Chronic DBP exposure may cause reduced fertility in female mice by interfering with the HPO axis

In this study, we investigated the multigenerational effects of low-dose dibutyl phthalate (DBP) exposure on the reproductive system of female Kunming mice by simulating a long-term environmental exposure scenario for humans, using a food-contamination method for three consecutive generations (F0-F2). Results demonstrated significant reproductive dysfunction across generations, manifested by shortened diestrus intervals (P < 0.05) and prolonged estrus duration (P < 0.05) in F1-F2 generations. The number of pregnancies progressively declined, with numbers for the F1-F2 generations showing marked reductions (P < 0.01). In addition, the sex ratio of F2 offspring was imbalanced. Histopathological analysis revealed cumulative ovarian damage across generations, characterized by increased atretic follicles, disorganized granulosa cells, and structural deterioration of the uterine glands. Proteomic profiling identified generation-specific pathway alterations: DBP-exposed groups showed enrichment in estrogen signaling and oxidoreductase activity pathways, compared to controls; while intergenerational comparisons revealed differential regulation of thyroid hormone synthesis, cell junction pathways, and reactive oxygen-mediated carcinogenesis pathways. Molecular investigations demonstrated that DBP's disrupted hypothalamic-pituitary-ovarian (HPO) axis function through inhibition of steroidogenic genes (Cyp17a1, Hsd3b1), resulting in elevated serum follicle-stimulating hormone (FSH) and luteinizing hormone (LH) levels (P < 0.05). These findings collectively indicate that chronic low-dose DBP exposure induces transgenerational reproductive impairment through endocrine disruption and oxidative stress mechanisms, progressively compromising ovarian function and fertility across generations via HPO axis dysregulation. The study provides critical evidence for multigenerational reproductive risk associated with environmental phthalate exposure.