Laboratorio de Ecotoxicología, Instituto de Investigaciones Marinas y Costeras (IIMYC), Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad Nacional de Mar Del Plata (CONICET- UNMdP), Dean Funes 3350, 7600, Mar Del Plata, Buenos Aires, Argentina; Comisión de Investigaciones Científicas de La Provincia de Buenos Aires (CIC), Argentina.
Facultad de Ciencias Exactas y Naturales, UNMdP. Dean Funes 3350, 7600, Mar Del Plata, Buenos Aires, Argentina.
Ecotoxicol Environ Saf. 2021 Jan 1;207:111286. doi: 10.1016/j.ecoenv.2020.111286. Epub 2020 Sep 15.
Azoxystrobin (AZX) is a broad-spectrum systemic fungicide massively used worldwide. Its mode of action consists in the inhibition of mitochondrial respiration decreasing the synthesis of ATP and leading to oxidative stress in the target fungus. However, whether this effect occurs in non target organisms has been scarcely studied. The objectives of this work were (1) to evaluate biomarkers of oxidative stress, hematological, physiological and of genotoxicity in the native cichlid fish Australoheros facetus exposed to environmentally relevant concentrations of AZX and (2) to compare these biomarkers in different developmental stages using juvenile and adult fish (n = 6) exposed during 48 h. The exposure concentrations were 0 (negative control, C (-)), 0.05, 0.5, 5 and 50 μg/L AZX of the commercial formulation AMISTAR®. Blood was drawn to evaluate hematology, and DNA damage through the comet assay (CA) and micronucleus test (MN). Genotoxicity was observed by mean of both biomarkers in juvenile and adult fish at 50 μg/L AZX. Samples of liver and gills were used to determine antioxidant enzymes activity, hydrogen peroxide (HO) and malondialdehyde (MDA) contents. In juvenile fish inhibition of superoxide dismutase (SOD) was observed in liver at 0.05, 5 and 50 μg/L AZX and in gills at 5 and 50 μg/L AZX. Glutathione- S- transferases (GST) activity increased in gills at all AZX concentrations tested. In adult fish, increase of hepatic catalase (CAT) activity at 0.5 and 50 μg/L AZX and MDA content at 50 μg/L AZX were observed. In gills only HO content showed changes at 50 μg/L AZX. The sensitivity showed by gills constitutes the first report about AZX toxicity in this organ. All these negative effects were observed in the range of realistic AZX concentrations, which warns of the possible consequences that it may have on the health of aquatic biota. Differences between juvenile and adult fish demonstrate the relevance of considering the developmental stage on the evaluation of biomarkers.
唑菌胺酯（AZX）是一种广泛应用于全球的广谱系统性杀菌剂。其作用机制在于抑制线粒体呼吸，降低 ATP 的合成，导致靶真菌发生氧化应激。然而，这种效应是否会在非靶标生物中发生，还鲜有研究。本研究的目的是：（1）评估暴露于环境相关浓度唑菌胺酯的本地慈鲷鱼Australoheros facetus 的氧化应激生物标志物、血液学、生理学和遗传毒性；（2）使用暴露 48 小时的幼鱼和成年鱼（n=6）比较不同发育阶段的这些生物标志物。暴露浓度为 0（阴性对照，C（-））、0.05、0.5、5 和 50μg/L 的唑菌胺酯商品制剂 AMISTAR®。采集血液以评估血液学，并通过彗星试验（CA）和微核试验（MN）评估 DNA 损伤。在 50μg/L AZX 下，幼鱼和成年鱼的两种生物标志物均观察到遗传毒性。使用肝和鳃样本测定抗氧化酶活性、过氧化氢（HO）和丙二醛（MDA）含量。在幼鱼中，在 0.05、5 和 50μg/L AZX 下观察到肝中超氧化物歧化酶（SOD）的抑制，在 5 和 50μg/L AZX 下观察到鳃中 SOD 的抑制。在所有测试的 AZX 浓度下，鳃中谷胱甘肽-S-转移酶（GST）活性增加。在成年鱼中，在 0.5 和 50μg/L AZX 下观察到肝中过氧化氢酶（CAT）活性增加，在 50μg/L AZX 下观察到 MDA 含量增加。在 50μg/L AZX 下，仅观察到鳃中 HO 含量发生变化。鳃的敏感性是该器官中唑菌胺酯毒性的首次报道。所有这些负面影响都是在现实的 AZX 浓度范围内观察到的，这警告了它可能对水生生物群健康造成的潜在后果。幼鱼和成年鱼之间的差异表明，在评估生物标志物时，考虑发育阶段具有重要意义。
