Oral administration of Zuccagnia punctata extract improves lipid profile, reduces oxidative stress and prevents vascular dysfunction in hypercholesterolemic rabbits

Background: The consumption of flavonoids has been shown to prevent cardiovascular diseases including atherosclerosis. In this sense, in a recent in vitro study we demonstrated that a rich in flavonoids extract from Zuccagnia punctata has beneficial effects on vascular function in aorta from hypercholesterolemic rabbits. Purpose: The aim of this study was to evaluate the ability of a hydroalcoholic extract from Z.puncata (ZpE) to prevent alterations induced by high cholesterol diet in rabbits. Methods: The major components of the ZpE, flavonoids, were analyzed by using a validated reversed phase HPLC method. Rabbits were separated in five groups: fed standard chow (CD); CD orally administrated 2.5 mg, 5 mg or 10 mg GAE/day ZpE (ZpE- CD); fed 1% cholesterol-enriched chow (HD); HD orally administrated 2.5 mg GAE/day ZpE (ZpE-HD); HD orally administrated 2.5 mg rosuvastatin/day (Ro-HD). All diets were administrated by 6 weeks. Body weights (BW), mean blood pressure (MAP), heart rate (HR), visceral abdominal fat (VAF), organ weight (heart, kidney, liver) and vascular morphology were determined. Total cholesterol (TC), triglycerides (TG), fasting glucose (FG), aspartate amino transferase (AST), alanine amino transferase (ALT), bilirubin, creatinine, thiobarbituric acids reactive substances (TBARS) and glutathione reduced/oxidized index were measured in serum. Abdominal aorta was excised and vascular function was assessed by acetylcholine and sodium nitroprusiate relaxation and contractile response to norepinephrine and angiotensin II. Results: The major compounds of ZpE identified were chalcones: 2',4'-dihydroxy-3'-methoxychalcone and 2',4'dihydroxychalcone. Oral treatment with ZpE reduced MAP, TC, TG, TBARS, aortic intima/media ratio and increased glutathione reduced/oxidized index in HD rabbits. No differences were found in AST, ALT, bilirubin or creatinine. Acetylcholine relaxation was normalized and contractile response to norepinephrine and angiotensin II was reduced in ZpE-HD. Conclusion: Oral administration of ZpE as natural product in the prevention of cardiovascular disease related with hypercholesterolemia and endothelial dysfunction is very promising.