Effects of dietary pyrroloquinoline quinone on growth performance, serum biochemical parameters, antioxidant status, and growth-related genes expressions in juvenile yellow catfish, Pelteobagrus fulvidraco

This study aimed to evaluate the impacts of dietary pyrroloquinoline quinone (PQQ) supplement on growth performance, serum biochemical parameters, antioxidant status, and growth-related genes expressions in juvenile yellow catfish, Pelteobagrus fulvidraco . Triplicate groups of fish (n = 40) with an average weight of 5 g were fed with five gradient levels PQQ-incorporated diets (0 (basal), 1.5 mg/kg; 3.0 mg/kg; 4.5 mg/kg, 6.0 mg/kg) for 56 days. Our findings revealed that fish fed with the diets containing PQQ at the level of 3.0-6.0 mg/kg showed significantly higher final body weight, weight gain rate, and specific growth rate than those of that in the control group ( P < 0.05). The activities of protease were observed significantly increased in fish fed with diets containing 4.5 mg/kg and 6 mg/kg PQQ ( P < 0.05). Meanwhile, fish in 4.5 mg/kg PQQ group showed significantly lower levels of serum total cholesterol, triglycerides, and low-density lipoprotein cholesterol, and significantly higher level of the high-density lipoprotein cholesterol ( P < 0.05). The antioxidant-related parameters of superoxide dismutase and total antioxidant capacity were markedly elevated ( P < 0.05), while malondialdehyde content was significantly reduced in 3.0-6.0 mg/kg PQQ group ( P < 0.05). Meanwhile, the mRNA expression levels of growth-related genes ( growth hormone , insulin-like growth factor 1 , and insulin-like growth factor 2 ) were dramatically up-regulated in the liver of fish fed with the diets containing 3-6 mg/kg PQQ in comparison with the control group ( P < 0.05). In conclusion, dietary PQQ could improve the growth performance, serum biochemical parameters, antioxidant status, and growth-related genes expressions in juvenile yellow catfish, and the optimal dietary PQQ level was evaluated to be 4.92 mg/kg of dry diet for juvenile yellow catfish.