Laboratório de Enzimologia, Departamento de Bioquímica e Biologia Tecidual, Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP), SP, Brazil.
Laboratório de Ecotoxicologia e Biossegurança, EMBRAPA Meio Ambiente, Jaguariúna, SP, Brazil.
Ecotoxicol Environ Saf. 2018 Feb;148:367-376. doi: 10.1016/j.ecoenv.2017.10.054. Epub 2017 Nov 6.
The insecticide Diflubenzuron (DFB), used by many fish farming, when metabolized or degraded produces the extremely toxic compound p-chloroaniline (PCA). Once in the aquatic environment, these compounds can form mixtures and their bioavailability depends on factors such as the presence of soil. The toxic effects of the isolated compounds and their mixtures in the proportions: 75%, 50%, and 25% of PCA were analyzed in tilapia (Oreochromis niloticus) in the presence and absence of soil after 96h. The enzymes catalase (CAT), acid (AcP) and alkaline (AlP) phosphatases and alanine (ALT) and aspartate (AST) aminotransferases of the liver of the tilapia (Oreochromis niloticus) were used as biomarkers. DFB and the mixture containing 75% of this compound did not present high toxicity to fish; however, 25mg/L of PCA alone and 15mg/L of the mixture with 75% of this compound promoted 50% mortality of tilapia (Oreochromis niloticus). In the presence of soil, these toxicity values decreased to 37 and 25mg/L, respectively. Independent of the presence of soil, a synergistic effect was observed when the proportion of PCA was 75% and to the mixture, with 25% PCA was observed the antagonistic effect. Different concentrations of the compounds and their mixtures induced CAT activity independently of the presence of soil. Additionally, increases in phosphatases and transaminases activities were observed. In some cases, the enzymes also had their activities decreased and the dose-dependence effects were not observed. This research showed that the presence of soil influenced the toxicity of the compounds but not altered interaction type among them. Diflubenzuron, p-chloroaniline, and mixtures thereof caused disorders in enzymes important for the health of tilapia (Oreochromis niloticus).
杀虫剂除虫脲（DFB）被许多水产养殖所使用，当它被代谢或降解时会产生极其有毒的化合物对氯苯胺（PCA）。一旦进入水生环境，这些化合物可以形成混合物，它们的生物利用度取决于土壤等因素的存在。在存在和不存在土壤的情况下，分析了在罗非鱼（Oreochromis niloticus）中单独的化合物及其混合物在以下比例下的毒性作用：75％、50％和 25％的 PCA，时间为 96 小时。使用罗非鱼（Oreochromis niloticus）肝脏中的过氧化氢酶（CAT）、酸性（AcP）和碱性（AlP）磷酸酶以及丙氨酸（ALT）和天冬氨酸（AST）氨基转移酶作为生物标志物。DFB 和含有 75％该化合物的混合物对鱼类没有表现出高毒性；然而，单独的 25mg/L 的 PCA 和含有 75％该化合物的混合物的 15mg/L 分别导致罗非鱼（Oreochromis niloticus）的 50％死亡率。在存在土壤的情况下，这些毒性值分别降低至 37 和 25mg/L。无论土壤的存在与否，当 PCA 的比例为 75％时观察到协同作用，而当混合物中含有 25％的 PCA 时观察到拮抗作用。不同浓度的化合物及其混合物的 CAT 活性独立于土壤的存在而增加。此外，还观察到磷酸酶和转氨酶活性的增加。在某些情况下，酶的活性也降低，并且没有观察到剂量依赖性效应。这项研究表明，土壤的存在影响了化合物的毒性，但没有改变它们之间的相互作用类型。除虫脲、对氯苯胺及其混合物会导致罗非鱼（Oreochromis niloticus）健康相关酶的紊乱。
