Asperuloside Protects Against Age-Related Muscle Dysfunction by Enhancing FOXO3-Mediated Mitophagy

Mitophagy enhancers show great potential as therapeutic agents for preventing age-related muscle disorders. Asperuloside (ASP), a naturally occurring iridoid, has been shown to activate mitophagy and maintain mitochondrial homeostasis. However, the exact mechanisms underlying its action and its overall efficacy in relation to muscle aging have yet to be fully elucidated. In senescent myoblasts, techniques such as cell staining, western blotting, fluorescence imaging, and Seahorse analysis were employed to study the effects of ASP on senescence phenotypes, mitochondrial health, mitophagy, and related upstream regulators. Using small interfering RNA, the study explored whether mitophagy and its regulators mediated the effects of ASP. The efficacy of ASP on muscular health was characterized in 17-18-month-old high-fat diet-induced aging mice. Our study demonstrated that 2.5 μM ASP significantly alleviated senescence-associated phenotypes and enhanced mitochondrial health in senescent C2C12 myoblasts. Mechanistic investigations revealed that ASP induced BNIP3-dependent mitophagy by modulating the FOXO3 transcription factor, thus contributing to the maintenance of mitochondrial homeostasis. Moreover, the ASP intervention at a dose of 50 mg/kg BW/day reduced fat accumulation and other pathological changes in the gastrocnemius muscle of aging mice. Similarly, ASP supplementation also improved mouse muscle function and the morphology of muscular mitochondria. This study further identified ASP as a potential natural active component for the prevention of muscle aging. It emphasized the importance of mitochondrial homeostasis and the activation of appropriate mitophagy pathways in maintaining muscle health during the aging process.