Protective Mechanism of Crocin Against Zearalenone-Induced Oxidative Damage to Swine Testicle Cells

Zearalenone (ZEA), a mycotoxin produced in moldy feed, induces oxidative damage in testicular cells of male animals. These cells are crucial for androgen secretion and male reproductive health. Consequently, identifying effective and safe treatments to maintain testicular redox balance and ensure male animal fertility is imperative. Crocin, a natural compound with recognized antioxidant properties, shows promise; however, its mechanism for mitigating ZEA-induced testicular oxidative injury remains unclear. To elucidate crocin's action on oxidative stress and apoptosis in swine testicular (ST) cells, we treated cells with crocin after establishing a ZEA-induced oxidative stress model. Compared to ZEA treatment alone, crocin significantly ameliorated oxidative stress by inhibiting reactive oxygen species (ROS) and malondialdehyde (MDA) elevation, while promoting the activity/levels of catalase (CAT), total antioxidant capacity (T-AOC), and superoxide dismutase (SOD). Furthermore, crocin effectively alleviated ZEA-induced apoptosis by attenuating mitochondrial membrane potential (MMP) depolarization, reducing the apoptosis rate, suppressing the expression of key apoptotic genes caspase 3 (CASP3) and caspase 9 (CASP9), and improving ZEA-induced G1 phase cell cycle arrest. Mechanistically, crocin mitigated oxidative damage at both mRNA and protein levels by restoring the homeostasis of the nuclear factor erythroid 2-related factor 2 (Nrf2) and mitogen-activated protein kinase (MAPK) signaling pathways, which were dysregulated by ZEA. In conclusion, crocin protects ST cells against ZEA-induced oxidative damage by reducing oxidative stress markers, alleviating ZEA-induced dysregulation of the Nrf2 and MAPK pathways, preventing apoptotic damage, and enhancing cellular antioxidant capacity. This study provides theoretical support for developing crocin as a potential feed additive to prevent oxidative damage to the boar reproductive system.