Evaluation of potential toxicity of polyethylene microplastics on human derived cell lines

• Published in: The Science of the total environment Vol. 838; no. Pt 2; p. 156089
• Main Authors: Gautam, Ravi, Jo, JiHun, Acharya, Manju, Maharjan, Anju, Lee, DaEun, K.C., Pramod Bahadur, Kim, ChangYul, Kim, KilSoo, Kim, HyoungAh, Heo, Yong
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 10.09.2022
• Subjects: Microplastics; Nitric oxide; Polyethylene; Proinflammatory cytokines; Reactive oxygen species; Polyethylene; Reactive oxygen species; Microplastics; Proinflammatory cytokines; Nitric oxide
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2022.156089

Microplastics bare of major concern for environmental conservation and animal welfare in recent years as its use has increased tremendously. Polyethylene microplastics (PE-MPs) are the most common microplastics and could get exposed to humans via different routes with oral>inhalation>dermal. Internalization of MPs through epithelial tissue could expose MPs to various cells such as dendritic cells, macrophages/monocytes, and/or T cells. In this study, we aimed at identifying the effects of two different sized (30.5 ± 10.5 and 6.2 ± 2.0 μm) PE-MPs on different human cell lines representing different tissues or cells that get exposed to MPs directly or indirectly. Six cell lines were cultured with different concentrations of PE-MPs and cell viability, intracellular reactive oxygen species (ROS), nitric oxide (NO), and cytokines were measured. PE-MPs did not substantially lower the cell viability of cells however highest concentration (1000 μg/mL) of both sized MPs slightly reduced cell viability in intestinal epithelial Caco-2 and lung epithelial A549 cells. Both sized PE-MPs induced higher NO in all the cell lines and upregulation of ROS generation was demonstrated at THP-1, Jurkat, and U937 immune cell lines. A pro-inflammatory cytokine response was seen in HaCaT keratinocyte cells when cultured with PE-MPs whereas the opposite effect was observed in THP-1 and U937 cells except with THP-1 cells cultured with larger-sized MPs. We found that the PE-MPs do not have the same effects on all kinds of cells and tissues exposed and the immune modulation is not necessarily inflammatory. Thus, this study gives insight into why more detailed studies focused on exposure routes and organ-specific effects of different MPs need to be carried out. [Display omitted] •Polyethylene microplastics with single or double μm size were cytotoxic to epithelial cell lines at high concentrations.•Polyethylene microplastics induced nitric oxide and generated reactive oxygen species in cell lines independently of size.•Polyethylene microplastics modulated proinflammatory cytokines production at keratinocyte and immune cell lines.