Yellow Tea Stimulates Thermogenesis in Mice Through Heterogeneous Browning of Adipose Tissues

Scope Large-leaf yellow tea (YT) exhibits interesting beneficial metabolic effects in previous studies. Here, the authors elucidated the actions of YT on thermogenesis, energy metabolism, and adipocyte metabolic conversion. Methods and Results Five-week-old male C57BL/6 mice are fed low-fat diet, high-fat diet (HFD), and HFD supplemented with 0.5% or 2.5% YT. After treatment for 10 or 14 weeks, YT enhances energy expenditure, O-2 consumption and CO2 production. YT strongly boosts thermogenic program in brown adipose tissue (BAT) and subcutaneous adipose tissue (SAT), while only weakly in epididymal adipose tissue (EAT). These are accompanied by higher body temperature, increased mitochondrial copy numbers, and upregulation of thermogenic genes (Ucp1, Pgc1 alpha, etc.) and proteins. The classic brown adipocyte markers (Eva1, Zic1) are induced only in BAT, while beige adipocyte markers (Tbx1, Tmem26) are boosted only in SAT. Furthermore, subcutaneous-originated preadipocytes are induced by YT in vitro to differentiate to brown-like adipocytes - a browning effect. Conclusion Dietary YT induces adaptive thermogenesis through increasing mitochondrial biogenesis in EAT, inducing beigeing in SAT and enhancing browning in the BAT.