Egg phospholipids exert an inhibitory effect on intestinal cholesterol absorption in mice

ABSTRACT

BACKGROUND/OBJECTIVES: Consumption of cholesterol-rich foods, such as eggs, has a minimal effect on circulating cholesterol levels in healthy humans. To gain insight, we investigated whether phospholipids rich in eggs (EPL) interfere with intestinal cholesterol absorption in vivo. MATERIALS/METHODS: To investigate the acute effect of EPL on intestinal cholesterol absorption, male C57BL/6J mice were orally administered with 6, 11, or 19 mg of EPL for three days. We also tested the effect of chronic EPL consumption on cholesterol metabolism in the small intestine and the liver in mice with diet-induced hypercholesterolemia. Male C57BL/6J mice were fed a high fat/high cholesterol (HF/HC; 35% fat, 0.25% cholesterol, w/w) diet for 4 weeks to induce hypercholesterolemia, and subsequently the mice were either fed 0, 0.4 or 0.8% (w/w) of EPL for 6 weeks. RESULTS: Intestinal cholesterol absorption was significantly decreased by the highest dose of acute EPL administration compared to control. Chronic EPL supplementation did not significantly alter intestinal cholesterol absorption nor plasma levels of total cholesterol and low-density lipoprotein cholesterol. In the small intestine and the liver, EPL supplementation minimally altered the expression of genes which regulate cellular cholesterol levels. CONCLUSION: Although chronic EPL consumption was not able to counteract hypercholesterolemia in HF/HC-fed mice, acute EPL administration decreased intestinal cholesterol absorption. This study provides in vivo evidence that acute administration of PLs in eggs prevent cholesterol absorption in the intestine, suggesting a mechanism for a minimal effect of egg consumption on circulating cholesterol levels.