State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, PR China.
State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, PR China.
Chemosphere. 2019 Apr;221:333-341. doi: 10.1016/j.chemosphere.2019.01.056. Epub 2019 Jan 8.
Microplastics in the environment may gain entry the human gastrointestinal tract through the food chain. However, information on different adverse effects of microplastics at nanometer or micrometer scales in human intestine cells is limited. This study compared the cytotoxicity and efflux pump inhibition ability of 0.1 μm and 5 μm polystyrene microplastics (PS-MPs) in the human colon adenocarcinoma Caco-2 cells. Both PS-MP sizes exhibited low toxicity on cell viability, oxidative stress, and membrane integrity and fluidity. However, the mitochondrial membrane potential was disrupted by both sizes of PS-MPs, and the 5 μm PS-MPs induced higher effects than 0.1 μm PS-MPs. Furthermore, 0.1 μm (≥20 μg/mL) or 5 μm (≥80 μg/mL) PS-MPs inhibited plasma membrane ATP-binding cassette (ABC) transporter activity and increased arsenic (one substrate of ABC transporter) toxicity. The 0.1 μm PS-MPs might act as substrates of ABC transporter to reduce the transport capacity of other substrates. However, high concentrations of 5 μm PS-MPs might reduce ABC transporter activity through induction of mitochondrial depolarization and potential depletion of ATP. This study provides basic information on the toxicity of 0.1 μm and 5 μm PS-MPs in human intestine cells, which are useful for assessing the risk of PS-MPs in humans.
环境中的微塑料可能通过食物链进入人体胃肠道。然而，关于人类肠道细胞中纳米或微米级微塑料的不同不良影响的信息有限。本研究比较了 0.1μm 和 5μm 聚苯乙烯微塑料（PS-MPs）在人结肠腺癌细胞（Caco-2 细胞）中的细胞毒性和外排泵抑制能力。两种 PS-MP 尺寸对细胞活力、氧化应激和膜完整性及流动性的毒性都较低。然而，两种 PS-MP 尺寸均破坏了线粒体膜电位，且 5μm PS-MP 诱导的作用大于 0.1μm PS-MP。此外，0.1μm（≥20μg/mL）或 5μm（≥80μg/mL）PS-MP 抑制质膜 ABC 转运体活性并增加砷（ABC 转运体的一种底物）毒性。0.1μm PS-MP 可能作为 ABC 转运体的底物，降低其他底物的转运能力。然而，高浓度的 5μm PS-MP 可能通过诱导线粒体去极化和潜在的 ATP 耗竭来降低 ABC 转运体的活性。本研究提供了 0.1μm 和 5μm PS-MP 在人肠道细胞中毒性的基本信息，这对于评估 PS-MP 在人体中的风险具有重要意义。
