Lactoferrin: The Bioactive Peptide that Fights Disease
Readers note: This article can also be found in the Oct 2000 issue of the Life Extension Magazine.
As regular readers of the my articles are aware, whey protein appears to function as a natural food against cancer, HIV, overtraining syndrome in athletes and a host of pathologies. In particular, whey’s effects on glutathione levels and immunity are well documented in many animal studies with a growing number of human studies confirming the results with animals. Whey is one of two major proteins found in milk (the other being casein). When we talk about whey we are actually referring to a complex protein made up of many smaller protein subfractions (peptides), including beta-lactoglobulin, alpha-lactalbumin, immunoglobulins (IgGs), glycomacropeptides, bovine serum albumin (BSA), and minor peptides such as lactoperoxidases, lysozyme and lactoferrin. Each of the subfractions found in whey has its own unique biological properties. Up until quite recently, separating these subfractions on a large scale was either impossible or prohibitively expensive. Modern filtering technology has improved dramatically in the past few years allowing a handful of companies to separate some of the highly bioactive peptides from whey, such as lactoferrin. Many of these subfractions are only found in very minute amounts in cows milk, normally at less than 1%. For example, lactoferrin makes up approximately 0.5% – 1% or less of whey protein derived from cows milk (where as human mothers milk will contain up to 15% lactoferrin). Lactoferrin appears to be the subfraction of whey with documented anti-viral, anti-microbial, anti-cancer and immune modulating/enhancing effects. There is little doubt that lactoferrin could become the natural compound of choice in the treatment and prevention of a host of human ailments. To follow is a summary of what lactoferrin might have to offer.
Found in human mothers milk, lactoferrin appears to have a wide variety of uses in biological systems and is considered a first line immune defense in the human body.
A minor fraction of whey, lactoferrin appears to have a wide variety of uses in biological systems and is considered a first line immune defense in the human body. Though a natural component of cows and human mothers milk, lactoferrin is found throughout the human body and occurs in all secretions that bathe mucous membranes such as saliva, tears, bronchial and nasal secretions, hepatic bile, pancreatic fluids, and is an essential factor in the immune response. Lactoferrin is concentrated in oral cavities where it will come in direct contact with pathogens (i.e. viruses, bacteria, etc.) and kills or greatly suppresses these pathogens through a variety of different mechanisms. Exactly how lactoferrin exerts all of its immune modulating or immune enhancing functions is not entirely clear, but it is known to enhance the immune response both directly and indirectly (passively) in response to a wide range of immune challenges. Specific receptors for lactoferrin are found on many key immune cells such as lymphocytes, monocytes and macrophages, and is known to be directly involved in the upregulation of natural killer (NK) cell activity. Most research points to lactoferrin as being more of an immune modulator rather than a simple immune stimulant.
Published studies that have examined the use of lactoferrin as a supplement and its effects on immunity have been quite promising. Research using various animals models (i.e., rats, sheep, pigs and cats, as well as others) has found the ingestion of lactoferrin to have direct protective effects on the regulation and modulation of the immune system.
For example, one study that examined the immune response to an endotoxin (lipopolysaccharide) known to cause severe septic shock found that feeding lactoferrin to mice dramatically reduced the lethality of this endotoxin while improving immune response parameters.(1) Another study with baby pigs found only 17% of the pigs died when fed lactoferrin and injected with the endotoxin escherichia coli as opposed to 74% of the pigs that died without the lactoferrin!(2) This could be a major finding, as septic shock is the most frequent cause of death for intensive care patients and the 13th leading cause of death in the United States. Two studies using healthy human volunteers found the ingestion of lactoferrin derived from cows milk had positive immunoregulatory effects that were specific to the individual. That is, depending on the initial profile of the immune system of each person, lactoferrin ingestion augmented the immune response, leading the researchers to conclude “. . .the data suggests that bovine (cows) lactoferrin may be applied in the clinic to improve the immune status of the patients.”(3) A similar human study using ten people who ingested lactoferrin concluded “these results suggest that lactoferrin administration may influence the primary activation of the host defense system.”(4)
Lactoferrin appears to be particularly important in the health and function of the intestinal tract and has been found to greatly reduce systemic and intestinal inflammation in such conditions as inflammatory bowel disease and others. Animals subjected to a variety of pathogens known to cause both systemic and intestinal inflammation and damage show much greater resistance and reduced inflammation when fed lactoferrin. The gastrointestinal tract must be viewed as an ecologic system in which a balance between both good and bad bacterial flora (micro flora) exists. An overgrowth of bad bacteria in the intestinal tract is known to cause a wide range of sever problems that cause a myriad of pro-inflammatory mediators to be released, causing disruptions throughout the entire body.
When fed to adult animals and human infants, lactoferrin showed a dramatic increase in good micro flora—such as bifidus—and a decrease in bad bacteria, such as E. coli, streptococcus, clostridium and others. The result was desirable intestinal flora, which is known to be essential for optimal health, immunity and resistance to disease. An extensive review that examined the role of lactoferrin in inflammation and the health of the intestinal tract stated, “The possibility that lactoferrin limits the autodestructive inflammatory response presents a new alternative for the future management of systemic inflammation.”(5) Some research also suggests that lactoferrin is able to stimulate intestinal cell growth and may lead to better digestive functions, in addition to its ability to enhance the growth of “good” microflora in the intestine. There is little doubt that in addition to its immunomodulating effects, this natural peptide derived from whey has powerful pro-biotic properties.
How to Obtain Lactoferrin
Lactoferrin is a natural constituent of whey protein found in milk. High quality whey protein supplements contain about 0.5% lactoferrin. That means a 20 gram scoop of high quality whey protein isolate provides about 100mg of lactoferrin.
An adequate and cost effective dose of lactoferrin for the adjunctive treatment of disease is estimated to be 300 mg a day. There are dietary supplements that provide potent doses of lactoferrin extracted from whey. When using these supplements, it is important to use a form of lactoferrin called “apolactoferrin” that is depleted of iron. The apolactoferrin form has been shown in studies to provide the benefits of lactoferrin as an antioxidant, and studies show the “apo” form may have additional benefits over that of other forms of lactoferrin.
Lactoferrin has been found to both directly and indirectly inhibit several viruses that cause disease in humans. It directly inhibits viruses by binding to viral receptor sites, thus preventing the virus from infecting healthy cells. For example, in vitro studies have found that lactoferrin strongly binds to the V3 loop of the gp120 receptor on HIV-1 and HIV-2, resulting in inhibition of virus-cell fusion and entry of the virus into cells.10 In addition, lactoferrin indirectly kills or inhibits viruses by augmenting the systemic immune response to a viral invasion. It’s interesting to note that there is a systemic deficiency of lactoferrin in people with HIV infection. One study that examined 22 asymptomatic and 45 symptomatic patients with HIV compared to 30 healthy controls found that “levels of plasma lactoferrin are decreased in HIV-1 infected patients in relation to the progression of the disease.”(6) Another study found that the lack of lactoferrin (and secretory Iga) found in the oral cavities of people with HIV correlated strongly with the frequent infections in those areas often seen with patients with AIDS.(11) Lactoferrin was also found to have “potent” anti-viral effects against the replication of both human HIV and cytomegalovirus (CMV) virus in several in vitro studies with no cytopathic effects on healthy cells.
In addition to HIV and CMV, additional studies have found that lactoferrin inhibits herpes simplex type 1 infection of healthy cells. The latter likely occurs by preventing viral attachment to healthy cells via the blocking of viral proteins and direct immune interactions with natural killer cells, lymphocytes and phagocytes.(7,8,9,10)
The importance of lactoferrin in viral infections warrants a great deal of further research and use by clinicians. There is little doubt that lactoferrin is a key molecule for the body and the immune system in the fight against viruses and other microbes, and could be an effective supplement for people with viral infections.
Perhaps one of the most promising uses for lactoferrin may be in its potential as a nontoxic adjuvant cancer treatment agent. Extensive in-vitro (test tube) and in-vivo research with animals has shown lactoferrin to be a powerful anti-cancer agent.
Two studies using healthy human volunteers found the ingestion of lactoferrin derived from cow’s milk had positive immunoregulatory effects.
Multiple studies using both rats and mice exposed to a toxic chemical (azoxymethane) known to cause tumors throughout the gastrointestinal tract, administered concomitantly with lactoferrin, showed a large reduction in intestinal polyp development.(12,13) Just as important, there were no toxic effects to intestinal epithelial tissues. Another study found the addition of lactoferrin to cancer prone mice subjected to cancer causing chemicals reduced the number of tumors and suppressed angiogenesis (the production of new blood vessels), which tumors need to survive. This study also found lactoferrin “significantly inhibited” liver and lung metastasis of cancer cells in these animals.(14) In addition to what appears to be direct cancer inhibiting properties of lactoferrin, additional studies have found it increased natural killer (NK) cell toxicity to several cancer cell lines at low concentrations. This shows lactoferrin plays a systemic role in improving immune cell effectiveness to cancer cells, as well as a direct effect through mechanisms that are not fully clear at this time.
Yet another study found lactoferrin to be very effective at suppressing the growth of human pancreatic cancer cells. So much so the researchers concluded that lactoferrin “…might become one of the new drugs of choice for the adjuvant therapy against pancreatic cancer.”(15) Additional published studies have found both direct cancer suppressing activities of lactoferrin as well as systemic immune improvements in animals fed lactoferrin with chemical induced cancers. One study that examined lactoferrin’s effects on chemically induced colon cancer found that “no effects indicative of toxicity were noted [from the use of lactoferrin], but significant reductions in both incidence and number of adenocarcinomas (tumors) of the large intestine were observed in almost all treatments.”(12)
Probably lactoferrin’s best known role is as an iron binding protein. It’s referred to as hololactoferrin in its iron bound form and apolactoferrin in its iron depleted form. Studies have found it’s the apolactoferrin form that has the most powerful effects as an anti-microbial agent. Directly related to lactoferrin’s previously mentioned ability to suppress certain health degrading bacteria in the intestine, lactoferrin is a powerful anti-microbial that inhibits a wide range of pathogenic bacteria and other microbes. The mechanism appears to lie with lactoferrin’s ability to bind iron, as it is known to have an extremely high affinity for this metal. Many pathogenic bacteria need a supply of free iron to multiply—in the presence of lactoferrin, they are strongly inhibited or killed.
Extensive in-vitro (test tube) and in-vivo research with animals has shown lactoferrin to be a powerful anti-cancer agent.
One study looked at lactoferrin as a “natural antibiotic” and found that lactoferrin both in-vitro and in-vivo strongly inhibited the toxic bacteria helicobacter pylori. They stated “It is concluded that bovine (cows) lactoferrin has significant antimicrobial activity against helicobacter species in-vitro and in-vivo.”(16) Another study using both in-vitro and in-vivo methods added lactoferrin to the drinking water of mice and subjected them to the toxic microbe staphylococcal. The study found that the mice getting the lactoferrin as 2% of calories reduced kidney infections by 40% to 60% and reduced bacterial counts 5- to 12-fold. They concluded “the results suggest a potential for the use of lactoferrin as natural anti-bacterial proteins for preventing bacterial infections.”(17) Interestingly, some studies have found lactoferrin from cows to be more effective than lactoferrin from humans for anti-bacterial properties(18) (though it’s well established that human mothers milk confers a great deal of protection to the newborn due to many factors, including a high lactoferrin content). Several studies have found lactoferrin to inhibit a wide range of gram positive and gram negative bacteria, yeasts and even certain intestinal parasites. Cholera, escherichia coli, shigella flexneri, staphylococcus epidermidis, pseudomonas aeruginosa, candida albicans and others have all been found to be strongly or partially inhibited in the presence of lactoferrin.(19,20) (It should be noted not every microbe that is pathogenic to humans is suppressed by lactoferrin).
Maybe most promising and interesting, there is research that points to lactoferrin being able to improve the efficiency of antibiotic treatments in the fight against pathogenic microbes. Considering the out of control use of antibiotics and the rise in antibiotic resistant strains of “bad bugs,” this is very good news. Would the combination of lactoferrin and antibiotics be the knockout punch to certain bacteria that are not being killed by antibiotic treatments alone? More research is needed, but the evidence is very compelling.
Lactoferrin as an antioxidant
Finally, lactoferrin is an antioxidant that scavenges free iron, helping to prevent uncontrolled iron based free radical reactions, thus protecting certain cells from peroxidation. Though lactoferrin is both an iron scavenger and donor (depending on the cellular environment), it has been found to scavenge or donate iron at the appropriate times when the body is in need of the reaction. At normal physiological PH, lactoferrin binds iron tightly thus diminishing oxidative stress to tissues (from free radical production of iron). As would be expected, apolactoferrin, but not hololactoferrin, has been shown to prevent lipid peroxidation. However, there are times in fact when iron is needed as part of a controlled oxygen radical generating system by certain immune cells to kill microorganisms. Lactoferrin has been found to be an iron donor to this system under reduced PH conditions.
Several studies suggest lactoferrin reduces oxidative stress. Diseases such as cancer, heart diseases and AIDS are all closely related to oxidative stress either as a causative factor or as a factor in progression of the disease. One study that examined the role of whey proteins, multifermented whey proteins and lactoferrin in oxidative stress made the bold statement, “We can conclude that whey protein, lactoferrin and multifermented whey are good candidates as dietary inhibitors of oxidative stress and should be considered as potential medicinal foods in various pathologies as HIV infection and cancer.”(21) We couldn’t have said it better ourselves!
There is little doubt that lactoferrin is a major find and a potential breakthrough as a natural nontoxic treatment in an array of human ailments. Though a handful of companies are able to produce lactoferrin at this time, there is only one company producing the apolactoferrin (iron depleted) form in large quantity. Studies suggest that the superior form to supplement with is apolactoferrin.
Arao S, Matsuura S, Nonomura M, Miki K, Kabasawa K, Nakanishi H. Measurement of urinary lactoferrin as a marker of urinary tract infection. J Clin Microbiol 1999 Mar;37(3):553-7.
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Manev V, Maneva A, Sirakov L. Effect of lactoferrin on the phagocytic activity of polymorpho-nuclear leucocytes isolated from blood of patients with autoimmune diseases and Staphylococcus aureus allergy. Adv Exp Med Biol 1998;443:321-30.
Marchetti M, Longhi C, Conte MP, Pisani S, Valenti P, Seganti L. Lactoferrin inhibits herpes simplex virus type 1 adsorption to Vero cells. Antiviral Res 1996 Mar;29(2-3):221-31.
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Roozendaal C, Horst G, Pogany K, van Milligen de Wit AW, Kleibeuker JH, Haagsma EB, Limburg PC, Kallenberg CG. Prevalence and clinical significance of anti-lactoferrin auto-antibodies in inflammatory bowel diseases and primary sclerosing cholangitis. Adv Exp Med Biol 1998;443:313-9.
Swart PJ, Kuipers ME, Smit C, Pauwels R, deBethune MP, de Clercq E, Meijer DK, Huisman JG. Antiviral effects of milk proteins: acylation results in polyanionic compounds with potent activity against human immunodeficiency virus types 1 and 2 in vitro. AIDS Res Hum Retroviruses 1996 Jun 10;12(9):769-75.
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