Tissue accumulation of microplastics in mice and biomarker responses suggest widespread health risks of exposure

Abstract

Microplastics (MPs) are a significant environmental health issue and increasingly greater source of concern. MPs have been detected in oceans, rivers, sediments, sewages, soil and even table salts. MPs exposure on marine organisms and humans has been documented, but information about the toxicity of MPs in mammal is limited. Here we used fluorescent and pristine polystyrene microplastics (PS-MPs) particles with two diameters (5 μm and 20 μm) to investigate the tissue distribution, accumulation, and tissue-specific health risk of MPs in mice. Results indicated that MPs accumulated in liver, kidney and gut, with a tissue-accumulation kinetics and distribution pattern that was strongly depended on the MPs particle size. In addition, analyses of multiple biochemical biomarkers and metabolomic profiles suggested that MPs exposure induced disturbance of energy and lipid metabolism as well as oxidative stress. Interestingly, blood biomarkers of neurotoxicity were also altered. Our results uncovered the distribution and accumulation of MPs across mice tissues and revealed significant alteration in several biomarkers that indicate potential toxicity from MPs exposure. Collectively, our data provided new evidence for the adverse consequences of MPs.

Commentary: Tissue accumulation of microplastics in mice and biomarker responses suggest widespread health risks of exposure

“…The same group has now reported a similar analysis in a mammalian species (Deng et al, 2017). Ingested by the mice through drinking water, 5 and 20 µm polystyrene micro-particles elicited somewhat similar pathological and physiological changes in mice.…”

“…On the whole, the findings of Deng et al (2017) were made under conditions that mimic a massive overdose of microplastics and the results seen are limited to what might resemble a tissue limited acute inflammatory response. Documenting the fact that such responses could be elicited by the presumably chemically inert pristine microplastics is not without value, but the suggestion of "widespread health risks of (microplastics) exposure" cannot be taken without some reservations.…”

“…Tissue accumulation of microplastics in mice and biomarker responses suggest widespread health risks of exposure by Deng, Y., Zhang, Y., Lemos, B., and Ren, H. (2017). Sci.…”

Uptake of microplastics and related health effects: a critical discussion of Deng et al., Scientific reports 7:46687, 2017

“…In a recent paper, Yongfeng Deng and colleagues have analyzed the uptake of 5 µm and 20 µm polystyrene particles in mice and have monitored exposure-associated consequences with a focus on energy and lipid metabolism. The authors conclude that their data suggest widespread health risks of exposure to microplastic particles (Deng et al 2017).…”

Microplastics Exposure Causes Negligible Effects on the Oxidative Response Enzymes Glutathione Reductase and Peroxidase in the Oligochaete Tubifex tubifex

“…More recently, Lu et al [21] showed that the freshwater fish Danio rerio (zebrafish) exhibited a higher oxidative stress status after seven days of exposure to polystyrene MP, revealed by increased SOD and catalase (CAT) activities. Deng et al [22] tested the effect of fluorescent polystyrene MP in mice, revealing increased activities for SOD and GPx and decreased CAT activity, signifying the potential health risk MPs represent to biota. Nevertheless, only a few of these studies report on the physiological effects of MP exposure in biota from aquatic environments, where MP abundance is most often reported [3][4][5][6][7][8].…”