Abstract: Objective: To discuss the effect of Sparassis crispa polysaccharides on blood lipids in hyperlipidemic rats from a metabolomics perspective and to investigate the change of serum metabolites. Methods: The effect of intragastric administration of Sparassis crispa polysaccharides at different doses for eight weeks on serum lipids in hyperlipidemic rats was evaluated. Serum metabolites were detected by gas chromatography-mass spectrometry (GC-MS), and the differential metabolites in serum samples from different animal groups were screened out. The metabolic pathways in which these differential metabolites may be involved were analyzed, and the most influential pathway was verified. Results: Compared with the normal control (NC) group, the levels of serum total cholesterol (TC), low density lipoprotein cholesterol (LDL-C) and total bile acid (TBA) were increased significantly in the high-fat, high-cholesterol model (HFCM) group (P < 0.05), while high density lipoprotein cholesterol (HDL-C) was significantly reduced (P < 0.05). Compared with the HFCM group, serum TC in the high-dose polysaccharide (HFC + HD) group were significantly decreased (P < 0.05), and 14 metabolites such as isoleucine, tyrosine, glycine, threonine, serine, alanine, glucose, glycerol, butanedioic acid, cholesterol and hexadecanoic acid were significantly changes (P < 0.05). Eight metabolic pathways such as glutamic acid and glutamine metabolism, the synthesis of valine, leucine and isoleucine, the synthesis of phenylalanine, tyrosine and tryptophan, and glycerol phospholipid metabolism were related to the lipid lowering activity of Sparassis crispa polysaccharides. Among them, glutamic acid and glutamine metabolism had the greatest influence. Compared with the NC group, serum glutamic acid level in the HFCM group decreased significantly (P < 0.05). Compared with the HFCM group, serum glutamic acid in the low-dose polysaccharide group was significantly increased (P < 0.05), and both glutamic acid and glutamine level in the middle- and high-dose polysaccharide groups were significantly increased (P < 0.05). Conclusion: Sparassis crispa polysaccharides can improve dyslipidemia in hyperlipidemia rats, and its mechanism may be related to amino acid and lipid metabolism, especially glutamic acid and glutamine metabolism.

Key words: Sparassis crispa polysaccharides; dyslipidemia; serum metabonomics; gas chromatography-mass spectrometry