Figure 3. MTS cell proliferation assay to demonstrate the inhibitory effect on proliferation of the three melanoma cell lines: M23 cell (Upper panel), OCM1 cell (Center panel), and SP6.5 cell (Bottom panel). For M23 and SP6.5 cells, HDP-PMEG demonstrated a similar inhibitory effect to 5-FU while HDP-PMEG had a consistent stronger inhibitory effect than 5-FU on the OCM1 cell. Daunorubicin had the strongest inhibitory effect on all the three cell lines.