The Digestibility of Branched-chain Triacylglycerols and Their Effects on Plasma and Hepatic Lipid Levels in the Rat

抄録

The digestibility of triacylglycerols (TAGs) comprising branched-chain fatty acids (BCFAs) and the effects on plasma and hepatic lipid levels in rats were investigated by feeding male Sprague-Dawley rats diets containing 5% (w/w) experimental fats for two weeks. Safflower oil (SO), tripalmitoylglycerol (C16TAG), tri-2-methylpalmitoylglycerol (MeC16TAG), and tri-5, 9, 13-trimethylmyristoylglycerol (Me₃C14TAG) were used as experimental fats. The apparent digestibility followed the order of SO > C16TAG > Me₃C14TAG > MeC16TAG. Plasma total and free cholesterol levels were significantly lower in the MeC16TAG-fed rats, while plasma HDL-cholesterol level was lower in the Me₃C14TAG-fed rats. The plasma TAG level was also very low in the Me₃C14TAG group. However, liver lipid level was not influenced by the dietary fat type. 2-Methylpalmitic acid (MeC16) was not detected in liver lipids of the MeC16TAG group although a low level of MeC16 was present in plasma lipids. A low level of 3, 7, 11-trimethyllauric acid (Me₃C12) and high level of 5, 9, 13-trimethylmyristic acid (Me₃C14) existed in plasma and liver lipids of the Me₃C14TAG-fed rats. These results demonstrated that BCFA-containing TAGs affect the lipid metabolism in rats.