2.7. Caspase-3 assay
Caspase activity was measured by using Caspase-Glo 3/7 assay kit (Promega
Corporation, Australia). Briefly, SK-MEL-28 cells (1 104 cells/well) were seeded
in a luminometer plate (BD Biosciences, USA) and incubated for 24 h at 37 C. Cells
were then treated with different concentrations of individual compound for 48 h.
In parallel, cell number after treatment was measured by crystal violet assay
to normalize the result. To each well, 50 ll of caspase 3/7 reagents were added
and the luminescence was recorded every 10 min for 1 h at 28 C in a microplate
reader.