Endothelium-Dependent Effect of Sesame Seed Feeding on Vascular Reactivity of Streptozotocin-Diabetic Rats: Underlying Mechanisms



Roghani M¹ ; Jalalinadoushan MR² ; Baluchnejadmojarad T³ ; Vaez Mahdavi MR¹ ; Naderi G⁴ ; Roghani Dehkordi F⁵ ; Taghi Joghataei M⁶
Source: Iranian Journal of Pharmaceutical Research Published:2013

Abstract

Cardiovascular disorders continue to constitute major causes of morbidity and mortality in diabetic patients. In this study, the effect of chronic administration of sesame (Sesamum indicum L) seed feeding was studied on aortic reactivity of streptozotocin (STZ)-diabetic rats. Male diabetic rats received sesame seed-mixed food at weight ratios of 3% and 6% for 7 weeks, one week after diabetes induction. Contractile responses to KCl and phenylephrine (PE) and relaxation response to acetylcholine (ACh) and sodium nitroprusside (SNP) were obtained from aortic rings. Maximum contractile response of endothelium-intact rings to PE was signifcantly lower in sesame-treated diabetic rats (at a ratio of 6%) relative to untreated diabetics and endothelium removal abolished this difference. Endothelium-dependent relaxation to ACh was also signifcantly higher in sesame-treated diabetic rats (at a ratio of 6%) as compared to diabetic rats and pretreatment of rings with nitric oxide synthase inhibitor, N(G)-nitro-l-arginine methyl ester (L-NAME) signifcantly attenuated the observed response. Two-month diabetes also resulted in an elevation of malondialdehyde (MDA) and decreased superoxide dismutase (SOD) activity and sesame treatment signifcantly reversed the increased MDA content and restored activity of SOD. We thus conclude that chronic treatment of diabetic rats with sesame seed could in a dose-manner prevent some abnormal changes in vascular reactivity through nitric oxide and via attenuation of oxidative stress in aortic tissue and endothelium integrity is necessary for this benefcial effect. © 2013 by School of Pharmacy.