Triglyceride-lowering effect of rice protein due to the regulation of fatty acid uptake and transport of triglyceride in rats fed normal/oil-enriched diets

Dysregulation of fatty acid uptake and triglyceride transport can induce excess triglyceride accumulation. We propose that rice protein might suppress fatty acid uptake and/or triglyceride transport. To elucidate potential mechanisms, expressions of cluster determinant 36 (CD36), microsomal triglyceride transfer protein (MTP), fatty acid transport protein-2 (FATP-2), fatty acid-binding protein-1 (FABP-1), lipoprotein lipase (LPL) and Niemann-Pick C1-like 1 (NPC1L1) were investigated in growing and adult male Wistar rats fed with caseins and rice proteins under normal and oil-enriched dietary conditions. After two weeks of feeding, rice protein depressed the gene and protein expressions of CD36, MTP, FATP-2, FABP-1 and NPC1L1, whereas rice protein up-regulated those of LPL. As a result, rice protein significantly reduced the concentrations of triglyceride and fatty acid in the plasma and liver (<i>P</i> < 0.05) as well as the deposit of perirenal, epididymal and mesenteric fat (<i>P</i> < 0.05). The present study demonstrates an association between the depression of fatty acid uptake and triglyceride transport and the triglyceride-lowering effect of rice protein.