Study supplementation of astaxanthin in high‐fat diet on growth performance, antioxidant ability, anti‐inflammation, non‐specific immunity and intestinal structure of juvenile Trachinotus ovatus

A 6-week feeding experiment was conducted to evaluate whether dietary supplementation of astaxanthin could mitigate negative effects of high-fat diet on growth performance, antioxidant capacity, anti-inflammation, non-specific immunity and intestinal structure of Trachinotus ovatus. Three isonitrogenous diets were formulated supplementing with or without high-fat or astaxanthin (lipid positive (LP): 130 g/kg lipid, lipid negative (LN): 210 g/kg lipid, lipid negative astaxanthin (LNA): 210 g/kg lipid with 0.5 g/kg astaxanthin). Results showed that the growth performance (weight gain (WG) and specific growth rate (SGR)) of T. ovatus in the LN group were significantly lower than that of growth performance in the LP group (p < .05), while growth performance data in the LNA group were significantly higher than those data in the LN group (p < .05) and without statistical difference with the LP group (p > .05). There were significantly lower levels of antioxidant contents (malondialdehyde (MDA) and Glutathione (GSH)) and transcriptional level of antioxidant-related gene (Nrf2, keap1, Mn-SOD, GSH-PX, HO-1 and CAT) in the LNA group when compared to the LN group (p < .05), while no statistical differences were detected between the LNA and LP groups (p > .05). NF-κB signal pathway key gene (p65) and non-specific immunity-related genes (IRF3, IRF7 and MyD88) of T. ovatus were significantly lower in the LNA and LP groups when compared to the LN group (p < .05). Fewer hepatic lipid droplets and more goblet cells of mid-gut were found in T. ovatus from the LNA group than those from the LN group. These results indicate that a diet supplementation of 0.5 g/kg astaxanthin mitigates detrimental effects of T. ovatus growth performance caused by high-fat diet by decreasing hepatic lipid accumulation and improving antioxidant, anti-inflammation, non-specific immunity and intestine barrier capacities.