Monensin, an antibacterial commonly used in animal fattening, can enter aquatic ecosystems and harm non-target organisms. Since there are no previous studies about the effects of monensin on amphibians, the aim of the present study was to evaluate the lethal and sublethal toxicity of a commercial formulation of monensin (CFM) through standardized bioassays with embryos and larvae of the amphibian . Oxidative stress (catalase and glutathione S-transferase activities, and reduced glutathione and lipid peroxidation levels), cholinesterasic effect (acetylcholinesterase and butyrylcholinesterase activities) and mutagenicity (micronuclei frequency) biomarkers were evaluated. The CFM produced teratogenic effects, with a teratogenic index of 6.21. Embryos (504 h-LC50: 273.33 µg/L) were more sensitive than larvae, as no significant mortality was observed on larvae exposed up to 3000 µg/L for 504 h. However, oxidative stress, cholinesterasic effect and mutagenicity biomarkers were altered on larvae exposed for 96 h to environmentally relevant concentrations (4, 12 and 20 µg/L of monensin active ingredient). The CFM caused adverse effects on the exposed organisms, primarily on embryos, leading to lethal and sublethal effects, which could impact the wildlife when it reaches aquatic ecosystems.

中文翻译：

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莫能菌素商业制剂对沙蚕胚胎和幼虫毒性的多方法分析

莫能菌素是一种常用于动物育肥的抗菌剂，可进入水生生态系统并伤害非目标生物。由于之前没有关于莫能菌素对两栖动物影响的研究，本研究的目的是通过两栖动物胚胎和幼虫的标准化生物测定来评估莫能菌素商业制剂（CFM）的致死和亚致死毒性。评估了氧化应激（过氧化氢酶和谷胱甘肽S-转移酶活性，以及​​降低的谷胱甘肽和脂质过氧化水平）、胆碱酯酶作用（乙酰胆碱酯酶和丁酰胆碱酯酶活性）和致突变性（微核频率）生物标志物。 CFM产生致畸作用，致畸指数为6.21。胚胎 (504 h-LC50: 273.33 µg/L) 比幼虫更敏感，因为暴露于 3000 µg/L 浓度 504 h 的幼虫没有观察到明显的死亡率。然而，暴露于环境相关浓度（4、12 和 20 µg/L 莫能菌素活性成分）96 小时的幼虫的氧化应激、胆碱酯酶效应和致突变性生物标志物发生了改变。 CFM 对暴露的生物体（主要是胚胎）造成了不利影响，导致致命和亚致死效应，当野生动物到达水生生态系统时可能会对其产生影响。