medicines available on the market but might be used as natural supplements in diets
and or food-drug medical therapies for the control of type 2 diabetes [99].
Liu et al. [100] recently reviewed the peptides inhibitory properties of DPP IV
enzyme from food-derived sources.
5.2.2 Inhibition of a-Glucosidase
Another strategy for the control of type 2 diabetes is the inhibition of carbohydrate
hydrolyzing enzymes such as a-glucosidase. The enzyme is bound to the membrane
of the epithelial mucosa of the small intestine, decreasing blood glucose levels
[101]. WPC and b-LG hydrolysates obtained with serine protease isolated from
Cucurbita ficifolia inhibited a-glucosidase of Saccharomyces cerevisiae [102].
Additionally, in vivo studies showed that the peptides released from whey protein
hydrolysates or b-LG and a-LA proteins inhibited a-glucosidase in the intestine of
rats by 36, 33, and 24%, respectively, as compared to non-hydrolyzed protein
substrates that did not show detectable enzyme inhibition [103]. However, because
of the small number of non-saccharide inhibitors of the a-glucosidase, investigations should focus on the identification of peptides responsible for inhibiting this
enzyme. These investigations will positively contribute further to our understanding
of the in vivo inhibition mechanism and its physiological role.
Wang et al. [104] recently reviewed different properties of bioactive peptides,
including a-glucosidase inhibitory peptides from soy protein.
5.3 Antihypertensive Peptides in the Cardiovascular System
Hypertension, also known as high blood pressure, is one of the main risk factors for
cardiovascular diseases, a group of heart and blood vessel disorders that include
coronary, cerebrovascular, peripheral arterial, rheumatic and congenital diseases of
the heart. One of the most studied bioactivities of peptides is the ability to reduce
blood pressure. Many antihypertensive peptides are shown to inhibit the
angiotensin-converting enzyme (ACE) (also known as peptidyl-dipeptide hydrolase, EC 3.4.15.1). This enzyme plays a fundamental physiological role in
renin-angiotensin, kallikrein-kinin, and immune systems. Thus, synthetic ACE
inhibitors such as enalapril, lisinopril, captopril, and ramipril have been widely used
as drugs with antihypertensive activity. However, these synthetic drugs demonstrated several side effects, such as increased potassium levels, reduced renal
function, allergic reactions, rashes, and taste disorders [105].
Several bioactive peptides derived from whey protein were isolated and evaluated for their antihypertensive activity by inhibiting ACE activity and avoiding
undesirable side effects. Also, these peptides minimize the cost associated with
synthetic drug therapy. Some fragments were released from a-LA and identified,
such as LAHKAL f(105–110), KGYGGVSL f(16–23), KGYGGVSLPEW f(16–26),
DKVGINYW f(97–104), and DKVGINYf(97–103) [41]. Besides, the fragments
LAMA f(22–25), LDAQSAPLR f(32–40), VLDTDYK f(94–100), and VAGTW
f(15–19) were released from b-LG, among many others [106].
494
A. F. A. Salvado et al.
and or food-drug medical therapies for the control of type 2 diabetes [99].
Liu et al. [100] recently reviewed the peptides inhibitory properties of DPP IV
enzyme from food-derived sources.
5.2.2 Inhibition of a-Glucosidase
Another strategy for the control of type 2 diabetes is the inhibition of carbohydrate
hydrolyzing enzymes such as a-glucosidase. The enzyme is bound to the membrane
of the epithelial mucosa of the small intestine, decreasing blood glucose levels
[101]. WPC and b-LG hydrolysates obtained with serine protease isolated from
Cucurbita ficifolia inhibited a-glucosidase of Saccharomyces cerevisiae [102].
Additionally, in vivo studies showed that the peptides released from whey protein
hydrolysates or b-LG and a-LA proteins inhibited a-glucosidase in the intestine of
rats by 36, 33, and 24%, respectively, as compared to non-hydrolyzed protein
substrates that did not show detectable enzyme inhibition [103]. However, because
of the small number of non-saccharide inhibitors of the a-glucosidase, investigations should focus on the identification of peptides responsible for inhibiting this
enzyme. These investigations will positively contribute further to our understanding
of the in vivo inhibition mechanism and its physiological role.
Wang et al. [104] recently reviewed different properties of bioactive peptides,
including a-glucosidase inhibitory peptides from soy protein.
5.3 Antihypertensive Peptides in the Cardiovascular System
Hypertension, also known as high blood pressure, is one of the main risk factors for
cardiovascular diseases, a group of heart and blood vessel disorders that include
coronary, cerebrovascular, peripheral arterial, rheumatic and congenital diseases of
the heart. One of the most studied bioactivities of peptides is the ability to reduce
blood pressure. Many antihypertensive peptides are shown to inhibit the
angiotensin-converting enzyme (ACE) (also known as peptidyl-dipeptide hydrolase, EC 3.4.15.1). This enzyme plays a fundamental physiological role in
renin-angiotensin, kallikrein-kinin, and immune systems. Thus, synthetic ACE
inhibitors such as enalapril, lisinopril, captopril, and ramipril have been widely used
as drugs with antihypertensive activity. However, these synthetic drugs demonstrated several side effects, such as increased potassium levels, reduced renal
function, allergic reactions, rashes, and taste disorders [105].
Several bioactive peptides derived from whey protein were isolated and evaluated for their antihypertensive activity by inhibiting ACE activity and avoiding
undesirable side effects. Also, these peptides minimize the cost associated with
synthetic drug therapy. Some fragments were released from a-LA and identified,
such as LAHKAL f(105–110), KGYGGVSL f(16–23), KGYGGVSLPEW f(16–26),
DKVGINYW f(97–104), and DKVGINYf(97–103) [41]. Besides, the fragments
LAMA f(22–25), LDAQSAPLR f(32–40), VLDTDYK f(94–100), and VAGTW
f(15–19) were released from b-LG, among many others [106].
494
A. F. A. Salvado et al.