Effect of the total replacement of fishmeal with plant proteins and supplemental essential amino acids in the extruded diet on antioxidants genes, enzyme activities, and immune response in juvenile blunt snout bream

Four diets were formulated with or without fishmeal (FM) and essential amino acid (EAA) supplementation fed to the blunt snout bream throughout 8 weeks. The results showed that total cholesterol level (TC) was decreased significantly against FM reduction (P 0.05). Catalase (CAT) activity and glutathione (GSH) content were significantly augmented and diminished in the group fed diet 3 respectively (P 0.05). Glutathione peroxidase (GPx) activity was elevated significantly either by reducing FM or supplementing EAA (P 0.05), whereas the relative expression of copper-zinc superoxide dismutase (Cu/Zn-SOD) decreased against FM reduction (P < 0.05). The relative expressions of Interleukin 8 (IL-8), tumour necrosis factor-α (TNF-α), interleukin 10 (IL10), and nuclear factor-kappa B (NF-κB) were diminished significantly in FM-reduced groups (P < 0.05). The supplementation of EAA significantly increased the relative expression of signal transducer and activator of transcription 4 (STAT4) (P < 0.05). In conclusion, the results revealed that dietary plant proteins with EAA supplementation significantly affected the physiological status and immune responses in blunt snout bream.