Authors: Anja Haasbroek-Pheiffer, Clarissa Willers, Matthew Glyn, Lissinda du Plessis, Josias Hamman
co-administration of absorption enhancing agents with macromolecular drugs (e.g., protein and peptide drugs) has been identi?ed as a means to improve the oral bioavailability of these drugs, Absorption-enhancing agents of natural origins, Aloe vera leaf (e.g., gel and whole leaf extract) have shown a potential to enhance drug permeation across the intestinal epithelial barrier, The mechanism of the drug-absorption-enhancement action and the capacity for absorption-enhancement of the Aloe Vera Gel gel , decrease in transepithelial electrical resistance (TEER) of Caco-2 cell monolayers, indicated the opening of tight junctions between the epithelial cells, transport of Fluorescein isothiocyanate (FITC)-dextran, with a molecular weight of 4 kDa (FD-4), could be enhanced across the Caco-2 cell monolayers, aloe vera gel extract, but not the FITC-dextran with larger molecular weights(i.e., 10, 20, and 40 kDa), which indicated a limited drug absorption enhancement capacity, in terms of the molecular size, paracellular transport of FD-4 occurred after the interaction of the Aloe Vera Gel gel with the epithelial cell monolayers, changes in the F-actin distribution in the cytoskeleton of the Caco-2 cell monolayers was observed by means of a ?uorescence staining, which con?rmed tight junction modulation as the mechanism of action for the absorption enhancement effect of the Aloe vera gel
