Dietary lipid levels affected growth performance, lipid accumulation, inflammatory response and apoptosis of japanese seabass (lateolabraxjaponicus)

An eight weeks feeding trial was conducted to investigate the effects of dietary lipid levels on growth performance, lipid metabolism and immune response of Japanese seabass (Lateolabrax japonicus). Five diets were formulated with gradient dietary lipid levels (79.6, 104.4, 129.1, 154.9 and 178.6 g kg−1). Results revealed that growth and feed utilization of fish were significantly lower in group L178.6 than other groups (p < 0.05). Lipid accumulation in whole body, muscle and intraperitoneal were increased with increasing dietary lipid levels. The mRNA levels of adipose triglyceride lipase, carnitine palmitoyl transferase 1, acetyl CoA carboxylase, cholesterol 7 alpha-hydroxylase and retinoid X receptor in liver were also increased with increasing dietary lipid levels (p < 0.05). The mRNA levels of apolipoprotein A1 and peroxisome proliferator activating receptor α were higher in fish fed L178.6 than those fed other diets. Oxidative stress in plasma and liver were induced when dietary lipid exceed 154.9 g kg−1. L154.9 and L178.6 significantly increased the inflammatory related gene expression of fish. These results suggested that high-fat diet impaired the growth performance and induced lipid accumulation, inflammation and apoptosis of Japanese seabass. The suitable dietary lipid level of Japanese seabass may not exceed 129.1 g kg−1.