Dietary supplementation of glycyrrhetinic acid benefit growth performance and lipid metabolism in blunt snout bream (Megalobrama amblycephala) juveniles

The present study investigated the effects of glycyrrhetinic acid (GA) supplementation on the growth performances and lipid metabolism of blunt snout bream juveniles. Fish (100 ± 0.36g) were randomly allocated into 12 cages (20 per cage) in four replicates. Three diets were formulated to contain three levels of GA (0, 0.3 and 3mg/kg) and were fed for 56 days. Compared with the control group, dietary GA levels show no significant effect on fish growth performance and feed utilization. Hepatosomatic index and liver lipid content tend to be reduced significantly as dietary GA level increased, whereas the opposite trend was observed in glucose and cortisol level compared with the control. Plasma Hepatic Lipase and total lipase were significantly higher in fish fed 0.3 mg/kg GA compare to the fish fed the control diet. Transcriptome analysis reveals that lipid transport promoters (SREBP, FAS, HL, LPL, ApoE GPAT, DGAT, LDLR, ACCα and ACCβ), fatty acid oxidation promoters (CPT1 and CPT2) and fatty acid transport promoter FABP1 and FATP were not affected by the GA treatment. In conclusion, the results of this study indicate that 0.3 mg/kg GA had a positive impact on improving lipid deposition in blunt snout bream without adverse effect on growth performance.