Verapamil enhances cell viability and delays cellular senescence. (A) Viability of MRC-5 cells in the absence (Ctrl) or presence of verapamil (Ver) at different concentrations. (B) SA-β-Gal staining of MRC-5 cells and quantification of SA-β-Gal-positive cells at a late passage (P31). Verapamil (3 μM) delayed the senescence of MRC-5 cells (*P < 0.05). Metformin (100 μM) was used as positive control (*P < 0.05). An unpaired t-test was used to calculate the P-values and error bars represent SEM.