The major whey protein in mother’s milk and has an inmate immune host defenses.

Lactoferrin protein is not restricted to milk. 


At least 60 gene sequences of lactoferrin have been characterized in mammals: variation may indicate functional differences between different types of lactoferrin.


The lactoferrin gene LTF is located on the third chromosome in the locus 3q21-q23. 


Lactoferrin can exist in different polymeric forms in plasma and secretory fluids ranging from monomers to tetramers. 

It tends to polymerize, especially at high concentrations.

The dominant form of lactoferrin in physiological conditions is a tetramer, with the monomer:tetramer ratio of 1:4.

Monomeric, but not tetrameric lactoferrin can strongly bind to DNA.

It preferably binds to double-stranded DNA rather than single-stranded DNA. 

In the immune system lactoferrin protein is a common defense against bacterial infections, by its binding to iron with a higher affinity than most proteins.


Lactoferrin, is a component of innate immune system.

Lactoferrin prevents bacterial biofilm development, and the loss of its microbicidal activity and increased formation of biofilm is observed in patients with cystic fibrosis.

In cystic fibrosis, antibiotic susceptibility may be modified by lactoferrin.

A Cochrane review suggests that oral lactoferrin decreases late onset of sepsis and necrotizing enterocolitis in preterm infants.

Lactoferrin levels in tear fluid are decreased in dry eye diseases such as Sjögren’s syndrome.

Measurement of lactoferrin levels in human tear fluid can improve diagnosis of Sjögren’s syndrome and other forms of dry eye disease.


The lung and saliva contain a wide range of antimicrobial compounds including producing hypothiocyanite and lactoferrin, with hypothiocyanite missing in cystic fibrosis patients.

Its primary role is to sequester free iron.


It removes free iron an essential substrate required for bacterial growth.


Additionally, antibacterial activity of lactoferrin occurs in the presence of specific receptors on the cell surface of microorganisms as it binds to lipopolysaccharide of bacterial walls, and the oxidized iron part of the lactoferrin oxidizes bacteria via formation of peroxides. 


Lactoferrin prevents the attachment of H. pylori in the stomach, which in turn, aids in reducing digestive system disorders. 

Such binding affects the membrane permeability and results in the cell breakdown.


Its main biological function is  binding and transport of iron ions.


Lactoferrin is one of the transferrin proteins that transfer iron to the cells and control the level of free iron in the blood and external secretions. 


Lactoferrin’s affinity for iron is 300 times higher than that of transferrin.

Lactoferrin facilitates the transfer of iron from transferrin to lactoferrin during inflammations.

As the pH of tissues decreases due to accumulation of lactic and other acids, it increases the transfer of iron from transferrin to lactoferrin 


The saturated iron concentration in lactoferrin in human milk is estimated as 10 to 30%.

Lactoferrin is involved in the transport of iron, zinc and copper, but also in the regulation of their intake.


Lactoferrin is present in the milk of humans and other mammals.

Fecal lactoferrin is a non-invasive, qualitative biomarker that can predict colitis risk.

It is in the blood plasma and neutrophils and is one of the major proteins of virtually all exocrine secretions, such as saliva, bile, tears and pancreas.



Concentration of lactoferrin in  milk : varies from 7 g/L in the colostrum to 1 g/L in mature milk.



Lactoferrin is based on one polypeptide chain that contains about 700 amino acids and forms two homologous globular domains named N-and C-lobes. 



Lactoferrin protein exists in two forms: iron-rich hololactoferrin and iron-free apolactoferrin. 



Each lactoferrin molecule can reversibly bind two ions of iron, zinc, copper or other metals.



Lactoferrin forms reddish complex with iron.

Bovine Lactoferrin inhibits growth of bacteria, fungi, viruses, and parasites by direct action toward the membrane components, immunologic modulation, and synergism with anti-infective agents.

Lactoferrin acts on a wide range of human and animal viruses based on DNA and RNA genomes: herpes simplex virus 1 and 2, cytomegalovirus, HIV, hepatitis C virus, hantaviruses, rotaviruses, poliovirus type 1, human respiratory syncytial virus, murine leukemia viruses 


and Mayaro virus.


A number of viruses bind to the lipoproteins of the cell membranes that allows them to penetrate into the cell, and lactoferrin binds to the same lipoproteins thereby repelling the virus particles. 



Lactoferrin also directly binds to viral particles: hepatitis viruses, rotaviruses.


Lactoferrin suppresses virus replication after penetrated into the cell, by affecting natural killer cells, granulocytes and macrophages.

Bovine Lactoferrin and human Lactoferrin have a 77% homology for amino acids.

Bovine lactoferrin is used as an ingredient in yogurt, chewing gums, infant formulas, and cosmetics.

Lactoferrin inhibits in vitro growth of Trichophyton mentagrophytes, which are responsible for several skin diseases such as ringworm, acts against the Candida albicans.



A combination of lactoferrin with fluconazole can act against fluconazole-resistant strains of Candida albicans as well as other types of Candida: C. glabrata, C. krusei, C. parapsilosis and C. tropicalis.



Lactoferrin binds the plasma membrane of C. albicans inducing an apoptosis.

Poorly absorbed in the G.I. tract and resist digestive tract proteolysis.

Bovine Lactoferrin has anti-infectious activity.

Lactoferrin also has antibacterial, antiviral, antiparasitic, catalytic, anti-cancer, and anti-allergic functions and properties.



Lactoferrin hydrolyzes RNA and exhibits the properties of pyrimidine-specific secretory ribonucleases. In particular, by destroying the RNA genome:


Parsi women in West India have the milk RNase level markedly lower than in other groups, and their breast cancer rate is three times higher than average.

Bovine Lactoferrin supplementation alone or in combination with Lactobacillus rhamnosus probiotic reduces the incidence of first episode of late onset sepsis in very low birth weight neonates as reflected in a prospective, double blind randomized trial in Italian, tertiary neonates in intensive care units assigned to receive bovine Lactoferrin alone, or placebo (Manzoni).

Ribonucleases of milk, and lactoferrin in particular, might play an important role in pathogenesis of breast cancer.



The lactoferrin receptor plays internalizes lactoferrin, and facilitates absorption of iron ions by lactoferrin. 



Its gene expression increases with age in the duodenum and decreases in the jejunum.



It has positive effects on bone turnover, decreasing bone resorption and increasing bone formation. 



It reduces osteoclast formation, which signifies a decrease in pro-inflammatory responses and an increase in anti-inflammatory responses which indicates a reduction in bone resorption as well.



The fraction of protein extracted from milk, contains 3.3% RNA.


Leave a Reply

Your email address will not be published. Required fields are marked *