Transepithelial Transport ofp-Coumaric Acid and Gallic Acid in Caco-2 Cell Monolayers

Non-Involvement of the Human Monocarboxylic Acid Transporter 1 (MCT1) in the Transport of Phenolic Acid

“…The cells were seeded at a density of 1 Â 10 5 /cm 2 and grown in Transwell inserts with a semipermeable membrane coated with type I collagen, as previously reported. [4][5][6][7][8]12,13) The integrity of the cell layer was evaluated by measuring the transepithelial electrical resistance (TER) with Millicell-ERS equipment (Millipore, Billerica, MA, USA). A monolayer with a TER value of more than 300 Ácm 2 was used for the transepithelial transport experiments.…”

“…The amount of p-coumaric or salicylic acid in this extract was estimated by using HPLC-ECD equipment fitted with an ESA coulometric detection system (ESA, Boston, MA, USA) as described in previous studies. [4][5][6][7][8]12,13) In brief, to measure p-coumaric acid, chromatographic separation was performed in a C18 column (ODS150, MC Medical, Tokyo, Japan) with mobile phase A (solvent A) of 50 mM sodium acetate containing 5% methanol (pH 3.0) and mobile phase B (solvent B) of 50 mM sodium acetate containing 40% acetonitrile and 20% methanol (pH 3.5). Eight electrode detector potentials (from 0 to 700 mV in increments of 100 mV) were used.…”

“…The level of p-coumaric acid and salicylic acid in the extract of oocytes was determined by using a highly sensitive (detection limit < 0.5 pmol) and reproducible assay, as reported previously. [4][5][6][7][8]12,13) The retention time (RT) and dominant oxidation potential for p-coumaric and salicylic acids were respectively 14.7 min and 600 mV, and 19.4 min and 800 mV (Figs. 3A and B).…”

“…MCT-mediated absorption, partial MCT-mediated absorption, paracellular diffusion, and transcellular passive diffusion). [4][5][6][7][8] We have also established that the absorption characteristics of these compounds in the Caco-2 cell line are correlated with their absorption efficiency and bioavailability in vivo. [9][10][11] Furthermore, the microbial metabolites of poorly absorbed parent polyphenols are also thought to be absorbed and distributed by MCT, in a similar way to phenolic acids.…”

Tissue distribution and excretion of the five components of Portulaca oleracea L. extract in rat assessed by UHPLC

“…After oral administration of the POE in rats, only p-CA and FA were found in all tissues (except for p-CA in the brain). The reason why p-CA was higher in tissues (except for the brain) is that the transepithelial transport of p-CA depends on concentration and saturation (Konishi, Kobayashi, Shimizu, 2003), and higher FA levels in the intestine could partly be attributed to gradual efflux from the stomach. CA was only observed in the stomach and intestine at the different five points, and in the muscle at the first point.…”