Network toxicology and experimental validation reveal the molecular mechanism of DEHP-induced cochlear hair cell apoptosis and hearing loss

As a widely utilized plasticizer, di(2-ethylhexyl) phthalate (DEHP) is recognized as a classic environmental endocrine-disrupting chemical. Although DEHP has been implicated in multi-organ toxicity, its ototoxic effects and underlying mechanisms remain poorly understood. This study aimed to investigate DEHP-induced ototoxicity and elucidate the associated molecular mechanisms. First, network toxicology and molecular docking approaches were employed to predict potential targets and signaling pathways of DEHP. By integrating multiple databases, 55 potential gene targets related to DEHP-induced hearing impairment were identified, with the PI3K/AKT/FOXO signaling pathway being significantly enriched. Molecular docking further revealed strong binding affinities between DEHP and the core targets AKT1, EGFR, and TP53. In vivo and in vitro assays were carried out to confirm these results. C57BL/6 J mice were administered DEHP via gavage for 30 consecutive days. Auditory function was assessed using auditory brainstem response tests, and cochlear hair cell morphology was examined by histology and IF. Results showed that DEHP exposure significantly elevated ABR thresholds and induced structural damage to cochlear hair cells. IF analyses confirmed that DEHP modulated the PI3K/AKT/FOXO pathway in cochlear tissues. In vitro, DEHP treatment in HEI-OC1 cells reduced cell viability and promoted apoptosis. Taken together, these findings demonstrate that DEHP exposure induces auditory dysfunction and cochlear hair cell damage through modulation of the PI3K/AKT/FOXO signaling pathway and subsequent activation of apoptotic cascades. This study provides the first mechanistic evidence linking DEHP exposure to hearing loss and identifies potential molecular targets for therapeutic intervention.