Effects of glycerol monolaurate on lipid metabolism of Lateolabrax maculatus

In this study, we evaluated the effect of glycerol monolaurate (GML) on lipid metabolism by feeding four diets containing 0 mg·kg⁻¹ (control group), 1 000 mg·kg⁻¹ (low-dose group), 2 000 mg·kg⁻¹ (medium-dose group) and 4 000 mg·kg⁻¹ (high-dose group) on Lateolabrax maculatus with initial body mass of (230±20) g for eight weeks. The results show that: 1) The intraperitoneal fat ratio (IPF) of the GML supplementation groups decreased significantly, and compared with the 4^th week, the hepatosomatic index (HIS) decreased significantly (P<0.05). 2) The triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C) contents and aspartate aminotransferase (AST) activities in low- and medium-dose groups were lower than those of high-dose group (P<0.05). 3) The high-density lipoprotein cholesterol (HDL-C) contents in medium-dose group were higher than those of the other groups (P<0.05). 4) The activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and the contents of glutathione (GSH) increased in the liver of the GML supplementation groups, while the malondialdehyde (MDA) contents decreased significantly (P<0.05). 5) The activities of fatty acid synthase (FAS), acetyl-CoA carboxylase (ACC) and lipid deposition decreased in the liver of GML supplementation groups significantly (P<0.05); the lipoprotein lipase (LPL) activities in medium-dose group were significantly higher than those of the other groups (P<0.05). In summary, the dietary supplementation with GML can improve the lipid metabolism of L. maculatus significantly, and the suitable does is 2 000 mg·kg⁻¹.