Hydrangea serrata Tea Enhances Running Endurance and Skeletal Muscle Mass

Skeletal muscle mass and quality can be negatively affected by aging, inactivity, and disease, while a loss of muscle mass is associated with chronic disease status, falls, and mortality. We investigate the effects of Hydrangea serrata on skeletal muscle mass and function, along with the underlying mechanisms.

H. serrata, identified through MyoD transcription activity screening, increases myogenic differentiation via Akt and p38. C57BL/6 mice are fed a 0.25% or 0.5% H. serrata diet for 8 weeks. H. serrata increased treadmill running distance and maximum speed, as well as skeletal muscle mass. H. serrata promotes the expression of myosin heavy chain 1 (MHC1) and MHC2A but not MHC2B. H. serrata also upregulates the protein expression of peroxisome proliferator-activated receptor δ (PPARδ) and mitochondrial complexes, and enhances citrate synthase and mitochondrial complex І activity. Transforming growth factor-β (TGF-β), myostatin, and growth differentiation factor 11 (GDF11) are attenuated by H. serrata, together with associated downstream signaling factors including phospho-Smad3 and NADPH oxidase 4 (NOX4).

H. serrata enhances exercise endurance by upregulating PPARδ and downregulating TGF-β, myostatin, and GDF11. H. serrata is a potential candidate for the development of functional food to maintain skeletal muscle mass and function.