Impact of microplastics and nanoplastics on liver health: Current understanding and future research directions

Abstract

With continuous population and economic growth in the 21^st century, plastic pollution is a major global issue. However, the health concern of microplastics/ nanoplastics (MPs/NPs) decomposed from plastic wastes has drawn public attention only in the recent decade. This article summarizes recent works dedicated to understanding the impact of MPs/NPs on the liver-the largest digestive organ, which is one of the primary routes that MPs/NPs enter human bodies. The interrelated mechanisms including oxidative stress, hepatocyte energy re-distribution, cell death and autophagy, as well as immune responses and inflammation, were also featured. In addition, the disturbance of microbiome and gut-liver axis, and the association with clinical diseases such as metabolic dysfunction-associated fatty liver disease, steatohepatitis, liver fibrosis, and cirrhosis were briefly discussed. Finally, we discussed potential directions in regard to this trending topic, highlighted current challenges in research, and proposed possible solutions.

Keywords: Autophagy; Cell death; Gut-liver axis; Innate immunity; Liver; Metabolic dysfunction-associated fatty liver disease; Microplastics; Nanoplastics; Reactive oxidative species.

Figure 1

An overview of interrelated mechanisms behind the microplastics and nanoplastics-induced hepatotoxicity. ER: Endoplasmic reticulum.