Phenolic Absorption and Antioxidant Activity of Tea-Macerated Wine in a Caco-2 Intestinal Cell Culture Model

Abstract

A novel type of flavored wine was developed by macerating either green tea or black tea into Chardonnay wine. The bioaccessibility and bioavailability of phenolic compounds in green/black tea-macerated Chardonnay wine were investigated. Catechin, caffeine and epicatechin gallate, originating from the tea-macerated wine, displayed high absorption rates with apparent permeability coefficient values above 10 × 10-6 cm/s in a human Caco-2 intestinal cell model. A paracellular pathway was proposed to drive the transport of catechin and epicatechin gallate, while the possible transport pathway of caffeine is passive transcellular diffusion route. Co-supplementation of flavonoids of quercetin or naringenin (20 μM) could further enhance the uptake of catechin and epicatechin gallate, but reduce the absorption of caffeine. Great in vitro and cellular antioxidant activities were observed in the tea-macerated wine samples. The wine samples also neutralized the negative impact of tert-butyl hydroperoxide (25 μM) on intracellular malondialdehyde levels, apoptosis induction, glutathione S-transferase and glutathione levels. RNA-sequencing with limma method revealed a total of 1473 and 406 differentially expressed genes in the 21-day-old Caco-2 intestinal cells treated with the green tea- and black tea-macerated wines for 5 h respectively, indicating metabolic changes in the cells from different wines. This study fulfilled the pursuit of the absorption and antioxidant capacities of bioactive phenolics in tea-flavored wines.

Keywords: Tea-macerated wine, Phenolic compounds, Absorption, Antioxidant activity, Cytoprotective effect, RNA-sequencing