Cocoa-rich diet improves hepatic lipid metabolism in Zucker diabetic fatty rats

Abstract

[Background and objectives]: Diabetes is associated with altered lipid metabolism that could lead to ectopic-hepatic lipid deposition. Cocoa has been suggested to exert different biological activities contributing to prevent alterations of lipid metabolism as occurs in type 2 diabetes. The aim of the present study is to analyze the role of a cocoa-enriched diet in improving lipid metabolism in the liver of type 2 diabetic Zucker diabetic fatty (ZDF) rats. [Methodology] Male ZDF rats were fed a control or cocoa-rich diet (10%), and Zucker lean (ZL) animals received the control diet. Serum and hepatic lipid levels, protein kinase B (AKT), 51-AMP-activated protein kinase (AMPK), protein kinase Cζ (PKCζ), fatty acid synthase (FAS), sterol regulatory element-binding protein 1 (SREBP-1) and proliferator-activated receptor ζ (PPARζ) expression were evaluated. [Results] ZDF rats fed with cocoa decreased body weight gain and improved circulating and hepatic lipid levels, namely triglycerides, cholesterol and non-esterified fatty acids. The lipid-lowering effect was related to the diminished synthesis mediated by SREBP1-c and FAS and the increased fatty acid oxidation (values of PPARζ). All these effects depend on AMPK, AKT and PKCζ, whose levels of phosphorylation were returned to control values upon cocoa administration in ZDF rats. [Conclusion] Cocoa improves lipid metabolism in ZDF rats through the modulation of multiple signalling pathways.