Pretreatment with selenium prevented the accumulation of hexavalent chromium in rainbow trout (Oncorhynchus mykiss) and reduced the potential health risk of fish consumption

Hexavalent chromium (Cr6+) is a toxic element in environment. Selenium (Se) is an essential micronutrient trace element for living organisms and can ameliorate the adverse effects induced by Cr6+. However, the correlations between Se and Cr in fish have been rarely reported. The present study focused on the antagonistic effects of Se on Cr-induced accumulation in tissues (blood, gills, intestines, liver, kidney and muscle) of rainbow trout. Initially, a 42-day feeding trail was conducted as the fish were fed with basal diet supplemented with or without 4 mg/kg Se (as Se-yeast). A remarkable increase of Se in tissues was observed. Se was predominately accumulated in liver and the Se significantly decreased the initial Cr level in liver. Furthermore, after the pretreatment of Se, the fish were exposed to 1 mg/L Cr solution and it could be found that all the tissues showed a significant accumulation of Cr. An exciting result was obtained that the pretreatment of Se could prevent the Cr accumulation in fish muscle and reduced the health risk of fish consuming. A pearson correlation analysis was conducted to examine the relationship between Se and Cr and a significant negative correlation was found in muscle. Overall, it could be concluded that the pretreatment of Se in rainbow trout could effectively prevent the Cr accumulation in muscle, which is beneficial for reducing health risk of fish consumption.