We studied the effect of Ninjinyoeito in relation to the endothelial c
ells of the human aorta. Ninjinyoeito produced a cell proliferation ac
celeration effect, resulting in suppression of the synthesis and accel
eration of the disintegration of endothelin, which acts as a vasoconst
rictor and vasopressor. Also, acceleration of the synthesis of prostac
yclin, which shows antithrombosis and platelet coagulation suppressing
effects, was observed. The results suggest that Ninjinyoeito accelera
tes physiological function of in vitro human aorta endothelial cells.