Lariciresinol and secoisolariciresinol enhance myogenic differentiation and mitochondrial biogenesis in C2C12 myotubes

Lariciresinol (LR) and secoisolariciresinol (SLR), phytochemicals found in pine bark and flaxseed, are known for their anticancer effects, risk reduction of cardiovascular disease, hormone regulation, and antioxidant activities. However, researches on their effects on skeletal muscle function are scarce. Therefore, this study aimed to investigate the efficacy of LR and SLR in promoting muscle hypertrophy and mitochondrial function in C2C12 mouse-derived myoblasts. LR and SLR were found to enhance myogenic differentiation as indicated by increased fusion index via myotube immunostaining and upregulation of MHC-Myogenin expression. These effects are caused by upregulated Akt phosphorylation, which is associated with protein synthesis pathways. In addition, LR and SLR supplementation led to increased mitochondrial biogenesis and enhanced mitochondrial function through upregulation of PGC-1α/SIRT1. These findings indicate that LR and SLR supplementation promotes muscle development and suggests potential for the prevention and treatment of sarcopenia.