Figure 1

Cell viability of mouse fibroblasts. Effect of different concentrations (1 – 1000 μg/ml) of freeze-dried Echinacea suspension (ES) on cell viability of mouse fibroblasts cultured in Dulbecco’s Modified Eagle Medium (DMEM), and incubated with re-suspended freeze dried ES for 16 h. Oxidative stress was artificially induced by incubating cultured cells with 150 μM hydroxide peroxide for 2 h. The percentage of viable cells with respect to untreated cultures was measured through the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. ES fermented for 24 h at 30°C with Lactobacillus plantarum 1MR20 (1MR20-ES), C2 (C2-ES) and POM1 (POM1-ES), and with the association between strains 1MR20 and C2 (1MR20/C2-ES) were assayed. ES-CT, chemically acidified ES, without bacterial inoculum, and incubated for 24 h at 30°C, was the control. α-Tocopherol (α-t1, 250 μg/ml, and α-t2, 500 μg/ml) was used as the positive control. Data are the means of three independent experiments twice analysed.