1) Inhibition of blood glucose level rise
In recent years, the number of diabetics in
Japan has tended to increase year by year due to changes in diet and lifestyle.
Therefore, we conducted an animal study to investigate the effect of a protein
prepared from dulse (dulse protein) on the suppression of elevated blood
glucose levels. The results showed that dulse protein significantly suppressed
the increase in blood glucose levels after glucose loading. We now speculate
that dulse protein may inhibit the absorption of glucose in the small
intestine.
2) Angiotensin I-converting enzyme (ACE)
inhibition
Treatment and prevention of hypertension is
an important issue because if left untreated, it causes arteriosclerosis, which
in turn leads to various vascular diseases such as heart disease and stroke.
Therefore, the ACE inhibitory effect of dulse protein was investigated. As a
result, a peptide (dulse peptide) hydrolyzed by protease from dulse protein was
found to have a strong ACE inhibitory effect. Next, the dulse peptides were
fractionated and the amino acid sequences of the active peptides were
determined, and we found that many of these sequences were present in the
primary structure of dulse-derived phycoerythrin. Based on these results, we
speculate that phycoerythrin is the primary protein that derived the dulse ACE
inhibitory peptide.
3) Antioxidant action
It has been revealed that oxidative damage
to living organisms caused by reactive oxygen species is a cause of aging and
various diseases, and foods rich in antioxidants are attracting attention. Therefore,
we investigated the antioxidant effects of dulse protein using radical
scavenging activity as an indicator. As a result, antioxidant activity was
observed in dulse protein. On the other hand, the pigmentless dulse
phycoerythrin expressed in coli bacteria showed almost no antioxidant activity.
This indirectly suggested that the major site of antioxidant activity of dulse
protein is the pigmented part, not the apoprotein part.
