Flaxseed‐derived peptides ameliorate hepatic cholesterol metabolism in <scp>Sprague–Dawley</scp> rats fed a high‐cholesterol and high‐fat diet
Xingyu Yuan, Xiaolan Bao, Xiaojing Liu, Xuexin Li
Abstract
Abstract BACKGROUND Plant peptides have been reported to have cholesterol‐lowering activities. Previous research has found that ≤1 kDa flaxseed peptide (FP 5 ) reduces cholesterol absorption and synthesis in vitro . In this research, we investigated the cholesterol‐lowering activity of FP 5 in Sprague–Dawley (SD) rats fed a high‐cholesterol and high‐fat diet. In addition, amino acid sequences of FP 5 were determined by high‐performance liquid chromatography–electrospray ionization–Orbitrap mass spectrometry. RESULTS FP 5 supplement significantly decreased the serum and hepatic cholesterol levels and modulated the hepatic gene and protein expression of cholesterol metabolism‐related enzymes or regulators (3‐hydroxy‐3‐methylglutaryl coenzyme A reductase, Low‐Density Lipoprotein Receptor (LDLR), Cholesterol 7 α‐hydroxylase, Niemann–Pick C1‐like 1, ATP‐binding cassette transporters G5 and G8). Eleven peptides were identified from FP 5 . These peptides were characterized as hydrophobic amino acids such as leucine (L), proline (P), glycine (G), isoleucine (I) and continuous sequences, including LP, LL, LG and II, with low molecular weights. CONCLUSION FP 5 has a certain cholesterol‐lowering activity in SD rats fed a high‐cholesterol and high‐fat diet . The possible mechanism for ameliorating hepatic cholesterol metabolism of FP 5 includes inhibiting hepatic cholesterol de novo synthesis, promoting the synthesis and excretion of bile acids, and inhibiting the reabsorption of bile acids during enterohepatic circulation. © 2022 Society of Chemical Industry.