纳米ZnO和常规ZnO、ZnSO4对斑马鱼毒性效应的比较

为比较纳米ZnO、常规ZnO和ZnSO_4对斑马鱼氧化应激毒性的强弱,探究纳米ZnO的毒性作用与其释放的Zn2+和本身特性的关系,研究了纳米ZnO、常规ZnO、ZnSO_4对斑马鱼肝脏、肠、鳃组织中抗氧化酶活性及炎症凋亡基因表达的影响。实验将斑马鱼分别暴露于纳米ZnO、常规ZnO、ZnSO_4水体中,在4、24和96 h后,用分光光度法检测斑马鱼肝脏、肠、鳃中过氧化氢酶(CAT)、谷胱甘肽(GSH)、谷胱甘肽硫转移酶(GST)、活性氧自由基(ROS)的变化;采用荧光定量PCR技术,测定实验组中肝脏、肠和鳃中Bax、Bcl-2、TNF-α及IL-6的mRNA相对表达量。结果显示,纳米ZnO、常规ZnO、ZnSO_4均引起斑马鱼各组织的氧化应激反应,且使组织中凋亡基因和炎症基因表达水平发生变化,激活生物体内的细胞坏死和细胞凋亡途径,引起细胞死亡或机体炎症,其中纳米ZnO的致氧化损伤作用最强。研究表明,纳米ZnO对斑马鱼的氧化应激毒性强于常规ZnO和ZnSO_4,而纳米颗粒本身特性是导致纳米ZnO毒性作用的主要原因。

Comparative toxicity effect of nano-ZnO, bulk-ZnO, and ZnSO4 on oxidative stress in zebrafish(Danio rerio)

In order to explore the toxicity of nano ZnO and its relationship with the release of Zn²⁺ and its own characteristics, zebrafish were exposed to the nano-ZnO, bulk-ZnO, and ZnSO₄ suspension for 4, 24 and 96 hours by using the acute toxicity test, and the glutathione-s-transferase (GST), catalase (CAT), and the levels of glutathione (GSH) and reactive oxygen species (ROS), the relative expression levels of Bax, Bcl-2, TNF- alpha and IL-6 in liver, intestine and gill of zebrafish were measured. The objective of this study was to compare the the strength of oxidative stress effects of nano-ZnO, bulk-ZnO and ZnSO₄ in zebrafish, and discuss whether the toxicity of nano-ZnO is related to the releasing Zn²⁺ or nanoparticles itself. Results showed that nano-ZnO, bulk-ZnO, and ZnSO₄ can cause oxidative stress in the tissues of zebrafish, and the nano-ZnO induced more oxidative damage than the other two forms of zinc. Consequently, we can conclude that the toxicity of nano-ZnO was higher than that of bulk-ZnO and ZnSO₄ on oxidative stress in zebrafish and the toxicity of nano-ZnO was mainly attributed to the nanoparticles itself.