Sesamin is one of the lignans found in high concentration in sesame seeds and oil. Several studies have demonstrated the protective effects of sesamin against the liver injury, which is mainly due to its antioxidative activity. However, little is known about the biological activities of sesamin in cardiovascular system. We have recently obtained evidence that dietary sesamin efficiently suppressed the development and maintenance of hypertension in deoxycorticosterone acetate (DOCA)-salt-induced hypertensive, two-kidney, one-clip renal hypertensive, and salt-loaded stroke-prone spontaneously hypertensive rats. The suppressive effect of sesamin on blood pressure elevation was closely related to an inhibitory effect on excessive superoxide (O2 -) production in the aorta of hypertensive animals. In addition, dietary sesamin normalized the decrease in endothelium-dependent vasodilatory responses and the increase in α1- adrenoceptor-dependent vasoconstrictor responses in DOCA-salt hypertensive model. We propose that the dietary sesamin is useful as a prophylactic treatment in the development of hypertension and endothelial dysfunction, and suggest that the antioxidative property of sesamin may apply to the prevention of oxidative stress-related diseases, such as diabetes, hypercholesterolemia, and atherosclerosis.