The reactive oxygen species as pathogenic factors of fragmented microplastics to macrophages. (15th July 2021)

• Record Type: Journal Article
• Authors: Jeon, Soyeon; Lee, Dong-Keun; Jeong, Jiyoung; Yang, Sung Ik; Kim, Ji-Su; Kim, Jinsik; Cho, Wan-Seob
• Is Part Of: Environmental pollution. Volume 281(2021)
• Publication Date: 2021-07-15
• Subjects: Cytotoxicity -- Inflammation -- Microplastics -- Reactive oxygen species -- Weathering; Pollution -- Periodicals; Pollution -- Environmental aspects -- Periodicals; Environmental Pollution -- Periodicals; Pollution -- Périodiques; Pollution -- Aspect de l'environnement -- Périodiques; Pollution -- Effets physiologiques -- Périodiques; Pollution; Pollution -- Environmental aspects; Periodicals; Electronic journals; 363.73
• DOI: 10.1016/j.envpol.2021.117006
• Languages: English
• ISSNs: 0269-7491

Abstract

Abstract: The presence of microplastics in the various food web raised concerns on human health, but little is known about the target cells and mechanism of toxicity of microplastics. In this study, we evaluated the toxicity of microplastics using relevant cell lines to the oral route of exposure. Approximately 100 μm-sized fragment-type polypropylene (PP) and polystyrene (PS) particles were prepared by sieving after pulverization and further applied the accelerated weathering using ultraviolet and heat. Thus, the panel of microplastics includes fresh PP (f-PP), fresh PS (f-PS), weathered PP (w-PP), and weathered PS (w-PS). The spherical PS with a similar size was used as a reference particle. Treatment of all types of PP and PS did not show any toxic effects to the Caco-2 cells and HepG2 cells. However, the treatment of microplastics to THP-1 macrophages showed significant toxicity in the order of f-PS > f-PP > w-PS > w-PP. The weathering process significantly reduced the reactive oxygen species (ROS) generation potential of both microplastics because the weathered microplastics have an increased affinity to bind serum protein which acts as a ROS scavenger. The intrinsic ROS generation potential of microplastics showed a good correlation with the toxicity endpoints including cytotoxicity and pro-inflammatory cytokines in THP-1 macrophages. In conclusion, the results of this study suggest that the target cell type of microplastics via oral administration can be macrophages and the pathogenic factor to THP-1 macrophages is the intrinsic ROS generation potential of microplastics. Nevertheless, the toxic effect of microplastics tested in this study was much less than that of nano-sized particles. Graphical abstract: Image 1 Highlights: Fragmented PP and PS microplastics with accelerated weathering was prepared. Microplastics showed no toxicity to the Caco-2 cells and HepG2 cells. Microplastics showed toxicities to THP-1 macrophages by the role of ROS. The weathering process increased serum protein binding, acting as a ROS scavenger. The pathogenic factor of microplastics is the intrinsic oxidative potential.