Effect of sodium selenite and selenium nanoparticles on biochemical parameters of muscle, serum, antioxidant defense and exposure to mercury chloride in Acanthopagrus latus

Mercury causes oxidative stress in the body by producing oxygen free radicals and destroying antioxidant sources. The most important application of selenium is its role in the construction of antioxidant enzymes such as glutathione peroxidase, the function of which is to eliminate free radicals and reactive oxygen species. The aim of this study was to investigate the antioxidant effect of selenium nanoparticles and sodium selenite on biochemical parameters and antioxidant defense in Acanthopagrus latus in the presence of mercury chloride. A total number of 300 fish (25±3 g) were randomly distributed in five groups according to diet: control, nanoSe and sodium selenite (1 and 1.5 mg/kg). Fish were fed with experimental diets for six weeks. They were then exposed to a sublethal dose of HgCl2 for two weeks. At the end of the feeding period and after exposure, blood and liver samples were taken from all treatments and the activity of liver enzymes and antioxidants were measured. After six weeks of feeding the results showed that the form of selenium nanoparticles improved growth performance, increased the activity of antioxidant enzymes GPX and CAT and reduced the content of MDA, AST and ALT (p<0.05). The results showed that the form of selenium nanoparticles was more effective than the inorganic form of selenium during the period of exposure in increasing the activity of the antioxidant enzymes GPX and CAT. Decreased MDA content in the liver of fish fed selenium nanoparticles indicated a reduction in lipid peroxidation and a reduction in oxidative stress. The activity of ALT, AST and ALP enzymes increased more in the groups fed with selenium sodium than in the groups fed with nanoparticles (p<0.05). This study showed that the addition of selenium nanoparticles to the basic diet was more effective in terms of growth and antioxidant indices in yellowfin porgy (A. latus) after exposure to mercury chloride.