Comparison of the Modulating Effect of Anthocyanin-Rich Sour Cherry Extract on Occludin and ZO-1 on Caco-2 and HUVEC Cultures

Abstract

Increased permeability of the epithelial and endothelial cell layers results in the onset of pathogenic mechanisms. In both cell types, cell–cell connections play a regulatory role in altering membrane permeability. The aim of this study was to investigate the modulating effect of anthocyanin-rich extract (AC) on TJ proteins in inflammatory Caco-2 and HUVEC monolayers. Distribution of Occludin and zonula occludens-1 (ZO-1) were investigated by immunohistochemical staining and the protein levels were measured by flow cytometry. The mRNA expression was determined by quantitative real-time PCR. The transepithelial electrical resistance (TEER) values were measured during a permeability assay on HUVEC cell culture. As a result of inflammatory induction by TNF-α, redistribution of proteins was observed in Caco-2 cell culture, which was reduced by AC treatment. In HUVEC cell culture, the decrease in protein and mRNA expression was more dominant during inflammatory induction, which was compensated for by the AC treatment. Overall, AC positively affected the expression of the examined cell-binding structures forming the membrane on both cell types.

Recent Options and Techniques to Assess Improved Bioavailability: In Vitro and Ex Vivo Methods

“…The integrity of the monolayer is a vital factor for transport studies, especially when the passive transport of drug or formulation through tight junctions can be expected. To check the high confluency, besides confocal microscopy, fluorescently-labeled markers such as fluorescein [33,37], lucifer yellow [38], or radiolabeled markers like C 14 mannitol [24] are used. Additionally, the transepithelial electrical resistance (TEER) should be monitored on a regular basis using a volt-ohmmeter equipped with a "chopstick" electrode [38,39].…”

“…To check the high confluency, besides confocal microscopy, fluorescently-labeled markers such as fluorescein [33,37], lucifer yellow [38], or radiolabeled markers like C 14 mannitol [24] are used. Additionally, the transepithelial electrical resistance (TEER) should be monitored on a regular basis using a volt-ohmmeter equipped with a "chopstick" electrode [38,39]. The integrity of the Caco-2 monolayer can be considered sufficient if the TEER values are at least 800-900 Ω cm 2 [35,36].…”

“…The integrity of the Caco-2 monolayer can be considered sufficient if the TEER values are at least 800-900 Ω cm 2 [35,36]. This must be checked before and after the transport experiment well by well [38]. A sudden drop in the TEER values indicates a breakdown in the cellular barrier integrity [40].…”

“…On the other hand, the kinetics of epithelial cell reaction to excipients or formulations can be monitored by impedance measurement with a real-time cell analyzer. This method is non-invasive and label-free, and it linearly correlates with the growth, adherence, and viability of cells [38].…”

HPLC Analysis of Polyphenols Derived from Hungarian Aszú from Tokaj Wine Region and Its Effect on Inflammation in an In Vitro Model System of Endothelial Cells

“…Previous studies have demonstrated that polyphenols possess anti-inflammatory effects and vasorelaxation activity due to the suppression of the release of pro-inflammatory mediators [ 16 , 17 , 18 ]. We have also recently published several studies that investigated the relationship between the inflammation-induced HUVEC model and bioflavonoids, primarily anthocyanins [ 19 , 20 ]. Flavonoids are phenolic compounds which are found in plants, vegetables and fungi as secondary metabolites.…”