In the studies of the inhibitory activities of shoyuflavones against HDC
obtained from mouse mastocytoma P-815 cells, shoyuflavones
B and C were more potent inhibitors than (+)-catechin
and their own aglycones, that is, daidzein and
genistein. The inhibition of HDC activity by shoyuflavones
may attenuate excessive gastric acid secretion and inflammation,
which results in the prevention of allergic reactions.
Shoyuflavones are more water soluble than their own aglycones,
and fermented soy sauce contains approximately 60
ppm of shoyuflavones. On the other hand, the isoflavones in
soy sauce are present at approximately 5 ppm.