Modulation of lipid metabolism by oyster peptides in mice with high-fat diet-induced obesity

Oysters (Crassostrea gigas) are rich in proteins and a source of valuable peptides. Previous studies have revealed that oral administration of oyster peptides (OP) obtained by simulating gastrointestinal digestion reduced the weight of mice. However, the underlying regulatory mechanisms are unclear. We speculate that OP may be able to reduce fatty acid absorption by inhibiting pancreatic lipase activity. Therefore, we investigated the regulatory effects of OP on lipid metabolism in mice with high-fat diet-induced obesity. The body weight (BW), fat weight, lipid parameters, lipid metabolism-related gene expression, and serum lipid profiles were determined by MS-based lipidomics. Daily supplementation with 500 mg of OP/kg BW in obese mice reduced their BW gain and organ weights, improved dyslipidemia, and downregulated the genes expression of encoding proteins involved in fatty acid uptake, including acetyl coenzyme A carboxylase 1 (Acc1), fatty acid synthase (Fas), and sterol regulatory element binding protein 1c (Srebp-1c). Moreover, administration of OP resulted in significant changes in the lipid profile of mice. We screened 129 differential metabolites to identify biomarkers for OP intervention and analyzed the effects of OP on the metabolism of sphingolipids, glycerophospholipids, linoleic acid, and α-linolenic acid. In summary, OP can improve obesity-induced lipid metabolism dysfunctions by inhibiting enzyme activity and regulating fatty acid uptake.