• Journal of Ginseng Research
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• v.41 no.4
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• pp.608-614
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• 2017

Background: Ginsenoside Rg1 belongs to protopanaxatriol-type ginsenosides and has diverse pharmacological activities. In this report, we investigated whether Rg1 could upregulate muscular stem cell differentiation and muscle growth. Methods: C2C12 myoblasts, MyoD-transfected 10T1/2 embryonic fibroblasts, and HEK293T cells were treated with Rg1 and differentiated for 2 d, subjected to immunoblotting, immunocytochemistry, or immunoprecipitation. Results: Rg1 activated promyogenic kinases, p38MAPK (mitogen-activated protein kinase) and Akt signaling, that in turn promote the heterodimerization with MyoD and E proteins, resulting in enhancing myogenic differentiation. Through the activation of Akt/mammalian target of rapamycin pathway, Rg1 induced myotube growth and prevented dexamethasone-induced myotube atrophy. Furthermore, Rg1 increased MyoD-dependent myogenic conversion of fibroblast. Conclusion: Rg1 upregulates promyogenic kinases, especially Akt, resulting in improvement of myoblast differentiation and myotube growth.

• Journal of Ginseng Research
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• v.47 no.6
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• pp.726-734
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• 2023

Background: Skeletal muscles play a key role in physical activity and energy metabolism. The loss of skeletal muscle mass can cause problems related to metabolism and physical activity. Studies are being conducted to prevent such diseases by increasing the mass and regeneration capacity of muscles. Ginsenoside Rg5 has been reported to exhibit a broad range of pharmacological activities. However, studies on the effects of Rg5 on muscle differentiation and growth are scarce. Methods: To investigate the effects of Rg5 on myogenesis, C2C12 myoblasts were induced to differentiate with Rg5, followed by immunoblotting, immunostaining, and qRT-PCR for myogenic markers and promyogenic signaling (p38MAPK). Immunoprecipitation confirmed that Rg5 increased the interaction between MyoD and E2A via p38MAPK. To investigate the effects of Rg5 on prevention of muscle mass loss, C2C12 myotubes were treated with dexamethasone to induce muscle atrophy. Immunoblotting, immunostaining, and qRT-PCR were performed for myogenic markers, Akt/mTOR signaling for protein synthesis, and atrophy-related genes (Atrogin-1 and MuRF1). Results: Rg5 promoted C2C12 myoblast differentiation through phosphorylation of p38MAPK and MyoD/E2A heterodimerization. Furthermore, Rg5 stimulated C2C12 myotube hypertrophy via phosphorylation of Akt/mTOR. Phosphorylation of Akt induces FoxO3a phosphorylation, which reduces the expression of Atrogin-1 and MuRF1. Conclusion: This study provides an understanding of how Rg5 promotes myogenesis and hypertrophy and prevents dexamethasone-induced muscle atrophy. The study is the first, to the best of our knowledge, to show that Rg5 promotes muscle regeneration and to suggest that Rg5 can be used for therapeutic intervention of muscle weakness and atrophy, including cancer cachexia.