Abstract:Dendrobium aphyllum polysaccharides (DAP) was used as the study object, and the monolayer cell model of the human intestinal epithelial (Caco-2) cells (the human colon carcinoma cell line) was used to simulate in vitro the transport/translocation of DAP in the small intestine. Based on the DAP obtained at the early stage, the influence of the viscosity of DAP on its transport was investigated, and the Caco-2 cell model was established at the same time. The effect of DAP on the survival rate of Caco-2 cells was determined by the MTT method, and the absorption and transport of DAP in the small intestine were investigated. The results showed that the viscosity of DAP was negatively correlated with its transport capacity in the Caco-2 cells. The higher the viscosity, the lower the transport rate was. The TEER value and the permeation of sodium luciferin were measured, while the morphology of the Caco-2 cells was observed. The obtained results indicated that a suitable cell model was established. In the presence of DAP, the survival rate of the Caco-2 cells was greater than 91.8%, thus, DAP had no effect on the survival of the Caco-2 cells. The transfer rates of DAP in different Caco-2 monolayers were 0.35%±0.02% and 0.32%±0.02% respectively, with the apparent permeability being (0.42±0.02)×10-6 cm/s and (0.19±0.18)×10-6 cm/s, indicating that DAP was not easily absorbed in the small intestine. The findings obtained in this study lay a foundation for further study on the absorption mechanism of DAP in the intestinal tract.
