EN
Lactoferrin (LF) is an iron-binding protein from the transferrin family present in mucosal secretions, several organs, secondary granules of neutrophils and the serum of mammals. Many biological functions have been attributed to lactoferrin, including immunomodulatory and anti-inflammatory properties. Although the presence of LF in fish is unknown, it has similar effects in fish as in mammals. In the majority of the investigated fish species LF promoted proliferative response of lymphocytes, modulated macrophage functions or increased phagocytosis and respiratory burst of fish leukocytes in vitro. Administration of LF reduced the mortality of fish challenged with pathogenic bacteria and viruses, and enhanced the resistance of fish to parasitic infections. Moreover LF treatment reduced the stress response of aquatic organisms cultured under deteriorating conditions. As a natural protein LF shows very low toxicity, high biocompatibility and biodegradability, and is considered safe for the environment and consumer health as well. Although LF had no effect on the immune system of several fish species, its use as an immunostimulant in aquaculture is still a promising area.