Effects of dietary fish oil replacement by linseed oil on plasma biochemical parameters and hepatic glucose and lipid metabolism in Larimichthys crocea

LI Na; WU Jiashun; WEI Zehong; LIU Ningning; ZHANG Zhinan; YAN Binlun; GAO Huan; MU Hua

doi:10.13557/j.cnki.issn1002-2813.2025.21.015

Abstract：This experiment aimed to investigate the effects of replacing dietary fish oil with linseed oil on plasma biochemical parameters and hepatic glucose and lipid metabolism in Larimichthys crocea.A total of 360 healthy Larimichthys crocea with an initial body weight of(3.89±0.01)g were randomly divided into two groups,with three replicates per group and 60 fish per replicate.The control group(group FO)was fed a basal diet containing 6％fish oil,while the experimental group(group LO)received an isonitrogenous and isolipidic diet with linseed oil completely replacing fish oil.The pre-test period was two weeks,and the formal test period was 10 weeks.The results showed that compared with the FO group,the concentrations of crude fat(EE)and triglycerides(TG)in the liver of the LO group were significantly increased,while the glycogen content was significantly decreased(P＜0.05).Hepatic linoleic acid andα-linolenic acid concentrations in group LO were significantly increased(P＜0.05),while arachidonic acid,eicosapentaenoic acid(EPA),and docosahexaenoic acid(DHA)content were significantly reduced(P＜0.05).Plasma glucose(GLU)and TG concentrations,as well as alanine aminotransferase(ALT)and aspartate aminotransferase(AST)activities in group LO were significantly increased(P＜0.05).Histopathological examination revealed hepatic steatosis,severe vacuolization,reduced and displaced nuclei,and substantial lipid droplet accumulation in group LO.The relative expression levels of adenosine activated protein kinase α1(AMPKα1),glucose transporter 2(GLUT2),glycogen synthase(GYS),glucokinase(GK),adipose triglyceride lipase(ATGL),peroxisome proliferator-activated receptor α(PPARα),and carnitine palmitoyltransferase 1(CPT1)in group LO were significantly down-regulated(P＜0.05).The relative expression levels of phosphoenolpyruvate carboxykinase(PEPCK),fructose-1,6-bisphosphatase(FBP),glycogen phosphorylase(PYG),cluster of differentiation 36(CD36),fatty acid transport protein 1(FATP1),and sterol regulatory element-binding protein 1(SREBP1)were significantly up-regulated(P＜0.05).The study indicates complete replacement of fish oil with linseed oil can affect the expression of hepatic AMPKα1 and related glucose and lipid metabolism genes of Larimichthys crocea,elevate blood glucose levels,induce hepatic lipid deposition and tissue damage.