Background and Objectives: Cancer is one of the leading causes of death in the world affecting millions
of people. The commercially available anticancer drugs lack the selectivity and show several undue side
effects during the biologically targeted therapy, thus calling for the exploration of wider chemical space to furnish
new structural leads with promising anticancer potential. In this endeavor, we synthesized a series of coumarinyl
thiazolotriazoles with diverse functional group tolerance and will be tested for their anticancer properties
against cancer cell lines (HeLa and MCF-7) and a normal cell line (BHK-21).
Materials and Methods: To overcome such complications, in the current study, we evaluated the cytotoxic effects
of coumarinyl thiazolotriazole hybrids on human breast adenocarcinoma (MCF-7), cervical adenocarcinoma
(HeLa) cells and normal cells i.e., Baby Hamster Kidney cells (BHK-21) using MTT (dimethyl-2-thiazolyl-
2,5-diphenyl-2H-tetrazolium bromide) assay. DNA binding studies of compound 6c was performed on Herring-
Sperm DNA (HS-DNA) and docking studies were also carried out. The mechanistic studies were performed
on potent compounds by fluorescent microscopic studies, release of Lactate Dehydrogenase (LDH) and
mitochondrial membrane potential, activation of caspase-9 and -3 and flow cytometric analysis.
Results: As revealed by MTT assay, compounds 6m and 6c were identified as the most potent derivatives
among the tested series with IC50 values of 5.64 and 29.1 μM against HeLa and MCF cells, respectively as compared
to cisplatin which gave IC50 values of 11.3 and 6.20 μM, respectively. DNA binding studies of compound
6c showed the binding of compound in DNA with Gibbs free energy of ‒17 KJ/mol and docking studies validated
the DNA binding studies. Fluorescent microscopic studies using 4′,6-diamidino-2-phenylindole (DAPI) and
Propidium Iodide (PI) staining confirmed the occurrence of apoptosis in HeLa cells treated with the most active
compound 6m. Moreover, compounds 6m and 6c also triggered the release of Lactate Dehydrogenase (LDH) in
treated HeLa and MCF-7 cells while a luminescence assay displayed a remarkable increase in the activity of
caspase-9 and -3. Moreover, flow cytometric results revealed that compound 6m caused G0 /G1 arrest in the
treated HeLa cells.
Conclusion: Our results suggested that the compound possesses chemotherapeutic properties against breast cancer
and cervical adenocarcinoma cells, thus warranting further research to test the anticancer efficacy of this
compound at clinical level.