Growth performance and protective effect of vitamin E on oxidative stress pufferfish (Takifugu obscurus) following by ammonia stress.

This study was conducted to determine the effects of vitamin E on growth performance, biochemical parameters, and antioxidant capacity of pufferfish (Takifugu obscurus) exposed to ammonia stress. The experimental basal diets supplemented with vitamin E at the rates of 2.31 (control), 21.84, 40.23, 83.64, 158.93, and 311.64 mg kg dry weight were fed to fish for 60 days. After the feeding trial, the fish were exposed to 100 mg L ammonia-nitrogen for 48 h. The results shown that the vitamin E group significantly improved weight gain, specific growth rate, and the expression levels of growth hormone receptors and insulin-like growth factor. Fish fed with the vitamin E-supplemented diets could increase plasma alkaline phosphatase activities and decrease plasma glutamicoxalacetic transaminase and glutamic-pyruvic transaminase activities. The relative expression levels of heat shock proteins (40.23-311.64 mg kg vitamin E diet group), manganese superoxide dismutase (83.64-158.93 mg kg vitamin E diet group), catalase (40.23-311.64 mg kg vitamin E diet group), and glutathione reductase (40.23-311.64 mg kg vitamin E diet group) were upregulated. On the other hand, the decreased level of reactive oxygen species (ROS) was observed in the 83.64-311.64 mg kg vitamin E additive group. These results showed that vitamin E might have a potentially useful role as an effective antioxidant to improve resistance in pufferfish.