Effect of cadmium-polluted diet on growth, salinity stress, hepatotoxicity of juvenile Pacific white shrimp (Litopenaeus vannamei): Protective effect of Zn(II)–curcumin

Cadmium (Cd) is one of the major transitional metals that have toxic effects on aquatic organisms. To investigate the effects of dietary cadmium on growth, salinity stress, hepatotoxicity in juvenile Pacific white shrimp (L. vannamei) and potential protective effect of Zn(II)–curcumin, five experimental diets (control, 100 mg/kg Zn(II)–curcumin, 30 mg/kg Cd, 30 mg/kg Cd+100 mg/kg Zn(II)–curcumin, 30 mg/kg Cd+200 mg/kg Zn(II)–curcumin) were formulated. The results showed that Cd at 30 mg/kg induced significant increase in weight gain, specific growth rate and visible alterations to the hepatopancreas structures of L. vannamei. Compared with control diet, 100 mg/kg Zn(II)–curcumin added diet had no effect on growth performance or feed utilization, while healthier hepatopancreas and less plasma ALT, AST production was found. Moreover, 200 mg/kg dietary Zn(II)–curcumin significantly ameliorated the Cd induced hepatotoxicity while 100 mg/kg dietary Zn(II)–curcumin slightly ameliorated. Cd accumulation in the whole body was decreasing and Metallothioneins like was increasing in hepatopancreas with increasing dietary Zn(II)–curcumin level. The shrimp fed with dietary Zn(II)–curcumin showed higher survival rate after acute salinity change. Therefore, it can be demonstrated that hepatotoxicity and hormesis could be induced by Cd when Cd levels were 30 mg/kg, Zn(II)–curcumin could mitigate the effects of dietary Cd on L. vannamei.