Cytotoxicity evaluation for some of the new Pd (II) complexes: synthesis, characterization and their ability to induce apoptosis study

The present study reports the design, synthesis, and comprehensive evaluation of a novel di-azo imidazole ligand and its palladium (II) complex [Pd 2 (L1)Cl 2 ] for dual applications in catalysis and anticancer therapy.The ligand was obtained via diazotization and coupling of 4-aminophenyl sulfone with 1-methylimidazole, yielding a highly conjugated scaffold capable of coordinating through both azo and imidazole nitrogen atoms.Spectroscopic and analytical characterization, including UV, FT-IR, 1 H NMR, mass spectrometry, and elemental analysis, confirmed the proposed structures.Biological evaluations focused on human lung A549 cells versus non-tumorigenic WRL-68 hepatocytes.The MTT assay revealed a pronounced, dose-dependent cytotoxicity of Pd-L, with an IC 50 in the low micromolar range for A549 cells and significantly higher values in healthy cells, suggesting a favorable therapeutic window.Quantitative real-time PCR revealed that Pd (II) complex treatment resulted in a 78% reduction in MCL-1 mRNA expression (p <0.0001), indicating activation of the intrinsic pathway.Correspondingly, caspase-3 activity increased markedly with the complex concentration, confirming apoptotic induction.