ETAS®, a Standardized Extract of Asparagus officinalis Stem, Alleviates Sarcopenia via Regulating Protein Turnover and Mitochondrial Quality

<b>Background</b>: ETAS^®, a standardized extract of <i>Asparagus officinalis</i> stem, has been found to alleviate cognitive impairment in senescence-accelerated mice prone 8 (SAMP8) and is now considered a functional food in aging. The present study aimed to investigate the impacts of ETAS^® on relieving aging-related muscle atrophy in SAMP8 mice. <b>Methods</b>: The SAMP8 mice were fed a regular diet supplemented with 200 or 1000 mg/kg BW ETAS^®50 for 12 weeks. Grip strength, muscle mass, and molecular markers of protein synthesis, degradation, and mitochondrial quality were assessed. <b>Results</b>: We found that ETAS^® significantly increased grip strength and muscle mass in SAMP8 mice. At the molecular level, ETAS^® significantly upregulated protein synthesis via PI3K/Akt/mTOR/p70S6K and downregulated protein degradation via FoxO1a/atrogin-1 and MuRF-1 and myostatin via NFκB expression. In addition, ETAS^® improved mitochondrial quality via promoting mitochondrial biogenesis genes, oxidative respiration genes, fusion/fission genes, PGC1α, and PINK1 proteins and maintained the autophagic flux via reducing ATG13, LC3-II/LC3-I, and p62. <b>Conclusions</b>: ETAS^® exerts beneficial effects on sarcopenia by modulating the positive protein turnover and improving mitochondrial quality in aging.