Effects of Sesamin on Aortic Oxidative Stress and Endothelial Dysfunction in Deoxycorticosterone Acetate-Salt Hypertensive Rats

Abstract

Sesamin is one of the lignans contained abundantly in sesame oil. Previous studies have indicated that sesamin inhibits lipid metabolism, such as desaturation in polyunsaturated fatty acid biosynthesis 1) and cholesterol absorption. 2) In recent studies, we have demonstrated the antihypertensive effect of sesamin using several types of experimental hypertensive models. [3][4][5] The most efficient antihypertensive activity was observed in the deoxycorticosterone acetate (DOCA)-salt hypertensive rat model. Moreover, a development of cardiovascular hypertrophy in these animals was attenuated by the sesamin-feeding. 3)There is accumulating evidence indicating that an oxidative stress in vascular tissues is closely related to the development of hypertensive diseases. 6) Nakazono et al. 7) have shown that blood pressure of spontaneously hypertensive rats (SHR) was decreased markedly by administration of heparinbinding superoxide dismutase (SOD) which bound to vascular endothelial cells. In angiotensin II-induced hypertensive rats, both the development of hypertension and the altered endothelium-dependent vascular relaxation were improved by the treatment with membrane-targeted forms of SOD. 8)These findings suggest that vascular superoxide (O 2 Ϫ ) production is increased in several animal models of hypertension and contributes to the development and/or maintenance of their high blood pressure and endothelial dysfunction.Most recently, we noted that the increased vascular O 2 Ϫ production in DOCA-salt hypertensive animals was normalized almost completely by the feeding of sesamin-containing diet. 9) On the other hand, a previous in vitro study has shown that stretching vascular smooth muscle cells results in increased O 2 Ϫ production, 10) thereby suggesting that the high blood pressure by itself may increase the vascular O 2 Ϫ production. Therefore the possibility that dietary sesamin-induced decreases in vascular O 2 Ϫ production may result from a decrease in blood pressure cannot be ruled out. Thus in the present study, we further evaluated the relationship between the antihypertensive effect of sesamin and its antioxidative activity in DOCA-salt hypertensive rats. MATERIALS AND METHODSMaterials Sesamin was prepared from refined sesame oil and purified as described previously.11) Sesamin-containing diets (0.1, 1 w/w% in commercial normal diet, NMF) were obtained from Oriental Yeast Co., Ltd. (Tokyo, Japan). Reserpine and hydralazine hydrochloride were purchased from Tokyo Kasei Kogyo Co. (Tokyo, Japan). All other reagents used were obtained from Sigma Chemical Co. (St. Louis, Missouri, U.S.A.) and Nacalai Tesque (Kyoto, Japan).Animal Experiments Male Sprague-Dawley rats (6 weeks old) (SLC, Inc., Hamamatsu, Japan), were anesthetized with sodium pentobarbital (40 mg/kg, i.p.), and the right kidney was removed via a right flank incision. After a 1-week postsurgical recovery period, rats were separated into a sham-operated group and a DOCA-salt group. Each group was further divided into five groups: i) normal diet gro...

Effect of Sesame Lignans on TNF-α-Induced Expression of Adhesion Molecules in Endothelial Cells

“…20,21) In addition, the o-dihydroxyphenyl structure (catechol moiety) at the 3 0 -and 4 0 -positions of B ring flavonoids is necessary for high antioxidative activity, such as radical scavenging and the suppression of lipid peroxidation reactions. 15,17,22) Furthermore, it has been suggested that the gallate group plays an important role in modulating the expression of CAMs in endothelial cells. 9) In the present study, we found that sesaminol-6-catechol had a potent suppressive effect of CAM expression, and that sesaminol, with a hydroxyphenyl group, did not exhibit any inhibitory activity on CAM expression (Fig.…”

Formation of two methylenedioxy bridges by a Sesamum CYP81Q protein yielding a furofuran lignan, (+)-sesamin

“…It has a growth-retarding effect on some plants, as well as a synergistic effect with pyretherum insecticides (5,6). (ϩ)-Sesamin has been shown to have a wide range of biological effects: protection against ethanol-and carbon tetrachloride-induced liver damage (7,8), improvement of fatty acid metabolism (9)(10)(11), antiinflammatory effects (12), increased vitamin E activities (13,14), inhibition of vascular superoxide production (15,16), and induction of nitric oxide (17). Therefore, it is an extremely interesting natural compound from the viewpoint of health care (18).…”

Pharmacology in Health Foods: Improvement of Vascular Endothelial Function by French Maritime Pine Bark Extract (Flavangenol)

“…Several antioxidative substances have been reported to exert a preventive effect against endothelial dysfunction observed in hypertensive patients and experimental animals (16,18,19). Daily feeding of PBE improves the microcirculation and platelet function in patients with coronary artery diseases.…”