Theabrownin from dark tea can potentially reverse insulin resistance and regulate glycolipid metabolism, with longer fermented samples showing greater effects.
The study focused on TB1 and TB2, theabrownin isolated from dark tea. TB1 was fermented for 7 days whereas TB2 was fermented for 14 days. The research used HepG2 cells for the experiment. Various techniques such as Western blot and real-time PCR experiments were employed to measure the effects of TB on oxidative stress, mitochondrial function, and glycolipid regulation, which are key components of insulin resistance.
The results suggest TB can significantly improve oxidative stress conditions by enhancing mitochondrial function. TB unveiled its potential in improving glycogen synthesis and glucose consumption. Furthermore, TB was found to inhibit harmful processes like gluconeogenesis and fatty acid synthesis via the regulation of various enzymes and proteins. The researchers investigated this by focusing on a signaling pathway (IRS-1/PI3K/Akt). Verification of the effects of TB on glycolipid metabolism was done using a PI3K inhibitor, highlighting a positive correlation between PI3K activation and TB's activity. Notably, the experiment showed TB2, which was fermented longer, was more effective in improving insulin resistance.
