Purification and identification of lipid-lowering peptides from Tartary buckwheat protein and study on the mechanism of lipid-lowering activity.

Highly active lipid-lowering peptides were isolated from Tartary buckwheat through enzymatic hydrolysis, ultrafiltration, and reversed-phase high-performance liquid chromatography (RP-HPLC). Liquid chromatography-tandem mass spectrometry (LC-MS/MS) and molecular docking techniques were employed to identify and screen lipid-lowering peptide monomers. The lipid-lowering effects and underlying mechanisms were evaluated through molecular docking visualization, in vitro chemical assays, the 3 T3-L1 cell model, and the Caenorhabditis elegans(C. elegans) model. Five novel peptides were identified: FHWDYPQA, FHWDYPQALE, LFHWDYPQA, LPSYSNAPYI, and NAIIGPRW. These peptides bind to receptor proteins 1LPB and 1F6W via hydrogen bonds, hydrophobic interactions, and electrostatic interactions. These peptides significantly inhibited pancreatic lipase activity, effectively reduced lipid accumulation in 3 T3-L1 cells, and lowered triglycerides (TG), total cholesterol (TC), and low-density lipoprotein cholesterol (LDL-C) levels. In addition, LI-10, FE-10, and LA-9 significantly elevated high-density lipoprotein cholesterol (HDLC) levels. Additionally, five peptides effectively reduced lipid accumulation in high-fat-fed C. elegans, decreased TG, glucose (GLU), and malondialdehyde (MDA) levels. Overall, these findings elucidate the lipid-lowering mechanisms of five novel peptides identified from Tartary buckwheat protein hydrolysates, providing a scientific foundation for the future development of Tartary buckwheat protein-derived functional products targeting hyperlipidemia.