Postfermented Tea Extract Potently Alleviates Glucose Metabolism Disorders In Vitro and In Vivo

This study explores the efficacy of postfermented tea extract in mitigating type 2 diabetes mellitus (T2DM), a condition characterized by insulin resistance and reduced insulin secretion, leading to significant healthcare challenges and increased mortality. We investigated the impact of postfermented tea extract on glucose metabolism in TNF-α-stimulated C2C12 cells and its therapeutic potential in streptozotocin-induced diabetic rats. Our results showed that postfermented tea extract enhances glucose uptake in a dose-dependent manner, indicated by increased 2-NBDG absorption. This effect is linked to the activation of IRS, PI3K, and Akt pathways and the upregulation of GLUT4 expression in C2C12 cells, suggesting a reduction in insulin resistance. Additionally, the oral administration of the extract significantly lowered plasma glucose levels in diabetic rats during glucose tolerance tests. These findings underscore the potential of postfermented tea extract as a functional food ingredient for T2DM prevention, highlighting its role in ameliorating glucose metabolism disorders.