Lactoferrin is a globular multifunctional protein with antimicrobial activity (bacteriocide, fungicide). It is a part of the innate defense, mainly at mucoses. It is a glycoprotein that belongs to the iron transporter or transferrin family. It was originally isolated from bovine milk, where it is found as a minor protein component of whey proteins. Lactoferrin contains 703 amino acids. In addition to its presence in milk, it is also found in exocrine secretions of mammals and is released from neutrophil granules during inflammation. It appears to play several biological roles. Owing to its iron-binding properties, Lactoferrin is thought to play a role in iron uptake by the intestinal mucosa of the suckling neonate. That is, it appears to be the source of iron for breast-fed infants. It also appears to have antibacterial, antiviral, antifungal, anti-inflammatory, antioxidant and immunomodulatory activities.
Bovine Lactoferrin, derived from whey proteins, is marketed as a nutritional supplement. Supplemental Lactoferrin typically contains low amounts of iron. The possible antibacterial activity of supplemental Lactoferrin might be accounted for, in part, by its ability to strongly bind iron. Iron is essential to support the growth of pathogenic bacteria. Lactoferrin may also inhibit the attachment of bacteria to the intestinal wall. A breakdown product of Lactoferrin is the peptide lactoferricin. Lactoferricin, classified as a bioactive peptide, may also have antibacterial, as well as antiviral, activity. The possible antiviral activity of supplemental Lactoferrin may be due to its inhibition of virus-cell fusion and viral entry into cells. It is often referred to as an innate defense protein and frequently serves as the first line of defense in protection against pathogens. Lactoferrin is also considered as a novel bone growth factor. It may have a physiological role in bone growth and healing, and a potential therapeutic role as an anabolic factor in osteoporosis.
References:
PDR Health. http://www.pdrhealth.com/drug_info/nmdrugprofiles/nutsupdrugs/lac_0314.shtml
Lactoferrin Research. http://www.lactoferrinresearch.org/
PubMed Central. http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1183439
Dorit Naot, PhD, Andrew Grey, MD, Ian R Reid, MD, and Jillian Cornish, PhD
