Abstract:

The Caco-2 cell model, an intestinal endothelial model for transport study, was established to study the absorption
mechanism of the antihypertensive peptides, Val-Pro-Pro (VPP) and Ile-Pro-Pro (IPP). The Caco-2 cell model was
evaluated by morphological features, transepithelial electrical resistance and the transmittance of fluorescein sodium. We
comparatively investigated the effects of transport time, peptide concentration, enhancers and inhibitors on the transport
pathways and efflux mechanisms of VPP and IPP. The results showed the established Caco-2 cell model could be used
to study the intestinal absorption of VPP and IPP. Paracellular diffusion was suggested to be the main mechanism for the
absorption of the two antihypertensive peptides. The transports of both peptides were influenced by the efflux pump. The
efflux affected VPP more than IPP. Thus, IPP showed higher bioavailability.

Key words: antihypertensive, Val-Pro-Pro, Ile-Pro-Pro, Caco-2 cell, transport