Content uploaded by A. Suha Yalçin
Author content
All content in this area was uploaded by A. Suha Yalçin on Jun 13, 2014
Content may be subject to copyright.
Current Pharmaceutical Design, 2006, 12, 1637-1643 1637
1381-6128/06 $50.00+.00 © 2006 Bentham Science Publishers Ltd.
Emerging Therapeutic Potential of Whey Proteins and Peptides
A. Süha Yalçın
*
Department of Biochemistry, School of Medicine, Marmara University, Istanbul, Turkey
Abstract: Whey is a natural by-product of cheese making process. Bovine milk has about 3.5 % protein, 80 % of which
are caseins and the remaining 20 % are whey proteins. Whey proteins contain all the essential amino acids and have the
highest protein quality rating among other proteins. Advances in processing technologies have led to the industrial pro-
duction of different products with varying protein contents from liquid whey. These products have different biological ac-
tivities and functional properties. Also recent advances in processing technologies have expanded the commercial use of
whey proteins and their products. As a result, whey proteins are used as common ingredients in various products including
infant formulas, specialized enteral and clinical protein supplements, sports nutrition products, products specific to weight
management and mood control. This brief review intends to focus on scientific evidence and recent findings related to the
therapeutic potential of whey proteins and peptides.
Key Words: Whey proteins, α-lactalbumin, β-lactoglobulin, immunoglobulin, lactoferrin, bioactive peptide.
INTRODUCTION
Whey is a natural by-product of cheese making process.
Bovine milk has about 3.5 % protein, 80 % of which are ca-
seins and the remaining 20 % are whey proteins. During
cheese manufacture when casein is removed from whole
milk, what remains is whey which contains lactose, proteins
and lipids. Advances in processing technologies have led to
the industrial production of different products with varying
protein contents from liquid whey [1]. Table 1 lists some of
these products and their functional properties.
Recent studies have shown that whey proteins contain all
the essential amino acids and have the highest protein quality
rating among other proteins [2]. Whey proteins are also con-
sidered to be “fast proteins” since they reach the jejunum
almost immediately, their hydrolysis within the intestine is
slower than other proteins and their digestion and absorption
occurs over a greater length of the intestine [2, 3]. Some
whey proteins have even been detected intact in the intestinal
lumen. Recent advances in processing technologies have
expanded the commercial use of whey proteins and their
products [4, 5]. As a result, whey proteins are used as com-
mon ingredients in various products including infant formu-
las, specialized enteral and clinical protein supplements,
sports nutrition products, products specific to weight man-
agement and mood control [6-8]. This brief review intends to
focus on scientific evidence and recent findings related to the
therapeutic potential of whey proteins and peptides.
MILK
Milk is a complex food containing different bioactive
molecular species. It is produced by the mammary glands to
nourish and protect the mammalian young. Milk contains
*Address correspondence to this author at the Department of Biochemistry,
School of Medicine, Marmara University, 34668, Haydarpasa-Istanbul,
Turkey; Tel: 90-216-4144733; Fax: 90-216-4181047;
E-mail: asyalcin@marmara.edu.tr
essential nutrients as well as hormones, modulators and
growth factors that are capable of influencing the develop-
ment and growth of the gastrointestinal tract [9, 10]. Milk
influences other specific organs, modulates the gut micro-
flora population, provides immunological protection, im-
munoregulation and non-immune defence. Factors such as
breeding conditions, seasonal differences and geographic
variations affect milk composition. Approximate composi-
tion of milk may be given as: 87 % water, 5 % sugar (mainly
lactose), 3.5 % fat and 3.5 % proteins (casein micelles and
soluble whey proteins) and 1 % salts (minerals). The nitro-
gen content of milk is distributed among caseins, whey pro-
teins and non-protein compounds.
CASEINS
Caseins represent around 80 % of milk proteins. The
principal casein fractions are α-s1- and α-s2-caseins, β-
casein and κ-casein. All are conjugated proteins, most with
phosphate groups esterified to serine residues. Phosphate
groups are important for the structure of the casein micelle.
The distinguishing property of caseins is their low solubility
at pH 4.6. The high number of proline residues causes par-
ticular bending of the protein chain and inhibits the forma-
tion of close-packed, ordered secondary structures. Most of
the casein proteins exist in colloidal particles known as the
casein micelle. Casein micelles carry large amounts of highly
insoluble CaP and form a clot in the stomach for more effi-
cient nutrition [2]. Caseins do not contain disulfide bonds.
Although the casein micelle is fairly stable, there are differ-
ent ways by which its aggregation may be induced. Chy-
mosin or rennet is most often used for enzymatic coagulation
of casein micelles. Different forms of caseins have distin-
guishing features, for example κ-casein is very resistant to
calcium precipitation and stabilizes other caseins. Rennet
cleavage eliminates the stabilizing ability of κ-casein by
forming hydrophobic (para-κ-casein) and hydrophilic (κ-
casein glycomacropeptide or caseinomacropeptide) portions.
1638 Current Pharmaceutical Design, 2006, Vol. 12, No. 13 A. Süha Yalçın
WHEY PROTEINS
Proteins appearing in the supernatant of milk after pre-
cipitation of casein are called whey proteins. These globular
proteins are more water soluble than caseins and are subject
to heat denaturation [9, 10].
Whey proteins are grouped as major and minor protein
fractions each with different molecular weights and critical
for healthy metabolism (Table 2). The major whey proteins
are β-lactoglobulin, α-lactalbumin, serum albumin, immu-
noglobulins and glycomacropeptide, while minor proteins
include lactoperoxidase, lactoferrin, β-microglobulin,
lysozyme, insulin-like growth factor (IGF), γ-globulins and
several other small proteins [10-12].
ß-Lactoglobulin is a major whey protein that corresponds
to approximately half of the total whey proteins in bovine
milk. It is a noncovalently linked dimer that has two internal
disulfide bonds and one free thiol group. It binds calcium
and zinc and has partial sequence homology to retinol bind-
ing proteins. ß-Lactoglobulin has numerous binding sites for
minerals, fat-soluble vitamins and lipids.
α-Lactalbumin is another major whey protein that makes
up 25 % of total bovine whey protein. It is a calcium binding
protein that enhances calcium absorption and is a rich source
of lysine, leucine, threonine, tryptophan and cystine. α-
Lactalbumin is specifically produced during lactation in the
mammary epithelial cells and plays an essential role in milk
synthesis. It is one of the few proteins that remains intact
upon pasteurization.
Serum albumin and immunoglobulins are blood proteins
that become incorporated into milk and are recoverable as
whey proteins. Serum albumin binds fatty acids as well as
other small molecules. Immunoglobulins include IgG1,
IgG2, IgA and IgM. Bovine immunoglobulins have been put
forward as possible effective means of preventing and com-
batting bacteria.
Glycomacropeptide, the glycosylated portion of caseino-
macropeptide, is present in sweet whey formed after cleav-
age of κ-casein by rennin [13, 14]. This protein is absent
from acid whey that is formed when caseins are precipitated
by lowering the pH to 4.6. Glycomacropeptide is a powerful
stimulator of cholecystokinin which is an appetite suppress-
ing hormone that has essential roles relating to gastrointesti-
nal function. In addition to being a regulator of food intake,
cholecystokinin stimulates gallbladder contraction and bowel
motility, regulates gastric emptying and stimulates the re-
lease of enzymes from the pancreas. Glycomacropeptide
alters pigment production in melanocytes, may act as a pre-
biotic and has immunomodulatory action [14].
Table 1. Typical Composition of Whey Products and their Functional Properties
Product Typical Composition Functional Properties
Sweet whey powder Protein: 11.0 % - 14.5 %
Lactose: 63.0 % - 75.0
Fat: 1.0 % - 1.5 %
Ash: 8.2 % - 8.8 %
Moisture: 3.5 % - 5.0 %
Low protein source
Dairy flavor and solids
Solubility
Dispersible
Acid whey powder Protein: 11.0 % - 13.5 %
Lactose: 61.0 % - 70.0
Fat: 0.5 % - 1.5 %
Ash: 9.8 % - 12.3 %
Moisture: 3.5 % - 5.0 %
Low protein source
Dairy flavor and solids
Solubility
Dispersible
Whey protein concentrate
(34 % protein)
Protein: 34.0 % - 36.0 %
Lactose: 48.0 % - 52.0
Fat: 3.0 % - 4.5 %
Ash: 6.5 % - 8.0 %
Moisture: 3.0 % - 4.5 %
Protein source
Emulsification
Solubility
Mild dairy flavor
Color and flavor development
Whey protein concentrate
(80 % protein)
Protein: 80.0 % - 82.0 %
Lactose: 4.0 % - 8.0
Fat: 4.0 % - 8.0 %
Ash: 3.0 % - 4.0 %
Moisture: 3.5 % - 4.5 %
High protein source
Emulsification
Whipping
Fat binding
Solubility
Heat setting/gelling
Water binding
Whey protein isolate Protein: 90.0 % - 92.0 %
Lactose: 0.5 % - 1.0
Fat: 0.5 % - 1.0 %
Ash: 2.0 % - 3.0 %
Moisture: 4.5 %
High protein source
Solubility
Adapted from [1].
Emerging Therapeutic Potential of Whey Proteins and Peptides Current Pharmaceutical Design, 2006, Vol. 12, No. 13 1639
Lactoperoxidase and lactoferrin are minor whey proteins.
The lactoperoxidase system inactivates a broad spectrum of
microorganisms through an enzymatic reaction [15]. The
reaction involves hydrogen peroxide and thiocyanate which
together with the enzyme constitute the lactoperoxidase sys-
tem. The lactoperoxidase system is a major part of the anti-
bacterial activity of milk. Lactoferrin is a member of the
transferrin gene family with metal binding properties [16,
17]. It is a 78 kDa glycoprotein made up of a single poly-
peptide chain and is linked to two glycans by N-glycosidic
linkages. Metals that are bound by lactoferrin are mainly
Fe
+2
and Fe
+3
, but Cu
+2
, Zn
+2
, Mn
+2
are bound as well. Lac-
toferrin is important for the delivery of essential metals to
the newborn and is considered to be an important component
of the non-specific immune system. Lactoferrin plays a stra-
tegic role in the first line of defense against many pathogens
that tend to enter the body via mucosa. It is present in several
mucosal secretions such as tears, saliva, seminal and vaginal
fluids.
THERAPEUTIC USE OF WHEY PROTEINS AND
PEPTIDES
Whey proteins of special therapeutic importance are α-
lactalbumin, β-lactoglobulin, bovine serum albumin, immu-
noglobulins, lactoferrin and lactoperoxidase. These proteins
exhibit different biological activities and are used as ingredi-
ents in different forms of pharmaceuticals, nutraceuticals and
cosmeceuticals [5-7, 12]. Additionally, specific digestion
products of milk proteins identified as bioactive peptides
have diverse biological activities [18-20]. The bioactive
peptide sequences are in an inactive state inside the polypep-
tide chain of the intact whey protein. Peptides released dur-
ing intestinal digestion of whey proteins may be involved in
the regulation of nutrient entry as well as postprandial me-
tabolism via stimulation of hormone secretion. Therapeutic
benefits of whey proteins can also result from bioactive pep-
tide production during fermentation [20]. Infant formula de-
velopment has been a long lasting effort to create a substitute
for mother’s milk. It is aimed to approach the nutrient com-
position of human breast milk using bovine milk as raw ma-
terial. However, the protein composition of human milk dif-
fers both quantitatively and qualitatively from that of bovine
milk [21]. The use of individual whey proteins particularly
α-lactalbumin to enrich infant formulas has significantly
increased after large-scale fractionation procedures utilizing
membrane filtration and ion-exchange techniques became
available [22].
Table 2. Concentration and Biological Activities of Milk Proteins
Protein Concentration (g/L) Biological Activity
Caseins 28
Transport of ions (Ca, PO
4
, Fe, Zn, Cu)
Precursor of bioactive peptides
β-lactoglobulin 1.3
Retinol carrier
Binding of fatty acids
Antioxidant
α-lactalbumin 1.2
Lactose synthesis
Ca carrier
Immunomodulation
Anticarcinogenic
Immunoglobulins 0.7 Immune protection
Glycomacropeptide 1.2
Bifidobacteria growth
Immunomodulation
Antiviral
Lactoferrin 0.1
Antimicrobial, wound healing
Antiviral
Antioxidant
Anticarcinogenic
Antitoxin
Antiinflammatory
Antithrombotic
Immunomodulation
Fe absorption
Lactoperoxidase 0.03 Antimicrobial, wound healing
Lysozyme 0.0004
Antimicrobial, wound healing
Synergistic effect with lactoferrin
Synergistic effect with immunoglobulins
Adapted from [11].
1640 Current Pharmaceutical Design, 2006, Vol. 12, No. 13 A. Süha Yalçın
Immune Function
The human immune system has a central role in the de-
fence against bacterial, viral, fungal and parasitic infections
as well as different forms of cancers [23]. Deficiencies in
any aspect of the immune system can predispose an individ-
ual to a greater risk of infection and may enhance severity of
a disease. The immune system employs both specific and
nonspecific immune responses for protection against disease.
Specific immune responses are mediated by T-lymphocytes
and antibodies produced by B-lymphocytes. Non-specific
components of the host defense include physicochemical
barriers such as skin, mucus, lysozyme, complement and
interferons, as well as natural killer cells and phagocytic
cells.
Milk contains unique constituents which have been
shown to modulate immune function [24, 25]. Among these
are immunoglobulins, lactoferrin, growth factors and amino
acids necessary to support glutathione production. Pluripo-
tent polypeptides called cytokines that have autocrine and/or
paracrine actions are also present in milk. An active area of
research is the formation of biologically active peptide se-
quences during digestion and their effects on secretion of
enterohormones as well as immune enhancement [26].
Passive immunity against infection in the intestinal lu-
men is afforded by lysozyme, lactoperoxidase, lactoferrin,
and caseinomacropeptides all of which are constituents of
whey that could also reduce oxidant burdens imposed by
inflammation [27]. Immunoglobulins are also involved in the
passive protection of the young and they partly resist degra-
dation in the intestinal lumen [28]. Studies have also been
performed using immunoglobulins from non-immunized
cows and from cows hyperimmunized against specific
pathogens [29-32]. Colostrum, which is the first milk pro-
duced after birth, is particularly rich in immunoglobulins,
antimicrobial peptides, growth factors as well as other bio-
active molecules [33]. Immunoglobulin concentrations are
greater in whey derived from colostrum. The high immuno-
globulin concentration of colostrum declines during lacta-
tion.
Lactoferrin
Whey products provide active lactoferrin/metal-binding
activities. Lactoferrin acts as a means of both stable iron
delivery and scavenging of free iron by binding iron which
would otherwise catalyze oxidative reactions [34]. Lactofer-
rin has bacteriostatic and bacteriocidal activity against both
Gram-negative and Gram-positive bacteria [35]. Binding to
lipopolysaccharides of Gram-negative bacteria is one of the
antibacterial mode of action of lactoferrin. Fungicidal activ-
ity particularly against Candida species has also been de-
scribed [36]. These activities are not only related to depriva-
tion of iron from the microenvironment but also to binding
of lactoferrin to cell walls causing membrane perturbation
and leakage of intracellular components. Besides a broad
antimicrobial spectrum against bacteria and fungi, lactoferrin
is capable of inhibiting replication of viruses [37]. Lactofer-
rin prevents infection of the host cell, rather than inhibiting
virus replication after the target cell has become infected.
The antiviral activity is in the early phase of the infection
where lactoferrin prevents entry of virus into the host cell,
either by blocking cellular receptors, or by direct binding to
the virus particles. Proteolysis of lactoferrin by pepsin pro-
duces an antimicrobial peptide called lactoferricin. Various
synthetic analogs of lactoferricin are also available. Lactofer-
ricin kills target organisms by membrane perturbation and
acts synergistically with some antimicrobial agents. It inhib-
its a diverse range of microorganisms such as Gram-negative
bacteria, Gram-positive bacteria, yeast, filamentous fungi,
and parasitic protozoa, including some antibiotic-resistant
pathogens [38].
Oxidative Stress and HIV Infection
A seemingly important feature of whey proteins is the
high concentration of cysteine which is a rate-limiting amino
acid in glutathione synthesis. Glutathione is a major nonpro-
tein sulfhydryl compound of the living cells. It is also a key
molecule for cellular protection against free radicals and
oxidative stress [39]. It has been reported that whey protein
feeding enhances immune responsiveness by increasing tis-
sue glutathione levels [40, 41]. Whey proteins are also good
candidates for dietary suppression of oxidative stress. They
have enhanced host antioxidant defenses and lowered oxi-
dant burden in different experimental models [42-45]. Anti-
oxidant status of the host organism is very important in viral
infections since virulence is linked to passage of non-virulent
forms through hosts with compromised antioxidant status.
HIV infection is characterized by increased oxidative stress
and a systemic deficiency of glutathione [46, 47]. HIV has a
dual response to glutathione. Low cellular glutathione levels
allow the virus to multiply, whereas high glutathione dra-
matically slows viral replication [48]. It was reported that
supplementation with whey proteins increased plasma glu-
tathione levels in glutathione-deficient patients with HIV-
infection [49-51].
Anticancer Activity
Nutritional studies, reports and trials to identify antican-
cer properties of foods have been extensive [52]. It is gener-
ally agreed that diets that are high in grains, green vegeta-
bles, fresh fruit and fiber, and low in total and saturated fats
are beneficial to health. Relatively less emphasis has been
placed on bovine milk. Epidemiological studies indicate that
humans who consume milk are less likely to develop cancer
of the colon and rectum than those who do not consume milk
[53]. Calcium and vitamin D were identified as protective
against colorectal cancer. The results of a recent study
showed that whey protein concentrate renders tumor cells
more vulnerable to chemotherapy by depleting glutathione
[54]. Whey proteins have also been reported to protect
against chemically induced carcinogenesis in animal models
[55, 56].
Stress, Depression and Anxiety
Stress is an important problem of the urban and industri-
alized society. People with increased brain serotonin levels
are able to cope with stress conditions, while a decline in
serotonin activity is associated with depression and anxiety.
Elevated levels of serotonin in the body will result in the
relief of depression, as well as a substantial reduction of pain
sensitivity, anxiety and stress [57]. Recently, investigators
Emerging Therapeutic Potential of Whey Proteins and Peptides Current Pharmaceutical Design, 2006, Vol. 12, No. 13 1641
examined whether α-lactalbumin would increase plasma
tryptophan levels and reduce cortisol concentrations in sub-
jects considered to be vulnerable to stress [58]. They sug-
gested that whey proteins may serve as safe and effective
supplements in the battle against depression and stress.
Oral Health
Adequate flow of saliva is a prerequisite for good oral
health. Hyposalivation leads to many oral problems includ-
ing rapid dental decay, mucosal infections and increased
susceptibility to fungal infections [59]. There have been at-
tempts to enhance or restore salivary antimicrobial capacity
using commercially available oral health care products. The
antimicrobial proteins used in these products are lysozyme,
lactoferrin and lactoperoxidase all of which are present in
whey [60]. On the other hand, demineralization of tooth
enamel, which consists mainly of crystalline calcium phos-
phate embedded in a protein matrix, is initially brought about
by the action of acids which create small cavities. Tooth de-
cay takes place by the action of microflora present in the
plaque. It has been shown that whey proteins exhibit protec-
tive effect against demineralization and act as anticariogenic
agents [61].
Gastrointestinal Health
Whey contains biologically active molecules capable of
enhancing intestinal health. There are four beneficial areas of
intestinal health modification with whey components: prebi-
otic effects, antimicrobial and antiviral properties, anticancer
properties and influences on immunity [62]. A prebiotic is a
nondigestible food ingredient that beneficially affects the
host by selectively stimulating the growth and/or activity of
one or a limited number of bacteria in the colon. Bifidobacte-
ria and lactobacilli are two groups of bacteria capable of
utilizing prebiotics [63]. They are considered to be beneficial
due to their antimicrobial effects against pathogenic bacteria,
production of B group vitamins, and inhibition of intestinal
precarcinogenic enzymes. Growth promotion of Bifidobacte-
rium species by different whey fractions have been reported
[64]. Glycomacropeptide and lactoferrin have been shown to
support the growth of Bifidobacteria and exhibit prebiotic
activity [65].
Antimicrobial and Bactericidal Activity
Whey contains several unique components with broad
antimicrobial and antibacterial properties. Significant levels
of these compounds have been shown to survive passage
through the stomach and small intestine, and arrive as intact
proteins in the large intestine where they exert their biologi-
cal effects. Immunoglobulins are the best-known of the whey
components that provide antimicrobial action in the intestinal
tract. They predominate in milk-derived sources and may
comprise up to 1 % of the total weight of whey proteins. IgG
has been shown to bind the toxin produced by Clostridium
difficile, thereby reducing the deleterious effects of infection
[66]. Glycomacropeptide also inhibits cholera toxin by
binding to receptors in the intestinal tract [14].
Antimicrobial peptides represent an important component
of the innate immunity. They can be generated through pro-
teolytic digestion of milk proteins and have the advantage of
being derived from harmless substances. A number of short
peptides with high bactericidal activity have been developed
from the bactericidal domains of α-lactalbumin and β-
lactoglobulin as well as lactoferrin [11, 67, 68].
Bioactive Peptides
The role of proteins in the diet as physiologically active
components has been increasingly acknowledged in recent
years [11, 12]. Accordingly, peptides from milk proteins
exhibiting different bioactivities, immunomodulatory action
and mineral utilization properties have been identified (Table
3). Bioactive peptides usually contain 3-20 amino acid resi-
dues per molecule. The biological activity is based on the
Table 3. Bioactive Peptides from Milk Proteins, their Precursors and Bioactivities
Bioactive Peptide Precursor Bioactivity
Casomorphins α- and β-Casein Opioid agonists
α-Lactorphin α-Lactalbumin Opioid agonist
β-Lactoglobulin β-Lactoglobulin Opioid agonist
Lactoferroxins Lactoferrin Opioid antagonists
Casoxins κ-Casein Opioid antagonists
Casokinins α- and β-Casein Antihypertensive
Lactokinins α-Lactalbumin and β-Lactoglobulin ACE-inhibitory
Casoplatelins κ-Casein and Transferrin Antithrombotic
Immunopeptides α- and β-Casein Immunostimulants
Phosphopeptides α- and β-Casein Mineral transport
Lactoferricin Lactoferrin Antimicrobial
Adapted from [11]
1642 Current Pharmaceutical Design, 2006, Vol. 12, No. 13 A. Süha Yalçın
inherent amino acid composition and sequence. Bioactivities
of several milk proteins are latent, either absent or incom-
plete in the native protein. The active peptide fractions are
released from the native protein/peptide during proteolytic
digestion of the protein. Once the bioactive peptides are lib-
erated, they may act as regulatory compounds with hormone-
like activity. There are a number of methods by which pep-
tides with biological activity can be produced. Pancreatic
enzymes have been utilized for the chemical characterization
and identification of many known bioactive peptides. ACE-
inhibitory peptides are most commonly produced by trypsin
but other enzymes and various combinations of proteinases
as well as enzymes from bacterial and fungal sources have
also been utilized to generate bioactive peptides [69].
CONCLUSION
The health promoting powers of whey was discovered
long time ago. Ancient Greeks as well as Hippocrates in 460
B.C., prescribed cheese whey for the assortment of human
ailments. Later in the 17th century during the Italian Renais-
sance sayings about whey flourished in Florence. The im-
portance of whey as a nutrient-rich protein source was rec-
ognized by the scientific community only recently. The
worldwide supply of whey as a co-product of cheese and
casein production has grown rapidly and along with ad-
vanced processing technologies this has expanded the com-
mercial use of whey proteins and their products. Today, it is
accepted that whey products offer a wide range of bioactive
elements capable of promoting health. Many in vitro and in
vivo studies have shown that individual whey proteins have
one or more biological activities.
Whey and its components are involved in different bio-
logical functions including antioxidant activity, anticarcino-
genic effects, immunomodulation, passive immunity, disease
protection, anti-bacterial, anti-microbial and anti-viral ef-
fects, binding of toxins, promotion of cell growth, platelet
binding, anti-inflammatory and anti-hypertensive actions. In
some cases the benefits of whey proteins and peptides have
been demonstrated by clinical trials on humans. In others
there are still gaps in scientific evidence. Nevertheless, the
attention devoted to whey proteins by the industry and the
scientific community strongly indicates that a dynamic
knowledge database will build upon current information and
expand the therapeutic use of whey proteins and peptides.
REFERENCES
References 70-72 are related articles recently published in
Current Pharmaceutical Design.
[1] Reference Manual for US Whey and Lactose Products, U.S. Dairy
Export Council, 2001; http://www.usdec.org/publications/PubDetail.
cfm?ItemNumber=587.
[2] Hoffman JR, Falvo MJ. Protein-which is best? J Sport Sci Med
2004; 3: 118-30.
[3] Boine Y, Dangin M, Gachon P, Vasson MP, Maubois JL, Beau-
frere B. Slow and fast dietary proteins differently modulate post-
prandial protein accretion. Procl Natl Acad Sci USA 1997; 94:
14930-5.
[4] Huffman L, Harper WJ. Maximizing the value of milk through
separation techniques. J Dairy Sci 1999; 82: 2238-44.
[5] Etzel MR. Manufacture and use of dairy protein fractions. J Nutr
2004; 134: 996-1002.
[6] Smithers GW, Ballard FJ, Copeland AD, De Silva KJ, Dionysius
DA, Francis GL, et al. New opportunities from the isolation and
utilization of whey proteins. J Dairy Sci 1996; 79: 1454-9.
[7] Horton BS. Commercial utilization of minor milk components in
the health and food industries. J Dairy Sci 1995; 78: 2584-9.
[8] Steijns JM. Milk ingredients as nutraceuticals. Int J Dairy Tech
2001; 54: 81-88.
[9] Jensen RG. Handbook of Milk Composition. Academic Press, San
Diego 1995.
[10] Fox PF, Flynn A. In: Fox PF Ed, Biological properties of milk
proteins. Advanced Dairy Chemistry. Elsevier, London 1992; Vol.
1: 255-84.
[11] Korhonen H, Pihlanto-Leppala A, Rantamaki P, Tupasela T. Im-
pact of processing on bioactive proteins and peptides. Trends Food
Sci Technol 1998; 9: 307-19.
[12] Pihlanto A, Korhonen H. In: Taylor SL Ed, Bioactive peptides and
proteins. Advances in Food and Nutrition Research, Elsevier, San
Diego 2003; 47: 175-276.
[13] Abd El Salam MH, El-Shibiny S, Buchheim W. Characteristics and
potential uses of the casein macropeptide. Int Dairy J 1996; 6: 327-
41.
[14] Brody EP. Biological activities of bovine glycomacropeptide. Br J
Nutr 2000; 84: S39-49.
[15] Reiter B, Harnulv G. Lactoperoxidase antibacterial system: natural
occurence, biological functions and practical applications. J Food
Prot 1984; 47: 724-32.
[16] Lonnerdal B, Iyer S. Lactoferrin: molecular structure and biological
function. Ann Rev Nutr 1995; 15: 93-110.
[17] Levay PF, Viljoen M. Lactoferrin: a general review. Haema-
tologica 1995; 80: 252-67.
[18] Meisel H. Bioactive peptides from milk proteins: a perspective for
consumers and producers. Aust J Dairy Tech 2001; 56: 83-92.
[19] Clare DA, Swaisgood HE. Bioactive milk peptides: a prospectus. J
Dairy Sci 2000; 83: 1187-95.
[20] Korhonen H, Pihlanto A. Food-derived bioactive pep-
tides—opportunities for designing future foods. Curr Pharm Des
2003; 9: 1297-308.
[21] Jenness R. In: Fox PF Ed, Interspecies comparison of milk pro-
teins. Developments in Dairy Chemistry. Appl Sci Pub, New York,
1982; 87-114.
[22] Jost R, Maire J-C, Maynard F, Secretin M-C. Aspects of whey
protein usage in infant nutrition, a brief review. Int J Food Sci
Technol 1999; 34: 533-42.
[23] Roitt I, Brostoff J, Male D. Immunology. Churchill Livingstone,
London 1985.
[24] Cross ML, Gill HS. Immunomodulatory properties of milk. Br J
Nutr 2000; 84: 81-9.
[25] Gill HS, Doull F, Cross ML. Immunoregulatory peptides in milk.
Br J Nutr 2000; 84: 111-7.
[26] Kilara A, Panyam D. Peptides from milk proteins and their proper-
ties. Crit Rev Food Sci Nutr 2003; 43: 607-33.
[27] Björck L, Hopkin E. Significance of the indigenous antimicrobial
agents of milk to the dairy industry. Bull Int Dairy Fed 1991; 246:
1-19.
[28] Roos N, Mahe S, Benamouzig R, Sick H, Rauterau J, Tome D.
15
N-
labeled immunoglobulins from bovine colostrum are partially re-
sistant to digestion in human intestine. J Nutr 1995; 125: 1238-44.
[29] Reiter B. Protective proteins in milk- biological significance and
exploitation. Bull Int Dairy Fed 1985; 191: 1-35.
[30] Goldman AS. Immunologic supplementation of cow’s milk for-
mulations. Bull Int Dairy Fed 1989; 244: 38-43.
[31] Weiner C, Pan Q, Hurtig M, Boren T, Bostwick E, Hammarström
L. Passive immunity against human pathogens using bovine anti-
bodies. Clin Exp Immunol 1999; 116: 193-205.
[32] Korhonen H, Marnila P, Gill S. Bovine milk antibodies for health.
Br J Nutr 2000; 84(Suppl 1): S135-S146.
[33] Uruakpa FO, Ismond MAH, Akobundu ENT. Colostrum and its
benefits: a review. Nutr Res 2002; 22: 755-67.
[34] Halliwell B, Gutteridge JMC. Free Radicals in Biology and Medi-
cine. 2
nd
Ed, Clarendon Press, Oxford 1989.
[35] Arnold RR, Cole MF, McGhee JR. A bactericidal effect for human
lactoferrin. Science 1977; 197: 263-5.
[36] Kuipers ME, de Vries-Hospers HG, Eikelboom MC, Meijer DKF,
Swart PJ. Synergistic fungistatic effects of lactoferrin in combina-
tion with antifungal drugs against clinical Candida isolates. An-
timicr Agent Chemother 1999; 43: 2635-41.
Emerging Therapeutic Potential of Whey Proteins and Peptides Current Pharmaceutical Design, 2006, Vol. 12, No. 13 1643
[37] Van der Strate BWA, Beljaars L, Molema G, Harmsen MC, Meijer
DKF. Antiviral activities of lactoferrin. Antiviral Res 2001; 52:
225-239.
[38] Wakayabashi H, Takase M, Tomita M. Lactoferricin derived from
milk protein lactoferrin. Curr Pharm Des 2003; 9: 1277-87.
[39] Meister A. Glutathione metabolism and its selective modification. J
Biol Chem 1988; 263: 17205-8.
[40] Bounous G, Letourneau L, Kongshavn PAL. Influence of dietary
protein type on the immune system of mice. J Nutr 1983; 113:
1415-21.
[41] Bounous G, Gold P. The biological activity of undenatured dietary
whey proteins: role of glutathione. Clin Invest Med 1991; 14: 296-
309.
[42] Kent KD, Harper WJ, Bomser JA. Effect of whey protein isolate on
intracellular glutathione and oxidant-induced cell death in human
prostate epithelial cells. Toxicol In vitro 2003; 17: 27-33.
[43] Bouthegourd J-C J, Roseau SM, Makarios-Lanham L, Leruyet PM,
Tome DG, Even PC. A preexercise α-lactalbumin-enriched whey
protein meal preserves lipid oxidation and decreases adiposity in
rats. Am J Physiol Endocrinol Metab 2002; 46: E565-72.
[44] Zommara M, Tachibana N, Sakono M, Suzuki Y, Oda T, Hashiba
H, et al. Whey from cultured skim milk decreases serum choles-
terol and increases antioxidant enzymes in liver and red blood cells
in rats. Nutrition Res 1996; 16: 293-302.
[45] Veliogˇlu-Ögˇünç A, Manukyan M, Cingi A, Aktan AÖ, Yalçın AS.
The effect of dietary whey supplementation on wound healing,
Med J Kocatepe 2003; S: 51-54.
[46] Legrand-Poels S, Vaira D, Pincemail J, van de Vorst A, Piette J.
Activation of human immunodeficiency virus type 1 by oxidative
stress. AIDS Res Hum Retrovir 1990; 6: 1389-97.
[47] Buhl R, Jaffe HA, Holroyd KJ, Wells FB, Mastrangeli A, Saltini C,
et al. Systemic glutathione deficiency in symptom-free HIV sero-
positive individuals. Lancet 1989; 2: 1294-8.
[48] Staal FJ. Glutathione and HIV infection: reduced reduced, or in-
creased oxidized? Eur J Clin Invest 1998; 28: 194-6.
[49] Bounous G, Baruchel S, Falutz J, Gold P. Whey proteins as a food
supplement in HIV-seropositive individuals. Clin Invest Med 1993;
16: 204-9.
[50] Micke P, Beeh KM, Schlaak JF, Buhl R. Oral supplementation with
whey proteins increases plasma glutathione levels of HIV-infected
patients. Eur J Clin Invest 2001; 31: 171-8.
[51] Micke P, Beeh KM, Buhl R. Effects of long-term supplementation
with whey proteins on plasma glutathione levels of HIV-infected
patients. Eur J Nutr 2002; 41: 12-8.
[52] Food, Nutrition and Cancer: a global perspective. World Cancer
Research Fund and American Institute for Cancer Research 1997.
[53] Gill HS, Cross ML. Anticancer properties of bovine milk. Brit J
Nutr 2000; 84: S161-6.
[54] Tsai WY, Chang W-H, Chen C-H, Lu F-J. Enhancing effect of
patented whey protein isolate (Immunocal) on cytotoxicity of an
anticancer drug. Nutr Canc 2000; 30: 200-8.
[55] Bounous G, Batist G, Gold P. Whey proteins in cancer prevention.
Cancer Lett 1991; 57: 91-4.
[56] Bounous G. Whey protein concentrate (WPC) and glutathione
modulation in cancer treatment. Anticancer Res 2000; 20: 4785-92.
[57] Stanford SC. In: Stanford SC, Salmon P Eds, Monoamines in re-
sponse and adaptation to stress. Stress: from Synapse to Syndrome.
London, Academic Press 1993; 24-30.
[58] Markus CR, Olivier B, de Haan EHF. Whey protein rich in α-
lactalbumin increases the ratio of plasma tryptophan to the sum of
the other large neutral amino acids and improves cognitive per-
formance in stress-vulnerable subjects. Am J Clin Nutr 2002; 75:
1051-6.
[59] Nederfors T. Xerostomia and hyposalivation. Adv Dent Res 2000;
14: 48-56.
[60] Tenovuo J. Clinical applications of antimicrobial host proteins
lactoperoxidase, lysozyme and lactoferrin in xerostomia: efficacy
and safety. Oral Dis 2002; 8: 23-9.
[61] Warner EA, Kanekanian AD, Andrews AT. Bioactivity of milk
proteins: 1. Anticariogenicity of whey proteins. Int J Dairy Technol
2001; 54: 151-3.
[62] Causey J, Thomson K. The whey to intestinal health. Today’s
Dietitian 2003; July: 22-25. http://www.wheyoflife.org/news/
WheyFeature.pdf
[63] Gibson GR, Roberfroid MB. Dietary modulation of the human
colonic microflora: introducing the concept of prebiotics. J Nutr
1995; 125: 1401-12.
[64] Petschow BW, Talbott RD. Growth promotion of Bifidobacterium
species by whey and casein fractions from human and bovine milk.
J Clin Microbiol 1990; 28: 287-92.
[65] Harper WJ. Biological properties of whey components: a review.
The American Dairy Products Institute, Chicago, 2000.
[66] Warny M, Fatima A, Bostwick EF, et al. Bovine immunoglobulin
concentrate –Clostridium difficile retains C. difficile toxin neutral-
izing activity after passage through the human stomach and small
intestine. Gut 1999; 44: 212-7.
[67] Kilara A, Panyam D. Peptides from milk proteins and their proper-
ties. Crit Rev Food Sci Nutr 2003; 43: 607-33.
[68] Dionysius DA, Milne JM. Antibacterial peptides of bovine lactofer-
rin: purification and characterization. J Dairy Sci 1997; 80: 667-74.
[69] Pihlanto-Leppala A. Bioactive peptides from bovine whey proteins:
opioid and ACE-inhibitory peptides. Trends Food Sci Technol
2000; 11: 347-56.
[70] Florisa R, Recio I, Berkhout B, Visser S. Antibacterial and antiviral
effects of milk proteins and derivatives thereof. Curr Pharm Des
2003; 9(16): 1257-75.
[71] Kitts DD, Weiler K. Bioactive proteins and peptides from food
sources. Applications of bioprocesses used in isolation and recov-
ery. Curr Pharm Des 2003; 9(16): 1309-23.
[72] Korhonen H, Pihlanto A. Food-derived bioactive peptides--
opportunities for designing future foods. Curr Pharm Des 2003;
9(16): 1297-308.
