Effects of waterborne selenium exposure on the antioxidant and immunological activity in the goldfish, Carassius auratus

Selenium (Se) is an essential element that has relevant roles in growth, immunity, and the protection of cell membranes in organisms under normal conditions. The aim of this study was to test the antioxidant and immune functions of goldfish Carassius auratus after Se treatment. At the end of the experiment, levels of antioxidant enzymes (superoxide dismutase, catalase, and glutathione peroxidase) and immune functions (immunoglobulin M protein and plasma lysozyme, thyroxine, and triiodothyronine) were significantly higher in goldfish exposed to 1 and 2 mg/L of Se than those exposed to 0.5 and 3 mg/L doses. In addition, plasma glutathione, H2O2, and lipid peroxidation levels were significantly lower in the 1 and 2 mg/L treatment group than 0.5 and 3 mg/L treatment group. These results indicated that 1 and 2 mg/L of Se enhance antioxidant defense and immune system function under aquarium conditions.