Normal (3A) or melanoma cell lines (3B) were treated with empty liposome, Celecoxib liposome (100 μmol/L), Plumbagin liposome (5 μmol/L), or CelePlum-777 (100 μmol/L Celecoxib + 5 μmol/L Plumbagin) for 24, 48, and 72 hours and cell survival assessed by MTS assay. Data represent averages of at least 3 independent experiments; bars, S.E.M.