Fish oil decreases hepatic lipogenic genes in rats fasted and refed on a high fructose diet.
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.
Department of Internal Medicine, Faculty of Medicine of Ribeirão Preto, University of São Paulo, Av. Bandeirantes 3900, Ribeirão Preto, SP, 14049-900, Brazil. gabriela.castro@usp.br.|Human Development and Health Academic Unit, Faculty of Medicine, University of Southampton, Tremona Road, Southampton, SO16 6YD, UK. gabriela.castro@usp.br.
Gabriela S
GS
de Castro
Department of Pathology Faculty of Medicine of Ribeirão Preto, University of São Paulo, Av. Bandeirantes 3900, Ribeirão Preto, SP, 14049-900, Brazil. jfcardoso@usp.br.
João Felipe R
JF
Cardoso
Human Development and Health Academic Unit, Faculty of Medicine, University of Southampton, Tremona Road, Southampton, SO16 6YD, UK. pcc@soton.ac.uk.
Philip C
PC
Calder
Department of Internal Medicine, Faculty of Medicine of Ribeirão Preto, University of São Paulo, Av. Bandeirantes 3900, Ribeirão Preto, SP, 14049-900, Brazil. alceu@fmrp.usp.br.
Alceu A
AA
Jordão
Department of Internal Medicine, Faculty of Medicine of Ribeirão Preto, University of São Paulo, Av. Bandeirantes 3900, Ribeirão Preto, SP, 14049-900, Brazil. hvannucc@fmrp.usp.br.
Helio
H
Vannucchi
D000818:Animals; D001835:Body Weight; D002352:Carrier Proteins / Q000378:metabolism; D004032:Diet; D004040:Dietary Carbohydrates / Q000008:administration & dosage / Q000009:adverse effects*; D005215:Fasting / Q000502:physiology*; D015525:Fatty Acids, Omega-3 / Q000494:pharmacology / Q000627:therapeutic use; D005395:Fish Oils / Q000494:pharmacology* / Q000627:therapeutic use; D005632:Fructose / Q000009:adverse effects*; D015870:Gene Expression; D050155:Lipogenesis / Q000187:drug effects* / Q000235:genetics; D008099:Liver / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D047493:PPAR alpha / Q000378:metabolism; D019518:Postprandial Period; D017208:Rats, Wistar; D014280:Triglycerides / Q000378:metabolism
D002352:Carrier Proteins; D004040:Dietary Carbohydrates; D015525:Fatty Acids, Omega-3; D005395:Fish Oils; D047493:PPAR alpha; D014280:Triglycerides; C106092:microsomal triglyceride transfer protein; D005632:Fructose