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Differentiated Caco‐2 Cell Monolayers Exhibit Differential Adaptation to Chronic Exposure of Green Tea and Grape Seed Extracts Rich in Flavan‐3‐ols
Author(s) -
Redan Benjamin,
Ferruzzi Mario
Publication year - 2015
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.29.1_supplement.249.4
Subject(s) - flavan , food science , proanthocyanidin , chemistry , grape seed , adaptation (eye) , caco 2 , botany , polyphenol , biology , cell , biochemistry , neuroscience , stereochemistry , antioxidant
Though low oral bioavailability limits potential flavan‐3‐ol benefits, evidence suggests bioavailability may be increased through chronic dosing. To model gut‐specific alterations occurring due to chronic flavan‐3‐ol exposure, Caco‐2 cells were cultured and differentiated on Transwell® inserts for 21 d. Culture media contained 0 (control), 1, or 10 μM gallic acid equiv. from extracts of green tea (GTE) rich in epigallocatechin (EGC) and epigallocatechin gallate (EGCG) or grape seed (GSE) rich in catechin (C) and epicatechin (EC) monomers and polymers. Cellular uptake and transcellular transport of flavan‐3‐ols in differentiated monolayers was assessed 0‐4 h from a final 100 μM acute dose of extract and measured by LC‐TOF‐MS. Greater cellular uptake of C but not EGCG or EGC was observed from GTE following pretreatment ( P < 0.05); however, no differences in transcellular transport of flavan‐3‐ols were observed. After 4 h, 10 μM GSE pretreated monolayers showed greater ( P < 0.05) transport of C and EC compared to the 1 μM treatment (615. ± 11.5 vs. 385 ± 2.50 pmol C/well; 1260 ± 67.6 vs. 940. ± 78.1 pmol EC/well). Further, P app calculated from C/EC transcellular flux was greater for 10 μM GSE pretreated cells (2.95 x 10 ‐6 [C] and 3.19 x 10 ‐6 cm/s [EC]) compared to control (2.17 x 10 ‐6 [C] and 2.52 x 10 ‐6 cm/s [EC]). Pretreatment with both extracts also increased ( P < 0.05) transepithelial electrical resistance of differentiated monolayers, suggesting that pretreatment affected tight junctions. Overall, these results suggest that intestinal adaptation to flavan‐3‐ol rich extracts alters intestinal barrier function and flavan‐3‐ol transport. Funding from NSF Grant DGE‐1333468