Lactoferrin: Benefits, Dosage, Contraindications

Antibacterial

Lf is both bacteriostatic and bactericidal. The main mechanism by which it exerts its bacteriostatic action is iron deprivation. Secreted in biological fluids in an unsaturated form (apo-Lf), it inhibits bacterial growth by competing with bacterial siderophores (these are iron chelators synthesized and secreted by microorganisms for iron sequestration). Besides this bacteriostatic activity, Lf also exerts a bactericidal activity independent of its iron chelating function. Through its ability to bind directly to lipopolysaccharides, lipoteichoic acids (bacterial wall molecules), or porins (membrane proteins forming channels), Lf destabilizes the bacterial membrane, causing their weakening and increasing their permeability. Lf's bactericidal activity also involves inhibiting bacterial attachment to host cells.

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Antiviral

Lactoferrin exerts antiviral activity against DNA and RNA viruses, particularly those of hepatitis, herpes, and HIV (human immunodeficiency virus). Although the precise mechanism of its antiviral action is not entirely elucidated, studies have shown that it prevents viruses from attaching and entering target cells. It achieves this by interacting with specific structures on the cell surface, called glycosaminoglycans (GAG) and integrins, which viruses typically use to infect cells. Additionally, lactoferrin has demonstrated its ability to inhibit the replication of certain viruses, such as HIV-1, chronic hepatitis C virus, and rotaviruses, under experimental laboratory conditions.

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Antifungal

Oral consumption of bovine lactoferrin (bLf) proves very effective in significantly reducing cases of oral candidiasis. This effectiveness is explained by several actions of lactoferrin: it binds to yeasts, disrupts their cell wall structure, and induces apoptosis, meaning the programmed death of these fungal organisms.

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Immunostimulant

The production of lactoferrin is positively regulated in response to inflammatory stimuli. It seems to bind to epithelial cells at the site of infection and inhibits the production of inflammatory cytokines. Preliminary evidence suggests that lactoferrin supplementation could increase the phagocytic activity of polymorphonuclear leukocytes and the proportion of natural killer cells in the host's defense system.

Antiparasitic

Lactoferrin (Lf) demonstrates a complex and effective antiparasitic activity, acting against several parasites responsible for specific diseases. It attaches to the membrane of the amoeba Entamoeba histolytica, which causes amoebiasis, an intestinal infection that can lead to symptoms like diarrhea and abdominal pain. It also inhibits the growth of Toxoplasma gondii, the parasite responsible for toxoplasmosis, an infection that can be severe for pregnant women and immunocompromised individuals. Lastly, lactoferrin interacts with specific receptors on Trichomonas vaginalis, the parasite behind trichomoniasis, a sexually transmitted infection, and Trypanosoma cruzi, responsible for Chagas disease, a potentially fatal condition affecting the heart and other organs.

Anti-inflammatory

Lactoferrin (Lf) plays an important role in regulating inflammation. It acts by interacting with lipopolysaccharides and various receptors present on epithelial cells (cells lining body surfaces) and immune cells. This interaction influences the production of cytokines, proteins that play a key role in controlling immune and inflammatory responses. Studies on animal models have shown that oral administration of bovine lactoferrin (bLf) can reduce inflammation in various tissues. This reduction of inflammation is mainly due to a decrease in the production of certain inflammatory cytokines, notably TNF-α (tumor necrosis factor) and IL-1β (interleukin-1 beta), and an increase in IL-10, an anti-inflammatory cytokine. Lactoferrin also helps reduce the recruitment of immune cells, such as leukocytes, to the site of inflammation, thereby contributing to attenuating the inflammatory response.

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Dermatological effect

Preliminary clinical research in healthy adults shows that daily intake of 200 to 600 mg of lactoferrin for 12 weeks improves skin hydration condition.

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Antioxidant

The activation of monocytes/macrophages by lipopolysaccharides or TNF-α triggers phagocytic activity and leads to increased production of reactive oxygen species, which can be amplified in the presence of free iron. Lf released at the site of inflammation, by trapping iron, limits this process and the damage caused to cell membranes by preventing lipid peroxidation. Recently, a clinical study on a cohort of 90 patients with chronic hepatitis C showed that subjects who ingested bLf presented an improvement in their hepatic oxidative status.

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Bone density

In vivo, bovine lactoferrin stimulates osteoblast proliferation by promoting bone growth. It also limits bone resorption by inhibiting osteoclastogenesis. These results are encouraging, but the mechanism of action remains to be elucidated. Nonetheless, Lf seems to play a key physiological role in bone formation and could be a potential therapeutic agent in combating osteoporosis.

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Anticancer

Lactoferrin (Lf) plays an important role in cancer prevention and inhibition of metastasis formation, acting as a potential tumor suppressor. It monitors and controls cell growth, which is crucial in fighting carcinogenesis. The antitumor properties of lactoferrin are notably due to its immuno-modulatory effect. It enhances the cytotoxicity of NK (Natural Killer) cells, which are essential in the immune defense against tumor cells. Furthermore, when administered (as in the case of bovine lactoferrin, bLf), it can inhibit angiogenesis. Angiogenesis is the process of forming new blood vessels, which is vital for tumor growth and metastasis spread. Moreover, lactoferrin can limit the growth of cancer cells by inducing a G1/S phase cell cycle arrest. This means it prevents cancer cells from multiplying, a key mechanism to curb cancer progression.