La administración oral de un extracto estandarizado de Zuccagnia punctata mejora la función vascular en un modelo experimental de sindrome metabólico

MIRTA MEDINA; SUSANA JEREZ; CATIANA ZAMPINI; AGOSTINA VALOY; MARÍA INES ISLA

San Miguel de Tucumán

Jornada; XXV Jornadas Científicas - 2018; 2018

Asociación de Biología de Tucumán

Previously, we characterized a high fat diet (HFD)-induced metabolically obese and normal weight rabbit model. This model was characterized by endothelial dysfunction and increased vascular reactivity to angiotensin II (Ang II). We have also demonstrated a beneficial effect of a standardized extract from Zuccagnia punctata (ZpE) on endothelial function in hypercholesterolemic rabbits. Objetive: to determine the effect of oral administration of ZpE on vascular dysfunction induced by HFD. Methods: male rabbits were separated in three groups: fed on regular diet, fed on HFD and fed on HFD orally administrated 2.5mgGAE/day ZpE (HFD+Zp). To check endothelial function, acetylcholine (Ach) relaxation in aortic rings and plasma nitrites concentrationby Griess reaction were measured. To check vascular reactivity to Ang II, aortic rings were exposed to the agonist in absence (control) or presence of tetraetilamonium (TEA, KCa channels blocker) or Bay K8644 (calcium channels activator, L-type, Cav).Results: oral administration of ZpE: -improved Ach relaxation and plasma nitrites levels (HFD 1.2x10-8±9.5x10-9, HFD+Zp 1.2x10-7±3.1x10-8 nmoles/mg proteins; decreased maximal response to Ang II (HFD 3880±542, HFD+Zp 2574±272 mg). TEA and Bay K8644 reversed the ZpE-effect on the contractile response toAng II. In conclusion, ZpE improved vascular function by increasing nitric oxidebioavailability and by decreasing the contractile response to Ang II. This latter mechanism would imply activation of KCa channels or inhibition of Cav . Therefore, ZpE could be used to prevent vascular dysfunction in normal weight obesity.