Inhibitory effect of soybean hypocotyls on Epstein-Barr virus early antigen induction and skin tumor promotion.

The in vitro anti-tumor promoting effect of hypocotyls from fresh soybeans was evaluated. The dimethyl sulfoxide extracts of hypocotyls showed a stronger inhibitory effect than that of soybeans on Epstein-Barr virus early antigen activation induced by 12-O-tetradecanoylphorbol-13-acetate. Daidzin, an isoflavone with the highest content of hypocotyls, was also inhibitory. An in vivo evaluation of anti-tumor promoting activity of hypocotyls against the skin of mice also revealed a significant inhibitory effect on tumor formation.