Environmental pollutants and autism spectrum disorder: Effects of plasticizers on core phenotypes and molecular targets

Autism spectrum disorder (ASD) is a complex neurodevelopmental disorder shaped by genetic and environmental factors. Phthalates, widely used as plasticizers in consumer products, have gained attention as potential environmental contributors to ASD; however, their pathogenic roles remain insufficiently defined. This study systematically investigated the molecular associations between three common phthalates, diethyl phthalate (DEP), dimethyl phthalate (DMP), and dioctyl phthalate (DOP), and ASD risk using integrated network toxicology and bioinformatics approaches. Intersection analysis of phthalate-associated targets and ASD-related genes revealed shared enrichment in lipid metabolism-related pathways. Protein-protein interaction network analysis identified 10 key targets: FAAH, CYP2C9, CYP24A1, ACHE, CYP11B1, TSPO, PTGS2, MIF, ADORA1, and ALDH3A1. Molecular docking and dynamics simulations indicated stable binding interactions between phthalates and the target. Mendelian randomization analysis further suggested that FAAH and ADORA1 serve as key pathogenic mediators linking phthalate exposure to ASD risk. In vivo experiments demonstrated that C57BL/6 mice exposed to individual or mixed phthalates exhibited ASD-like behaviors, including reduced social interaction, increased repetitive behaviors, and cognitive impairment, with the most pronounced effects observed in the DEP, DMP, and mixed exposure groups. qRT-PCR analysis of hippocampal tissue showed significant downregulation of Faah and upregulation of Adora1 in the DEP group. Collectively, these findings identify FAAH and ADORA1 as central molecular links between phthalate exposure and ASD-related phenotypes from a systems toxicology perspective, providing insight into environmental contributions to neurodevelopment and potential molecular targets for intervention.