Evidence that microplastics aggravate the toxicity of organophosphorus flame retardants in mice (Mus musculus)

Area of Science:

• Environmental Toxicology
• Chemical Health Risks
• Metabolomics

Background:

• Organophosphorus flame retardants (OPFRs) are widely used, raising concerns about their environmental persistence and health effects.
• Microplastics (MPs) are ubiquitous environmental contaminants with incompletely understood toxicological impacts.
• The combined effects of co-exposure to OPFRs and MPs on health remain largely uncharacterized.

Purpose of the Study:

• To investigate the health risks associated with co-exposure to OPFRs (TCEP, TDCPP) and common MPs (polyethylene, polystyrene) in a mouse model.
• To determine if MPs enhance the toxicity of OPFRs using biochemical markers and metabolomic profiling.
• To elucidate the metabolic pathways affected by combined OPFR and MP exposure.

Main Methods:

• Mice were exposed to OPFRs (TCEP, TDCPP) and MPs (PE, PS) individually and in combination for 90 days.
• Biochemical markers including superoxide dismutase (SOD), catalase (CAT), lactate dehydrogenase (LDH), and acetylcholinesterase (AChE) were analyzed.
• Untargeted metabolomics was employed to identify and quantify changes in metabolite profiles.

Main Results:

• Co-exposure to OPFRs and MPs resulted in significantly altered biochemical markers compared to OPFR exposure alone.
• Elevated LDH levels were observed in TDCPP + MP groups, while AChE levels decreased in TCEP + PE groups.
• Significant changes in 26-41 metabolites, primarily related to amino acid and energy metabolism, were detected in co-exposed groups.

Conclusions:

• Microplastics exacerbate the toxicity of organophosphorus flame retardants.
• Combined exposure to OPFRs and MPs poses significant health risks, affecting critical metabolic pathways.
• Further research is warranted to understand the long-term health implications of co-exposure to these environmental contaminants.