Li Maiquan, Li Wenlan, Dong Yunxia, Zhan Cai, Tao Tiantian, Kang Manjun, Zhang Can, Liu Zhonghua
College of Food Science and Technology, Hunan Provincial Key Laboratory of Food Science and Biotechnology, Hunan Agricultural University, Changsha, China.
Key Laboratory of Tea Science of Ministry of Education, National Research Center of Engineering Technology for Utilization of Functional Ingredients from Botanicals, College of Horticulture, Hunan Agricultural University, Changsha, China.
Crit Rev Food Sci Nutr. 2025;65(21):4195-4203. doi: 10.1080/10408398.2024.2384647. Epub 2024 Aug 2.
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 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.
茶黄素是红茶中的一种主要成分，据报道具有多种生物活性和健康功效。然而，茶黄素化学性质不稳定、生物利用度低且代谢途径不明确，其具体功效和应用仍有许多不足之处。本文提供了关于茶黄素消化、吸收、代谢、分布和排泄的全面知识。我们发现，pH依赖性稳定性、外排转运蛋白与茶黄素的低吸收率和低生物利用度密切相关。当通过胃肠道时，TFDG、TF2A和TF2B逐渐降解为TF1，并释放没食子酸。然后，茶黄素骨架在酶和微生物的作用下被降解为小分子酚类物质。此外，茶黄素在人体中广泛分布于脑、肺、心脏、肾脏、肝脏、血液组织中，但含量较低，可通过粪便排出。然而，消化酶屏障和肠道微生物屏障对茶黄素的影响仍不清楚。重要的是，大多数研究结果是通过方法和动物实验报道的，茶黄素在人体中的代谢产物和代谢途径尚未完全了解，需要进一步研究。我们希望为探索提高茶黄素生物利用度的方法以及扩大茶黄素在保健食品和药品中的应用奠定理论基础。
