Euterpe oleracea Mart.-derived polyphenols prevent endothelial dysfunction and vascular structural changes in renovascular hypertensive rats: role of oxidative stress.
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.
Department of Pharmacology, Institute of Biology, Rio de Janeiro State University, Av. 28 de Setembro, 87, Rio de Janeiro, 20 551-030, Brazil.
Cristiane Aguiar
CA
da Costa
Paola Raquel Braz
PR
de Oliveira
Graziele Freitas
GF
de Bem
Lenize Costa Reis Marins
LC
de Cavalho
Dayane Teixeira
DT
Ognibene
Andréa Fernandes Emiliano
AF
da Silva
Samuel
S
Dos Santos Valença
Karla Maria Pereira
KM
Pires
Pergentino José
PJ
da Cunha Sousa
Roberto Soares
RS
de Moura
Angela Castro
AC
Resende
D000818:Animals; D000975:Antioxidants / Q000302:isolation & purification / Q000494:pharmacology; D028023:Arecaceae / Q000737:chemistry*; D001794:Blood Pressure / Q000187:drug effects; D015153:Blotting, Western; D004195:Disease Models, Animal; D004730:Endothelium, Vascular / Q000187:drug effects / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects; D006978:Hypertension, Renovascular / Q000188:drug therapy* / Q000503:physiopathology; D008297:Male; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism; D052250:Nitric Oxide Synthase Type III / Q000378:metabolism; D018384:Oxidative Stress / Q000187:drug effects*; D010936:Plant Extracts / Q000494:pharmacology; D010991:Plethysmography; D059808:Polyphenols / Q000302:isolation & purification / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar
D000975:Antioxidants; D010936:Plant Extracts; D059808:Polyphenols; D052250:Nitric Oxide Synthase Type III; D020778:Matrix Metalloproteinase 2