Paeonol alleviates granulosa cell senescence in laying chickens via the PI3K/Akt/mTOR signaling pathway

Ovarian aging compromises reproductive health and reduces egg production, posing a persistent challenge to the poultry industry. Mitochondrial dysfunction in granulosa cells (GCs) accelerates reactive oxygen species (ROS) accumulation and induces apoptosis in both GCs and oocytes. The impact of Paeonol on mitochondrial function in avian GCs remains unclear.

In this study, we evaluated the antioxidant activity of Paeonol in a D-galactose (D-gal)-induced senescent GC model and further examined its effects in late-laying hens receiving dietary Paeonol supplementation. Cellular senescence, apoptosis, oxidative stress, mitochondrial status, and PI3K/Akt /mTOR signaling were assessed using molecular and cellular assays, complemented by transcriptomic analysis.

In vitro, Paeonol treatment significantly mitigated the D-gal-induced imbalance between proliferation and apoptosis in GCs, reduced mitochondrial ROS, increased mitochondrial membrane potential, and improved mitochondrial morphology, consistent with attenuated oxidative stress and mitochondrial dysfunction. Importantly, inhibition of the PI3K/Akt/mTOR pathway with LY294002 partially attenuated Paeonol's cytoprotective effects, suggesting pathway involvement. In vivo, dietary supplementation with Paeonol promoted follicular development and improved egg-laying performance. Paeonol also improved antioxidant capacity and increased the transcription of multiple antioxidant enzyme genes in GCs. In addition, mitochondrial dynamics-related proteins involved in fusion and fission were upregulated, implying improved maintenance of mitochondrial structure and function.

These findings indicate that Paeonol may mitigate D-gal-associated GC senescence and mitochondrial impairment, with PI3K/Akt /mTOR signaling potentially contributing to these effects. Paeonol warrants further evaluation as a dietary supplement for supporting reproductive function in late-laying hens.