Purification, characterization and anti-atherosclerotic effects of the polysaccharides from the fruiting body of Cordyceps militaris

Hyperlipidemia is one major cause of atherosclerosis, which is a basic pathological change of cardiovascular diseases. Polysaccharide is a water-soluble component with lipid-lowering effects. In this study, alkaline-extracted polysaccharides were obtained from the fruiting body of C. militaris. Polysaccharides were purified via anion exchange and size exclusion chromatography. Their structural characteristics were investigated via chemical and spectroscopic methods. CM3I was mainly composed of →4)α-D-Glcp(1 → glycosyls and differed from starch due to the presence of →4,6)β-D-Glcp(1 → glycosyls. CM3II was characterized by its backbone, which was composed of →4)-β-D-Manp(1 → 6)-α-D-Manp(1 → 6)-β-D-Manp(1 → linked glycosyls, and especially the presence of O-methyl. Moreover, CM3II exhibited powerful anti-atherosclerotic effects via lowering plasma lipid levels in apolipoprotein E-deficient mice. The underlying mechanisms were attributed to its promoting effect on LXRα and inhibitory effect on SREBP-2. Collectively, CM3I and CM3II are different from the previously reported polysaccharides from C. militaris, and CM3II has a potential application in hypolipidemia and anti-atherosclerosis.