Figure 4.

Effect of pan-caspase inhibitor Z-VAD-FMK on the cell viability (MTT assay) affected by MEV pathway modulators (atorvastatin—ATR, simvastatin—SIM). Differentiating C2C12 myoblasts were exposed for 24, 72, or 120 h to statins (IC₅₀), (Day 1—proliferating myoblasts; Day 3—differentiating myotubes; Day 5—differentiated myotubes). ATR diminished the fraction of viable cells (IC₅₀). Z-VAD-FMK itself did not affect cell viability, moreover, it could not recover ATR- or SIM-treated proliferating myoblasts (p > 0.05), but it significantly increased viable differentiating and differentiated myotubes treated with ATR or SIM (p < 0.05 and p < 0.001, respectively). * p < 0.05, *** p < 0.001, for comparison between the means. Statistically significant differences for untreated control cells are marked by # (at least at the level of p < 0.05). The results are indicative of three independent experiments performed in eight replicates.