中的微核核异常频率来评估MPs介导的遗传毒性，以及肝脏和肌肉组织的DNA损伤程度，而代谢改变也记录在两个组织。结果表明，原始和老年PE-MPs诱导的信号通路导致DNA损伤和核异常，以及所有研究组织中的代谢物变化。代谢变化揭示了核酸的代谢，能源,氨基酸,与肌肉相比，肝脏和老年PE-MPs对神经递质的破坏更大。用老化的PE-MP喂养的鱼表现出更大的DNA损伤，而饲喂原始PE-MPs的鱼的血细胞似乎比饲喂老年PE-MPs的鱼更容易出现核异常。此外，老年PE-MPs对鱼类组织的代谢谱产生了更急性的整体影响，并引发更强的压力反应，炎症,以及与原始鱼有关的鱼组织中的细胞损伤。原始和老化MPs的表征表明，后者表现出较低的结晶度和熔点，更不规则的形状和更高的氧和羰基部分，这可以归因于它们观察到的更高的毒性。研究结果为推进该领域的毒理学研究提供了重要见解。
