Fig. 1: Selection of growth culture condition for experiments on A6 cells

a Histograms  of cell cycle phase distribution: control cells 'C' and treated cells for 24 h with H₂O₂: 50, 100, 200, and 400 μM. b Effects of oxidative stress on cell viability: control cells 'C' and treated cells for 24 h with 50, 100, 200, and 400 μM. H₂O₂ assayed by trypan blue exclusion assays. c Histograms of cell cycle phase distribution during 24 h of treatment: control cells 'C' and treated cells with 400 μM H₂O₂ for 4, 8, 14 and 24 h. All data in histograms A, B and C were obtained from three independent experiments. The error bars indicate standard deviation. **P < 0.05, ***P < 0.005 vs control group. p38 is responsible for cell cycle progression. d-e Phosphorylated p38 kinase level of A6 cells after a 400 μM H₂O₂ 24 h treatment. Western blot d and quantification e of the two phosphorylated p38 kinase isoforms. Phosphorylated p38 levels in control A6 cells 'C' and in treated A6 cells (400 μM H₂O₂ for 4, 8, 14, 24 h). The levels of p38 were valuated after quantification of immunoreactive bands by Quantity One software. Data were obtained from three independent experiments. The error bars indicate standard deviation. f Histograms of cell  cycle phase distribution of treated A6 cells in presence of the p38 inhibitor SB202190. Control A6 cells 'C', treated A6 cells (400 μM H₂O₂ for 24 h) '24 h', treated (as 24 h) A6 cells with p38 inhibitor '24 h + SB202190'. Displayed are typical histograms from three independent experiments. Error bars indicate standard deviation