Environmentally Relevant Concentrations of the Flame Retardant Tris(2-butoxyethyl) Phosphate Accelerate Caenorhabditis elegans Senescence

Amid growing concerns surrounding the longevity of individuals, the acceleration of aging by pollutants has garnered significant attention. Tris­(2-butoxyethyl) phosphate (TBOEP), a widely used organophosphorus flame retardant (OPFR), has been frequently detected in the environment; however, its impact on organism life spans remains unclear. This study investigated the effects of TBOEP on the life span of Caenorhabditis elegans at environmentally relevant concentrations of 0, 50, 500, and 5000 ng/L. TBOEP exposure reduced motility and shortened the life span of C. elegans in a dose-dependent manner, with the most significant effects observed at 5000 ng/L. Transcriptomics and metabolomics revealed that 5000 ng/L TBOEP significantly disrupted longevity regulation in C. elegans. This was mainly attributed to the abnormal regulation of genes encoding the heat shock proteins, lipase, and stearoyl-CoA desaturase as well as the increased l-arginine content in C. elegans. Concurrently, exposure to 5000 ng/L TBOEP significantly upregulated the microRNAs in the lethal-7 family, thereby accelerating C. elegans senescence. Overall, this study provides important insights into the effects of TBOEP on C. elegans senescence and could inform further studies assessing the environmental health risks of OPFRs.