Krishnaraj Chandran, Harper Stacey L, Yun Soon-Il
Department of Food Science & Technology, College of Agriculture & Life Sciences, Chonbuk National University, Jeonju 561-756, Republic of Korea.
Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, OR 97331, United States.
J Hazard Mater. 2016 Jan 15;301:480-91. doi: 10.1016/j.jhazmat.2015.09.022. Epub 2015 Sep 14.
The present study examines the deleterious effect of biologically synthesized silver nanoparticles in adult zebrafish. Silver nanoparticles (AgNPs) used in the study were synthesized by treating AgNO3 with aqueous leaves extract of Malva crispa Linn., a medicinal herb as source of reductants. LC50 concentration of AgNPs at 96 h was observed as 142.2 μg/l. In order to explore the underlying toxicity mechanisms of AgNPs, half of the LC50 concentration (71.1 μg/l) was exposed to adult zebrafish for 14 days. Cytological changes and intrahepatic localization of AgNPs were observed in gills and liver tissues respectively, and the results concluded a possible sign for oxidative stress. In addition to oxidative stress the genotoxic effect was observed in peripheral blood cells like presence of micronuclei, nuclear abnormalities and also loss in cell contact with irregular shape was observed in liver parenchyma cells. Hence to confirm the oxidative stress and genotoxic effects the mRNA expression of stress related (MTF-1, HSP70) and immune response related (TLR4, NFKB, IL1B, CEBP, TRF, TLR22) genes were analyzed in liver tissues and the results clearly concluded that the plant extract mediated synthesis of AgNPs leads to oxidative stress and immunotoxicity in adult zebrafish.
本研究考察了生物合成的银纳米颗粒对成年斑马鱼的有害影响。本研究中使用的银纳米颗粒（AgNPs）是通过用锦葵（一种药用草本植物）的水叶提取物处理硝酸银作为还原剂合成的。观察到AgNPs在96小时时的半数致死浓度（LC50）为142.2μg/l。为了探究AgNPs潜在的毒性机制，将半数LC50浓度（71.1μg/l）的AgNPs暴露于成年斑马鱼14天。分别在鳃和肝脏组织中观察到AgNPs的细胞学变化和肝内定位，结果表明可能存在氧化应激迹象。除氧化应激外，在外周血细胞中还观察到遗传毒性效应，如微核的存在、核异常，并且在肝实质细胞中还观察到细胞接触丧失和细胞形状不规则。因此，为了证实氧化应激和遗传毒性效应，在肝脏组织中分析了应激相关（MTF-1、HSP70）和免疫反应相关（TLR4、NFKB、IL1B、CEBP、TRF、TLR22）基因的mRNA表达，结果清楚地表明植物提取物介导合成的AgNPs会导致成年斑马鱼出现氧化应激和免疫毒性。
