In vitro impacts of polystyrene microplastics and environmental pollutants on ethoxyresorufin-O-deethylase and glutathione S-transferase activity in Mossambica tilapia

• Published in: Toxicology in vitro 2024-10, Vol.100, p.105915, Article 105915
• Main Authors: Yin, Yan, Wang, Haiyan, Ouyang, Guijing, Han, Daxiong
• Format: Article
• Language: English
• Subjects: 7-ethoxyresorufin-O-deethylase; Brominated flame retardants; Glutathione S- transferase; Heavy metals; Microplastics; Pharmaceutically active compounds
• ISSN: 0887-2333; 1879-3177; 1879-3177
• DOI: 10.1016/j.tiv.2024.105915

Microplastic (MP) pollution is a potential threat to marine organisms. In vitro toxicity of MPs and other pollutants, such as pharmaceutically active compounds (PhACs) and brominated flame retardants (BFRs), has been understudied. This study aimed to investigate the effects of polystyrene microplastics (PS-MPs) with different particle sizes on two biomarkers: ethoxyresorufin-O-deethylase (EROD) and glutathione S-transferase (GST) in tilapia liver homogenates. The study also examined the combined effects of PS-MPs with various environmental contaminants, including three metal ions (Cu2+, Zn2+, Pb2+), three BFRs, and six PhACs. PS-MPs alone had no remarkable effects on the two biomarkers at the selected concentrations. However, PS-MPs combined with other pollutants significantly affected the two biomarkers in most situations. For EROD activity, PS + metal ions (except Zn2+ at 1000 μg/L), PS + BFRs (except decabromodiphenyl oxide (BDE-209)) or PS+ trimethoprim (TMP) significantly inhibited activity values, whereas PS+ 4-acetaminophen (AMP) induced EROD activity. For GST, PS together with most tested pollutants (except PS+ ibuprofen (IBF)) greatly decreased the activities. Accordingly, future research should focus on combined toxicity of mixtures to set more reasonable environmental safety evaluation standards. •PS-MPs alone had no significant effects on EROD or GST.•PS-MPs combined with other pollutants affected EROD and GST in most situations.•EROD and GST seemed to be suitable biomarkers to evaluate the combined effects of PS and other pollutants.