lactoferrin and Influenza--Human

Although lactoferrin has many biological functions, the host-protective effects against pathogenic microorganisms including bacteria, fungi, and viruses are regarded as one of the most important. Here, we review research on the protective role of lactoferrin administration against common viral infections. Many studies have shown the in vitro antiviral activity of lactoferrin against viral pathogens that cause common infections such as the common cold, influenza, gastroenteritis, summer cold, and herpes, where lactoferrin inhibits mainly viral attachment to the target cells. Recently, studies indicating the in vivo protective effects of lactoferrin by oral administration against common viral infections have been increasing. For instance, norovirus is an extremely important emerging human pathogen that causes a majority of gastroenteritis outbreaks worldwide that may be a target candidate for lactoferrin. Lactoferrin consumption reduced the incidence of noroviral gastroenteritis in children and a similar effect was observed in a wide range of ages in a preliminary survey. A recent in vitro study reported that lactoferrin inhibits both cellular attachment of the murine norovirus, a virus closely-related to the human norovirus, and viral replication in the cells by inducing antiviral cytokines interferon (IFN)-α/β. Lactoferrin administration also enhances NK cell activity and Th1 cytokine responses, which lead to protection against viral infections. In conclusion, lactoferrin consumption may protect the host from viral infections through inhibiting the attachment of a virus to the cells, replication of the virus in the cells, and enhancement of systemic immune functions.

Topics: Anti-Infective Agents; Caliciviridae Infections; Common Cold; Gastroenteritis; Herpes Simplex; Humans; Influenza, Human; Lactoferrin; Norovirus; Rotavirus Infections; Seasons

The common cold is the leading cause of doctor visits in the United States and annually results in 189 million lost school days. In the course of one year the U.S. population contracts approximately 1 billion colds. Influenza infection is still a leading cause of morbidity and mortality, accounting for 20-25 million doctor visits and 36,000 deaths per year in the United States. Conventional therapies for colds and flu focus primarily on temporary symptom relief and include over-the-counter antipyretics, anti-inflammatories, and decongestants. Treatment for influenza also includes prescription antiviral agents and vaccines for prevention. This article reviews the common cold and influenza viruses, presents the conventional treatment options, and highlights select botanicals (Echinacea spp., Sambucus nigra, larch arabinogalactan, Astragalus membranaceous, Baptisia tinctoria, Allium sativa, Panax quinquefolium, Eleutherococcus senticosus, Andrographis paniculata, olive leaf extract, and Isatis tinctoria) and nutritional considerations (vitamins A and C, zinc, high lactoferrin whey protein, N-acetylcysteine, and DHEA) that may help in the prevention and treatment of these conditions.

Topics: Acetylcysteine; Antiviral Agents; Common Cold; Dehydroepiandrosterone; Humans; Influenza Vaccines; Influenza, Human; Lactoferrin; Nonprescription Drugs; Phytotherapy; Zinc

Bovine lactoferrin is a biglobular multifunctional iron binding glycoprotein that plays an important role in innate immunity against infections. We have previously demonstrated that selected peptides from bovine lactoferrin C-lobe are able to prevent both Influenza virus hemagglutination and cell infection. To deeper investigate the ability of lactoferrin derived peptides to inhibit Influenza virus infection, in this study we identified new bovine lactoferrin C-lobe derived sequences and corresponding synthetic peptides were synthesized and assayed to check their ability to prevent viral hemagglutination and infection. We identified three tetrapeptides endowed with broad anti-Influenza activity and able to inhibit viral infection in a concentration range femto- to picomolar. Our data indicate that these peptides may constitute a non-toxic tool for potential applications as anti-Influenza therapeutics.

Topics: Animals; Antiviral Agents; Cell Line; Hemagglutination Tests; Hemagglutination, Viral; Humans; Influenza, Human; Lactoferrin; Magnetic Resonance Spectroscopy; Models, Molecular; Orthomyxoviridae; Peptides; Protein Conformation; Structure-Activity Relationship

To define the pattern of secretion production during influenza virus infection, 28 adult subjects were inoculated with influenza-A virus (H1N1) and cloistered for a period of 8 days. On each day, symptoms associated with virus infection were scored, nasal secretions were collected and nasal lavages were performed. Recovered lavage fluids were submitted for virus culture and assayed for proteins, histamine, and bradykinin. Twenty-one subjects were infected with influenza-A virus and had significant increases in daily secretion weights and symptom scores extending from day 2 to 7, post-inoculation. Plasma-derived proteins in the nasal lavage fluids showed an early increase to peak at day 4 and then decreased. Glandular proteins showed a later increase to peak at day 5. Bradykinin but not histamine was significantly elevated and tracked the changes in the glandular proteins. In contrast, a shallow increase in symptoms confined to day 2 post-inoculation, but no increase in daily secretion weights was documented in the seven uninfected subjects. There, an increase in plasma proteins was observed on days 1 and 2, but no change in glandular proteins was obvious. These results support a biphasic secretory response during influenza-virus infection with transudation dominating the early period and glandular secretions contributing later.

Topics: Adult; Blood Proteins; Bradykinin; Capillary Permeability; Female; Histamine; Humans; Immunoglobulin A, Secretory; Influenza A virus; Influenza, Human; Lactoferrin; Male; Muramidase; Nasal Lavage Fluid; Nasal Mucosa; Time Factors

The role of cytokines in the pathogenesis of pneumonia is still poorly understood. In a previous study the diagnostic value of measuring blood concentrations of interleukin 6 and interferon gamma was established. In the present study the value of blood concentrations of interleukin 8, granulocyte-colony stimulating factor, and lactoferrin as markers of bacteraemic pneumonia is evaluated.. The circulating concentrations of interleukin 8 (IL-8), granulocyte-colony stimulating factor (G-CSF), and lactoferrin were measured in 14 patients with bacteraemic pneumococcal pneumonia and 49 patients with atypical pneumonia or influenza A infection using enzyme immunoassays.. Serum G-CSF concentrations were higher in the group with bacteraemic pneumococcal pneumonia, and G-CSF values correlated with the white blood cell count and levels of C-reactive protein (CRP). The levels of IL-8 were higher in the group with bacteraemic pneumococcal pneumonia than the groups with Chlamydia pneumonia, Legionella pneumonia, or influenza A infection, but there was no difference when compared with the group with Mycoplasma pneumonia. A white blood cell count of > 15 x 10(9)/l was highly suggestive of bacteraemic pneumonia. The concentrations of lactoferrin were raised in all groups except those with influenza A infection, but no difference was found between the different aetiological groups. A correlation was found between lactoferrin and white blood cell counts.. Serum G-CSF and IL-8 concentrations are potential markers of bacteraemic pneumonia.

Topics: Acute Disease; Adult; Aged; Aged, 80 and over; Biomarkers; Chlamydia Infections; Cytokines; Female; Granulocyte Colony-Stimulating Factor; Humans; Influenza A virus; Influenza, Human; Interleukin-8; Lactoferrin; Legionnaires' Disease; Leukocyte Count; Male; Middle Aged; Pneumonia, Bacterial; Pneumonia, Mycoplasma; Pneumonia, Pneumococcal