Song Zhigang, Lv Jiadong, Sheikhahmadi Ardashir, Uerlings Julie, Everaert Nadia
Department of Animal Science and Technology, Shandong Agricultural University, Taian, 271018, Shandong, People's Republic of China.
Department of Animal Science, Faculty of Agriculture, University of Kurdistan, Sanandaj, 66177-15175, Iran.
Biol Trace Elem Res. 2017 Dec;180(2):306-313. doi: 10.1007/s12011-017-1016-0. Epub 2017 Apr 14.
Silver nanoparticles (AgNPs) have been increasingly used as antimicrobial and disinfectant. However, intestinal model studies have shown that AgNPs induce oxidative stress. Hence, this study aims to investigate the effects of dietary supplemental zinc (Zn) and vitamin E (VE; α-tocopherol acetate) on attenuating AgNP-induced intestinal oxidative stress in broiler chickens. The chickens were divided into two groups as follows: (1) control group fed with a corn-soybean meal basal diet and (2) nano group, received drinking water containing 1000 mg/kg AgNPs. All the nano-exposed birds were divided into six dietary treatment groups, namely, the basal diets supplemented with (1) 60 mg/kg Zn as ZnSO, (2) 120 mg/kg Zn, (3) 100 mg/kg VE, (4) 200 mg/kg VE, (5) 60 mg/kg Zn and 100 mg/kg VE, and (6) 120 mg/kg Zn and 200 mg/kg VE. Results showed that the AgNPs significantly reduced the body weights of the broilers after 42 days of oral administration of AgNPs (P < 0.05), and this effect was not alleviated by any of the dietary treatments. The activity of superoxide dismutase (CuZn-SOD) increased in all the AgNP-treated birds (P < 0.05); however, CuZn-SOD did not increase in birds fed with basal diet supplemented with 200 mg/kg VE. In this treatment, the VE exerted an antioxidant effect to prevent the activation of the CuZn-SOD enzyme. Furthermore, supplementing Zn increased the activities of catalase and glutathione peroxidase in the jejunal mucosa (P < 0.05), which were accompanied with increased malondialdehyde levels (P < 0.05) in the broilers. AgNP exposure resulted in a significant messenger RNA (mRNA) upregulation of toll-like receptor 4 (TLR4) and TLR2-1 in the jejunal mucosa (P < 0.05). However, supplemental ZnVE did not reduce TLRs' mRNA expression, except for the diminished TLR2-1 mRNA levels in birds fed with basal diet supplemented with 120 mg/kg Zn and 200 mg/kg VE. We concluded that although dietary Zn and VE supplementation did not attenuate growth depression effect of AgNP, it however attenuates intestinal oxidative stress in AgNP-treated broiler chickens.
银纳米颗粒（AgNPs）已越来越多地用作抗菌剂和消毒剂。然而，肠道模型研究表明，AgNPs会诱导氧化应激。因此，本研究旨在探讨日粮中补充锌（Zn）和维生素E（VE；α-生育酚醋酸酯）对减轻AgNP诱导的肉鸡肠道氧化应激的影响。将鸡分为两组：（1）对照组饲喂玉米-豆粕基础日粮；（2）纳米组，饮用含1000 mg/kg AgNPs的水。所有接触纳米颗粒的鸡被分为六个日粮处理组，即基础日粮分别补充：（1）60 mg/kg Zn（以ZnSO形式）、（2）120 mg/kg Zn、（3）100 mg/kg VE、（4）200 mg/kg VE、（5）60 mg/kg Zn和100 mg/kg VE、（6）120 mg/kg Zn和200 mg/kg VE。结果表明，口服AgNPs 42天后，AgNPs显著降低了肉鸡体重（P<0.05），且任何日粮处理均未缓解该效应。所有经AgNP处理的鸡超氧化物歧化酶（CuZn-SOD）活性均升高（P<0.05）；然而，在饲喂补充200 mg/kg VE基础日粮的鸡中，CuZn-SOD活性未升高。在此处理中，VE发挥抗氧化作用，阻止了CuZn-SOD酶的激活。此外，补充Zn可提高空肠黏膜中过氧化氢酶和谷胱甘肽过氧化物酶的活性（P<0.05），同时肉鸡丙二醛水平升高（P<0.05）。暴露于AgNP导致空肠黏膜中Toll样受体4（TLR4）和TLR2-1的信使核糖核酸（mRNA）显著上调（P<0.05）。然而，补充ZnVE并未降低TLRs的mRNA表达，但在饲喂补充120 mg/kg Zn和200 mg/kg VE基础日粮的鸡中，TLR2-1的mRNA水平有所降低。我们得出结论，虽然日粮中补充Zn和VE并未减轻AgNP对生长的抑制作用，但却减轻了AgNP处理的肉鸡的肠道氧化应激。
