Co-administration of Grape Seed Extract and Exercise Training Improves Endothelial Dysfunction of Coronary Vascular Bed of STZ-Induced Diabetic Rats

Abstract

BackgroundOne of the known complications of diabetes mellitus is vascular dysfunction. Inability of the coronary vascular response to cardiac hyperactivity might cause a higher incidence of ischemic heart disease in diabetic subjects. It has been indicated that regular exercise training and antioxidants could prevent diabetic cardiovascular problems enhanced by vascular damage.ObjectivesThe aim of this study was to determine the effects of grape seed extract (as antioxidant), with and without exercise training on coronary vascular function in streptozotocin induced diabetic rats.Materials and MethodsFifty male Wistar rats weighing 200 – 232 grams were randomly divided into five groups of 10 rats each: sedentary control, sedentary diabetic, trained diabetic, grape seed extract (200 mg/kg) treated sedentary diabetic and, grape seed extract treated trained diabetic. Diabetes was induced by one intraperitoneal injection of streptozotocin. After eight weeks, coronary vascular responses to vasoactive agents were determined.ResultsThe endothelium dependent vasorelaxation to acetylcholine was reduced significantly in diabetic animals; exercise training or grape seed extract administration partially improves this response. However, exercise training in combination with grape seed extract restores endothelial function completely. The endothelium independent vasorelaxation to sodium nitroprusside was improved by combination of exercise training and grape seed extract. On the other hand, the basal perfusion pressure and vasoconstrictive response to phenylephrine did not change significantly.ConclusionsThe data indicated that co-administration of grape seed extract and exercise training had more significant effects than exercise training or grape seed extract alone; this may constitute a convenient and inexpensive therapeutic approach to diabetic vascular complications.

Gallic acid improves endothelium‐dependent vasodilatory response to histamine in the mesenteric vascular bed of diabetic rats

“…Considerable evidence indicates that endothelium‐dependent relaxation is impaired in diabetes mellitus . Impairment of endothelial function may contribute to the pathogenesis of cardiovascular complications induced by diabetes .…”

“…Some of the mechanisms leading to these impairments in diabetes may include factors that decrease endothelium‐derived relaxation factors, such as NO and prostacyclin . It has been shown that endothelium‐derived NO is reduced in the diabetic milieu and that NO‐dependent vasodilation is reduced by oxidative stress, thereby impairing endothelial function . Nevertheless, conflicting results have been obtained in some studies reported in the literature.…”

“…Considerable evidence indicates that endotheliumdependent relaxation is impaired in diabetes mellitus. [20][21][22][23] Impairment of endothelial function may contribute to the pathogenesis of cardiovascular complications induced by diabetes. [24][25][26] Some of the mechanisms leading to these impairments in diabetes may include factors that decrease endothelium-derived relaxation factors, such as NO and prostacyclin.…”

“…2,27 It has been shown that endothelium-derived NO is reduced in the diabetic milieu and that NO-dependent vasodilation is reduced by oxidative stress, thereby impairing endothelial function. 20,21,23 Nevertheless, conflicting results have been obtained in some studies reported in the literature. For example, some studies have reported that endothelium-dependent relaxation does not differ between control and streptozotocin (STZ)-induced diabetic rats, 28,29 whereas others have reported enhanced vasodilatory response in STZdiabetic rats.…”

Protective effect of aqueous seed extract of Vitis Vinifera against oxidative stress, inflammation and apoptosis in the pancreas of adult male rats with diabetes mellitus

“…In experimental diabetic rats, consumption of V. Vinifera seed was found to delay the onset and progression of cataract [14], protects the liver against destruction [15], protects the nerve against damage [16] and protects the hippocampus against apoptosis [17]. V. Vinifera seed was also found to improve coronary vascular function in diabetes [18]. Currently, protective effect of aqueous seed extract of V. vinifera (VVSAE) against pancreatic dysfunction in diabetes is unknown.…”