Grape pomace and grape pomace extract improves insulin signaling in high-fat-fructose fed rats-induced metabolic syndrome.

PERDICARO DJ; MIATELLO RM; RODRIGUEZ LANZI MC; FONTANA AF; VAZQUEZ PRIETO MA; ANTONIOLLI A; BOTTINI R

Food and function

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 metabolic syndrome (MetS). MetS was developed by giving a high-fat-fructose (HFF) diet to Wistar rats. Six weeks of HFF diet induced weight gain, which was partially attenuated by GP (1 g Kg-1day-1) and GPE (300 mg Kg-1 day-1) supplementation. HFF diet increased systolic blood pressure, triglycerides, insulin resistance (HOMA:IR) and inflammation (c-reactive protein (CRP)). Supplementation with GP prevented SBP, triglycerides and CRP increased and partially attenuated insulin resistance. On the other hand, GPE partially reduced SBP and triglycerides and significantly prevented insulin resistance and inflammation. Also, HFF diet induced higher triglycerides content and enhanced NADPH oxidase activity in liver. As well, HFF diet increased epididymal adipose tissue weight, enlarged adipocytes size, and c-jun N-terminal kinase (JNK) activation, probably contributing with a pro-inflammatory cytokine pattern (higher resistin) and lower adiponectin protein expression. These alterations may result in an impairment of insulin signaling cascade observed in adipose, liver and muscle tissue (IRS1, Akt, and extracellular signal-regulated kinases (ERK1/2)) from HFF rats. Supplementation with GP and in a greater extent GPE attenuated liver triglyceride content and adiposity and restored adipose, liver and muscle response to insulin. These findings show that supplementation with GP and GPE in a greater extent can counteract adiposity, inflammation, liver damage and impaired insulin signaling associated to MetS, supporting the utilization of winemaking residues in food industry/human health due to their high amount of bioactive compounds.