PPG-SEA and NEEA/CRHEA/SHS, São Carlos Engineering School, University of São Paulo, São Carlos, Brazil.
Analytical Chemistry Department, Institute of Chemistry, University of Campinas, Campinas, São Paulo, Brazil.
Environ Toxicol Chem. 2024 Feb;43(2):405-417. doi: 10.1002/etc.5798.
Pesticides employed worldwide for crop protection easily reach aquatic systems, which act as the main reservoirs, and become a risk factor for aquatic fauna. Fipronil is a broad-spectrum insecticide acting on the insect nervous system; however, other effects and systems unrelated to this mechanism could be affected in non-target organisms. Thus, the present study aimed to assess the impact of fipronil on the suborganismal response (gene expression and enzymatic activity) of Chironomus riparius larvae as a model organism in ecotoxicology. To this end, short-term toxicity tests were carried out with fourth-instar larvae exposed to 0.001, 0.01, and 0.1 µg L of fipronil for 24 and 96 h. Messenger RNA levels of 42 genes related to diverse metabolic pathways were analyzed by real-time polymerase chain reaction, complemented with catalase (CAT), glutathione S-transferase (GST), and acetylcholinesterase (AChE) activities. Few effects were observed at 24 h; however, after longer exposure (96 h), genes involved in the endocrine, detoxification, stress, and immune response pathways were altered. Moreover, fipronil at 96 h increased CAT and GST activity at 0.01 µg L and AChE at the highest concentrations. The results demonstrate that even low environmentally relevant fipronil concentrations can modulate the molecular response of several cellular pathways in C. riparius after short-term exposure. These results bring new information about the underlying response of fipronil and its mode of action on a key aquatic invertebrate. Despite no effects on mortality, strong modulation at the suborganismal level emphasizes the advantage of biomarkers as early damage responses and the harmful impact of this pesticide on freshwater organisms. Environ Toxicol Chem 2024;43:405-417. © 2023 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.
全世界用于作物保护的农药很容易进入水生系统，水生系统是主要的蓄积地，成为水生动物的一个风险因素。氟虫腈是一种作用于昆虫神经系统的广谱杀虫剂；然而，在非靶标生物中，可能会对与该机制无关的其他作用和系统产生影响。因此，本研究旨在评估氟虫腈对摇蚊幼虫亚机体反应（基因表达和酶活性）的影响，摇蚊幼虫作为生态毒理学的模式生物。为此，进行了短期毒性试验，第四龄幼虫暴露于 0.001、0.01 和 0.1μg/L 的氟虫腈中 24 和 96 小时。通过实时聚合酶链反应分析了与多种代谢途径相关的 42 个基因的信使 RNA 水平，并补充了 CAT（过氧化氢酶）、GST（谷胱甘肽 S-转移酶）和 AChE（乙酰胆碱酯酶）活性。24 小时内观察到的影响很少；然而，在更长的暴露时间（96 小时）后，参与内分泌、解毒、应激和免疫反应途径的基因发生了改变。此外，氟虫腈在 96 小时时在 0.01μg/L 时增加了 CAT 和 GST 活性，在最高浓度时增加了 AChE 活性。结果表明，即使是低浓度的环境相关氟虫腈也可以在短期暴露后调节摇蚊幼虫的几个细胞途径的分子反应。这些结果提供了关于氟虫腈及其对关键水生无脊椎动物作用模式的潜在反应的新信息。尽管死亡率没有影响，但亚机体水平的强烈调节强调了生物标志物作为早期损伤反应的优势，以及该农药对淡水生物的有害影响。环境毒理化学 2024；43:405-417。©2023 作者。环境毒理化学由 Wiley 期刊公司代表 SETAC 出版。
