Abstract：
Food grade titanium dioxide E171 has been used in products such as confectionery, doughs and flours to enhance organoleptic properties. The European Union has warned about adverse effects on humans due to oral consumption. After oral exposure, E171 reaches the bloodstream which raises the concern about effects on blood cells such as monocytes. One of the main functions of these cells is the differentiation of macrophages leading to the phagocytosis of foreign particles. The aim of this study was to evaluate the effect of E171 exposure on the phagocytic capacity and differentiation process of monocytes (THP-1) into macrophages. Physicochemical E171 properties were evaluated, and THP-1 monocytes were exposed to 4, 40 and 200 μg/ml. Cell viability, uptake capacity, cytokine release, the differentiation process, cytoskeletal arrangement and E171 internalization were assayed. Results showed that E171 particles had an amorphous shape with a mean of hydrodynamic size of ∼46 nm in cell culture media. Cell viability decreased until the 9th day of exposure, while the uptake capacity decreased up to 62% in a concentration dependent manner in monocytes. Additionally, the E171 exposure increased the proinflammatory cytokines release and decreased the cell differentiation by a 61% in macrophages. E171 induced changes in cytoskeletal arrangement and some of the E171 particles were located inside the nuclei. We conclude that E171 exposure in THP-1 monocytes induced an inflammatory response, impaired the phagocytic capacity, and interfered with cell differentiation from monocytes to macrophages.
摘要：
食品级二氧化钛E171已用于糖果等产品，面团和面粉，以增强感官特性。欧盟警告说，口服对人类的不利影响。口腔暴露后，E171到达血流，这引起了人们对单核细胞等血细胞的影响的关注。这些细胞的主要功能之一是巨噬细胞的分化，导致外源颗粒的吞噬作用。这项研究的目的是评估E171暴露对单核细胞（THP-1）吞噬能力和向巨噬细胞分化过程的影响。对E171的理化性质进行了评估，和THP-1单核细胞暴露于4、40和200μg/ml。细胞活力，吸收能力，细胞因子释放，分化过程,测定细胞骨架排列和E171内化。结果表明，E171颗粒在细胞培养基中呈无定形形状，平均流体动力学尺寸为〜46nm。细胞活力下降，直到暴露的第9天，而单核细胞的摄取能力以浓度依赖性方式下降高达62％。此外,E171暴露增加了促炎细胞因子的释放,并使巨噬细胞的细胞分化减少了61%.E171诱导细胞骨架排列的变化，一些E171颗粒位于细胞核内。我们得出结论，THP-1单核细胞中的E171暴露诱导了炎症反应，吞噬能力受损，并干扰细胞从单核细胞分化为巨噬细胞。
