The effect of milk polar lipids separated from butter serum on the lipid levels in the liver and the plasma of obese-model mouse (KK-Ay)

The effect of lipid concentrated-butter serum (LC-BS) on the plasma and hepatic cholesterol and triacylglycerol levels of obese-model mouse (KK-Ay) was evaluated. The same analysis was done on the main lipid fractions from LC-BS, namely, ceramide rich fraction (Ceramide-fr), phosphatidylethanolamine (PE) rich fraction (PE-fr), and sphingomyelin (SPM) rich fraction (SPM-fr). Plasma cholesterol of mice fed LC-BS and Ceramide-fr was significantly (P < 0.05) lower than that of the control. Hepatic total cholesterol and triacylglycerol levels was also reduced significantly by Ceramide-fr feeding (P < 0.05). Although there was no significant difference in the fatty acid composition of all dietary lipids, significant decrease (P < 0.05) in content of 18:1n-9 was found in the liver lipids of the mice fed Ceramide-fr containing diet. The level of 16:1n-7 and 18:1n-7 was also reduced by Ceramide-fr feeding. This result suggests the down-regulation of stearoyl-CoA desaturase-1 (SCD1) by milk ceramides, which would be related to the decrease in triacylglycerol and cholesterol levels in the liver and in the plasma.

► We evaluated the effect of lipid concentrated-butter serum (LC-BS) on the plasma and hepatic lipid levels of mouse.
► The same analysis was done on the main lipid fractions from LC-BS.
► We found the reducing effect of LC-BS on plasma and hepatic lipid levels. Milk ceramide was an active component of LC-BS.
► We showed the down-regulation effect of SCD1 by milk ceramides.
► This may be one of the major molecular mechanisms for the explanation of its effect on lipid metabolism.