Protective Effect of Açai Seed Extract ( Euterpe oleracea Mart.) Combined with Exercise Training on Cardiovascular Alterations,Oxidative Stress,and Loss of Physical Performance in Spontaneously Hypertensive Rats

Abstract

Hypertension increases the risk of mortality from cardiovascular complications. The objective of this study was to evaluate whether Euterpe oleracea Mart. (açaí) seed extract (ASE), a polyphenol-rich Amazonian plant, and moderate exercise training (TR), in combination or not, exert beneficial effects on cardiovascular structural and functional changes, oxidative stress, and loss of physical performance (PP) in spontaneously hypertensive rats (SHR). Five groups were assigned: Control (CT), SHR, SHR + ASE (200 mg/kg/day by gavage), SHR + TR, and SHR + TR + ASE. The TR was performed on a treadmill for 8 weeks (5×/week) for 30 min. Blood pressure, cholesterol, and triglyceride levels were measured. Vascular reactivity was evaluated in the mesenteric arterial bed (MAB) and aortic ring. Aorta samples were obtained for biochemical, immunohistochemical, and morphological assessments. Running distance and exercise time increased in SHR + TR compared with the first maximal stress test. This performance was lost in the third test but restored with ASE. Hypertension, aorta hypertrophy, reduced acetylcholine-induced vasodilation, phosphorylated endothelial nitric oxide synthase (p-eNOS) expression, oxidative damage (3,4-methylenedioxyamphetamine), and superoxide dismutase activity were improved by ASE but not TR. ASE and TR alone improved endothelial dysfunction in MAB and fibrosis in the aorta. The lipid profile and glutathione peroxidase activity improvement were observed only in SHR + TR + ASE, and additional p-eNOS expression and anti-hypertrophy effect were observed. In conclusion, ASE was superior to TR as an antihypertensive strategy because it improved vascular endothelial dysfunction, hypertrophy, and oxidative stress in SHR. The association of both strategies further improves vascular hypertrophy, antioxidant defense, the loss of PP, and lipid profile, which may benefit hypertension-related cardiovascular risks.