 |
 |
昆布の新機能(1)
International Conference on Food Factors の略でICoFF（アイコフと発音）という、食品の機能性を発表する国際的な講演（カンファレンス）の第２回目が１９９９年１２月１３日（日）〜１７日（金）の間、京都の国際会館で開催されました。
そのなかでの、昆布に関する発表の要約を載せます。
THE TRADITIONAL UTILITY OF KOMBU(LAMINARIA JAPONICA) IN JAPAN AND ITS NEW FUNCTION
Japanese have been taking the various seaweed for long time. Among them, Kombu is one of the most popular
and famous seaweed. Kombu is known to be healthy foodstuff in
Japan, because it contains the dietary fiber or the
polysaccharide.
Various phytochemicals have been known to inhibit the
carcinogenesis process.
At the final process(the progression process), the
polysaccharides have been found to be protective.
The protective actions are classifiled into two activities. One
is mitogenic activity on lymphocyte and another is immune
activation.
We firstly investigated the mitogenic activity and the immune activation of several seaweed and vegetables. Mitogenic activity was determined with cell viability by MTT assay and the immune activation was evaluated with NO production. We found that the seaweed had both activities and their activity was stronger than those of vegetables.
Next we investigated that the effect of Kombu on
Benzpyrene(BaP) administered mouse.
Kombu powder and BaP were added in the diet. Kombu powder was
added with 2% and 5% by weight instead of cellulose. We
prepared 6 groups of mouse : Control diet group (without BaP and
Kombu powder), 2%Kombu group, 5%Kombu group, BaP group,
BaP+2%Kombu group and BaP+5%Kombu group. After around 150 days,
every group showed similar growth. Control group and BaP alone
group showed similar changes and they stopped the growth or they
had a little reduced body weight gain. One the other hand,
BaP+5%Kombu group sustained the body weight constantly in this
phase. In BaP alone group, 70% mice were died around 300 days
old and one of 7 mice in BaP+2%Kombu group was also died. These
results clearly indicate that 5% Kombu in the diet can prevent
from the carcinogenecity of BaP, but 2%Kombu failed a little in
the prevention.
We also measured BaP excreted through faces. In BaP alone group, small amount of BaP was detected in pieces. And half of this was free form and another half was absorbed into the fecal fiber. In this case, the fiber is cellulose in the diet. On the contrary, in Kombu powder adding group, free BaP was small and most of excreted BaP was absobed into the fical fiber, including the metabolite BaP epoxide which is ultimate carcinogenic form and 5%Kombu group more largely absorbed BaP and BaP epoxide.
This result indicates that Kombu fiber, polysaccharide can more effectively absorbed BaPs than cellulose. We think Kombu is protective against the dietary carcinogenesis : One action is the mitogenic activity and or the immune activity, and another action is the absorption of the toxicants in the intestine and the excretion through feces before being incorporated into the body.
|
|