The Cell Proliferation ELISA, BrdU (colorimetric) assay was also
performed to quantitate cell proliferation based on the measurement
of BrdU incorporation during DNA synthesis in replicating
(cycling) cells. Interestingly, the compounds tested in this assay
caused DNA synthesis inhibitory effects on A549 cell line, whereas
the compounds did not exhibit DNA synthesis inhibitory activity
against C6 cell line. This outcome demonstrated the selective DNA
synthesis inhibitory effects of the compounds on A549 cells. It can
be attributed to the structural differences between A549 human
lung adenocarcinoma and C6 rat glioma cell lines.