Figure 1.

MTS assay of hydroxytyrosol treated melanoma cells. (A) Structure of hydroxytyrosol. A375 (B), HT-144 (C), and M74 (D) melanoma cells were treated with 50 μM, 100 μM, 200 μM, and 250 μM of hydroxytyrosol for 24 h, 48 h, and 72 h. The mean values of almost three different experiments performed in triplicate are reported in the histograms (B–D). The error bars indicate the standard deviation and statistical significance was analysed by Student’s t-test: * p < 0.05 was considered significant; ** p < 0.01 highly significant; *** p < 0.001 very highly significant.