Effects of orally administered lactoferrin and lactoperoxidase on symptoms of the common cold.

Objectives: Lactoferrin (LF) and lactoperoxidase (LPO) are present in human saliva. LF has been demonstrated to show antibacterial and antiviral activities. In saliva, LPO catalyzes the hydrogen peroxide-dependent oxidation of thiocyanate to hypothiocyanite that exhibits antimicrobial and antiviral properties.

Effects of lactoferrin on the production of interferon-λ by the human intestinal epithelial cell line HT-29.

We examined the in-vitro effects of bovine lactoferrin (LF) on the production of interferon-λ (IFN-λ), an antiviral cytokine important for the defense of enterocytes, using the human intestinal epithelial cell line HT-29. HT-29 cell cultures were treated with LF for 1 h, and the cultures were stimulated with polyinosinic-polycytidylic acid (poly I:C). LF increased the concentration of IFN-λ in the culture supernatant after stimulation in a dose-dependent manner.

Structure of iron saturated C-lobe of bovine lactoferrin at pH 6.8 indicates a weakening of iron coordination.

The bilobal lactoferrin is an approximately 76 kDa glycoprotein. It sequesters two Fe(3+) ions together with two CO(3)(2-) ions. The C-terminal half (residues, Tyr342-Arg689, C-lobe) of bovine lactoferrin (BLF) (residues Ala1-Arg689) was prepared by limited proteolysis using trypsin.

Inactivating effects of the lactoperoxidase system on bacterial lyases involved in oral malodour production.

The main components of oral malodour have been identified as volatile sulfur compounds (VSCs), including hydrogen sulfide (H(2)S) and methyl mercaptan (CH(3)SH). The lactoperoxidase (LPO) system (consisting of LPO, glucose oxidase, glucose and thiocyanate) was previously shown to exhibit antimicrobial activities against some oral bacteria in vitro and suppressive effects on VSCs in mouth air in a clinical trial. Here, we examined the in vitro effects of the LPO system on the activities of the bacterial lyases involved in the production of VSCs by oral anaerobes.

Preparation and antimicrobial action of three tryptic digested functional molecules of bovine lactoferrin.

Lactoferrin is an 80 kDa bilobal, iron binding glycoprotein which is primarily antimicrobial in nature. The hydrolysis of lactoferrin by various proteases in the gut produces several functional fragments of lactoferrin which have varying molecular sizes and properties. Here, bovine lactoferrin has been hydrolyzed by trypsin, the major enzyme present in the gut, to produce three functional molecules of sizes approximately 21 kDa, 38 kDa and 45 kDa.

A lactoferrin-receptor, intelectin 1, affects uptake, sub-cellular localization and release of immunochemically detectable lactoferrin by intestinal epithelial Caco-2 cells.

Intelectin 1 (IntL) is known as a lectin expressed in intestinal epithelia and also as a receptor for an iron-binding protein, lactoferrin (LF). Uptake of LF with bound iron by enterocytes via receptor-mediated endocytosis has been well investigated, whereas subsequent fate of endocytized LF and LF/IntL complexes remains largely unknown. In the present study, we examined contribution of IntL to the uptake, sub-cellular localization and subsequent release of LF by intestinal Caco-2 IntL-transfectants using two-site ELISA and fluorescence confocal microscopy.

Intracellular retention and subsequent release of bovine milk lactoferrin taken up by human enterocyte-like cell lines, Caco-2, C2BBe1 and HT-29.

Lactoferrin (LF) is an iron-binding glycoprotein contained in milk and other exocrine fluids, and is believed to have multiple biological functions. We investigated the intracellular dynamics of LF taken up by three lines of human enterocytes and the subsequent release of internalized LF by using two-site ELISA and confocal microscopy. LF taken up by Caco-2 cells was kept partially intact within the cells and subsequently released to the medium as degraded fragments of 30-50 kDa.

Antibacterial activity of the lactoperoxidase system combined with edible Laminaria hot-water extract as a source of halide ions.

Hot-water extracts prepared from nine out of 12 samples of dried edible Laminaria reduced the viable numbers of Aggregatibacter actinomycetemcomitans, Staphylococcus aureus, and Esherichia coli below the detection limit after incubation for 5 min when combined with lactoperoxidase, glucose oxidase, and glucose. Some extracts showed higher bactericidal activity and a higher OI(-) concentration in the assay mixture after ultrafiltration.

Effects of a composition containing lactoferrin and lactoperoxidase on oral malodor and salivary bacteria: a randomized, double-blind, crossover, placebo-controlled clinical trial.

We report a clinical trial of the effects of test tablets containing bovine lactoferrin and lactoperoxidase on oral malodor and salivary bacteria. Fifteen subjects with volatile sulfur compounds (VSCs) in mouth air above the olfactory threshold (H(2)S >1.5 or CH(3)SH >0.

Orally administered lactoperoxidase ameliorates dextran sulfate sodium-induced colitis in mice by up-regulating colonic interleukin-10 and maintaining peripheral regulatory T cells.

We previously demonstrated orally administered bovine lactoperoxidase (LPO) ameliorated dextran sulfate sodium-induced colitis in mice. Here, we examine the mechanism of action of LPO. Three days after colitis induction, expression of interferon-gamma mRNA in colonic tissue was significantly decreased in mice administered LPO; while mRNA expression of interleukin (IL)-10 and regulatory T cell (Treg) marker, Foxp3, were significantly increased.

Inhibition of lactoperoxidase by its own catalytic product: crystal structure of the hypothiocyanate-inhibited bovine lactoperoxidase at 2.3-A resolution.

To the best of our knowledge, this is the first report on the structure of product-inhibited mammalian peroxidase. Lactoperoxidase is a heme containing an enzyme that catalyzes the inactivation of a wide range of microorganisms. In the presence of hydrogen peroxide, it preferentially converts thiocyanate ion into a toxic hypothiocyanate ion.

Recombinant human intelectin binds bovine lactoferrin and its peptides.

Intelectin (IntL), a lectin that exists on the brush border membrane of the small intestine, plays a role in the innate immune response and also acts as a receptor for lactoferrin (LF), an iron-binding glycoprotein found in milk and other secretions. Similar to human LF (hLF), bovine LF (bLF) has been shown to induce proliferation and differentiation of human enterocytes and to modulate their cytokine productions. To evaluate the interaction between human IntL (hIntL) and bLF, recombinant hIntL (rhIntL) conjugated with a tag sequence was examined for its ligand-binding capacity by using microtiter plates coated with LF or other proteins.

Effects of orally administered bovine lactoperoxidase on dextran sulfate sodium-induced colitis in mice.

The effect of lactoperoxidase (LPO) on dextran sulfate sodium-induced colitis was examined in mice. After 9 d of colitis induction, weight loss, colon shortening, and the histological score were significantly suppressed in mice orally administered LPO (62.5 mg/body/d) as compared to a group administered bovine serum albumin.

Twenty-five years of research on bovine lactoferrin applications.

Lactoferrin (LF) was identified as a milk protein in 1960. Large-scale manufacturing of bovine LF (bLF) was established more than 20 years ago. Using this commercially available material, research for bLF applications has advanced from basic studies to clinical studies, and bLF has been applied to commercial food products for the last 25 years.

In vitro and in vivo effects of a composition containing lactoperoxidase on oral bacteria and breath odor.

The antimicrobial activity of a composition containing bovine lactoperoxidase (LPO), glucose oxidase, glucose and buffer salts was tested against oral bacteria in vitro. A preliminary in vivo study was conducted to test the effect on breath odor of the tablets containing this composition. Suspension of the composition in filter-sterilized saliva or phosphate-buffered saline containing sodium thiocyanate (NaSCN) at a physiological concentration showed bactericidal activity against Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis.

Orally administered lactoperoxidase increases expression of the FK506 binding protein 5 gene in epithelial cells of the small intestine of mice: a DNA microarray study.

Lactoperoxidase (LPO) is a component of milk and other external secretions. To study the influence of ingested LPO on the digestive tract, we performed DNA microarray analysis of the small intestine of mice administered LPO. LPO administration upregulated 78 genes, including genes involved in metabolism, immunity, apoptosis, and the cell cycle, and downregulated nine genes, including immunity-related genes.

Bovine lactoferrin: benefits and mechanism of action against infections.

Ingestion of bovine lactoferrin (bLF) has been reported to show anti-infective, anti-cancer, and anti-inflammatory effects. In particular, it has become evident that oral bLF had a beneficial effect on infections of both digestive and nondigestive tract tissue in various animal models. Furthermore, the effects of bLF have been indicated in clinical studies on patients with Helicobacter pylori infection, chronic hepatitis C, tinea pedis, and other diseases.

Transfer of antigen-pulsed dendritic cells induces specific T-Cell proliferation and a therapeutic effect against long-term Helicobacter pylori infection in mice.

Helicobacter pylori causes persistent infection of the stomach and results in chronic gastritis and peptic ulcers. Jaws II cells, derived from mouse bone marrow, were pulsed with live or formalin-killed or whole-cell sonicates (WCS) of H. pylori.

Effects of orally administered bovine lactoferrin and lactoperoxidase on influenza virus infection in mice.

Milk contains a wide variety of host protective factors against infectious microbes. Among these protective factors, lactoferrin (LF) and lactoperoxidase (LPO) have been reported to exhibit antiviral activities as well as immuno-modulatory effects. In the present study, the effects of orally administered LF and LPO were assessed in a mouse influenza virus infection model.

Polymerase chain reaction--restriction fragment length polymorphism analysis of clarithromycin-resistant Helicobacter pylori infection in children using stool sample.

Background: To analyze clarithromycin-resistant Helicobacter pylori infection in children, we developed a method of polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis using stool samples.

Materials And Methods: Twenty-three children without significant upper abdominal symptoms were included (mean age 7.0 years).

Oral lactoferrin prevents body weight loss and increases cytokine responses during herpes simplex virus type 1 infection of mice.

Lactoferrin (LF), a multifunctional milk protein, is known to inhibit in vitro infection by viruses such as herpes simplex virus type 1 (HSV-1). We evaluated the influence of LF feeding on the HSV-1 cutaneous infection of mice. Bovine LF was administered to mice and, after 10 d, the mice were infected with HSV-1.