Dietary exogenous supplementation of nucleotides strengthens the disease resistance, antioxidant capacity and immunity in the gill of on-growing grass carp (Ctenopharyngodon idella) following a challenge with Flavobacterium columnare

Low-molecular-weight nucleotides are very important for fish and terrestrial animals, which have been verified to possess multidirectional biological functions including anti-inflammatory, anti-microbial, anti-oxidant, anti-apoptotic effects. This research was designed fully explore the possible impacts of dietary exogenous supplementation on gill disease resistance, antioxidant capacity, antibacterial activity, inflammatory cytokines associated signaling mechanisms in on-growing grass carp (Ctenopharyngodon idella) (200.0 ± 1.0 g). Fish were fed six diets containing graded levels at 0, 200.0, 400.0, 600.0, 800.0 1000.0 mg/kg triplicate 60 days, followed by a challenge with Flavobacterium columnare 3 days. Our results showed that compared 0 diet group, 600.0 group markedly decreased rot morbidity induced F. (P < 0.05), significantly enhanced related enzymes activities corresponding gene expressions partly ascribed modulation Nrf2 0.05). Meanwhile, dramatically elevated antimicrobial substances (lysozyme IgM) productions peptides (such as β-defensin) Mucin-2 expression 0.05) well altered profiles main inflammatory-related genes interleukin-1β IL-8) correlated action NF-κB TOR However, groups did not alter TNF-α, IFN-γ, IL-12p35 IL-4/13B > Dietary has potential benefits strengthening capacity immunity carp, optimal recommended be 526.4–639.8 based health-related indices.