Effect of Ilex paraguariensis ingestion on proteins expression related to the insulin signalling in the liver of rats submitted to high fat diet

• Grant number: 09/12790-0
• Support Opportunities: Scholarships in Brazil - Master
• Start date: March 01, 2010
• End date: February 29, 2012
• Field of knowledge: Agronomical Sciences - Food Science and Technology - Food Science
• Principal Investigator: Marcelo Macedo Rogero
• Grantee: Patrícia Silva Jacob
• Host Institution: Faculdade de Saúde Pública (FSP). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

Obesity represents a serious problem in public health that affect both developed and in development countries. It is related to a chronic, low grade inflammation status that predisposes insulin resistance and diabetes mellitus development and, consequently, increases the risk for cardiovascular diseases. In this context, it can be verify that obesity changes the hepatic metabolism by the increase of glucose production and output and by the acute protein syntheses like protein C reative. Moreover, it can be verify that obesity-induced chronic inflammation increases the hepatic expression of kinases, such as inhibitor of ºB (IºB) kinase (IKK) and c-Jun N-terminal kinase (JNK), that contribute to the occurrence of peripheral insulin resistance, since these kinases phosphorylates the serine 307 of insulin receptor substrates (IRS-1). This fact decreases the phosphatidylinositol 3-kinase activity (PI3K) and, consequently, reduces the glucose transport. Yerba Maté (Ilex paraguariensis) contains bioactive compounds, such as cafeic acid, kaempferol, quercetin and 3,5-dicaffeoylquinic acid, which can reduce the genes expression involved in inflammatory response. The present project aims to investigate the effect of Yerba Maté aqueous extract ingestion on proteins involved in the regulation of insulin signaling in the liver of rats fed a high-fat diet. Wistar male rats will be fed a control diet (n= 24) or a high-fat diet (n= 24) during 12 weeks. After this period, 8 animals from each group will be sacrificed, while the remaining animals will be distributed to two groups: one of which will receive, by gavage, Yerba Maté aqueous extract (1 g/kg body weight) for four weeks. Then, all animals will be sacrificed and, by the liver extraction, it will be evaluate JNK, IRS-1 and IKK- ² protein expression (total and phosphorylated). Body composition of animals' carcasses will be analyzed and the blood will be used for the determination of glucose, insulin, total cholesterol, HDL-cholesterol, LDL-cholesterol, VLDL-cholesterol, triacilglicerols, leptin, adiponectin, tumor necrosis factor (TNF)- ±, interleukin (IL)-6, plasminogen activator inhibitor (PAI)-1, monocyte chemotactic protein (MCP)-1 and the enzyme activities of alanin aminotransferase (ALT) and aspartate aminotransferase (AST). Animals will be submitted to an oral glucose tolerance test (OGTT) in the first, tenth and sixteenth experimental protocol week.

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

DE MENESES FUJII, TATIANE MIEKO; JACOB, PATRICIA SILVA; YAMADA, MONICA; BORGES, MARIA CAROLINA; NORDE, MARINA MAINTINGUER; PANTALEAO, LUCAS CARMINATTI; DE OLIVEIRA, DANIELA MOURA; TIRAPEGUI, JULIO; DE CASTRO, INAR ALVES; BORELLI, PRIMAVERA; et al. Yerba Mate (Ilex paraguariensis) modulates NF-kappaB pathway and AKT expression in the liver of rats fed on a high-fat diet. INTERNATIONAL JOURNAL OF FOOD SCIENCES AND NUTRITION, v. 65, n. 8, p. 967-976, DEC 2014. (09/12790-0, 10/14164-7, 10/14609-9)

Academic Publications

(References retrieved automatically from State of São Paulo Research Institutions)

JACOB, Patrícia Silva. Effect of the high-fat diet and yerba mate aqueous extract intake (Ilex paraguariensis) on the expression of proteins involved in the inflammatory response and insulin signaling regulation in the liver of Wistar rats. 2012. Master's Dissertation - Universidade de São Paulo (USP). Faculdade de Saúde Pública (FSP/CIR) São Paulo.