Caco-2 cell monolayers as a model for drug transport across the intestinal mucosa.
ABSTRACT Human colon adenocarcinoma (Caco-2) cells, when grown on semipermeable filters, spontaneously differentiate in culture to form confluent monolayers which both structurally and functionally resemble the small intestinal epithelium. Because of this property they show promise as a simple, in vitro model for the study of drug absorption and metabolism during absorption in the intestinal mucosa. In the present study, the transport of several model solutes across Caco-2 cell monolayers grown in the Transwell diffusion cell system was examined. Maximum transport rates were found for the actively transported substance glucose and the lipophilic solutes testosterone and salicyclic acid. Slower rates were observed for urea, hippurate, and saliylate anions and were correlated with the apparent partition coefficient of the solute. These results are similar to what is found with the same compounds in other, in vivo absorption model systems. It is concluded that the Caco-2 cell system may give useful predictions concerning the oral absorption potential of new drug substances.
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ABSTRACT: Total flavones of Hippophae rhamnoides L. (TFH) are extracted from the widely distributed thorny bush Sea buckthorn (Hippophae rhamnoides L.). Isorhamnetin (IS) is one of the representative ingredients in TFH. In this study, the absorption properties of IS in TFH and its pure form were compared through transepithelial transport and cellular uptake experiments in a Caco-2 cell model. Our results show that the absorption properties of IS in TFH and its pure form were remarkably different: (1) Both PappAB and PappBA of IS in TFH were dramatically increased compared with those of IS pure form; consequently, its Pratio was 2.3-fold higher than that of IS; (2) Both the accumulation and efflux of IS in TFH were significantly enhanced compared with the single compound. One likely reason for these differences is that the multiple components in TFH significantly down regulated the mRNA expression level of MRP2, which lead to a decrease in the protein level of MRP2, based on western blotting and RT-PCR assays. This study highlights the significant differences in the absorption properties of flavonoid components in different forms and the potential multi-component interactions in TFH. Copyright © 2015. Published by Elsevier B.V.European journal of pharmaceutical sciences: official journal of the European Federation for Pharmaceutical Sciences 03/2015; 73. DOI:10.1016/j.ejps.2015.03.008 · 3.01 Impact Factor
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ABSTRACT: The release of wheat gluten exorphins (GEs) A5, A4, B5, B4, C5, Gd-7 and dGd-7 during in vitro gastrointestinal digestion (GID) of bread and pasta samples has been investigated by UPLC/ESI-HRMS. The GEs that survived in vitro GID were studied for transport studies across monolayers of 70% Caco-2/30% HT-29 co-culture grown on semi-permeable membranes, used as a model of the human intestinal epithelium. Among the GEs, only the peptides A5 and C5 were detected at the end of in vitro GID of bread and pasta samples. Levels of GEs A5 and C5 were in the range 0.747–2.192 mg kg- 1 and 3.201–6.689 mg kg- 1, respectively. The absorption behavior of A5 and C5 was studied in detail using synthetic peptides. The two peptides were susceptible to the action of Caco-2/HT-29 co-culture peptidases, and 3% and 1% of A5 and C5, respectively, added to the apical chamber were transported to the basolateral chamber after 120 min of incubation, without being hydrolysed. Several hydrolytic fragments of both GEs crossed the co-culture layer and were found in the basolateral chamber. For the first time, these results demonstrate that GEs are released during in vitro GID of real wheat-derived foods and highlight the possibility of transport of the GEs A5 and C5 across the human intestinal mucosa.Food Research International 04/2015; 72. DOI:10.1016/j.foodres.2015.04.002 · 3.05 Impact Factor
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ABSTRACT: Histatins (Hsts) are histidine-rich peptides exclusively present in the saliva of higher primates. In this study, we explored the effects of Hsts on cell-substrate and cell-cell adhesion. Histatin (Hst)-1 caused a significant (>2-fold) increase (EC50 = 1 µM) in the ability of human adherent cells to attach and spread, even in conditions that impaired cell spreading. Other tested Hsts did not stimulate cell spreading, indicating a specific effect of Hst1. The effect of Hst1 on cell-cell adhesion was investigated by using transepithelial resistance (TER) measurements in the human cell line Caco-2, a widely used model for the epithelial layer. We found that 10 µM Hst1 caused a 20% increase in TER compared to the negative control, indicating a function for Hst1 in intercellular cell adhesion and epithelial integrity. A role for Hst1 in both cell-substrate and cell-cell adhesion is highly conceivable, because these 2 modes of adhesion are closely related via shared components and connected signaling pathways.-Van Dijk, I. A., Nazmi, K., Bolscher, J. G. M., Veerman, E. C. I., Stap, J. Histatin-1, a histidine-rich peptide in human saliva, promotes cell-substrate and cell-cell adhesion. © FASEB.The FASEB Journal 04/2015; DOI:10.1096/fj.14-266825 · 5.48 Impact Factor