Effect on mouse fibroblasts after induced oxidative stress. Effect of different concentrations (1–10 mg/ml) of freeze-dried myrtle berry homogenates on the cell viability of mouse fibroblasts after oxidative stress. Mouse fibroblasts were cultured in Dulbecco’s Modified Eagle Medium (DMEM), and incubated with re-suspended freeze-dried homogenates for 16 h. Oxidative stress was artificially induced by incubating cultured cells with 400 μM hydroxide peroxide for 2 h. The percentage of viable cells was measured through the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The viability of H2O2-stressed cells incubated without antioxidant compounds (reference, rf) was also included. A myrtle homogenate fermented for 48 h at 30°C with Lactobacillus plantarum C2 (Mf) and a myrtle homogenate non-inoculated and chemically acidified, incubated under the same conditions (Mct), were assayed at concentration ranging from 1 to 10 mg/ml. α-Tocopherol (α-tp; 250, 500, and 1000 μM) was used as the positive control. rf: H2O2-stressed cells. Data are the means of three independent experiments twice analysed. a-eColumns with different superscript letters differ significantly (P < 0.05).