Effects of tannase-converted green tea extract on skeletal muscle development

Abstract

Background: The aim of this study was to investigate the effect of tannase-converted green tea extract with a high (−)-epicatechin (EC), (−)-epigallocatechin (EGC), and gallic acid (GA) content on myotube density and fusion in normal and oxidative stress-induced C2C12 skeletal muscle cells. Although the use of green tea extract is considered beneficial, cellular and molecular mechanisms of action of tannase-converted green tea extracts that are used as potential muscle growth materials have not been thoroughly studied.Methods: This 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. Results: 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 (normal cells: P < 0.01; oxidative stress-induced cells: P < 0.05). In addition, tannase-converted green tea extract and green tea extract treatments significantly upregulated the genetic expression of myogenin, Myf5, and MyoD (P < 0.05). 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 (P < 0.05).Conclusions: Taken together, our findings describe that the high levels of EC, EGC, and GA in the tannaseconverted green tea extract are attributable to the morphological changes in C2C12 cells and intercellular signaling pathways. Therefore, tannase-converted green tea extract can be used in the treatment of sarcopenia.

(−)-Epicatechin-Enriched Extract from Camellia sinensis Improves Regulation of Muscle Mass and Function: Results from a Randomized Controlled Trial

“…The results obtained in this study suggest that green tea extract improves muscle mass and strength potentially by influencing myostatin levels. These observations are consistent with previous results from our group showing that EC administration resulted in a significant increase in the expression of muscle differentiation genes, such as myoblast determination protein (MyoD) and myogenin genes in stressed C2C12 muscle cells [20]. The levels of factors related to muscle degradation or loss, such as forkhead box protein O3 (FOXO3), myostatin, muscle RING finger protein-1 (MuRF-1), and atrogin-1, were also significantly reduced by treatment with green tea extract with a high EC content in aged mice [21].…”

“…The use of tannase-treated green tea extract containing a high content of EC and GA has been reported to improve skeletal muscle recovery [20,21]. However, whether such beneficial effects occur in humans without added exercise is unknown.…”

Restorative potential of (−)-epicatechin in a rat model of Gulf War illness muscle atrophy and fatigue

“…Lee et al, reported that Epi promotes myogenic differentiation in C2C12 cells by increasing the protein levels of MyoD, myogenin leading to increases in MHC 51 . Epi also increased SkM mRNA levels of MyoD and decreased the expression of FoxO3, myostatin and MuRF1 53 . Si et al 54 reported that Epi increases the survival rate of aged mice and delays SkM degeneration.…”

Polyphenols and Their Effects on Muscle Atrophy and Muscle Health

“…It also upregulated mitochondrial biogenesis, oxidative phosphorylation, myosin heavy chain (MyHC) content, autophagy/mitophagy, and the fusion/fission index of mitochondria in C2C12 myotubes [ 29 ]. Gallic acid (GA) in combination with epicatechin (EC) and epigallocatechin (EGC) increased muscle differentiation by inducing the myogenic regulatory factors myogenin, Myf5, and MyoD in C2C12 myotubes [ 30 ]. Another compound of this class, ellagic acid, exerts antioxidant, anti-inflammatory, anticancer, hypolipidemic, and neuroprotective effects [ 31 ].…”

“…In this review, we reported several compounds that enhance mitochondrial functions by increasing mitochondrial biogenesis or reducing mitochondrial dysfunction [ 29 , 36 , 56 , 74 , 78 , 79 , 105 , 125 ]. Furthermore, several polyphenolic compounds were found to stimulate myogenesis for the growth and differentiation of muscle cells [ 30 , 71 , 81 , 146 ]. Thus, for future antiatrophic treatment, both the catabolic/anabolic modulators and mitochondrial bioenergetics will be useful therapeutic targets.…”