Area of Toxicology, Faculty of Pharmacy, University of Seville, Profesor García González n°2, 41012 Seville, Spain.
Food Chem Toxicol. 2013 Jul;57:266-75. doi: 10.1016/j.fct.2013.03.043. Epub 2013 Apr 8.
Montmorillonite based clays have a wide range of applications that are going to contribute to increase human exposure to these materials. One of the most promising uses of clays is the development of reinforced food contact materials that results in nanocomposites with improved barrier properties. Different organoclays have been developed introducing modifiers in the natural clay which is commercially available. However, the toxicological aspects of these materials have been scarcely studied so far. In the present study, the cytotoxic effects of a non-modified clay (Cloisite Na+) and an organoclay (Cloisite 30B) have been investigated in the hepatic cell line HepG2. Only Cloisite 30B showed cytotoxicity. In order to elucidate the toxic mechanisms underlying these effects, apoptosis, inflammation, oxidative stress and genotoxicity biomarkers were assayed. Moreover, a morphology study with light and electron microscopy was performed. Results showed genotoxic effects and glutathione decrease. The most relevant ultraestructural alterations observed were mitochondrial degeneration, dilated endomembrane systems, heterophagosomes formation, fat droplets appearance and presence of nuclear lipid inclusions. Cloisite 30B, therefore, induces toxic effects in HepG2 cells. Further research is needed to assess the risk of this clay on the human health.
蒙脱石基粘土具有广泛的应用，这将有助于增加人类接触这些材料的机会。粘土最有前途的用途之一是开发增强型食品接触材料，从而得到具有改善的阻隔性能的纳米复合材料。已经开发出了不同的有机粘土，在商业上可获得的天然粘土中引入了改性剂。然而，到目前为止，这些材料的毒理学方面还很少被研究。在本研究中，研究了肝细胞系 HepG2 中未改性粘土（Cloisite Na+）和有机粘土（Cloisite 30B）的细胞毒性作用。只有 Cloisite 30B 表现出细胞毒性。为了阐明这些作用的毒性机制，测定了凋亡、炎症、氧化应激和遗传毒性生物标志物。此外，还进行了光镜和电子显微镜的形态学研究。结果显示遗传毒性和谷胱甘肽减少。观察到的最相关的超微结构改变是线粒体退化、内质网系统扩张、异噬体形成、脂肪滴出现和核脂质内含物的存在。因此，Cloisite 30B 会诱导 HepG2 细胞产生毒性作用。需要进一步研究来评估这种粘土对人类健康的风险。
