Using Caffeine and Free Amino Acids To Enhance the Transepithelial Transport of Catechins in Caco-2 Cells

Abstract

Catechins are well-known to possess health-promoting functions. The interaction of the catechins with other components in tea could alter their absorption and efflux. This study investigated whether the absorption of catechins is affected by caffeine and amino acids using the Caco-2 monolayer cell model. We found that (−)-epigallocatechin gallate (EGCG), (−)-epicatechin gallate (ECG), and (−)-epicatechin (EC) were all actively effluxed. Co-transportation of EGCG, ECG, or EC with caffeine, theanine, serine, or glycine increased their apparent permeability coefficient [P app(AP−BL) ] value by 3.42−5.40-fold, 1.19−5.75-fold, and 1.55−8.01-fold, respectively. Meanwhile, their efflux ratio values were significantly decreased. Moreover, the expression of multi-drug resistance protein 2 (MRP2) after 3 h of incubation with either 50 μM EGCG or 50 μM EC was elevated by 1.58-and 2.98-fold, respectively, while 50 μM ECG had no significantly effects. In addition, the expression of Pglycoprotein (P-gp) after treatment with either 50 μM EGCG, 50 μM ECG, or 50 μM EC was enhanced by 1.53-, 1.63-, and 1.80-fold, respectively. The addition of either caffeine or any one of the three amino acids decreased the expression of both MRP2 and P-gp induced by EGCG, and the expression of P-gp induced by ECG or EC also decreased. In contrast, only glycine decreased the expression of MRP2 induced by EC. Taken together, our data indicated that caffeine and theanine, glycine, or serine in tea might increase the absorption of catechins by the selectively suppressed expression of the efflux transporters induced by catechins.

Theanine Improves High-Dose Epigallocatechin-3-Gallate-Induced Lifespan Reduction in Caenorhabditis elegans

“…Interestingly, in terms of antibacterial properties and antibiotic sensitization, galloylated catechins (ECG and EGCG) have more significant effects than non-galloylated catechins (EC and EGC) because of their unique molecular structure [ 32 ]. This may be related to the fact that the ester group alters the membrane permeability by binding to the cell membrane to affect the transmembrane transport of substances [ 32 , 33 ]. Thus, it might improve the bioavailability of galloylated catechins to extend the lifespan in C. elegans .…”

“…Caffeine and theanine were recently found to increase the absorption of EGCG [ 33 ]. In our study, theanine alleviated high-dose EGCG-induced lifespan shortening, while caffeine did not ( Figure 2 A,D).…”

Lactobacillus murinus Improved the Bioavailability of Orally Administered Glycyrrhizic Acid in Rats

“…The expression of intestinal transporters that are involved in drug transport plays an important role in drug bioavailability. MDR1, MRP2/MRP4, and BCRP all belong to the ABC transporters, mainly distributed in the apical membrane of IECs (Harwood et al, 2013;Wang et al, 2019). L. murinus treatment significantly reduced the gene expression of MDR1 and MRP2, which were directly involved in drug efflux, while MRP4 and BCRP were not affected by co-culturing with L. murinus.…”

Tea components influencing bioavailability of fluoride and potential transport mechanism in the Caco‐2 cell line model

“…Aluminium was reported to interfere with fluoride absorption (Fawell et al , ; Gao et al , ). Tea polyphenols influenced the bioavailability of other tea compounds, such as caffeine and theanine (Wang et al , ). Thereinto, EGCG was the major bioactive polyphenolic compound in tea.…”