254
β-lactoglobulin against cancer development in animal models (Goldman et al. 1990;
Chatterton et al. 2006), and inhibitory effects of bovine serum albumin in MCF-7
human breast cancer cell growth (Laursen et al. 1989) and in a Chinese hamster
epithelial cell line (Bosselaers et al. 1994).
Various peptides purified from bovine casein proteins have shown antitumor
activity, for instance: (1) β-casein peptides inhibiting proliferation of human ovarian
cancer cells partially (Wang et al. 2013) and displaying cytotoxic activity toward
B16F1O melanoma cells (Azevedo et al. 2012), (2) α-casein peptides inhibiting
growth of T47D human breast cancer cells (Kampa et al. 1996) and inducing necrosis of leukemic B- and T-cells (Otani and Suzuki 2003), and (3) κ-casein peptides
displaying cytotoxicity toward mammalian cells (Matin and Otani 2002).
Another group of bioactive peptides generated during digestion of caseins are
caseinophosphopeptides (CPPs), containing high number of phosphorylated sites
which can bind and solubilize calcium (Berrocal et al. 1989). This characteristic
helps CPPs to mediate the growth and apoptosis of cells, thereby demonstrating
their antitumor activities against intestinal cancerous cells (Perego et al. 2012; Sah
et al. 2015).
Thus, several studies have displayed the anti-tumoral and cytotoxic activity of
milk derived bioactive peptides against different cancer cell lines. However, clinical
data is still lacking, and the anticancer activity of such peptides must be thoroughly
investigated in controlled trials before drawing any conclusions (Cicero et al. 2017)
Hypoglycemic Effects
Diabetes mellitus is a widely prevalent disease which results in high blood sugar
levels and is known to cause complications like hypertension and cardiovascular
disease. Impaired insulin secretion and insulin resistance characterizes type 2 diabetes, whereas type 1 diabetes is characterized by body’s inability to secrete insulin
(Brandelli et al. 2015; Shori 2015).
Management of type 2 diabetes is mainly focused on increasing insulin availability, either by direct delivery of insulin or through agents that have specific roles
(e.g. improving insulin sensitivity, enhancing insulin secretion, increasing glucose
excretion) (DeFronzo et al. 2014). Upon ingesting food, incretin hormones like
glucagon-like peptide 1 (GLP-1) and glucose-dependent insulinotropic polypeptide
(GIP) are secreted which modulate gut motility, helps in nutrient absorption, and
stimulate insulin secretion (Drucker and Nauck 2006). However, a serine exopeptidase, dipeptidyl-peptidase IV (DPP-IV) inhibits the GLP-1 and GIP hormones making treatment of type 2 diabetes complicated. Hence, DPP-IV inhibitors and GLP-1
analogues resistant to DPP-IV action are currently the therapies available to manage
type 2 diabetes (Fadini and Avogaro 2011).
Influence on glycaemia by bioactive peptides may be exerted through different
mechanisms including incretin secretion, insulinotropic activity and regulation of
S. Maqsood et al.
β-lactoglobulin against cancer development in animal models (Goldman et al. 1990;
Chatterton et al. 2006), and inhibitory effects of bovine serum albumin in MCF-7
human breast cancer cell growth (Laursen et al. 1989) and in a Chinese hamster
epithelial cell line (Bosselaers et al. 1994).
Various peptides purified from bovine casein proteins have shown antitumor
activity, for instance: (1) β-casein peptides inhibiting proliferation of human ovarian
cancer cells partially (Wang et al. 2013) and displaying cytotoxic activity toward
B16F1O melanoma cells (Azevedo et al. 2012), (2) α-casein peptides inhibiting
growth of T47D human breast cancer cells (Kampa et al. 1996) and inducing necrosis of leukemic B- and T-cells (Otani and Suzuki 2003), and (3) κ-casein peptides
displaying cytotoxicity toward mammalian cells (Matin and Otani 2002).
Another group of bioactive peptides generated during digestion of caseins are
caseinophosphopeptides (CPPs), containing high number of phosphorylated sites
which can bind and solubilize calcium (Berrocal et al. 1989). This characteristic
helps CPPs to mediate the growth and apoptosis of cells, thereby demonstrating
their antitumor activities against intestinal cancerous cells (Perego et al. 2012; Sah
et al. 2015).
Thus, several studies have displayed the anti-tumoral and cytotoxic activity of
milk derived bioactive peptides against different cancer cell lines. However, clinical
data is still lacking, and the anticancer activity of such peptides must be thoroughly
investigated in controlled trials before drawing any conclusions (Cicero et al. 2017)
Hypoglycemic Effects
Diabetes mellitus is a widely prevalent disease which results in high blood sugar
levels and is known to cause complications like hypertension and cardiovascular
disease. Impaired insulin secretion and insulin resistance characterizes type 2 diabetes, whereas type 1 diabetes is characterized by body’s inability to secrete insulin
(Brandelli et al. 2015; Shori 2015).
Management of type 2 diabetes is mainly focused on increasing insulin availability, either by direct delivery of insulin or through agents that have specific roles
(e.g. improving insulin sensitivity, enhancing insulin secretion, increasing glucose
excretion) (DeFronzo et al. 2014). Upon ingesting food, incretin hormones like
glucagon-like peptide 1 (GLP-1) and glucose-dependent insulinotropic polypeptide
(GIP) are secreted which modulate gut motility, helps in nutrient absorption, and
stimulate insulin secretion (Drucker and Nauck 2006). However, a serine exopeptidase, dipeptidyl-peptidase IV (DPP-IV) inhibits the GLP-1 and GIP hormones making treatment of type 2 diabetes complicated. Hence, DPP-IV inhibitors and GLP-1
analogues resistant to DPP-IV action are currently the therapies available to manage
type 2 diabetes (Fadini and Avogaro 2011).
Influence on glycaemia by bioactive peptides may be exerted through different
mechanisms including incretin secretion, insulinotropic activity and regulation of
S. Maqsood et al.