Shuwei Zhang1, Christina Ohland2, Christian Jobin2, Shengmin Sang1. 1. Laboratory for Functional Foods and Human Health, Center for Excellence in Post-Harvest Technologies, North Carolina Agricultural and Technical State University, North Carolina Research Campus, 500 Laureate Way, Kannapolis, NC, 28081, USA. 2. Department of Infectious Diseases and Immunology, University of Florida, Gainesville, FL, 32611, USA.
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.
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.
Authors: Gerald Münch; Claire E Shepherd; Heather McCann; William S Brooks; John B J Kwok; Thomas Arendt; Marianne Hallupp; Peter R Schofield; Ralph N Martins; Glenda M Halliday Journal: Neuroreport Date: 2002-04-16 Impact factor: 1.837
Authors: David S Wishart; Yannick Djoumbou Feunang; Ana Marcu; An Chi Guo; Kevin Liang; Rosa Vázquez-Fresno; Tanvir Sajed; Daniel Johnson; Carin Li; Naama Karu; Zinat Sayeeda; Elvis Lo; Nazanin Assempour; Mark Berjanskii; Sandeep Singhal; David Arndt; Yonjie Liang; Hasan Badran; Jason Grant; Arnau Serra-Cayuela; Yifeng Liu; Rupa Mandal; Vanessa Neveu; Allison Pon; Craig Knox; Michael Wilson; Claudine Manach; Augustin Scalbert Journal: Nucleic Acids Res Date: 2018-01-04 Impact factor: 16.971