Laboratory of Pathoneurochemistry, Department of Neurochemistry, Mossakowski Medical Research Centre, Polish Academy of Sciences, 5 Pawińskiego str, 02-106, Warsaw, Poland.
Department of Animal Environment Biology, Unit of Zoology, Faculty of Animal Sciences, Warsaw University of Life Sciences, 8 Ciszewskiego str, 02-787, Warsaw, Poland.
Neurotox Res. 2019 Apr;35(3):495-504. doi: 10.1007/s12640-018-9977-0. Epub 2018 Nov 8.
Currently, silver nanoparticles (AgNPs) are frequently used in a wide range of medical and consumer products. Substantial usage of AgNPs is considered to create substantive risks to both the environment and the human health. Since there is increasing evidence that the main mechanism of toxicity of AgNPs relates to oxidative stress, in the current study we investigate oxidative stress-related biochemical parameters in myelin isolated from adult rat brain subjected to a low dose of AgNPs. Animals were exposed for 2 weeks to 0.2 mg/kg b.w. of small (10 nm) AgNPs stabilized in citrate buffer or silver citrate established as a control to compare the effects of particulate and ionic forms of silver. We observe enhanced peroxidation of lipids and decreased concentrations of protein and non-protein -SH groups in myelin membranes. Simultaneously, expression of superoxide dismutase, a free radical scavenger, is increased whereas the process of protein glutathionylation, being a cellular protective mechanism against irreversible oxidation, is found to be inefficient. Results indicate that oxidative stress-induced alterations in myelin membranes may be the cause of ultrastructural disturbances in myelin sheaths.
目前，纳米银颗粒（AgNPs）被广泛应用于医疗和消费品领域。大量使用 AgNPs 被认为会对环境和人类健康造成实质性的风险。由于越来越多的证据表明，AgNPs 的毒性主要与氧化应激有关，因此在本研究中，我们研究了成年大鼠脑髓鞘中与氧化应激相关的生化参数，这些髓鞘在低剂量的 AgNPs 下受到了影响。动物被暴露于 0.2mg/kg b.w. 的小（10nm）AgNPs 中持续 2 周，AgNPs 被柠檬酸盐缓冲液稳定化，或被银柠檬酸稳定化作为对照，以比较颗粒和离子形式的银的影响。我们观察到髓鞘膜中脂质的过氧化作用增强，蛋白质和非蛋白质 -SH 基团的浓度降低。同时，自由基清除剂超氧化物歧化酶的表达增加，而作为细胞对抗不可逆氧化的保护机制的蛋白质谷胱甘肽化过程则被发现效率低下。结果表明，氧化应激诱导的髓鞘膜改变可能是髓鞘鞘层超微结构紊乱的原因。
