Effect of beet molasses pre-treatment on serum immunity indices of common carp (Cyprinus carpio) in exposure to iron nanoparticles

This study aimed to investigate the protective effect of molasses pre-treatment on serum immunity indices of Cyprinus carpio exposed to iron nanoparticles. A total of 250 fish with an average weight of 25±0.62 were divided into four treatments, including without molasses (treatment 1), diet containing 0.5% molasses (treatment 2), diet containing 1% molasses (treatment 3) and diet containing 2% molasses (treatment 4). After 42 days, three fish were taken from each replicate and presented as "no nanoparticles" in the results. Then fish were exposed to 50% of the lethal concentration of iron nanoparticles (96h LC50) for 14 days. After 14 days, three blood samples were taken from each replicate and presented as "nanoparticles" in the results. Blood samples were taken and serum was isolated to measure serum biochemical parameters, including hepatic enzymes (ALT, AST, ALP), glucose, total protein, immunoglobulin, albumin. The molasses treatments had a significant effect on serum immune parameters (P<0.05). With increasing molasses concentration, levels of the serum total protein, immunoglobulin, albumin and glucose were significantly increased. In the treatment of nano iron and nano-iron with molasses, the amount of these indices significantly increased. AST and ALP levels significantly decreased by molasses-fed treatments, but significantly increased in nano-iron treatment in this treatment. In the treatment of nano-iron with molasses, the amount of this index decreased, but it increased significantly in comparison to the molasses group, which means that the molasses alone reduced the index, but in combination with nano-iron, it did not increase the effect of nano-iron, neutralize or even improve it. In the combination of nano-iron and molasses, the amount of ALP and AST indices significantly decreased, that means molasses in combination with nano-iron could improve the nano-iron supplementation, but in the remaining indices, molasses could not neutralize increase effect of nano-iron.