Whey protein stimulated the proliferation and differentiation of osteoblastic MC3T3-E1 cells.
Takada Y, Aoe S, Kumegawa M
Nutritional Science Laboratory, Snow Brand Milk Product Co. Ltd., Saitama, Japan.
Biochem Biophys Res Commun 1996 Jun 14;223(2):445-9
We examined the effects of whey protein on osteoblastic MC3T3-E1 cells. This protein caused dose-dependent increases in [3H]thymidine incorporation and DNA content in the cells. It also increased the total protein and hydroxyproline contents in the cells. These activities were heat resistant when the protein was heated at 75 degrees C to 90 degrees C for 10 min. Heat-treated whey protein was first fractionated on a Mono S column, and the active fraction (basic protein fraction) was then applied to Superose 12. The molecular weights of the active components were approximately 10,000 and 14,000 Da, as determined with gel filtration. The inner solution of an everted gut-sac incubated in a solution of intact BP (basic protein), pepsin-digested BP or pepsin/pancreatin-digested BP also stimulated the [3H]thymidine incorporation. Thus these active components can possibly permeate or be absorbed by the intestines. We propose the possibility that the active component in the whey protein plays an important role in bone formation by activating osteoblasts.
Whey and Cancer
Kennedy RS Konok GP Bounous G Baruchel S Lee TD
Anticancer Res (1995 Nov-Dec) 15(6B):2643-9
Glutathione (GSH) concentration is high in most tumor cells and this may be an important factor in resistance to chemotherapy. Previous in- vitro and animal experiments have shown a differential response of tumor versus normal cells to various cysteine delivery systems. More specifically, an in-vitro assay showed that at concentrations that induce GSH synthesis in normal human cells, a specially prepared whey protein concentrate, Immunocal, caused GSH depletion and inhibition of proliferation in human breast cancer cells. On the basis of this information five patients with metastatic carcinoma of the breast, one of the pancreas and one of the liver were fed 30 grams of this whey protein concentrate daily for six months. In six patients the blood lymphocyte GSH levels were substantially above normal at the outset, reflecting high tumor GSH levels. Two patients (#1, #3) exhibited signs of tumor regression, normalization of haemoglobin and peripheral lymphocyte counts and a sustained drop of lymphocyte GSH levels towards normal. Two patients (#2, #7) showed stabilization of the tumor, increased haemoglobin levels. In three patients (#4, #5, #6,) the disease progressed with a trend toward higher lymphocyte GSH levels. These results indicate that whey protein concentrate might deplete tumor cells of GSH and render them more vulnerable to chemotherapy.
The influence of dietary whey protein on tissue glutathione and the diseases of aging
Bounous G, Gervais F, Amer V, Batist G, Gold P
Clin Invest Med (1989 Dec) 12(6):343-9
This study compared the effects of a whey-rich diet (20 g/100 g diet), with that of Purina mouse chow or casein-rich diet (20 g/100 g diet), on the liver and heart glutathione content and on the survival of old male C57BL/6NIA mice. The study was performed during a limited observation period of 6.3 months. In mice fed the whey protein-rich diet between 17 months and 20 months of age, the heart tissue and liver tissue glutathione content were enhanced significantly above the corresponding values of the casein diet-fed and Purina-fed mice. Mice fed the whey protein diet at the onset of senescence at 84 weeks exhibited increased longevity as compared to mice fed Purina mouse chow over the 6.3-month observation period extending from the age of 21 months (corresponding to a human age of 55 years) to 26-27 months of age (corresponding to a human age of 80 years), during which time 55% mortality was observed. The corresponding mean survival time of mice fed the defined casein diet is almost identical to that of Purina-fed controls. Body weight curves were similar in all three dietary groups. Hence a whey protein diet appears to enhance the liver and heart glutathione concentration in aging mice and to increase longevity over a 6.3-month observation period.
Lowering effect of dietary milk-whey protein v. casein on plasma and liver cholesterol concentrations in rats
Zhang X, Beynen AC
Br J Nutr (1993 Jul) 70(1):139-46
The effect of dietary whey protein versus casein on plasma and liver cholesterol concentrations was investigated in female, weanling rats. Balanced, purified diets containing either whey protein or casein, or the amino acid mixtures simulating these proteins, were used. The high-cholesterol diets (10 grams of cholesterol per kg feed) had either 150 or 300 grams protein or amino acids/kg feed. The diets were given for 3 weeks. At the low dietary protein level, whey protein versus casein did not affect plasma total cholesterol, but lowered the concentration of liver cholesterol. At the high dietary-protein level, whey protein significantly lowered plasma and liver cholesterol and also plasma triacylglycerols. The hypocholesterolemic effect of whey protein was associated with a decrease in very-low-density-lipoprotein cholesterol. At the high dietary protein concentration, whey protein reduced the fecal excretion of bile acids when compared with casein. The effects of intact whey protein versus casein were not reproduced by the amino acid mixtures simulating these proteins. It is suggested tentatively that the cholesterol-lowering effect of whey protein in rats is caused by inhibition of hepatic cholesterol synthesis.
Antibacterial spectrum of lactoferricin B, a potent bactericidal peptide derived from the N-terminal region of bovine lactoferrin
Bellamy W, Takase M, Wakabayashi H, Kawase K, Tomita M
J Appl Bacteriol (1992 Dec) 73(6):472-9
A physiologically diverse range of Gram-positive and Gram-negative bacteria was found to be susceptible to inhibition and inactivation by lactoferricin B, a peptide produced by gastric pepsin digestion of bovine lactoferrin. The list of susceptible organisms includes Escherichia coli, Salmonella enteritidis, Klebsiella pneumoniae, Proteus vulgaris, Yersinia enterocolitica, Pseudomonas aeruginosa, Campylobacter jejuni, Staphylococcus aureus, Streptococcus mutans, Corynebacterium diphtheriae, Listeria monocytogenes and Clostridium perfringens. Concentrations of lactoferricin B required to cause complete inhibition of growth varied within the range of 0.3 to 150 micrograms/ml, depending on the strain and the culture medium used. The peptide showed activity against E. coli O111 over the range of pH 5.5 to 7.5 and was most effective under slightly alkaline conditions. Its antibacterial effectiveness was reduced in the presence of Na+, K+, Mg2+ or Ca2+ ions, or in the presence of various buffer salts. Lactoferricin B was lethal, causing a rapid loss of colony-forming capability in most of the species tested. Pseudomonas fluorescens, Enterococcus faecalis and Bifidobacterium bifidum strains were highly resistant to this peptide.
Damage of the outer membrane of enteric gram-negative bacteria by lactoferrin and transferrin
Ellison RT 3d, Giehl TJ, LaForce FM
Infect Immun (1988 Nov) 56(11):2774-81
We hypothesized that the iron-binding proteins could affect the gram-negative outer membrane in a manner similar to that of the chelator EDTA. The ability of lactoferrin and transferrin to release radiolabeled lipo polysaccharide (LPS) from a UDP- galactose epimerase deficient Escherichia coli mutant and from wild-type Salmonella typhimurium strains was tested. Initial studies in barbital-acetate buffer showed that EDTA and lactoferrin cause significant release of LPS from all three strains. Further studies found that LPS release was blocked by iron saturation of lactoferrin, occurred between pH 6 and 7.5, was comparable for bacterial concentrations from 10(4) to 10(7) CFU/ml, and increased with increasing lactoferrin concentrations. Studies using Hanks balanced salt solution lacking calcium and magnesium showed that transferrin also could cause LPS release. Additionally, both lactoferrin and transferrin increased the antibacterial effect of a subinhibitory concentration of rifampin, a drug excluded by the bacterial outer membrane. This work demonstrates that these iron-binding proteins damage the gram-negative outer membrane and alter bacterial outer membrane permeability.
Antibacterial activity of lactoferrin and a pepsin-derived lactoferrin peptide fragment
Yamauchi K, Tomita M, Giehl TJ, Ellison RT 3d,
Infect Immun (1993 Feb) 61(2):719-28
Recent work has indicated that in addition to binding iron, human lactoferrin damages the outer membrane of gram-negative bacteria. In this study, we determined whether bovine lactoferrin and a pepsin- derived bovine lactoferrin peptide (lactoferricin) fragment have similar activities. We found that both 20 microM bovine lactoferrin and 20 microM lactoferricin release intrinsically labeled [3H]lipopolysaccharide ([3H]LPS) from three bacterial strains, Escherichia coli CL99 1-2, Salmonella typhimurium SL696, and Salmonella montevideo SL5222. Under most conditions, more LPS is released by the peptide fragment than by whole bovine lactoferrin. In the presence of either lactoferrin or lactoferricin there is increased killing of E. coli CL99 1-2 by lysozyme. Like human lactoferrin, bovine lactoferrin and lactoferricin have the ability to bind to free intrinsically labeled [3H]LPS molecules. In addition to these effects, whereas bovine lactoferrin was at most bacteriostatic, lactoferricin demonstrated consistent bactericidal activity against gram-negative bacteria. This bactericidal effect is modulated by the cations Ca2+, Mg2+, and F3+ but is independent of the osmolarity of the medium. Transmission electron microscopy of bacterial cells exposed to lactoferricin show the immediate development of electron-dense "membrane blisters." These experiments offer evidence that bovine lactoferrin and lactoferricin damage the outer membrane of gram-negative bacteria. Moreover, the peptide fragment lactoferricin has direct bactericidal activity. As lactoferrin is exposed to proteolytic factors in vivo which could cleave the lactoferricin fragment, the effects of this peptide are of both mechanistic and physiologic relevance.