Sinensetin regulates age-related sarcopenia in cultured primary thigh and calf muscle cells

BACKGROUND: Sarcopenia, the decline of skeletal muscle tissue attributed to primary aging is a major concern in older adults. Flavonoids might have potential benefits by modulating the regulation of satellite cells, thus preventing muscle loss. Sinensetin (SIN), a citrus methylated flavone with anti-inflammatory and anti-proliferative activity, can enhance lipolysis. The objective of the present study was to investigate whether SIN might have sarcopenia-suppressing effect on satellite cells from thigh and calf muscle tissues of young and old rats. METHODS: Primary muscle cells were obtained from thigh and calf tissues of young and old group rats by dissection. Obtained satellite cells were incubated with indicated concentrations of SIN (50 and 100 μM) treated and untreated condition in differentiation medium. Morphological changes of cells were examined using a phase-contrast microscope. Protein expression levels of myoD and myogenin were analyzed by Western blot. Cells treated with or without SIN under differentiation condition were also immunocytochemically stained for myogenin and 4',6-diamidino-2-phenylindole (DAPI). RESULTS: Morphologically, the differentiation extracted satellite cells was found to be more evident in SIN treated group of aged rat's cells than that in SIN untreated group. Expression levels of myoD and myogenin proteins involved in myogenesis were increased upon treatment with SIN. CONCLUSIONS: Collectively, our results indicate that SIN can alleviate age-related sarcopenia by increasing differentiation rate and protein levels of myoD and myogenin.