Black Tea Theaflavin Detoxifies Metabolic Toxins in the Intestinal Tract of Mice

Abstract

Scope This study is to determine the in vivo efficacy of black tea theaflavin (TF) to detoxify two metabolic toxins, ammonia and methylglyoxal (MGO), in mice Methods and results Under in vitro conditions, TF is able to react with ammonia, MGO, and hydrogen peroxide to produce its aminated, MGO conjugated, and oxidized products, respectively. In TF‐treated mice, the aminated TF, the MGO conjugates of TF and aminated TF, and the oxidized TF are searched using LC‐MS/MS. The results provide the first in vivo evidence that the unabsorbed TF is able to trap ammonia to form the aminated TF; furthermore, both TF and the aminated TF have the capacity to trap MGO to generate the corresponding mono‐MGO conjugates. Moreover, TF is oxidized to dehydrotheaflavin, which underwent further amination in the gut. By exposing TF to germ‐free (GF) mice and conventionalized mice (GF mice colonized with specific‐pathogen‐free microbiota), the gut microbiota is demonstrated to facilitate the amination and MGO conjugation of TF. Conclusion TF has the capacity to remove the endogenous metabolic toxins through oxidation, amination, and MGO conjugation in the intestinal tract, which can potentially explain why TF still generates in vivo efficacy while showing a poor systematic bioavailability.

Biotransformation of Barley Phenolamide by Mice and the Human Gut Microbiota and Quantitative Analysis of the Major Metabolites in Mice

“…The preparation method of the fecal and urinary samples were processed as described previously with some modification. [13,18] In brief, fecal samples (100 mg) were homogenized by 80% methanol (1 mL) with 0.1% formic acid, and the samples were sonicated for 30 min and centrifuged for 20 min. Urinary samples (50 μL) were mixed with a NaOAc buffer (147.5 μL), 10% ascorbic acid in NaOAc buffer (w/w, 5 μL), glucuronidase (12.5 μL; 125 U), and sulfatase (35 μL; 15 U).…”

Anticancer Effects and Molecular Target of Theaflavins from Black Tea Fermentation in Vitro and in Vivo

“…In general, theaflavins can not only achieve biotransformation under the mediation of microbial enzymes but also produce small molecules of phenolic acid or valerolactone through colonic catabolism and blood metabolism. In view of the low oral bioavailability of theaflavins, some studies speculate that the metabolites degraded by intestinal microorganisms may be the key factor in their biological activity. ,, …”

“…53 Theaflavins have poor system bioavailability due to their large structural size (larger than catechins) after oxidation and polymerization. 54 Reports have shown that a trace amount of theaflavins absorbed by the human body is equivalent to only 0.001% of the intake, 55 which shows that the bioavailability of theaflavins is poor. One study reported that men who drank six cups of black tea a day for 3−8 weeks had no theaflavins in their urine or prostate tissue.…”

“…In view of the low oral bioavailability of theaflavins, some studies speculate that the metabolites degraded by intestinal microorganisms may be the key factor in their biological activity. 54,65,66 Structure−Activity Relationship on Antioxidant and Anticancer Actions of Theaflavins. The strong antioxidant activity of theaflavins gives them unique physiological functions.…”

Efficient Preparation of Black Tea Extract (BTE) with the High Content of Theaflavin Mono- and Digallates and the Protective Effects of BTE on CCl4-Induced Rat Liver and Renal Injury

“…The structures of four dominant catechins and four dominant theaflavins are illustrated in Figure A. It was demonstrated that theaflavins possess strong antioxidant, anti-inflammatory, − and antiglycation properties . Therefore, the enrichment of theaflavin content from around 2% in current black tea products to 40% or more is of critical importance in exploring more anti-inflammatory property-related health beneficial effects of theaflavins.…”