Effect of administration of bifidobacteria and lactic acid bacteria to newborn calves and piglets

The effect of oral administration of bifidobacteria and lactic acid bacteria on newborn livestock was investigated. Oral administration of Bifidobacterium pseudolongum or Lactobacillus acidophilus to calves improved BW gain and feed conversion over that of untreated controls. The frequency of diarrhea occurrence was decreased in the group fed probiotics. However, there was no significant difference between calves administered B. pseudolongum and those administered L. acidophilus. Under conditions of feeding without antibiotics, the frequency of diarrhea was decreased markedly by administration of probiotics. The BW gain of piglets was significantly greater during both the suckling and weaning periods for the group fed probiotics than for the control group. The effect was more evident during the suckling period than during the weaning period. Under conditions of feeding without antibiotics, the frequency of piglet mortality was decreased markedly by administration of probiotics. The probiotics tested here had useful effects, including improved BW gain, feed conversion, and fecal condition of both newborn calves and piglets.

Bifidobacterium longum, a lactic acid-producing intestinal bacterium inhibits colon cancer and modulates the intermediate biomarkers of colon carcinogenesis

The human colon can be described as a complex microbial ecosystem, comprising several hundred bacterial species. Some of these enteric bacteria are beneficial to the host and have been shown to exert antimutagenic and anticarcinogenic properties. We have investigated the colon tumor inhibitory activity of Bifidobacterium longum, a lactic acid-producing enterobacterium. The modifying effects of this lactic culture on colonic mucosal and/or tumor cell proliferation, ODC activity and ras-p21 oncoprotein expression in colon carcinogenesis were also analyzed. Male F344 rats were fed a modified AIN-76A diet containing 0 or 2% lyophilized cultures of B. longum and s.c. administered azoxymethane (AOM) dissolved in normal saline at a dose of 15 mg/kg body wt, once weekly for 2 weeks. Vehicle controls received an equal volume of normal saline s.c. Animals were maintained on control or experimental diets until termination of the study. Animals intended for analysis of cell proliferation were killed 20 weeks after the second AOM injection, whereas animals intended for colon tumor analysis and measurement of ODC activity and ras-p21 expression were killed 40 weeks after the last AOM injection. The data demonstrate that dietary administration of lyophilized cultures of B. longum resulted in significant suppression of colon tumor incidence and tumor multiplicity and also reduced tumor volume. Results also revealed that ingestion of B. longum significantly inhibited AOM-induced cell proliferation, ODC activity and expression of ras-p21 oncoprotein. Data suggest that oral administration of probiotic B. longum exerts strong antitumor activity, as indicated by modulation of the intermediate biomarkers of colon cancer, and consequently reduced tumor outcome.

Killing of Candida albicans by lactoferricin B, a potent antimicrobial peptide derived from the N-terminal region of bovine lactoferrin

Candida albicans was found to be highly susceptible to inhibition and inactivation by lactoferricin B, a peptide produced by enzymatic cleavage of bovine lactoferrin. Effective concentrations of the peptide varied within the range of 18 to 150 micrograms/ml depending on the strain and the culture medium used. Its effect was lethal, causing a rapid loss of colony-forming capability. 14C-labeled lactoferricin B bound to C. albicans and the rate of binding appeared to be consistent with the rate of killing induced by the peptide. The extent of binding was diminished in the presence of Mg2+ or Ca2+ ions which acted to reduce its anticandidal effectiveness. Binding occurred optimally at pH 6.0 and killing was maximal near the same pH. Such evidence suggests the lethal effect of lactoferricin B results from its direct interaction with the cell surface. Cells exposed to lactoferricin B exhibited profound ultrastructural damage which appeared to reflect its induction of an autolytic response. These findings suggest that active peptides of lactoferrin could potentially contribute to the host defense against C. albicans.

A review: the active peptide of lactoferrin

A potent antimicrobial peptide, 'lactoferricin', was found to be generated upon gastric pepsin cleavage of lactoferrin. The active peptide consists mainly of a loop of 18 amino acid residues, derived from the N-terminal region of the lactoferrin molecule. Like various other antimicrobial peptides that display membrane-disruptive properties, it contains a high proportion of basic amino acid residues. A physiologically diverse range of micro-organisms was tested and found to be susceptible to inhibition by this natural peptide including Gram-negative and Gram-positive bacteria, yeasts and filamentous fungi. Its antimicrobial effect against sensitive micro-organisms was lethal. Electron microscopy studies revealed that it induces a profound change in cell ultrastructural features and causes substantial cell damage in bacteria and fungi. These findings suggest the possibility that active peptides of lactoferrin may have a role in the host defense against microbial disease. If produced in substantial quantities in vivo such peptides could have important physiological significance, especially in nursing infants.

Relationship between oxygen sensitivity and oxygen metabolism of Bifidobacterium species

Bifidobacteria, which are obligate anaerobes, were studied to determine the relationship between their sensitivity to oxygen and oxygen metabolism. Among the four species tested, Bifidobacterium infantis, Bifidobacterium breve, and Bifidobacterium longum differed from Bifidobacterium adolescentis in sensitivity to oxygen. The former three species showed marked growth under conditions of partial aeration, whereas the growth of B. adolescentis was suppressed by low concentrations of oxygen. Bifidobacteria express reduced NAD-oxidase and -peroxidase activities, which function in a pathway for two-electron reduction of molecular oxygen, producing hydrogen peroxide and, subsequently, water. Activities of reduced NAD-oxidase and -peroxidase were inversely correlated with their sensitivities to oxygen. Bifidobacterium adolescentis exhibited lowered activities of these two enzymes; the activities were 10 to 20% of those observed with B. infantis, B. breve, and B. longum. These observations are compatible with the hypothesis that reduced NAD-oxidase and reduced NAD-peroxidase in Bifidobacterium species play a role in prevention of oxygen toxicity. Superoxide dismutase activity was also detected in Bifidobacterium species. Superoxide dismutase is probably not involved in detoxification of oxygen, because the activity of this enzyme was extremely low, and the sensitivity to oxygen varied independently of superoxide dismutase activity.

Effects of lactoferrin and its peptides on proliferation of rat intestinal epithelial cell line, IEC-18, in the presence of epidermal growth factor

The cell growth-stimulating activity of lactoferrin (LF) in combination with epidermal growth factor (EGF) was evaluated by using a rat intestinal epithelial cell line, IEC-18. LF was found to be more effective than EGF for inducing an increase in cell numbers when cultured for over 6 days using a medium containing 0.2% fetal calf serum (FCS), although the 3H-thymidine incorporation-stimulating activity of EGF was more potent than that of LF. A synergistic effect of LF and EGF was observed in both cell proliferation and DNA synthesis assays. The increase in cell numbers when stimulated with LF plus EGF corresponded to about 5 times that of the control. Iron was not required for manifestation of these effects of LF. On the other hand, iron-saturated transferrin (TF) had cell-growth-stimulating activity, but iron-free TF did not, either in the presence or absence of EGF. These results indicate that LF induces cell proliferation by a mechanism distinct from that of TF. A pepsin-generated hydrolysate of LF (LFH) had an activity similar to that of undigested LF, and a peptide with cell-growth-stimulating activity from bovine LFH was isolated by monitoring its effects in combination with EGF on DNA synthesis in IEC-18 cells. Sequence analysis indicated that the peptide has the structure Ala-Glu-Ile-Tyr-Gly-Thr-Lys-Glu-Ser-Pro-Gln-Thr-His-Tyr-Tyr, corresponding to residues 79-93 of bovine LF.

Effects of lactoferrin and lactoferricin on the release of interleukin 8 from human polymorphonuclear leukocytes

Human or bovine lactoferrin (LF) and lactoferricin (LFcin), a peptide derived from the N-terminal region of LF, each have the ability to stimulate the release of neutrophil-activating polypeptide interleukin 8 (IL-8) from human polymorphonuclear leukocytes (neutrophils, PMNs). This finding suggests that LF and LFcin may both function as immunomediators for activating the host defense system. A basic peptide, protamine, exerted the same effect as that of LF and LFcin, suggesting the importance of the basic nature of LF and LFcin in acting as an inducer of IL-8 release from PMNs.

Potent bactericidal activity of bovine lactoferrin hydrolysate produced by heat treatment at acidic pH

A hydrolysate of bovine lactoferrin produced by heat treatment under acidic conditions had antibacterial activity at concentrations of 10 micrograms/ml in the culture medium. The optimal degree of hydrolysis for this activity was about 10%. Heat-treated lactoferrin, treated at pH 2.0 and 120 degrees C for 15 min and degree of hydrolysis of about 10%, had no Fe-binding capacity (0%) and less antigenicity (about 10(-6) than untreated lactoferrin. Heat-treated lactoferrin increased in antibacterial activity, and the activity was maintained in an Fe-rich medium. After fractionation of heat-treated lactoferrin by reverse-phase HPLC, several peptide fractions were found that had strong antibacterial activity. It was suggested that lactoferrin latently contains at least one bactericidal domain that is activated upon release by limited acid hydrolysis of the protein. The bactericidal activity of the peptide fragments of lactoferrin was shown to have no relation to Fe chelation, in contrast with the antibacterial mechanism of native lactoferrin.

Bacteriostatic effect of orally administered bovine lactoferrin on proliferation of Clostridium species in the gut of mice fed bovine milk

When milk-fed mice were orally inoculated with Clostridium ramosum C1, this strain proliferated in the gut and became the dominant component of the fecal microflora. In this experimental model, bovine lactoferrin (bLF) administered with milk suppressed the proliferation of this strain in vivo and decreased the numbers of C. ramosum and other bacteria in the feces. This bacteriostatic effect of bLF was dependent on the concentration of bLF, the duration of feeding, and the administered dose of C. ramosum C1. Compared with bovine serum albumin, ovalbumin, bovine whey protein isolate, or bovine casein, only bLF showed this specific activity. A similar effect of bLF was observed after oral inoculation with C. ramosum JCM 1298, C. paraputrificum VPI 6372, or C. perfringens ATCC 13124. A hydrolysate prepared by digestion of bLF with porcine pepsin showed the same inhibitory effect on proliferation of C. ramosum in vivo as occurred with undigested bLF. These results indicate that ingested bLF can exert a bacteriostatic effect against clostridia in the gut even after it has been digested to some extent.

13-Week oral repeated administration toxicity study of bovine lactoferrin in rats

Bovine lactoferrin (LF), which is an iron-binding glycoprotein in milk, was administered orally to groups of 12 males and 12 female rats at dose levels of 200, 600 and 2000mg/kg/day once daily for 13 weeks and its toxicity on repeated administration was examined. Throughout the administration period, there were no deaths caused by administration of the test compound, nor were there any adverse effects noted in the general condition of the animals. The study findings concerning body weight and food consumption, ophthalmology, urinalysis including water consumption, haematology, blood chemistry, necropsy, organ weights and histopathology revealed that there were no apparent changes due to administration of LF. Therefore, the level of LF at which no adverse effect was observed was considered to be 2000mg/kg/day for both sexes.

Distally based dorsalis pedis island flap for coverage of the distal portion of the foot

A distally based dorsalis pedis island flap is described which has been successfully used for reconstructing the distal portion of the foot in two patients with amputation of all 5 toes. The indication for this flap is a wide skin defect of the distal half of the dorsal foot without history of local vascular disorder. The arterial inflow of the flap comes from the posterior tibial artery via the deep plantar branch of the dorsalis pedis artery, while the venous drainage is most likely to be through the venae comitantes of the dorsalis pedis artery to those of the deep branch.

Orally administered bovine lactoferrin inhibits bacterial translocation in mice fed bovine milk

Feeding of bovine milk to mice induced a high incidence of bacterial translocation from the intestines to the mesenteric lymph nodes, and the bacteria involved were mainly members of the family Enterobacteriaceae. Supplementation of the milk diet with bovine lactoferrin or a pepsin-generated hydrolysate of bovine lactoferrin resulted in significant suppression of bacterial translocation. Our findings suggest that this ability of lactoferrin to inhibit bacterial translocation may be due to its suppression of bacterial overgrowth in the guts of milk-fed mice.

Iron-binding properties of bovine lactoferrin in iron-rich solution

The iron-binding properties of bovine lactoferrin in iron-rich solution were investigated. Ferrous iron was not stable in solution and was easily changed to the insoluble ferric state, but solubility of ferrous iron was stabilized by the presence of lactoferrin. However, casein hydrolysate or BSA was not effective in stabilizing iron in solution. As indicated by use of cibacron blue affinity gel, iron bound to lactoferrin, and the charge of supersaturated lactoferrin was higher than that of normal iron-saturated lactoferrin according to native PAGE electrophoresis. The evidence suggests that lactoferrin can bind iron at sites other than its chelate-binding sites, thereby stabilizing iron in solution.

Glycans of bovine lactoferrin function as receptors for the type 1 fimbrial lectin of Escherichia coli

Bovine lactoferrin strongly inhibited the hemagglutination activity of type 1 fimbriated Escherichia coli. In addition, it agglutinated these bacteria. The agglutination reaction was specifically inhibited by glycopeptides derived from bovine lactoferrin or alpha-methyl-D-mannoside. These observations indicate that the glycans of bovine lactoferrin can serve as receptors for type 1 fimbrial lectin.

Identification of bifidobacteria from dairy products and evaluation of a microplate hybridization method

Sixteen strains of Bifidobacterium isolated from 15 dairy products such as yogurt, cultured milk, butter and cheese were characterized on the basis of phenotypic characteristics and DNA similarities were examined by a microplate hybridization method. Three of the strains were identified as Bifidodobacterium longum, one strain was identified as Bifidobacterium bifidm, and one strain was assigned to the species Bifidobacterium breve on the basis of phenotypic characteristics, and this identification was confirmed by the analysis of DNA similarities. The remaining 11 strains could not be identified by examining their phenotypic characteristics and, contrary to the product label information, these strains were identified as Bifudidobacterium animalis on the basis of DNA similarities. The applicability of the colorimetric hybridization method in micro dilution wells to genetic identification of Bifidobacterium species was also studied.

Lactoferrin inhibits cholesterol accumulation in macrophages mediated by acetylated or oxidized low-density lipoproteins

When macrophages are incubated with acetylated or oxidized low-density lipoproteins (Ac- or OxLDL), cellular cholesteryl esters (CE) increase significantly. In the present study, we investigated the effect of whey protein on Ac- or OxLDL mediated accumulation of CE in macrophages and found that lactoferrin (Lf), a minor protein component of whey, inhibits the accumulation of CE dose-dependently. In the presence of bovine Lf (1 mg/ml), CE accumulation in macrophages incubated with AcLDL (100 micrograms of protein/ml) decreased by more than 80%. Human Lf was less potent than bovine Lf, and bovine transferrin had no effect. Binding of 125I-AcLDL to macrophages was also inhibited by Lf. Agarose gel electrophoresis revealed that Lf binds to Ac- or OxLDLs and neutralizes their negative charges. These results indicate that Lf inhibits the binding of modified LDLs to macrophages by direct interaction with modified LDLs, resulting in their loss of function as ligands of the scavenger receptor. Modification of the arginine residues of Lf with 1,2-cyclohexanedione abolished its ability to bind to AcLDL, suggesting that a region rich in basic amino acid residues near the N-terminus of Lf, which resembles the ligand-binding site of the scavenger receptor, may be responsible for this binding ability. As a result, the inhibitory effect of Lf on CE accumulation in macrophages was significantly weakened by this modification. Our results suggest the possibility that Lf in the blood stream may act as an anti-atherogenic agent in vivo.

Analysis of human and bovine milk lactoferrins by Rotofor and chromatofocusing

1. Isoelectric points of human and bovine lactoferrins were evaluated by Rotofor and chromatofocusing analysis. 2. By Rotofor, the isoelectric value of human lactoferrin fraction was determined at 8.7 and that of bovine lactoferrin at 8.8. 3. By chromatofocusing analysis, human and bovine lactoferrins showed different elution patterns. Human lactoferrin was eluted at pH 6.8-8 and bovine lactoferrin eluted at pH 8.2-8.9.

Genetic and molecular analysis of the rpoD gene from Lactococcus lactis

A gene of Lactococcus lactis ATCC19435, the product of which is homologous with the principal sigma factors of Escherichia coli and Bacillus subtilis, was cloned and sequenced. The deduced amino acid sequence of the 340-residue protein and the upstream open reading frame of the cloned gene showed a homology to B. subtilis sigma 43 factor (the rpoD product) and DNA primase (the dnaE product), respectively, suggesting that L. lactis also has the rpoD operon. Surprisingly, introduction of the cloned L. lactis rpoD gene into a rpoD temperature-sensitive mutant of E. coli caused partial complementation.

Association of CrkL with STAT5 in hematopoietic cells stimulated by granulocyte-macrophage colony-stimulating factor or erythropoietin

CrkL is an adapter protein comprising Src homology (SH) 2 and SH3 domains. We investigated the molecule(s) associated with CrkL in factor-dependent cell lines. In the granulocyte-macrophage colony-stimulating factor (GM-CSF)-dependent cell lines TF-1 and UT-7, an approximately 95-kDa tyrosine-phosphorylated protein was precipitated along with CrkL after GM-CSF stimulation. The same protein was also observed when we used the erythropoietin (EPO)-dependent cell line UT-7/EPO, in an EPO stimulation-dependent manner. We identified it as STAT5 (signal transducer and activator of transcription 5, 96 kDa) by STAT5-specific antibodies. The direct binding of the SH2 domain of CrkL to STAT5 was demonstrated in far Western blotting and pull-down experiments using the glutathione S-transferase (GST) fusion construct CrkL-SH2. The addition of the oligopeptide containing phosphotyrosine 694 in STAT5A impaired the association between GST-CrkL-SH2 and STAT5. Furthermore, in a gel shift assay using prolactin-inducible element (PIE) as the probe, the DNA binding activity of STAT5 was inhibited by the interaction with GST-CrkL-SH2 in vitro. Finally, we found that STAT5 associated with CrkL did not bind to PIE sequence. These results suggest that CrkL participates in the Janus kinase (JAK)-STAT pathway by direct association with STAT5.

Identification of a novel apoptosis-inducing factor derived from leukemic cells: endothelial interleukin-8, but not monocyte-derived, induces apoptosis in leukemic cells

The human myelogenous leukemia cell line HL-60, treated with phorbol 12, 13-dibutyrate (PDBu), produces apoptosis-inducing factors (AIFs) in leukemic cells. We have purified AIF against leukemic cell line K562 as target cells, and N-terminal amino acid sequencing analysis revealed that this purified protein is identical to endothelial cell-derived interleukin-8 ([(Ala)-IL-8]77). In Western blot analysis of supernatants of PDBu-treated HL-60 cells, only [(Ala)-IL-8]77 was detected. Moreover, recombinant human [(Ala)-IL-8]77 induced apoptosis in leukemic cell lines such as K562, HL-60, KG-1, U937, THP-1 and Jurkat, but monocyte-derived IL-8 ([(Ser)-IL-8]72) did not. Therefore [(Ala)-IL-8]77 plays an important role in inducing apoptosis against leukemic cells and may lead to a new therapy for leukemia.

Purification, primary structure, and antimicrobial activities of bovine apolipoprotein A-II

We purified an antimicrobial protein of 76 residues, denoted bovine antimicrobial protein-1 (BAMP-1), from fetal calf serum using hydrophobic chromatography, gel filtration, and reverse-phase high-performance liquid chromatography. The amino acid sequence of BAMP-1 was similar to that of human apolipoprotein A-II (apo A-II), a major component of high-density lipoprotein (HDL), and the amino acid composition was almost identical to that of a previously reported candidate for bovine apo A-II. BAMP-1 was recovered from the post-HDL fraction, but not from the HDL fraction of the serum and was associated with a small amount of triglycerides (5%, w/w). These results suggest that BAMP-1 is the bovine homologue of apo A-II and is present in almost free form in serum. BAMP-1 showed a weak growth-inhibitory activity against Escherichia coli and yeasts tested in phosphate-buffered saline (PBS).