Treatment of human stomach cancer KATO III cells with hot-water extracts from 
adzuki beans led to their growth inhibition as well as apoptosis induction. 
There are morphological changes in the cultured cells treated with the extracts, 
by which DNA fragmentation characteristic of apoptosis was actualized both 
concentration- and time-dependently. In contrast, N-acetyl-L-cysteine suppressed 
such DNA fragmentation, implying that the extracts from adzuki beans might exert 
antitumorigenicity via active oxygen-induced apoptosis. In order to verify this 
hypothesis in animal experiment, the 40% ethanol fraction of hot-water extracts 
was examined for its preventive effect against benzo(a)pyrene-induced 
tumorigenesis in the forestomach of A/J mice, given as drinking water containing 
the above fraction at 0.5-2.0% levels. Consequently, forestomach cancer has 
turned out to be reduced by 36-62% in tumor weight relative to the control. 
These results suggest that the fraction of hot-water adzuki extracts may serve 
as a nutrapharmaceutical or functional food available for cancer prevention.