Obesity-induced chronic inflammation is associated with macrophages migration to adipose tissue, which produce proinflammatory cytokines, such as tumor necrosis factor (TNF)-alpha, interleukin (IL)- 1 e IL-6, contributing to type 2 diabetes mellitus and metabolic syndrome pathogenesis. In macrophages, the modulation of gene expression of many cytokines involved in inflammatory processes is controlled by a transcription factor named nuclear factor-kappa B (NF-kappa B). Yerba Maté (Ilex paraguariensis) contains bioactive compounds, such as cafeic acid, kaempferol and quercetin, which reduce in vitro NF-kappaB activation in macrophages. This project aims to investigate the effect of Yerba Maté aqueous extract ingestion on NF-kappaB signaling pathway in peritoneal macrophages of rats fed a high-fat diet. Wistar male rats will be fed a control diet (n= 30) or a high-fat diet (n= 30) during 12 weeks. After this period, 10 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, the peritoneal macrophages will be collected, stimulated with lipopolysaccharides (LPS) and used to evaluate TNF-alpha, IL-1beta e IL-6 mRNAs expression; NF-kappaB activation; IKK-beta and IKB-alpha (total and phosphorylated) expression and in vitro synthesis of TNF-alpha, IL-1beta e IL-6. Body composition of animals' carcasses will be analyzed and the blood will be used for the determination of glucose, total cholesterol, HDL-cholesterol, LDL-cholesterol, VLDL-cholesterol, triacilglicerols, insulin, leptin, adiponectin, TNF-alpha, IL-6, monocyte chemotactic protein (MCP)-1, plasminogen activator inhibitor (PAI)-1, alanin aminotransferase (ALT) and aspartate aminotransferase (AST) concentrations.
News published in Agência FAPESP Newsletter about the scholarship: