Advances in metabolism pathways of theaflavins: digestion, absorption, distribution and degradation

Abstract

Theaflavins, a major kind of component in black tea, have been reported to show a variety of biological activities and health effects. However, the unstable chemical properties, low bioavailability and unclear metabolism pathways of theaflavins have left much to be desired in terms of its specific efficacy and applications. This paper provides a comprehensive knowledge on the digestion, absorption, metabolism, distribution and excretion of theaflavins. We find that pH-dependent stability, efflux transport proteins are closely related to the low absorption rate and low bioavailability of theaflavins. When pass through the gastrointestinal tract, TFDG, TF2A and TF2B are gradually degraded to TF1, and release gallic acid. Then, the theaflavins skeleton are degraded into small molecular phenolic substances under the action of enzymes and microorganisms. In addition, theaflavins are widely distributed in the human body including brain, lung, heart, kidney, liver, blood tissue in a low content and can be excreted through feces. However, the influence of digestive enzymes barrier and gut microbial barrier on theaflavins are still unclear. Importantly, most findings are reported by in vitro methods and animal experiments, the metabolites and metabolic pathways of theaflavins in human body are not fully understood and need to be further investigated. We hope to lay a theoretical basis for exploring methods to improve the bioavailability of theaflavins and expanding the application of theaflavins in health foods as well as pharmaceuticals.

Keywords:

• Theaflavins
• Digestion
• Absorption
• Metabolism
• Distribution
• Excretion

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This research was funded by the National Key Research and Development Program of China [No. 2022YFE0111200], National Natural Science Foundation of China [No. 32001680], the Scientific Research Foundation of Hunan Provincial Education Department [No. 23A0187] and the Graduate Innovation Project by Postgraduate Innovation Project of Hunan Provence [No. CX20230721].