Selective cytotoxic and genotoxic activities of 5-(2-bromo-5-methoxybenzylidene)-thiazolidine-2,4-dione against NCI-H292 human lung carcinoma cells

Background

Thiazolidine-2,4-dione ring system is used as a pharmacophore to build various heterocyclic compounds aimed to interact with biological targets. In the present study, benzylidene-2,4-thiazolidinedione derivatives (compounds 2–5) were synthesized and screened against cancer cell lines and the genotoxicity and cytotoxicity of the most active compound (5) was investigated on normal and lung cancer cell line.

Methods

For in vitro cytotoxic screening, the MTT assay was used for HL60 and K562 (leukemia), MCF-7 (breast adenocarcinoma), HT29 (colon adenocarcinoma), HEp-2 (cervix carcinoma) and NCI-H292 (lung carcinoma) tumor cell lines and Alamar-blue assay was used for non-tumor cells (PBMC, human peripheral blood mononuclear cells) were used. Cell morphology was visualized after Giemsa-May-Grunwald staining. DNA content, phosphatidylserine externalization and mitochondrial depolarization were measured by flow cytometry. Genotoxicity was assessed by Comet assay.

Results

5-(2-Bromo-5-methoxybenzylidene)-thiazolidine-2,4-dione (5) presented the most potent cytotoxicity, especially against NCI-H292 lung cancer cell line, with IC₅₀ value of 1.26 μg/mL after 72 h incubation. None of the compounds were cytotoxic to PBMC. After 48 h incubation, externalization of phosphatidylserine, mitochondrial depolarization, internucleosomal DNA fragmentation and morphological alterations consistent with apoptosis were observed in NCI-H292 cells treated with compound (5). In addition, compound (5) also induced genotoxicity in NCI-H292 cells (2.8-fold increase in damage index compared to the negative control), but not in PBMC.

Conclusion

Compound 5 presented selective cytotoxic and genotoxic activity against pulmonary carcinoma (NCI-H292 cells).