Dietary choline supplementation attenuated high-fat diet-inducedinflammation through regulation of lipid metabolism and suppression ofNFκB activation in juvenile black seabream (Acanthopagrus schlegelii)

Abstract

The present study aimed to investigate whether dietary choline can regulate lipid metabolism and suppress NFκB activation and, consequently, attenuateinflammation induced by a high-fat diet in black sea bream (Acanthopagrus schlegelii). An 8-week feeding trial was conducted onfish with an initial weight of8·16 ± 0·01 g. Five diets were formulated: control, low-fat diet (11 %); HFD, high-fat diet (17 %); and HFD supplemented with graded levels of choline (3,6 or 12 g/kg) termed HFD + C1, HFD + C2 and HFD + C3, respectively. Dietary choline decreased lipid content in whole body and tissues. Highest TAGand cholesterol concentrations in serum and liver were recorded infish fed the HFD. Similarly, compared withfish fed the HFD, dietary choline reducedvacuolar fat drops and ameliorated HFD-induced pathological changes in liver. Expression of genes of lipolysis pathways were up-regulated, and genes oflipogenesis down-regulated, by dietary choline compared withfish fed the HFD. Expression ofnfκband pro-inflammatory cytokines in liver and intestinewas suppressed by choline supplementation, whereas expression of anti-inflammatory cytokines was promoted infish fed choline-supplemented diets. Infish that received lipopolysaccharide to stimulate inflammatory responses, the expression ofnfκband pro-inflammatory cytokines in liver, intestine andkidney were all down-regulated by dietary choline compared with the HFD. Overall, the present study indicated that dietary choline had a lipid-loweringeffect, which could protect the liver by regulating intrahepatic lipid metabolism, reducing lipid droplet accumulation and suppressing NFκB activation,consequently attenuating HFD-induced inflammation inA. schlegelii.