Fig. 6

Cell viability (Caco-2 line) tested by XTT method. Cells were exposed for 24 h to a suspension of ZnO NPs doped with iron in different concentrations as follows: 0.001 mg/ml; 0.01 mg/ml; 0.1 mg/ml; and 1 mg/ml. Results represent mean percentage of viable cells (±SEM) for control and experimental groups (n = 4). Significant difference of **P ≤ 0.01 vs. control was marked on the graph