The prevalence of organic/chemical UV-filter compounds in aquatic ecosystems represents a growing environmental issue. The long-term toxicity risks of many UV-filters at environmentally relevant concentrations to aquatic biota are still less studied, especially in the case of invertebrates. This study was designed to evaluate the chronic toxicity of avobenzone (AVO), octocrylene (OCTO), and octinoxate (OCTI), three UV-filters which frequently occur in the aquatic environment, to the water flea (Daphnia magna) at an environmentally relevant concentration of 200 ng l-1 in a 21-day exposure. Potential alterations in the growth, reproduction, and heart rate were continuously monitored during the treatments. Filtration rate, swimming, and the state of the antioxidant- and metabolic functions were evaluated at the end of exposures. Avobenzone significantly increased the reproductive output, heart rate, and filtration rate, while evoked a significant decrease of swimming behavior, and inhibited the activity of catalase (CAT) and glutathione S-transferase (GST) enzymes. The body size, reproduction, heart rate, and superoxide dismutase (SOD) activity were significantly increased whereas the activity of GST and CAT was significantly reduced by OCTO. OCTI significantly increased reproduction, heart rate, CAT and SOD activity but significantly decreased the swimming behavior. Our results confirmed that chronic exposure to organic UV-filters even at environmentally relevant concentrations affect basic physiological traits and cellular defense pathways in D. magna. Highlighting, our observations revealed previously unknown physiological changes (e.g., altered heart rate, filtration rate, SOD activity) caused by the investigated UV-filter compounds. Future research is to be aimed at investigating the mixture effects of these compounds and at the understanding of the potential cellular and molecular mechanisms underlying the changes induced.

中文翻译：

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长期暴露于亚致死浓度有机紫外线过滤化合物对淡水模式物种的发育、行为和生化影响


有机/化学紫外线过滤化合物在水生生态系统中的普遍存在代表了一个日益严重的环境问题。许多环境相关浓度的紫外线过滤剂对水生生物群的长期毒性风险仍然较少研究，尤其是在无脊椎动物的情况下。本研究旨在评估阿伏苯宗 （AVO）、奥克立林 （OCTO） 和辛氧酸盐 （OCTI） 这三种经常出现在水生环境中的紫外线过滤剂对水蚤 （Daphnia magna） 的慢性毒性，环境相关浓度为 200 ng l-1 在 21 天的暴露中。在治疗期间持续监测生长、繁殖和心率的潜在变化。在暴露结束时评估过滤率、游泳以及抗氧化和代谢功能的状态。阿伏苯宗显著提高生殖输出量、心率和滤过率，同时诱导游泳行为显著减少，并抑制过氧化氢酶 （CAT） 和谷胱甘肽 S-转移酶 （GST） 酶的活性。OCTO 显着增加体型、生殖、心率和超氧化物歧化酶 （SOD） 活性，而 GST 和 CAT 活性显着降低。OCTI 显着增加生殖、心率、CAT 和 SOD 活动，但显着降低游泳行为。我们的结果证实，即使在环境相关浓度下，长期暴露于有机紫外线过滤剂也会影响 D. magna 的基本生理特性和细胞防御途径。值得注意的是，我们的观察揭示了由所研究的紫外线过滤化合物引起的以前未知的生理变化（例如，心率改变、过滤率、SOD 活性）。 未来的研究旨在研究这些化合物的混合效应，并了解诱导变化的潜在细胞和分子机制。