The consumption of
polyphenol-rich foods is associated with a decreased risk of mortality from
cardiovascular diseases. Previously, we have demonstrated that the stone of Euterpe oleracea Mart. (açaí) from the Amazon region exerts
vasodilator and
antioxidant actions. This study examined the effect of açaí stone extract (ASE) on the vascular functional and structural changes and oxidative stress associated with the two-kidney, one-
clip (2K-1C)
renovascular hypertension. 2K-1C and
sham-operated rats were treated with ASE 200 mg/kg/day (or vehicle) for 40 days. Blood pressure was measured by tail plethysmography, and the vascular reactivity was evaluated in the rat isolated mesenteric arterial bed. Mesenteric
protein expression of
endothelial nitric oxide synthase (eNOS),
superoxide dismutase 1 and 2 (SOD1 and SOD2),
metalloproteinase 2 (MMP-2), and tissue inhibitor of
MMPs (TIMP)-1 was assessed by Western blot; oxidative damage and
antioxidant activity by spectrophotometry; MMP-2 levels by
gelatin zymography; and structural changes by histological analysis. ASE prevented 2K-1C
hypertension and the reduction of
acetylcholine-induced vasodilation. The increased levels of
malondialdehyde and carbonyl
protein were reduced by ASE. SOD,
catalase, and
glutathione peroxidase activities and the expressions of SOD1 and SOD2, eNOS, and
TIMP-1 were decreased in 2K-1C rats and recovered by ASE. In 2K-1C rats, ASE prevented
vascular remodeling and the increased expression/levels of MMP-2. These findings indicate that ASE produces
antihypertensive effect and prevents the endothelial dysfunction and vascular structural changes in 2K-1C
hypertension, probably through mechanisms involving
antioxidant effects, NOS activation, and inhibition of MMP-2 activation.