Dietary isoleucine improved flesh quality, muscle antioxidant capacity, and muscle growth associated with AKT/TOR/S6K1 and AKT/FOXO3a signaling in hybrid bagrid catfish (Pelteobagrus vachelli♀ × Leiocassis longirostris♂)

Abstract Background Muscle is the complex and heterogeneous tissue, which comprises primary edible part of trunk fish mammals. Previous studies have shown that dietary isoleucine (Ile) exerts beneficial effects on growth in aquatic animals. However, there were limited regarding benefits Ile muscle their flesh quality growth. Thus, this study was conducted to explore whether had affected hybrid bagrid catfish ( Pelteobagrus vachelli♀ × Leiocassis longirostris♂ ). Methods A total 630 fish, with an initial average body weight 33.11 ± 0.09 g, randomly allotted into seven experimental groups three replicates each, respectively fed diets 5.0, 7.5, 10.0, 12.5, 15.0, 17.5, 20.0 g Ile/kg for 8 weeks. Results In present study, we demonstrated significantly: (1) increased protein lipid contents frequency distribution myofibers ≤ 20 μm ≥ 50 diameter; (2) improved pH value, shear force, cathepsin B L activities, hydroxyproline content, resilience, cohesiveness, decreased cooking loss, lactate hardness, springiness, gumminess, chewiness; (3) reactive oxygen species (ROS), malondialdehyde (MDA), carbonyl (PC) contents, GCLC Keap1 mRNA levels, up-regulated CuZnSOD , CAT GPX1a, GST Nrf2 levels; (4) insulin-like factor 1, 2 IGF-1 IGF-2 ), 1 receptor IGF-1R proliferating cell nuclear antigen PCNA Myf5 Myod Myog Mrf4 MyHC MSTN level; (5) deposition by activating AKT-TOR-S6K1 AKT-FOXO3a signaling pathways. Conclusion These results revealed quality, might be due increasing nutritional physicochemical, texture parameters, antioxidant ability; promoting affecting myocytes hyperplasia hypertrophy, associated synthesis degradation Finally, quadratic regression analysis chewiness, ROS, against levels suggested optimal estimated 14.19, 12.36, 12.78 g/kg diet, corresponding 36.59, 31.87, 32.96 protein, respectively.