184
8 Ulvans
and source dependent. Nonetheless, the low level of anticoagulant activity demonstrated in various studies is potentially relevant in developing anticoagulant agent
with potential for interfering in the body’s intrinsic anticoagulant mechanism.
8.7.5 Antihyperlipidemic
When there is an imbalance in the way the body distributes and eliminates lipids and
cholesterol, this leads to metabolic syndrome often associated with hyperlipidemia.
This is often a cause of cardiovascular diseases. The components of macroalgae have
been linked with having antihyperlipidemic effects and a diet including macroalgae
has been shown to have preventive or curative effect on hyperlipidemia. To isolate
specific components in order to develop therapies for hyperlipidemia, the sulfated
polysaccharides of macroalgae have been investigated for their antihyperlipidemic
effect.
Ulvans from species which include U. pertusa, U. lactuca, U. prolifera and Ulva
fasciata have shown significant hyperlipidemic effect when measured as a function of
serum total cholesterol using rat and mice models. Evidence suggests that increased
degree of sulfation of ulvan may improve the antihyperlipidemic effect of the ulvan.
Oversulfated ulvan with up to 40.6% sulfation achieves a total cholesterol-lowering
effect of 44% compared to a 28% reduction measured for crude ulvan with a degree
of sulfation of 22.5% (Qi and Sheng 2015). Although it is obvious that the structure of
ulvans affects the mechanism and level of antihyperlipidemic effect, the relationship
between the chemical structure of ulvan and its antihyperlipidemic effect is unclear.
Possible mechanisms presented include gene regulatory effect and interference in
metabolism and biosynthesis (Ali and Agha 2009).
8.7.6 Antiviral Property
While ulvans alone show moderate to low antiviral properties, more important is their
potential impact on vaccination. Combination of ulvans with vaccination can improve
vaccination effectiveness by as much as 100% compared to when vaccination is done
alone (Song et al. 2016). This enhancement of vaccination is thought to be associated
with ulvan’s immunomodulatory activity. The impact of this could be need for less
quantities of vaccine in achieving the same level of vaccination, particularly in cases
when such vaccines are scarce.
Although some evidence points to improve antiviral activity with higher molecular
weight and higher degree of sulfation, the number of studies and species investigated
are not enough to make a conclusive relationship between the structural parameters
and the antiviral property of ulvan.
Antiviral activities have been investigated in ulvan from species of
U. clathrata, U. pertusa and U. compressa (Aguilar-Briseno et al. 2015; Song et al.
8 Ulvans
and source dependent. Nonetheless, the low level of anticoagulant activity demonstrated in various studies is potentially relevant in developing anticoagulant agent
with potential for interfering in the body’s intrinsic anticoagulant mechanism.
8.7.5 Antihyperlipidemic
When there is an imbalance in the way the body distributes and eliminates lipids and
cholesterol, this leads to metabolic syndrome often associated with hyperlipidemia.
This is often a cause of cardiovascular diseases. The components of macroalgae have
been linked with having antihyperlipidemic effects and a diet including macroalgae
has been shown to have preventive or curative effect on hyperlipidemia. To isolate
specific components in order to develop therapies for hyperlipidemia, the sulfated
polysaccharides of macroalgae have been investigated for their antihyperlipidemic
effect.
Ulvans from species which include U. pertusa, U. lactuca, U. prolifera and Ulva
fasciata have shown significant hyperlipidemic effect when measured as a function of
serum total cholesterol using rat and mice models. Evidence suggests that increased
degree of sulfation of ulvan may improve the antihyperlipidemic effect of the ulvan.
Oversulfated ulvan with up to 40.6% sulfation achieves a total cholesterol-lowering
effect of 44% compared to a 28% reduction measured for crude ulvan with a degree
of sulfation of 22.5% (Qi and Sheng 2015). Although it is obvious that the structure of
ulvans affects the mechanism and level of antihyperlipidemic effect, the relationship
between the chemical structure of ulvan and its antihyperlipidemic effect is unclear.
Possible mechanisms presented include gene regulatory effect and interference in
metabolism and biosynthesis (Ali and Agha 2009).
8.7.6 Antiviral Property
While ulvans alone show moderate to low antiviral properties, more important is their
potential impact on vaccination. Combination of ulvans with vaccination can improve
vaccination effectiveness by as much as 100% compared to when vaccination is done
alone (Song et al. 2016). This enhancement of vaccination is thought to be associated
with ulvan’s immunomodulatory activity. The impact of this could be need for less
quantities of vaccine in achieving the same level of vaccination, particularly in cases
when such vaccines are scarce.
Although some evidence points to improve antiviral activity with higher molecular
weight and higher degree of sulfation, the number of studies and species investigated
are not enough to make a conclusive relationship between the structural parameters
and the antiviral property of ulvan.
Antiviral activities have been investigated in ulvan from species of
U. clathrata, U. pertusa and U. compressa (Aguilar-Briseno et al. 2015; Song et al.