Effects of poly--hydroxybutyrate on growth, antioxidant capacity and lipid metabolism of common carp (Cyprinus carpio) under waterborne copper exposure

This study reported that effects of dietary poly-beta-hydroxybutyrate (PHB) on growth performance, immunity, antioxidant capacity, apoptosis and lipid metabolism of common carp (Cyprinus carpio) under waterborne copper (Cu) exposure. In present study, 540 common carp (12.26 +/- 0.02 g) were divided into 4 groups by 2 x 2 factorial design, including two levels of waterborne Cu (0 and 0.2 mg/L Cu2+) and two levels of dietary PHB (0 and 4%) for 28 days. Results demonstrated that dietary PHB reversed waterborne Cu induced growth inhibition and decrease of feed utilization of common carp. Waterborne Cu increased the levels of Cu in hepatopancreas, reduced immune function, damaged hepatopancreas function and morphology, induced oxidative stress and inhibited antioxidant capacity, caused inflammation and apoptosis, promoted lipid deposition in hepatopancreas. In addition, these above waterborne Cu induced changes were reversed by dietary PHB (except the levels of Cu in hepatopancreas). These findings manifested dietary PHB effectively alleviated adverse effects of waterborne Cu on common carp.