Effects of α-lipoic acid on growth performance, body composition, antioxidant status and lipid catabolism of juvenile Chinese mitten crab Eriocheir sinensis fed different lipid percentage

This study evaluates the effects of dietary lipid percentage (7% and 13%) on growth performance, body composition, antioxidative status and hepatopancreas lipid catabolism of Chinese mitten crab Eriocheir sinensis. Each lipid diet was supplemented with three concentrations of α-lipoic acid at 0, 700 and 1400 mg/kg, and fed to E. sinensis juveniles for eight weeks. The weight gain and specific growth rate of crabs fed the diets supplemented with α-LA were significantly higher than those fed the control diet without α-LA, regardless of dietary lipid percentage. The α-LA significantly increased lipid accumulation in the whole body and hepatopancreas in a dose-dependent manner. Crabs fed 13% lipid showed a significantly higher hepatosomatic index than those fed 7% lipid. The mRNA expressions of triacylglycerol lipase and intracellular lipase increased with the increase of α-LA concentration in crabs fed 7% lipid. No significant difference was found in the CPT-1 mRNA expression among all treatments. The α-LA supplementation at 1400 mg/kg significantly improved oxidative stress due to lipid accumulation in the hepatopancreas of crabs fed 7% lipid as indicated by the high activity of superoxide dismutase and glutathione peroxidase and a low level of malondialdehyde. The diet with 13% lipid increased the lipid content in the hepatopancreas but suppressed glutathione peroxidase. Meanwhile, the total antioxidant capacity increased with the increase of α-LA concentration in crabs fed 13% lipid. This study indicates that α-LA supplementation can improve growth performance and accelerate lipid accumulation in the hepatopancreas by increasing lipid utilization efficiency. Furthermore, α-LA can relieve hepatopancreas oxidative damage induced by lipid accumulation and improve the health of E. sinensis.