Euterpe oleracea Mart. extract prevents vascular remodeling and endothelial dysfunction in spontaneously hypertensive rats

Summary. We assessed the effects of Euterpe oleracea Mart. (acai) seed extract (ASE) rich in proanthocyanidins and catechin on vascular dysfunction and oxidative stress associated with hypertension in spontaneously hypertensive rats (SHR). SHR and control rats were treated with ASE (200 mg/kg/day) or vehicle for 10 weeks. In the rat mesenteric arterial bed (MAB), acetylcholine response, endothelial nitric oxide synthase (eNOS) and superoxide dismutase 1 (SOD 1) expressions were studied. The antioxidant enzyme activity, oxidative damage and nitrite quantification were assessed in MAB and heart homogenates. eNOS immunohistochemistry and histological analysis was carried out on aortic sections. ASE was able to attenuate the hypertension and prevent the endothelial dysfunction in MAB of SHR. The increased levels of protein carbonylation and associated low levels of nitrite in MAB and heart of SHR were attenuated by ASE. The up-regulation of eNOS and SOD1 expression and the increased activity of SOD in MAB from SHR were normalized by ASE. In aorta from SHR, ASE prevented the increase in media thickness, media:lumen ratio and the decrease in the percentage of elastic fibers. Our results suggest that ASE produces antihypertensive effect and prevents the vascular dysfunction in SHR, through mechanisms involving antioxidant effects and NO production. Industrial relevance. Euterpe oleracea Mart. (Acai) has been considered one of the most important medicinal plants of the Amazon by its beneficial effects in the treatment of fever, pain, inflammation and anemia. More recently, Euterpe oleracea Mart. has been reported to reduce blood pressure with an important antioxidant property. The present research reports the protective effect of the extract of the seeds from Euterpe oleraca Mart. against high blood pressure and the associated vascular structural and functional changes. The test for antihypertensive and vascular anti-hypertrophic effect of the hydro-alcoholic extract of the seed of Euterpe oleracea Mart. provides scientific data to confirm the potentials of Euterpe oleracea Mart as an antihypertensive medicinal plant. Considering the large supply of Acai fruit in Brazil to obtain the extract, it provides a new therapeutic possibility of low cost for hypertensive patients. Keywords. Euterpe oleracea Mart; hypertension; oxidative stress; endothelial dysfunction; vascular hypertrophy.