Abstract

Cultured fish meat requires efficient in vitro expansion of piscine satellite cells (PSCs). However, prolonged culture impairs proliferation and differentiation. Here, astaxanthin (Ast) and naringin (Nar) were evaluated as food-grade alternatives to synthetic modulators such as MHY1485. The combination of Ast and Nar promoted proliferation by accelerating cell-cycle progression and reducing apoptosis. Synergy analysis (Bliss, HAS, and ZIP) indicated a synergistic effect between Ast and Nar. Ast combined with Nar also improved mitochondrial function and redox homeostasis, as evidenced by increased mitochondrial membrane potential, decreased mitochondrial superoxide, and decreased intracellular ROS levels. Furthermore, co-treatment upregulated the expression of myogenic markers, including MyoD1, MyoG, and MyHC, and promoted myotube formation. Mechanistically, these effects of Ast and Nar were associated with mTOR activation, as indicated by phosphorylation levels, while inhibition of mTOR with rapamycin (Rap) attenuated these effects. Collectively, these results highlighted that Ast combined with Nar was an excellent supplement for large-scale expansion and differentiation of PSCs.