Grape pomace and grape pomace extract improve insulin signaling in high-fat-fructose fed rat-induced metabolic syndrome

RODRIGUEZ LANZI, C; PERDICARO, DJ; ANTONIOLLI, ANDREA; FONTANA, ARIEL R.; MIATELLO R; BOTTINI R; VAZQUEZ M

Food and Function

The Royal Society of Chemistry

Año: 2016 vol. 7 p. 1544 - 1553

2042-6496

In this study the effect of diet supplementation with grape pomace (GP) and grape pomace extract (GPE)on insulin sensitive tissues (adipose, liver and muscle) was evaluated in an experimental model of metabolicsyndrome (MetS). MetS was developed by giving a high-fat-fructose (HFF) diet to Wistar rats. Sixweeks of HFF diet induced weight gain, which was partially attenuated by GP (1 g per kg per day) and GPE(300 mg per kg per day) supplementation. HFF diet increased systolic blood pressure, triglycerides, insulinresistance (HOMA:IR) and inflammation (c-reactive protein (CRP)). Supplementation with GP preventedSBP, triglycerides and CRP increased and partially attenuated insulin resistance. On the other hand, GPEpartially reduced SBP and triglycerides and significantly prevented insulin resistance and inflammation.Also, HFF diet induced higher triglycerides content and enhanced NADPH oxidase activity in the liver.Also, HFF diet increased the epididymal adipose tissue weight, enlarged adipocyte size, and c-junN-terminal kinase (JNK) activation, probably contributing to a pro-inflammatory cytokine pattern (higherresistin) and lower adiponectin protein expression. These alterations may result in an impairment of insulinsignaling cascade observed in adipose, liver and muscle tissue (IRS1, Akt, and extracellular signal-regulatedkinases (ERK1/2)) from HFF rats. Supplementation with GP and to a greater extent GPE attenuated liver triglyceridecontent and adiposity and restored adipose, liver and muscle response to insulin. These findingsshow that supplementation with GP and GPE to a greater extent can counteract adiposity, inflammation,liver damage and impaired insulin signaling associated to MetS, supporting the utilization of winemakingresidues in food industry/human health due to their high amount of bioactive compounds.