Although the use of green tea extract is considered beneficial, cellular and molecular mechanisms of action of tannase-converted green tea extracts, used as potential muscle growth materials, remains obscure.

The purpose of a new study published in BMC Complementary Medicine and Therapies was to investigate the effect of tannase-converted green tea extract with a high (-)-epicatechin (EC), (-)-epigallocatechin (EGC) and gallic acid (GA), on myotube density and fusion in normal and oxidative stress-induced C2C12 skeletal muscle cells.

The present study used histological analysis and molecular biology techniques, and compared the results with those for AMPK activator 5-aminoimidazole-4-carboxamide-1-β-D-ribonucleoside (AICAR) and green tea extracts.

It was found that the myotube density of normal and oxidative stress-induced C2C12 cells was significantly higher in the tannase-converted green tea extract-treated group than that observed in the other groups. Meanwhile, tannase-converted green tea extract and green tea extract treatments significantly upregulated the genetic expression of myogenin, Myf5 and MyoD. In addition, the levels of AMP-activated protein kinase-α (AMPKα) and muscle RING-finger protein-1 (MuRF-1) in the tannase-converted green tea extract group were higher than those in the AICAR and green tea extract groups.

The results suggested that high levels of EC, EGC and GA in tannase-converted green tea extract are attributable to the morphological changes in C2C12 cells and intercellular signaling pathways. Thus, it was concluded that tannase-converted green tea extract can be used in the treatment of sarcopenia.

Source: BMC Complementary Medicine and Therapies. 2020 Feb 11;20(1):47. doi: 10.1186/s12906-020-2827-7.