Consumption of Water-Soluble Egg Yolk Extract on Growth Rate, Changes in Blood Cholesterol Levels, and Immune Modulation in BALB/c Mice

Abstract

Egg consumption has been limited to avoid cardiovascular diseases such as atherosclerosis and hyperlipidemia, because the yolk contains high levels of cholesterol. This study was conducted to evaluate the effect of the water-soluble component of egg-yolk on the growth efficiency, immune modulation, and changes in serum lipid levels in BALB/c mice. A total 5 wk old 120 BALB/c male mice were divided into 4 groups and were fed 0, 2, 10, and 20 mg/d water-soluble egg yolk extract (WSEYE) for 5 wk. Water-soluble egg yolk extract (WSEYE) uptake resulted in a significant reduction in daily weight gain and feed efficiency rate (FER). The mouse groups treated with 2 and 20 mg/d WSEYE showed a significant increase in populations of monocytes at the third wk and B-lymphocyte activity at the fifth wk. In addition, WSEYE uptake did not influence serum immunoglobulin E levels. In serum lipid-profile studies, treatment of WSEYE did not alter total cholesterol and low-density lipoprotein levels; however, blood triglyceride levels were significantly diminished in mice treated with 2 mg/d at the third wk (p<0.05), and the level of high-density lipoprotein was significantly increased in the mice group treated with 2 and 10 mg/d WSEYE after 5 wk (p<0.05). Taken together, the data demonstrate the beneficial effects of WSEYE in the diet on immune modulation and serum lipid profiles in mouse models; therefore, this study suggests that ingestion of water-soluble fraction of egg yolk might not be related to the increased risk of heart disease, but can be an excellent candidate for maintaining health.