Comparative analysis of effects of dietary arachidonic acid and EPA on growth, tissue fatty acid composition, antioxidant response and lipid metabolism in juvenile grass carp, Ctenopharyngodon idellus

Br J Nutr. 2017 Sep;118(6):411-422. doi: 10.1017/S000711451700215X.

Abstract

Four isonitrogenous and isoenergetic purified diets containing free arachidonic acid (ARA) or EPA (control group), 0·30 % ARA, 0·30 % EPA and 0·30 % ARA+EPA (equivalent) were designed to feed juvenile grass carp (10·21 (sd 0·10) g) for 10 weeks. Only the EPA group presented better growth performance compared with the control group (P<0·05). Dietary ARA and EPA were incorporated into polar lipids more than non-polar lipids in hepatopancreas but not intraperitoneal fat (IPF) tissue. Fish fed ARA and EPA showed an increase of serum superoxide dismutase and catalase activities, and decrease of glutathione peroxidase activity and malondialdehyde contents (P<0·05). The hepatopancreatic TAG levels decreased both in ARA and EPA groups (P<0·05), accompanied by the decrease of lipoprotein lipase (LPL) activity in the ARA group (P<0·05). Fatty acid synthase (FAS), diacylglycerol O-acyltransferase and apoE gene expression in the hepatopancreas decreased in fish fed ARA and EPA, but only the ARA group exhibited increased mRNA level of adipose TAG lipase (ATGL) (P<0·05). Decreased IPF index and adipocyte sizes were found in the ARA group (P<0·05). Meanwhile, the ARA group showed decreased expression levels of adipogenic genes CCAAT enhancer-binding protein α, LPL and FAS, and increased levels of the lipid catabolic genes PPAR α, ATGL, hormone-sensitive lipase and carnitine palmitoyltransferase 1 (CPT-1) in IPF, whereas the EPA group only increased PPAR α and CPT-1 mRNA expression and showed less levels than the ARA group. Overall, dietary EPA is beneficial to the growth performance, whereas ARA is more potent in inducing lipolysis and inhibiting adipogenesis, especially in IPF. Meanwhile, dietary ARA and EPA showed the similar preference in esterification and the improvement in antioxidant response.

Keywords: Ctenopharyngodon idellus; ARA arachidonic acid; ATGL adipose TAG lipase; CAT catalase; COX cyclo-oxygenase; FAS fatty acid synthase; GSH-Px glutathione peroxidase; IPF intraperitoneal fat; LC-PUFA long-chain PUFA; LPL lipoprotein lipase; MDA malondialdehyde; NPL non-polar lipids; PL polar lipids; SOD superoxide dismutase; Antioxidant status; Lipid metabolism; Long-chain PUFA; Principle component analysis.

Publication types

  • Comparative Study

MeSH terms

  • Adipocytes / drug effects
  • Adipocytes / metabolism
  • Adipogenesis / drug effects
  • Adipogenesis / genetics
  • Animal Feed / analysis
  • Animals
  • Antioxidants / metabolism*
  • Arachidonic Acid / administration & dosage*
  • Body Composition*
  • CCAAT-Enhancer-Binding Protein-alpha / genetics
  • CCAAT-Enhancer-Binding Protein-alpha / metabolism
  • Carnitine O-Palmitoyltransferase / genetics
  • Carnitine O-Palmitoyltransferase / metabolism
  • Carps / physiology*
  • Diet / veterinary
  • Eicosapentaenoic Acid / administration & dosage*
  • Glutathione Peroxidase / blood
  • Hepatopancreas / drug effects
  • Hepatopancreas / metabolism
  • Lipid Metabolism*
  • Lipoprotein Lipase / blood
  • Malondialdehyde / blood
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • Superoxide Dismutase / blood

Substances

  • Antioxidants
  • CCAAT-Enhancer-Binding Protein-alpha
  • RNA, Messenger
  • Arachidonic Acid
  • Malondialdehyde
  • Eicosapentaenoic Acid
  • Glutathione Peroxidase
  • Superoxide Dismutase
  • Carnitine O-Palmitoyltransferase
  • Lipoprotein Lipase