The Hypolipidemic Effect of Curcumin Involves Up-regulation of CD36 Expression in Response to Higher Tissue Levels of cAMP

Curcumin (CUR), a polyphenol from turmeric (Curcuma longa), was shown to reduce inflammation, atherosclerosis and obesity in several animal studies. In Ldlr-/- mice fed a high fat diet (HFD), CUR reduced plasma lipid levels therefore contributing to a lower accumulation of lipids in peritoneal macrophages and to reduced expression of fatty acid transport proteins (CD36/FAT, FABP4/aP2). In the present study we analyzed the molecular mechanisms by which CUR (500, 1000, 1500 mg/kg diet, for 4 months) influences plasma and tissue lipid levels in Ldlr-/- mice fed a HFD. In liver, HFD increased expression of the CD36/FAT scavenger receptor/fatty acids transporter mRNA and protein levels, and slightly increased the uncoupling proteins 1 and 2 (UCP1/2) and fatty acid binding protein (FABP4/aP2). CUR further increased expression of CD36 and UCP2 mRNAs and protein, but reduced expression of UCP1 and FABP4/aP2. HFD also diminished cAMP levels in liver, adipose tissue, spleen, kidney, skeletal muscle and brain; this ...