Dietary naringenin modulates antioxidant status and hepatic lipid deposition in marine medaka (Oryzias dancena) fed a high-fat diet.

High-fat diets (HFDs) are widely used in aquaculture to improve growth and feed efficiency; however, prolonged feeding can disrupt lipid metabolism, induce oxidative stress, and impair physiological homeostasis. This study evaluated the protective effects of dietary naringenin against HFD-induced physiological alterations in the marine medaka Oryzias dancena. Fish were randomly assigned to one of four dietary treatments and fed the respective experimental diets for 45 days: a normal-fat diet (NFD, 8% crude lipid), a high-fat diet (HFD, 15% crude lipid), or an HFD supplemented with either 0.075% or 0.15% naringenin. Compared with the NFD group, HFD feeding impaired antioxidant status, altered the expression of genes associated with antioxidant defence and lipid metabolism, and promoted hepatic lipid accumulation. Dietary naringenin, particularly at 0.15%, mitigated these adverse effects by restoring muscle superoxide dismutase activity, enhancing total antioxidant capacity, reducing lipid peroxidation, partially normalizing the expression of lipid metabolism-related genes, and alleviating hepatic lipid vacuolation. These findings indicate that dietary naringenin improves antioxidant defence and helps maintain lipid metabolic homeostasis under high-fat feeding conditions, highlighting its potential as a functional dietary additive for aquaculture.