TITLE:
Chronic Supplementation with L-Isoleucine Alone or in Combination with Exercise Reduces Hepatic Cholesterol Levels with No Effect on Serum Glucose, Insulin, or Lipids in Rats Fed a High Fructose Diet
AUTHORS:
Michael Dellogono, Lyra Clark, Cynthia Ferrara, Mahdi Garelnabi, Thomas A. Wilson
KEYWORDS:
Isoleucine, Branched-Chain Amino Acids, Glucose Tolerance, Insulin, Cholesterol, Lipids
JOURNAL NAME:
Food and Nutrition Sciences,
Vol.14 No.5,
May
31,
2023
ABSTRACT: The thought of using branched-chain amino acids
(BCAA) in the prevention and treatment of
certain disorders is becoming increasingly popular. Individual BCAA use
has been associated with improving glucose tolerance and liver disease.
Previous studies have cited improvements in glucose metabolism with a single dose of L-isoleucine (ILE).
However, it is still unclear whether chronic consumption of ILE has any
direct benefit. The objective of this study was
to examine the influence of chronic ILE supplementation alone or in combination
with exercise on fasting serum glucose, insulin, lipids, and lipoprotein
cholesterol levels; glucose tolerance; and hepatic lipids in rats. Male
Sprague-Dawley rats (n = 40) were divided into Control (low fructose diet);
High Fructose diet (HF); HF plus 1.5% ILE (HF + ILE); HF plus exercise (HF +
EX); and HF plus 1.5% ILE and exercise (HF + ILE + EX). The HF diets consisted
of 70% kcalories from fructose. After 6 weeks of treatment, no significant
differences were observed between groups for changes in fasting serum glucose,
insulin, lipids, or lipoprotein cholesterol levels. However, hepatic total
cholesterol was significantly lower in the HF + ILE + EX compared to the
Control and HF, while, the HF + ILE had significantly lower hepatic free
cholesterol compared to the HF. We also found no differences between groups for
serum glucose response following an oral glucose tolerance test. In conclusion,
our study shows that ILE supplementation in rats does not influence serum
glucose and lipid biomarkers but may have an influence on lipid metabolic
pathways within the liver.