Affiliation:
1. Key Laboratory of Tea Science of Ministry of Education, National Research Center of Engineering and Technology for Utilization of Botanical Functional Ingredients, Co‐Innovation Center of Education Ministry for Utilization of Botanical Functional Ingredients, Key Laboratory for Evaluation and Utilization of Gene Resources of Horticultural Crops, Ministry of Agriculture and Rural Affairs of China Hunan Agricultural University Changsha China
Abstract
AbstractAn important concern for tea consumers is whether appropriate storage can effectively improve the ability of oolong tea to alleviate type 2 diabetes mellitus (T2DM). In this study, the antidiabetic effects of three aged oolong tea (2001, 2011, and 2020) extracts (aged TEs) in db/db T2DM mice were investigated and compared for the first time. The results showed that aged oolong tea extracts (aged TEs) alleviated the abnormal fasting blood glucose levels, lipid profiles, insulin resistance, and reduced ectopic fat deposition in liver. Moreover, aged TEs alleviated T2DM‐related tissue damage and activated insulin receptor (INSR)/insulin receptor substrate (IRS)/phosphatidylinositol‐3 kinase (PI3K)/phosphatidylinositol‐3 kinase (AKT)/glycogen synthase kinase 3 beta (GSK‐3β)/glycogen synthase (GYS)‐mediated hepatic glycogen synthesis signaling pathway. In addition, aged TEs altered gut microbiota composition and gut metabolite profiles associated with T2DM. Together, all three aged TEs (400 mg/kg/day in mice, a human equivalent dose of 7 g/60 kg/day), especially 2011, can effectively alleviate T2DM, and proper storage can effectively improve the ability of oolong tea to alleviate T2DM.