INVESTIGADORES
ISLA Maria Ines
artículos
Título:
Beneficial effects of hydroalcoholic extract and flavonoids from Zuccagnia punctata in a rabbit model of vascular dysfunction induced by high cholesterol diet
Autor/es:
ROCO, JULIETA; ALARCÓN, GABRIELA; SIERRA, LILIANA; ZAMPINI, IRIS CATIANA; INES ISLA, MARÍA; JEREZ, SUSANA
Revista:
MEDICINAL CHEMISTRY RESEARCH
Editorial:
BIRKHAUSER BOSTON INC
Referencias:
Año: 2017 vol. 26 p. 2336 - 2344
ISSN:
1054-2523
Resumen:
This study evaluated the effects of a Zuccagnia punctata standardized hydroalcoholic extract (ZpE) and three of its major flavonoids [2′,4′-dihydroxychalcone (DHC), 7-hydroxyflavanone (HF) and 3,7-dihydroxyflavone (DHF)] on the vascular reactivity of aortic rings with endothelial dysfunction induced by feeding rabbits on a high cholesterol diet. Rabbits were fed with either normal chow or a diet containing 1% cholesterol for 5?6 weeks. Isometric contractions were measured. Concentration response curves to ZpE (range from 4 × 10−2 to 4 × 10 µg gallic acid equivalent/ml), DHC, DHF or HF (range from 10−9 to 10−4 M) showed concentration-dependent relaxation of arteries pre-contracted with phenylephrine. ZpE (4 × 10−2, 4 × 10−1 and 4 µg gallic acid equivalent/ml), HF (10−9, 10−7, 10−5 M), DHC (10−9 M) and DHF (10−9 M) added to the bath improved acetylcholine affinity. Pre-treatment of arteries with ZpE (4 × 10−2 µg gallic acid equivalent/ml) and DHC (10−9 M) reduced phenylephrine-induced contraction. Incubation with the higher dose of ZpE (4 µg gallic acid equivalent/ml) reduced the angiotensin II-maximal contraction (Cmax) acting as a non-competitive antagonist, while DHC and DHF (10−5 M) caused a non-parallel rightward of the angiotensin II-concentration response curves and reduced the Cmax acting as mixed antagonists. ZpE (4 × 10−2 µg gallic acid equivalent/ml), DHC and DHF (10−9 M) caused a rightward displacement of angiotensin II-concentration response curves acting as competitive antagonists. In conclusion, the present study demonstrated that a ZpE and its major flavonoids had beneficial effects in arteries with vascular dysfunction induced by hypercholesterolemia. Therefore its use as herbal medicine to prevent cardiovascular risks factors may be promising.