Transport mechanism and subcellular localization of polysaccharides from Cucurbia Moschata across Caco-2 cells model.

Abstract Pumpkin polysaccharides with various bioactivities are mainly taken orally, thus detailed knowledge of the intestinal transport of which are essential for understanding its bioactivities. The Caco-2 cells monolayer model (mimic intestinal epithelium) was successfully constructed and Cucurbia moschata polysaccharides (PPc F) were successfully conjugated with fluorescein isothiocyanate (FITC) to evaluate the transcellular transport mechanism and subcellular localization of PPc. The transport process of PPc-F was energy-dependent, and a moderately-absorbed biological macromolecule according to the apparent permeability coefficients (Papp) value. The endocytosis process of PPc-F in Caco-2 cells included the clathrin- and caveolae (or lipid draft)-medicated routes. And the translocation process was related to endoplasmic reticulum (ER), golgi apparatus (GA), tubulin and the acidification of endosomes. As for the intracellular location of PPc F, it was mainly accumulated in ER. The study provided an understanding of the transmembrane transport of PPc F, and could help studying the mechanisms of its effects.