Structural characterisation and cholesterol efflux improving capacity of the novel polysaccharides from Cordyceps militaris

Water extracts of the edible mushroom Cordyceps militaris possess a lipid-lowering effect. However, the types of components and how they exert this effect are not clear. In this study, two novel polysaccharides, CM1 and CMS, were isolated, and their cholesterol efflux improving capacity was investigated in vitro. The molecular weight of CM1 was approximately 700 kDa, and its main chain was consisted of (1 → 4)-β-D-Glcp and (1 → 2)-α-D-manp branched at the O-6 positions of (1 → 2,6)-α-D-manp with (1 → 2) linked-β-D-galf, (1 → 2)-α-D-manp or methyl and terminated with β-D-Galf and α-D-Manp. The molecular weight of CMS was approximately 18.2 kDa, and it was a novel (1 → 6)-β-D-Glcp linked glucan. Both CM1 and CMS significantly increased [3H]-cholesterol efflux by activating the protein expression of ATP-binding cassette (ABC) G1. However, they showed no significant influence on the proteins expression of ABCA1 and scavenger receptor B type 1. Therefore, CM1 and CMS are effective water-soluble components with potential lipid-lowering activity. They may be exploited as potential candidates for dyslipidaemia-related diseases such as atherosclerosis.