Anti-proliferative effect on normal and transformed fibroblasts. a: In vitro growth curves of human transformed (BJ-EHLT) and normal telomerised (BJ-hTERT) fibroblasts exposed to 0.5 μM of 1 (○), 2 (▲) and 3 (×) or vehicle (□). The number of viable cells was determined daily. Three independent experiments were evaluated. Error bars indicate SD. b: Histograms show the percentage of growth inhibition of BJ-EHLT and BJ-hTERT cells treated with 0.5 μM of each compound versus untreated samples at the indicated times.