Study On The Mechanism Of PHGS In Cistanche In The Caco-2Cell Model

Aim:In this study, the use of sensitive indicators of biological activity, and HPLC method by Caco-2monolayer model to investigate the transport mechanism of phenylethanoid glycosides (PhGs), Acteoside (AC), Isoacteoside (IS) and Echinacoside (EC). Established in vitro characteristics of traditional Chinese medicine in line with multi-component transport study new models, new ways to absorbortion.Methods:Transport studies were performed in Caco-2cell monolayers21days after seeding; To assess the integrity of a monolayer prior to experiment, the transepithelial electrical resistance (TEER) and the transport marker lucifer yellow (LY) and fexofenadine were measured; Caco-2cell monolayer model was used to research the bi-direction transport of PhGs, AC, EC and IS; PhGs were assayed by biological activity, and their transport parameters, including apparent permeability coefficients (Papp), were then calculated; AC, EC and IS were assayed by HPLC, and their transport parameters, including Papp, were then calculated; The effects of time, concentration of PhGs, AC, EC and IS were studied.Results: The Papp values of PhGs, AC, EC and IS are all less than1.0×10-6cm/s, confirming that they had poor permeability. The transport of PhGs increased linearly as a function of concentration within the test range of100-200μM, thus passive diffusion mechanism was proposed. The transport of PhGs increased linearly as a function of time up to120min and concentration within the test range of100-300μM, so passive diffusion mechanism was proposed, there was no indication of efflux because the ratios of Papp AP-BL for PhGs, AC, EC and IS which were between0.90-1.55, less than2, which is the criterion of net efflux proposed by the FDA Guidance.Conclusion:PhGs, AC, EC and IS are poor permeability, passive diffusion mechanism and no indication of efflux. Study on mechanism of absorbtion and transport by sensitive biological activity of herbal (compound) is more representative of the overall. Researchers can find the test medicine (compound) sensitive biological activity of traditional Chinese medicine (compound) to study transport mechanism.