Efeito do extrato hidro-alcoólico do caroço do Açaí (Euterpe oleracea Mart.) sobre as alterações metabólicas em camundongos C57BL/6 submetidos à dieta hiperlipídica

Abstract

An Increased evidence has shown that a diet rich in polyphenols reduce cardiovascular risk. Our studies suggest that the hydro-alcoholic extract of the seed of the acai (ASE), rich in polyphenols improves many aspects of the metabolic syndrome (MS) induced by a high fat diet. The aim of this study was to evaluate the preventive effect of ASE on changes in hepatic metabolism of glucose and lipids, as well as the molecular mechanisms involved in these effects in C57BL / 6 mice fed high fat diet. Male C57BL / 6 mice 30 days of age were divided into 4 groups and received the following diets for 12 weeks: control group (C): standard diet; control group + ASE (C + ASE): standard diet + ASE; hyperlipidic Group (H): fat diet; hyperlipidic group + ASE (ASE + H) + ASE fat diet. Were evaluated: food intake, body weight, amount of visceral fat mass, plasma leptin levels, glucose levels, glucose tolerance, insulin resistance, adiponectin expression in epididymal adipose tissue, plasma lipids, liver triglycerides and cholesterol, liver histology, glycogen hepatic expression of proteins involved in the cascade of insulin (IR pIRS1, PI3K, pAKT and GLUT2) triglyceride synthesis (SREBP-1c, FAS and pACC) and cholesterol (HMG CoA R and pAMPK) and hepatic excretion cholesterol (ABCG5 and ABCG8), damage to lipids and activity of antioxidant enzymes (SOD, CAT and GPx) in liver and adipose tissue, serum protein oxidation in the liver, expression of SOD-2 and formation of liver nitrite. Treatment with ASE reduced the body weight, food intake, glucose tolerance, leptin sensitivity , hepatic steatosis, the accumulation of cholesterol and hepatic triglyceride, expression of lipogenic proteins, such as SREBP-1c and HMG CoA-R and normalized insulin signaling. Furthermore, increased insulin sensitivity, expression of adiponectin in the adipose tissue of pAMPK, carrier-cholesterol and ABCG8 showed an antioxidant effect on adipose tissue and liver to reduce the formation of byproduct of lipid peroxidation (MDA) and protein carbonyls and increase the activity of antioxidant enzymes. Thus, the ASE can modulate the expression of proteins in the insulin signaling pathway, and the pathway involved in lipogenesis, and cholesterol homeostasis. The synthesis of NO, the antioxidant activity and increased insulin sensitivity should play a central role in the effects of ASE.