Chemical characterisation and hypolipidaemic effects of two purified Pleurotus eryngii polysaccharides

This study is focused on the isolation and characterisation of two purified polysaccharide fractions (namely PPEP-1 and PPEP-2) from Pleurotus eryngii (P.eryngii) and evaluation of their hypolipidaemic effects. The Congo red analysis indicated that PPEP-2 but not PPEP-1 possessed a triple-helix conformation. The atomic force microscope analysis revealed that PPEP-1 and PPEP-2 showed different polysaccharide chain conformations. Importantly, the mice treated with PPEP-1 showed significantly lowered serum levels of total cholesterol (TC), triglyceride (TG) and low-density lipoprotein cholesterol (LDL-c) and increased high-density lipoprotein cholesterol when compared with the hyperlipidaemia mice induced by the high-fat diet. However, PPEP-2 revealed less hypolipidaemic effect than PPEP-1. Additionally, both PPEP-1 and PPEP-2 demonstrated remarkable hypolipidaemic effects by decreasing levels of serum TC, TG and LDL-c in the hyperlipidaemic model induced by P-407. Taken together, our findings suggest that the P.eryngii polysaccharides, especially PPEP-1, could be developed as a natural functional food supplement for preventing hyperlipidaemia.