Interactive Effects of Microplastics and Tetracycline on Bioaccumulation and Biochemical Status in Jian Carp (Cyprinus carpio var. Jian)

Chaonan Zhang,Jixing Zou,Qiujie Wang,Jianhua Ding,Guohuan Xu,Zhiheng Zuo

doi:10.3389/fenvs.2021.764344

Abstract

Microplastics (MPs) and tetracycline (TC) are severe emerging pollutants in the aquatic environment. But there is a lack of research to investigate the interactive effects of MPs and TC in vivo. This study used Jian carp (Cyprinus carpio var. Jian) as the model organism to explore the bioaccumulation and biochemical status when exposed to MPs and TC, alone and combined. The accumulation of TC and MPs in intestine, variation of enzyme activities in intestine, and expression of immune-related genes in muscle were evaluated. Our results found the bioaccumulation of MPs was not affected by TC, but the presence of MPs would change the content of TC within 48 h. The superoxide dismutase (SOD) and lactate dehydrogenase (LDH) activity showed that TC-MP combined exposure could reduce oxidative damage to Jian carps compared to MP exposure alone. The integrated biomarker response (IBR) index showed that SOD activity was sensitive to TC-MP exposure. In addition, co-exposure to MPs and TC could alleviate the overexpression of interleukin 1 beta (IL-1β), interleukin 10 (IL-10), transforming growth factor beta (TGF-β), and toll like receptor 2 (TLR-2) induced by TC in muscles. TLR-2 gene has the potential to be the candidate gene reflecting the injury of TC exposure. In conclusion, it is inferred that co-exposure may reduce the toxicity of individual exposure in the living organisms. This study provides essential information for the risk assessment of pollution with MPs and TC, individually and combined, as well as a foundation to investigate the interactive effects of MPs and antibiotics on aquatic ecosystems.

Highlights

Modern life seems to be inextricably linked to the use of plastics
Our results provide important information for the risk assessment of pollution caused by MPs and pharmaceutically active compounds (PHACs) on fish, as well as form a foundation to investigate the interactive impacts of MPs and antibiotics on aquatic ecosystems
MPs accumulate in the gastrointestinal tract of organisms, and the accumulation increases over time until an equilibrium state is reached (Zhang et al, 2019)

Summary

Introduction

Modern life seems to be inextricably linked to the use of plastics. Plastics have become an indispensable solution to meet the ever-changing needs of society. Microplastics (MPs), originating from both primary and secondary sources, are tiny plastic particles of less than 5 mm in size (Thompson et al, 2004; Cole et al, 2011). They are ubiquitously distributed in marine and freshwater ecosystems (Beaumont et al, 2019; Sarijan et al, 2021), atmosphere (Zhang et al, 2020a; Chen et al, 2020), and soil (He et al, 2018; Wang et al, 2020) and found in the most remote habitats (Morgana et al, 2018). MP pollution is drawing attention on a global scale

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Conclusion