Lactoferrin antimicrobial activity

The ability of lactoferrin to inhibit the growth of certain microorganisms "in vitro" has been well documented. The evidence for such activity "in vivo" is not as well defined (7). The role of lactoferrin in antimicrobial activity in the gut will not be discussed in this article. 

The functional properties of milk proteins in foods have recently been expertly treated by Holt and Roginski (2001). These authors described the antihypersensitive, opioid, immunomodulatory, and calcium-binding milk peptides, the antiviral properties of various milk components, and the antimicrobial activity of lactoperoxidase, lactoferrin, lactoferricins, casein peptides, and peptides from a-lactalbumin. 

Contrary to other whey proteins, a Fe " ion is present in lactoferrin molecule [3]. Similarly to immunoglobulins, it has the antimicrobial character [46]. Whey is appropriate for extraction of lactoferrin and cation-exchange chromatography is proposed for its purihcation. Heat treatment at pH 4.0 does not denature the protein therefore, this pH is suitable for its pasteurization. Recently, some beneficial aspects of lactoferrin on human s health have been regarded. Its exceptional properties such as antiinfective, anticancer, antioxidant and antimicrobial activities enhance its utility in pharmaceutical and food industries. Remarkably, lower pH values (2-3) enhance its antibacterial activity. The results of clinical studies about positive effects of lactoferrin on human and animals health have been published [49]. 

Barhiroli, A., Bonomi, F., Capretti, G., lametti, S., Manzoni, M., Piergiovanni, L., Rollini, M., 2012. Antimicrobial activity of lysozyme and lactoferrin incorporated in cellulose-based food packaging, ood Control 26, 387—392. 

The substance that enhances the activity of the lactoferrin is the IgA normally present in human milk, though IgA by itself has no antimicrobial activity whatever. It has been proposed that whereas lactoferrin (the active factor of milk) sequesters the iron and makes it unavailable to most microorganisms, the igA acts to depress the production or elaboration of microbial siderophores,... 

The demonsfrafion fhaf fhe bacteriostatic activity of lactoferrin can be independenf of fhe level of iron saturation (Arnold et ah, 1980) suggests that lactoferrin has ofher antimicrobial mechanisms. Lactoferrin has been... 

The successful isolation of primary cells is dependent on several factors, some of which are not subject to optimization, such as species, type of tissue, age and sex of donor, and presence of genetic modifications (e.g., knockout animals). Other factors such as the dissociation medium, enzymes and concentrations, temperature, and incubation times can be optimized to ensure the quality and consistency of a primary or cell line preparation. The identification and availability of key growth factors is an important determinant of which primary cells can be maintained in culture. For example lactoferrin is a pleiotropic factor with potent antimicrobial and immunomodulatory activities. Recently it has been shown that lactoferrin at physiological concentrations can also promote bone growth, potently stimulating the proliferation and differentiation of primary osteoblasts (Naot, 2005). 

Degranulation of PMN, releasing lactoferrin, can be induced by purified preparations of endogenous pyrogen and the activity may well reside within IL-1 (K18). Iron is essential for bacterial growth and the rapid sequestration of iron at inflammatory sites may serve as an antimicrobial mechanism and even the low-plasma iron may confer a protective effect (B67). 

Transferrins are also involved in the antimicrobial action of the white cells. Lactoferrin is an important component of neutrophils (Masson et al., 1969), and is crucial for the phagocytic activity of these cells. Thus, if lactoferrin present in the neutrophils is saturated with iron, the antibacterial action of the neutrophils is greatly compromised (Bullen and Armstrong, 1979). 

---