Background: Brominated 8-hydroxy, 8-methoxy, 8-amino quinolines 5, 6, 8, 9 and novel
cyano 8-hydroxyquinolines 11, 12 were evaluated in vitro for their anticancer effects on various cell
lines. 5,7-Dibromo- 5, 7-bromo- 6, 7-cyano- 11 and 5,7-dicyano-12 8-hydroxyquinolines were
shown to have strong antiproliferative activity against various tumor cell lines, including C6 (rat
brain tumor), HeLa (human cervix carcinoma), and HT29 (human colon carcinoma) with IC50 values
ranged from 6.7 to 25.6 µg/mL.
Methods: A structure activity relationship (SAR) was conducted that quinoline core containing
hydroxly group at C-8 positon led to more anti cancer potentials.
Results: The results of Lactate Dehydrogenase (LDH) cytotoxic, DNA laddering and inhibition
assays indicated that 5, 6, 11 and 12 have high cytotoxic effects and appototic potentials.
Conclusion: Furthermore, 5 and 12 have inhibitory effects on relaxation of supercoiled plazmid
DNA by supressed the Topoisomerase I enzyme. As a result, 5, 6, 11 and 12 may have promising
anticancer drug potential and 5 and 12 may be novel topoisomerase inhibitors.