The regulatory effects of fish oil and chitosan on hepatic lipogenic signals in high-fat diet-induced obese rats

•There were synergistic effects of fish oil and chitosan on body weights and food utilization in high fat-diet-fed rats.•Supplementation of chitosan/fish oil alone or combination performed amelioration in abnormal lipid accumulation in liver.•Fish oil displayed synergistic and additive effects to chitosan in the downregulation of hepatic lipid metabolism.•Chitosan/fish oil downregulated hepatic lipid metabolism via LXRα inhibition/PPARα promotion-mediated lipogenesis inhibition.

The present study investigated the regulatory effects of fish oil and chitosan on the signals of hepatic lipid metabolism and the postulated mechanism in high-fat diet-induced obese rats. Diet supplementation of chitosan and fish oil efficiently suppressed the increased weights in body and livers of high-fat diet-fed rats. Supplementation of chitosan and fish oil significantly decreased the activities of hepatic lipid biosynthesis-related enzymes and efficiently regulated plasma lipoprotein homeostasis. Both chitosan and fish oil significantly ameliorated the alterations in the protein expressions of hepatic lipogenic transcription factors (LXRα and PPARα), and could also significantly regulate the downstream hepatic lipogenic genes (FAS, HMGCR, CYP7A1, FATP, FABP, AOX, and ABCA) expressions in high-fat diet-fed rats. These results suggest that both fish oil and chitosan exerts downregulative effects on hepatic lipid metabolism in high-fat diet-induced obese rats via the LXRα inhibition and PPARα activation, which further affect the expressions of hepatic lipogenesis-associated genes.

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