Dietary egg yolk supplementation improves low-protein-diet-induced fatty liver in rats

Kazuo Erami, Yasutake Tanaka, Sayaka Kawamura, Motonori Miyago, Ai Sawazaki, Katsumi Imaizumi, Masao Sato

Research output: Contribution to journalArticle

Abstract

Egg yolk is an important source of nutrients and contains different bioactive substances. In the present study, we studied the benefits of egg yolk in preventing low-protein- diet-induced fatty liver in rats. Rats were fed the following diets, which were based on the AIN-76 formula, for 2 wk: an adequate-protein diet containing 20% casein (C), a lowprotein diet containing 5% casein (LP-C), a low-protein diet supplemented with 12.5% egg yolk (LP-EY), and a low-protein diet supplemented with 4.1% egg yolk oil (LP-EYO). The lowprotein diets were adjusted to contain 4.13% protein and 4.7% lipids. The LP-C diet resulted in a greater increase in the liver trigriceride (TG) and the vacuolation and a greater decrease in the serum TG and free fatty acid (FFA) than did the C diet. These deviations in the serum and liver TG, serum FFA levels and the liver histopathology were corrected in rats fed the LP-EY diet but not in those fed the LP-EYO diet. Compared to rats fed the LP-C diet, although the activities of lipogenesis-related enzymes (fatty acid synthase, glucose-6-phosphate dehydrogenase, and malic enzyme) decreased in rats fed both of the LP-EY and LP-EYO diets, the level of the microsomal TG transfer protein (MTP) increased only in rats fed the LP-EY diet. Collectively, these results suggest that dietary egg yolk supplementation decreases the LP diet-induced accumulation of TG in the liver by increasing transport of TG in the liver, and egg yolk oil alone is not sufficient enough to bring about these benefits.

Original languageEnglish
Pages (from-to)240-248
Number of pages9
JournalJournal of Nutritional Science and Vitaminology
Volume62
Issue number4
DOIs
Publication statusPublished - Jan 1 2016

Fingerprint

Protein-Restricted Diet
Egg Yolk
Fatty Liver
Diet
Liver
Caseins
Nonesterified Fatty Acids
Serum
Fatty Acid Synthases
Lipogenesis
Proteins
Glucosephosphate Dehydrogenase
Enzymes

All Science Journal Classification (ASJC) codes

  • Medicine (miscellaneous)
  • Nutrition and Dietetics

Cite this

Dietary egg yolk supplementation improves low-protein-diet-induced fatty liver in rats. / Erami, Kazuo; Tanaka, Yasutake; Kawamura, Sayaka; Miyago, Motonori; Sawazaki, Ai; Imaizumi, Katsumi; Sato, Masao.

In: Journal of Nutritional Science and Vitaminology, Vol. 62, No. 4, 01.01.2016, p. 240-248.

Research output: Contribution to journalArticle

Erami, Kazuo ; Tanaka, Yasutake ; Kawamura, Sayaka ; Miyago, Motonori ; Sawazaki, Ai ; Imaizumi, Katsumi ; Sato, Masao. / Dietary egg yolk supplementation improves low-protein-diet-induced fatty liver in rats. In: Journal of Nutritional Science and Vitaminology. 2016 ; Vol. 62, No. 4. pp. 240-248.
@article{b9f8fc7f307b4be59954caf612d00f82,
title = "Dietary egg yolk supplementation improves low-protein-diet-induced fatty liver in rats",
abstract = "Egg yolk is an important source of nutrients and contains different bioactive substances. In the present study, we studied the benefits of egg yolk in preventing low-protein- diet-induced fatty liver in rats. Rats were fed the following diets, which were based on the AIN-76 formula, for 2 wk: an adequate-protein diet containing 20{\%} casein (C), a lowprotein diet containing 5{\%} casein (LP-C), a low-protein diet supplemented with 12.5{\%} egg yolk (LP-EY), and a low-protein diet supplemented with 4.1{\%} egg yolk oil (LP-EYO). The lowprotein diets were adjusted to contain 4.13{\%} protein and 4.7{\%} lipids. The LP-C diet resulted in a greater increase in the liver trigriceride (TG) and the vacuolation and a greater decrease in the serum TG and free fatty acid (FFA) than did the C diet. These deviations in the serum and liver TG, serum FFA levels and the liver histopathology were corrected in rats fed the LP-EY diet but not in those fed the LP-EYO diet. Compared to rats fed the LP-C diet, although the activities of lipogenesis-related enzymes (fatty acid synthase, glucose-6-phosphate dehydrogenase, and malic enzyme) decreased in rats fed both of the LP-EY and LP-EYO diets, the level of the microsomal TG transfer protein (MTP) increased only in rats fed the LP-EY diet. Collectively, these results suggest that dietary egg yolk supplementation decreases the LP diet-induced accumulation of TG in the liver by increasing transport of TG in the liver, and egg yolk oil alone is not sufficient enough to bring about these benefits.",
author = "Kazuo Erami and Yasutake Tanaka and Sayaka Kawamura and Motonori Miyago and Ai Sawazaki and Katsumi Imaizumi and Masao Sato",
year = "2016",
month = "1",
day = "1",
doi = "10.3177/jnsv.62.240",
language = "English",
volume = "62",
pages = "240--248",
journal = "Journal of Nutritional Science and Vitaminology",
issn = "0301-4800",
publisher = "Center for Academic Publications Japan",
number = "4",

}

TY - JOUR

T1 - Dietary egg yolk supplementation improves low-protein-diet-induced fatty liver in rats

AU - Erami, Kazuo

AU - Tanaka, Yasutake

AU - Kawamura, Sayaka

AU - Miyago, Motonori

AU - Sawazaki, Ai

AU - Imaizumi, Katsumi

AU - Sato, Masao

PY - 2016/1/1

Y1 - 2016/1/1

N2 - Egg yolk is an important source of nutrients and contains different bioactive substances. In the present study, we studied the benefits of egg yolk in preventing low-protein- diet-induced fatty liver in rats. Rats were fed the following diets, which were based on the AIN-76 formula, for 2 wk: an adequate-protein diet containing 20% casein (C), a lowprotein diet containing 5% casein (LP-C), a low-protein diet supplemented with 12.5% egg yolk (LP-EY), and a low-protein diet supplemented with 4.1% egg yolk oil (LP-EYO). The lowprotein diets were adjusted to contain 4.13% protein and 4.7% lipids. The LP-C diet resulted in a greater increase in the liver trigriceride (TG) and the vacuolation and a greater decrease in the serum TG and free fatty acid (FFA) than did the C diet. These deviations in the serum and liver TG, serum FFA levels and the liver histopathology were corrected in rats fed the LP-EY diet but not in those fed the LP-EYO diet. Compared to rats fed the LP-C diet, although the activities of lipogenesis-related enzymes (fatty acid synthase, glucose-6-phosphate dehydrogenase, and malic enzyme) decreased in rats fed both of the LP-EY and LP-EYO diets, the level of the microsomal TG transfer protein (MTP) increased only in rats fed the LP-EY diet. Collectively, these results suggest that dietary egg yolk supplementation decreases the LP diet-induced accumulation of TG in the liver by increasing transport of TG in the liver, and egg yolk oil alone is not sufficient enough to bring about these benefits.

AB - Egg yolk is an important source of nutrients and contains different bioactive substances. In the present study, we studied the benefits of egg yolk in preventing low-protein- diet-induced fatty liver in rats. Rats were fed the following diets, which were based on the AIN-76 formula, for 2 wk: an adequate-protein diet containing 20% casein (C), a lowprotein diet containing 5% casein (LP-C), a low-protein diet supplemented with 12.5% egg yolk (LP-EY), and a low-protein diet supplemented with 4.1% egg yolk oil (LP-EYO). The lowprotein diets were adjusted to contain 4.13% protein and 4.7% lipids. The LP-C diet resulted in a greater increase in the liver trigriceride (TG) and the vacuolation and a greater decrease in the serum TG and free fatty acid (FFA) than did the C diet. These deviations in the serum and liver TG, serum FFA levels and the liver histopathology were corrected in rats fed the LP-EY diet but not in those fed the LP-EYO diet. Compared to rats fed the LP-C diet, although the activities of lipogenesis-related enzymes (fatty acid synthase, glucose-6-phosphate dehydrogenase, and malic enzyme) decreased in rats fed both of the LP-EY and LP-EYO diets, the level of the microsomal TG transfer protein (MTP) increased only in rats fed the LP-EY diet. Collectively, these results suggest that dietary egg yolk supplementation decreases the LP diet-induced accumulation of TG in the liver by increasing transport of TG in the liver, and egg yolk oil alone is not sufficient enough to bring about these benefits.

UR - http://www.scopus.com/inward/record.url?scp=84991271378&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84991271378&partnerID=8YFLogxK

U2 - 10.3177/jnsv.62.240

DO - 10.3177/jnsv.62.240

M3 - Article

C2 - 27725409

AN - SCOPUS:84991271378

VL - 62

SP - 240

EP - 248

JO - Journal of Nutritional Science and Vitaminology

JF - Journal of Nutritional Science and Vitaminology

SN - 0301-4800

IS - 4

ER -