Fish oil decreases hepatic lipogenic genes in rats fasted and refed on a high fructose diet

Nutrients. 2015 Mar 5;7(3):1644-56. doi: 10.3390/nu7031644.

Abstract

Fasting and then refeeding on a high-carbohydrate diet increases serum and hepatic triacylglycerol (TAG) concentrations compared to standard diets. Fructose is a lipogenic monosaccharide which stimulates de novo fatty acid synthesis. Omega-3 (n-3) fatty acids stimulate hepatic β-oxidation, partitioning fatty acids away from TAG synthesis. This study investigated whether dietary n-3 fatty acids from fish oil (FO) improve the hepatic lipid metabolic response seen in rats fasted and then refed on a high-fructose diet. During the post-prandial (fed) period, rats fed a FO rich diet showed an increase in hepatic peroxisome proliferator-activated receptor α (PPAR-α) gene expression and decreased expression of carbohydrate responsive element binding protein (ChREBP), fatty acid synthase (FAS) and microsomal triglyceride transfer protein (MTTP). Feeding a FO rich diet for 7 days prior to 48 h of fasting resulted in lower hepatic TAG, lower PPAR-α expression and maintenance of hepatic n-3 fatty acid content. Refeeding on a high fructose diet promoted an increase in hepatic and serum TAG and in hepatic PPAR-α, ChREBP and MTTP expression. FO did not prevent the increase in serum and hepatic TAG after fructose refeeding, but did decrease hepatic expression of lipogenic genes and increased the n-3 fatty acid content of the liver. n-3 Fatty acids can modify some components of the hepatic lipid metabolic response to later feeding with a high fructose diet.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Body Weight
  • Carrier Proteins / metabolism
  • Diet*
  • Dietary Carbohydrates / administration & dosage
  • Dietary Carbohydrates / adverse effects*
  • Fasting / physiology*
  • Fatty Acids, Omega-3 / pharmacology
  • Fatty Acids, Omega-3 / therapeutic use
  • Fish Oils / pharmacology*
  • Fish Oils / therapeutic use
  • Fructose / adverse effects*
  • Gene Expression
  • Lipogenesis / drug effects*
  • Lipogenesis / genetics
  • Liver / drug effects*
  • Liver / metabolism
  • Male
  • PPAR alpha / metabolism
  • Postprandial Period
  • Rats, Wistar
  • Triglycerides / metabolism

Substances

  • Carrier Proteins
  • Dietary Carbohydrates
  • Fatty Acids, Omega-3
  • Fish Oils
  • PPAR alpha
  • Triglycerides
  • microsomal triglyceride transfer protein
  • Fructose