Lipid-lowering activity and mechanism of peptides from jellyfish Nemopilema nomurai

Jellyfish peptides are of significant interest, due to their potential application as a source of bioactive peptides in pharmaceutical domains. Here, we investigated the action of Nemopilema nomurai peptides (NNPs) on lipids reduction in 3 T3-L1 adipocytes. We demonstrated for the first time that NNPs prepared by papain enzymolysis were able to reduce lipid accumulation in 3 T3-L1cells. Differentially expressed metabolites among control group, MDI group, GW9662 treatment group, and NNPs treatment group were identified using non-targeted liquid chromatography-mass spectrometry (LC-MS)-based metabolomics. A total of 105 differentially expressed metabolites were identified between MDI group and NNPs treatment group. These metabolites were predominantly enriched in amino acid, carbohydrate and lipid metabolism. Metabolomics analysis indicated that NNPs leads to imbalance of lipid, which represent as down-regulated glycerolipid and glycerophospholipid, upregulated sphingolipid metabolism and sphingolipid signaling pathway. Additionally, ATP level was significantly decreased in TCA cycle and oxidative phosphorylation pathway, which correlated with glucagon signaling pathway and fatty acid synthesis. The lipid-lowering activity of NNPs may associate with lipid and energy-related metabolism in 3 T3-T1 cell. ATP may be a potential biomarker for lipid-lowering, with a fold change of 0.534.