Objective: Non-small cell lung cancer (NSCLC), the most prevalent type of lung cancer, remains the leading cause of cancer-related deaths worldwide. Late-stage diagnosis and resistance to conventional treatments highlight the need for further research into its molecular mechanisms. This study aimed to evaluate the anticancer effects of several benzoxazole derivatives (2-(4-tert-butylphenyl)-5-nitrobenzoxazole (1a), 2-(4-tert-butylphenyl)-6-nitrobenzoxazole (1b), 2-(2,3-dimethylphenyl)-5-nitrobenzoxazole (2a), and 2-(2,3-dimethylphenyl)-6-nitrobenzoxazole (2b)) on the viability of A549 cells.
Materials and Methods: Cell viability was assessed using the MTT assay. We also performed a molecular docking study to investigate the interactions between the benzoxazole derivatives and caspase-3, a key executioner caspase involved in apoptosis.
Results: The benzoxazole derivatives coded 1a, 1b, 2a, and 2b exhibited anticancer activity against A549 cells, with half-maximal inhibitory concentration (IC50) values of 17.41±0.16, 20.50±0.08, 32.17±0.08, and 31.13±0.07 µM, respectively. Among the tested benzoxazoles, 1a and 1b showed activity comparable to cisplatin (IC50=19.65±0.09 µM). According to the docking results, all compounds demonstrated satisfactory docking scores ranging from -4.339 to -5.202 kcal/mol.
Conclusion: Our results demonstrate that the benzoxazole derivatives 1a and 1b exhibit significant anticancer effects by inhibiting lung cancer cell proliferation at low concentrations, similar to cisplatin. The structure-activity relationship suggests that substitution of a phenyl group at the 2-position of the benzoxazole ring with a tert-butyl group at the para position enhances anticancer activity against A549 cells. This preliminary study indicates that these benzoxazole derivatives have promising potential as cytotoxic agents for the treatment of NSCLC.