Antiviral activity of dairy proteins and hydrolysates on salmonid fish viruses

The aim of this work was to evaluate the antiviral properties of a number of milk proteins and enzymatic hydrolysates thereof on fish cell monolayers against the infectious pancreatic necrosis virus (IPNV) and infectious hematopoietic necrosis virus (IHNV). Results showed that the most potent antiviral activities against IHVN corresponded to the bovine lactoferrin-derived peptide lactoferricin, 3 h-total bovine casein peptic hydrolysate and 3 h-αs2-casein peptic hydrolysate of ovine and bovine origin, for which a therapeutic index (cytotoxic concentration50/MIC50) of approximately 30 was recorded. These studies are useful not only as a starting point for the search of specific active peptides from milk proteins, but also for a better understanding of the virus–cell interactions. Proteins and peptides from milk could have attractive applications in the control of viruses affecting fish species.