Dietary supplementation of Acer truncatum leaf extract alleviates oxidative-stress induced impairment of ovarian function in laying hens via Nrf2-mediated antioxidant defense and VEGF-mediated angiogenesis.

This study aimed to evaluate the potential of Acer truncatum leaf extract (ATLE) to mitigate oxidative-stress-induced impairment of reproductive function in laying hens, with a focus on mechanisms involving antioxidant defense, angiogenesis, and ovarian microenvironment homeostasis. Oxidative stress was induced by tert-butyl hydroperoxide (tBHP) injection. Hens were randomly assigned to a control group (CON), an oxidative stress group (BCON), and an oxidative stress group supplemented with 0.6% ATLE (BATLE). Egg-laying performance, ovarian morphology, reproductive hormones, oxidative stress markers, and angiogenesis indicators were evaluated and integrated with transcriptomic analysis. The results were as follows: 1) Production and Morphology: ATLE supplementation alleviated (P < 0.05) the tBHP-induced decrease in egg laying rate and elevation in feed conversion ratio (FCR). It also mitigated (P < 0.05) reductions in the number of hierarchical follicles and the ovarian stroma index while restoring (P < 0.05) serum concentrations of LH and GH, thereby re-establishing reproductive endocrine balance. 2) Antioxidant Defense: ATLE activated (P < 0.05) Nrf2 and increased (P < 0.05) transcription of downstream antioxidant genes, including SOD3, GPX3, PRDX4, GSR and CAT, thereby enhancing (P < 0.05) the SOD and CAT activities and reducing (P < 0.05) MDA concentrations within both serum and ovarian tissues. 3) Vascular Network Support: ATLE attenuated (P < 0.05) the tBHP-induced downregulation of angiogenic factors, including protein levels of VEGF, ANGPT1, and HIF-1α and mRNA expression levels of VEGFA, ANGPT1, ANGPT2, ITGA5, and MMP9. 4) Microenvironment Remodeling: Transcriptomic integration revealed that ATLE-mediated repair overlapped (> 88%) with oxidative-stress-induced damage across functional modules. By reversing dysregulation of key genes such as VEGFA, KDR, and FN1, ATLE restored core pathways including focal adhesion and ECM-receptor interaction, and coordinated processes such as extracellular matrix, angiogenesis, and response to wounding, driving a systemic remodeling of the ovarian reproductive microenvironment toward homeostasis. In summary, this study demonstrated that ATLE activated multiple signaling axes, notably Nrf2 and VEGF. As a result, ATLE enhanced antioxidant defenses against oxidative damage and promoted vascular health and microenvironmental remodeling in the ovary. Together, these effects preserved the structural integrity and function of the laying hen reproductive system. These findings supported the potential of ATLE as a natural feed additive and provided a scientific rationale for using nutritional strategies to alleviate oxidative stress and improve reproductive health in laying hens.