Human lactoferrin (recombinant)

Human lactoferrin (recombinant), biochemical grade, is an iron-binding protein. Structurally similar to the plasma iron transport protein transferrin; however, lactoferrin has a much higher affinity for iron (250-fold). Abundant in colostrum, lactoferrin is also found in small amounts in tears, saliva, mucus secretions, and the secondary granules of neutrophils. It is released by mucosal epithelium and neutrophils in response to inflammatory stimuli.

The multifaceted roles of lactoferrin include inhibiting bacterial growth by sequestering iron and enhancing bacterial cell wall permeability through its N-terminus binding to lipopolysaccharide. Lactoferrin can also inhibit viral infection by tightly binding to viral envelope proteins, preventing cell-virus fusion by blocking the binding domain. Furthermore, lactoferrin appears to activate the host defense system by stimulating the release of the neutrophil activator interleukin-8. Additionally, it may be involved in antibody and interleukin synthesis, lymphocyte proliferation, and complement activation.

In vitro experiments examining the effect of lactoferrin on epithelial cell adhesion used iron-limited media to culture Streptococcus mutans. The high-affinity iron-binding properties of lactoferrin contribute to its physiological effects, making it a key regulator in immune and defense mechanisms.