Metabolomics reveals that alcohol extract of propolis alleviates D-gal-induced skeletal muscle senescence in mice

Propolis is an important functional food with numerous biological properties, such as anti-oxidation, anti-inflammation, and immune regulation. However, there are few studies on the effects of propolis on aging-induced muscle atrophy. Here, we aimed to determine whether propolis exerts protective effects against muscle damage caused by d-galactose (D-gal)-induced aging in mice. Propolis was found to ameliorate the morphological alterations generated by D-gal in muscle fibers and considerably increase their cross-sectional area and diameter; ameliorate muscle oxidative stress by boosting Nrf2 and HO-1 expression and Nrf2 nuclear translocation; reduce apoptosis in muscle cells by dramatically increasing Bcl2 expression and decreasing Bax expression; and significantly decreased the level of MAFbx and MuRF1, thus inhibiting skeletal muscle proteolysis. Metabonomic studies showed that propolis can promote protein metabolism and reduce oxidative stress in skeletal muscle. Propolis may reduce prostaglandin and estriol levels by increasing the blood supply to aging skeletal muscles and reducing the lipid peroxide tablets. Propolis may inhibit skeletal muscle cell apoptosis by suppressing isoprenaline metabolism in skeletal muscle, thus playing a role in anti-skeletal muscle aging. Propolis delays skeletal muscle aging by reducing oxidative stress, inhibiting apoptosis, and regulating muscle protein metabolism.