BDE-47对斑马鱼胚胎-幼鱼的急性毒性及氧化应激作用

为研究2,2',4,4'-四溴联苯醚(BDE-47)对斑马鱼胚胎-幼鱼急性毒性、氧化应激及细胞凋亡的影响，以受精后3 h的斑马鱼胚胎为染毒对象，用概率单位法计算BDE-47对斑马鱼胚胎-幼鱼的96 h-LC₅₀；再参照96 h-LC₅₀按一定比例级差设置0.25、0.5、1.0、2.0 mg·L^-1 4个浓度组和1个对照组(0 mg·L^-1)进行96 h半静水式毒性试验，检测斑马鱼超氧化物歧化酶(SOD)及过氧化氢酶(CAT)活性、丙二醛(MDA)含量和细胞凋亡情况。结果表明，BDE-47对斑马鱼96 h的急性毒性LC₅₀为3.77 mg·L^-1(95%可信区间1.93～10.27 mg·L^-1)；2.0 mg·L^-1剂量组与对照组相比，SOD活性和MDA含量显著增加，且CAT活性与BDE-47染毒浓度之间存在明显的剂量-效应关系；0.5 mg·L^-1 BDE-47染毒96 h后，即观察到斑马鱼幼鱼出现明显细胞凋亡，主要集中于神经管和脑部。研究表明，BDE-47可以影响斑马鱼体内抗氧化防御系统，并能诱导细胞凋亡；BDE-47导致神经组织的氧化损伤可能在动物神经毒性中起重要作用。

Acute Toxicity and Oxidative Stress Effects of BDE-47 on Zebrafish Embryos and Larvae

The purpose of this study is to explore the acute toxicity and oxidative stress of BDE-47 to zebrafish embryos and larvae. The 96 h acute toxicity test was conducted using 3 hours post-fertilization zebrafish, and the 96 h-LC₅₀ of BDE-47 for adolescent zebrafish was calculated using Karber's method. The 4 days post-fertilization zebrafish was exposed to 0.25, 0.5, 1.0 and 2.0 mg·L^-1 of BDE-47 for 96 hours in semi-static test system to investigate the effect of BDE-47 on SOD and CAT activities, and MDA contents. Acridine orange (AO) staining was performed to observe the apoptosis caused by BDE-47. The results showed that the 96 h-LC₅₀ of BDE-47 for zebrafish was 3.77 mg·L^-1, with the 95% confidence interval of 1.93-10.27 mg·L^-1. The SOD activity and MDA content of zebrafish in 2.0 mg·L^-1 group were significantly higher compared with the control group. The CAT activity showed obvious dose-response relationship with BDE-47 concentration. After exposure to 0.5 mg·L^-1 of BDE-47 for 96 hours, significant apoptosis was observed in the larvae, which mainly accumulated in the neural tube and brain. It is indicated that BDE-47 exposure could induce oxidative stress and further cause cell apoptosis in larvae. The tissue oxidative damage might be one of the primary mechanisms of neurotoxicity of BDE-47.