Structural characterization and hypolipidemic activity of a hetero-galactan purified from Sanghuangporus vaninii based on modulation of TLR4/NF-κB pathway.

Sanghuangporus vaninii showed great activities of anti-inflammation and anti-tumor, due to its bioactive macromolecules. However, the hypolipidemic properties of polysaccharides isolated from S. vaninii have not been systematically reported. In this research, a polysaccharide of S. vaninii was obtained and its hypolipidemic activity was investigated. SVP3, a neutral hetero-galactan from S. vaninii, has a →6)-α-Galp-(1→ backbone with partial H-2 branches of α-Manp-(1→ or α-Manp-(1→2)-α-Fucp-(1→. In a hyperlipidemia mouse model, SVP3 significantly inhibited body weight gain and suppressed serum levels of total cholesterol, triglycerides, and low-density lipoprotein cholesterol. SVP3 inhibited the expansion of adipocytes in three types of white adipose tissues and attenuated hepatic injury and hepatic lipid deposition in the mice. The combined analysis of gut microbiota, serum metabolomics, and liver proteomics revealed that SVP3 effectively regulated the abundance of specific gut microbiota and serum metabolites and mediated the inhibitory effect on inflammation-associated toll-like receptor 4/nuclear factor kappa-B pathway by regulating the expression levels of glutathione S-transferase P1, stromal cell derived factor 2-like 1, ribosomal protein L10, thiosulfate sulfurtransferase, and biliverdin reductase A in liver, ultimately realizing the hypolipidemic activity. The results of the present study provide experimental evidence for the development of clinical adjuvant therapeutic drugs to treat hyperlipidemia.