Oxidative stress-mediated DNA damage and macrophage polarization microenvironment: A novel mechanism of DCHP-induced male reproductive system impairment.

The global decline in male fertility has emerged as a major public health challenge, with mounting evidence pointing to a close association between endocrine-disrupting chemicals (EDCs) and reproductive dysfunction. As a representative member of this class, dicyclohexyl phthalate (DCHP) exhibits strong environmental persistence and bioaccumulation potential within the mammalian reproductive system. In the present study, male ICR mice were orally administered DCHP at 10, 100, or 300 mg/kg/day for six consecutive weeks, and GC‑2 mouse spermatocyte cells were exposed to 5, 20, or 50 μM DCHP for 24 h. Long‑term, high‑dose DCHP exposure (300 mg/kg/day) was associated with significant testicular histopathological alterations and impaired epididymal sperm parameters in mice. Both the in vivo and in vitro models revealed that DCHP treatment correlated with cell cycle disruption and proliferative arrest. Western blotting and TUNEL assays further indicated that DCHP could triggered apoptosis. As an exploratory acute ex vivo assessment, 35 human semen samples were exposed to DCHP (5, 20 and 50 μM) for 12 h, which revealed a dose-dependent reduction in sperm quality. At the mechanistic level, our data suggest a potential cascade wherein DCHP exposure is linked to oxidative stress, concomitant DNA damage, and mitochondrial dysfunction. RNA‑seq analysis further highlighted the enrichment of inflammatory responses and related signaling pathways. Subsequent validation experiments showed that DCHP exposure was accompanied by an increased testicular M1 macrophage population, elevated secretion of pro‑inflammatory cytokines (IL‑6, TNF‑α), and activation of the NF‑κB pathway-changes that may collectively contribute to an unfavorable testicular microenvironment and impaired sperm quality. Overall, our findings reveal close associations between DCHP exposure and testicular injury, proposing a working model involving oxidative stress and inflammation; however, further functional studies are required to establish definitive causal relationships.