Characterization of a novel polysaccharide from Ganoderma lucidum and its absorption mechanism in Caco-2 cells and mice model

Fungal polysaccharides are mainly taken orally, so it is very important to study the absorption mechanism of which in vivo for understanding its biological activities. In this work, a polysaccharide fraction (GLP) was purified from G. lucidum by water extraction and alcohol precipitation. Physicochemical characterization indicated that GLP had a molecular weight of 108 kDa and consisted of glucose (35.56%), xylose (40.11%), rhamnose (16.45%) and l-arabinose (7.88%) in a molar radio of 4.51: 5.09: 2.88: 1.0. GLP was taken by Caco-2 cells through the pathway of macropinocytosis and it was a well-absorbed biological macromolecule testified by Papp value. Sugar transporters (SGLT1 and GLUT2) played different roles at different absorption stages of GLP, and the absorption of GLP during digestion in mice model was a time-dependent process. All these results could contribute to explore the absorption mechanism of polysaccharides in body.