Protective effects of fish oil on pre-diabetes: a lipidomic analysis of liver ceramides in rats

Food Funct. 2016 Sep 14;7(9):3981-3988. doi: 10.1039/c6fo00589f.

Abstract

A high intake of fat and sucrose can dramatically increase bioactive lipids such as ceramides in tissues. Ceramides regulate several steps in the insulin signal pathway. The effects of n-3 PUFA on insulin resistance are inconsistent, especially in liver. We investigated the effect of n-3 PUFA (EPA/DHA 1 : 1) from fish oil on hepatic ceramides in a pre-diabetic animal model. Three groups of rats were fed standard feed, high fat high sucrose feed (HFHS) or HFHS enriched with n-3 PUFA. We investigated by lipidomic analysis how supplementation of a HFHS diet with n-3 PUFA modifies the hepatic ceramide profile triggered by a HFHS diet. Our results show that n-3 PUFA modified the ceramide profile of the liver and reduced their total content in pre-diabetic rats. Significant linear correlations were observed between ceramides and biochemical insulin parameters. Long chain ceramide 18:1/18:0 showed a positive correlation with the HOMA index. Very long chain ceramide 18:1/24:0 showed a negative correlation with insulin and the HOMA index. Finally, very long chain ceramide 18:1/20:0 correlated negatively with glucose levels, plasmatic insulin levels and the HOMA index. In conclusion, the modulation of the ceramide profile in pre-diabetic rats may explain the protective action of n-3 PUFA against liver insulin resistance (IR) caused by an HFHS diet. We confirm the protective role of very long chain ceramide 18:1/24:0 and the harmful role of long chain ceramide 18:1/18:0 in the pre-diabetic state and propose ceramide 18:1/20:0 as a biomarker of early liver IR in rats.

MeSH terms

  • Animals
  • Biomarkers / blood
  • Biomarkers / metabolism
  • Ceramides / chemistry
  • Ceramides / metabolism*
  • Diet, Western / adverse effects
  • Dietary Supplements*
  • Fatty Acids, Omega-3 / therapeutic use*
  • Female
  • Fish Oils / therapeutic use*
  • Glycated Hemoglobin / analysis
  • Hypoglycemic Agents / therapeutic use
  • Insulin Resistance*
  • Lipid Mobilization
  • Liver / metabolism*
  • Metabolomics / methods
  • Molecular Weight
  • Prediabetic State / blood
  • Prediabetic State / etiology
  • Prediabetic State / metabolism
  • Prediabetic State / prevention & control*
  • Random Allocation
  • Rats, Inbred WKY

Substances

  • Biomarkers
  • Ceramides
  • Fatty Acids, Omega-3
  • Fish Oils
  • Glycated Hemoglobin A
  • Hypoglycemic Agents