Cell-growth assay (WST-8) at 12 hours (a) and at 24 hours (b) after the addition of skeletal muscle supernatant (n = 10) (*; p < 0.01, **; p < 0.05). The PBS group was treated with 5 μL PBS and the Supernatant group was treated with 5 μL of muscle supernatant (n = 10). Data are shown as means and standard deviation (*; p < 0.01,**; p < 0.05). The asterisks indicate that cell growth in the group treated with skeletal muscle supernatant was significantly higher than that of the PBS-treated group both at 24 and 72 hours.