Sadeghi L, Babadi V Yousefi, Tanwir F
Bratisl Lek Listy. 2018;119(6):379-384. doi: 10.4149/BLL_2018_070.
Manganese dioxide magnetic nanoparticle (MnO2-NP) with specific size range from 30 to 60 nm has widespread application in magnetic resonance imaging, medicine and drug delivery in exposed humans and animals. Manganese nanoparticles could affect hippocampus tissue and impose abnormal cognitive functions such as manganese ion. Therefore, to investigate whether MnO2-NP is damaging hippocampus tissue and inducing molecular and neurobehavioral abnormalities, we administrated different doses of synthesized nanoparticle to rats and measured behavioral, biochemical and histological parameters by standard methods.
Results showed that the treatment of rats with MnO2-NP during 15 days induced oxidative stress and reduced catecholamine content in hippocampus tissue. MnO2-NP affected hippocampus tissue appearance by increasing the number of apoptotic and necrotic cells suggested that approved nanoparticle penetrated blood brain barrier and reached the hippocampal cells. Interestingly, all biochemical and histological effects of MnO2-NP were dose dependent.
By considering that hippocampus plays an important role in cognitive function, behavioral abnormalities in intoxicated rats were predictable and nanoparticle administrated rats showed depression like behavioral signs dose dependently. Based on our results and previous studies that confirmed neurotoxicity of MnO2-NP in µg dose rang, the application of this nanoparticles should be limited and their waste should be neutralized before their release to the environment (Fig. 4, Ref. 31).
尺寸范围在30至60纳米的二氧化锰磁性纳米颗粒（MnO₂-NP）在暴露的人类和动物的磁共振成像、医学及药物递送方面有广泛应用。锰纳米颗粒可能会影响海马体组织，并引发如锰离子那样的异常认知功能。因此，为了研究MnO₂-NP是否会损害海马体组织并诱发分子及神经行为异常，我们给大鼠施用了不同剂量的合成纳米颗粒，并通过标准方法测量行为、生化及组织学参数。
结果显示，在15天内用MnO₂-NP处理大鼠会诱导氧化应激，并降低海马体组织中的儿茶酚胺含量。MnO₂-NP通过增加凋亡和坏死细胞数量影响海马体组织外观，这表明经批准的纳米颗粒穿透了血脑屏障并抵达了海马体细胞。有趣的是，MnO₂-NP的所有生化和组织学效应均呈剂量依赖性。
鉴于海马体在认知功能中起重要作用，中毒大鼠的行为异常是可预测的，且纳米颗粒处理的大鼠呈现出剂量依赖性的类似抑郁的行为迹象。基于我们的结果以及先前证实MnO₂-NP在微克剂量范围内具有神经毒性的研究，这种纳米颗粒的应用应受到限制，并且在其释放到环境之前应将其废物中和（图4，参考文献31）。
