Objective: To investigate the effect of Catalpa ovata fruit extract (COFE) on muscle growth and exercise performance in C2C12 myoblasts and mice. Methods: Cell viability was determined through a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Myogenic differentiation was observed using Giemsa staining. COFE was administered to mice orally at 50 and 200 mg/kg for 10 weeks. Muscular strength was evaluated using the whole-limb grip strength assay. The expression levels of myogenesis- and energy metabolism-related proteins in vitro and in vivo were determined using Western blotting. Results: COFE significantly improved myoblast-to-myotube differentiation in C2C12 myoblasts. It also increased the expression of myogenesis determination protein 1 and myogenin compared with the control group. Moreover, the expression levels of glucose transporter type 4 (Glut4) and peroxisome proliferator-activated receptor-gamma coactivator 1-alpha (PGC-1α) were significantly elevated in the presence of COFE in C2C12 myoblasts. COFE also markedly increased phosphorylation of AMP-activated protein kinase, which regulates Glut4 and POC-1α expression levels in C2C12 myoblasts. Mice treated with COFE showed improved grip strength. Myogenesis- and energy metabolism-related protein levels in muscle tissue were significantly increased in COFE-administered mice. Conclusions: COFE treatment improves exercise performance by controlling myogenesis and energy metabolism in skeletal muscle. COFE has the potential to be used as an effective natural agent for enhancing muscular strength.
Cho et al. (Thu,) studied this question.