Design and Biological Evaluation of Palladium(II)–Phosphine–Benzimidazole Complexes as Dual Antioxidant and Antiangiogenic Agents

High Resolution Image Download MS PowerPoint Slide The present study describes the design, synthesis, and characterization of two novel palladium(II) complexes incorporating phosphine and benzimidazole ligands, followed by a comprehensive evaluation of their antioxidant and antiangiogenic properties. The complexes were fully characterized using spectroscopic and analytical methods. Antioxidant capacity was investigated through a multiassay approach, including ferrous ion-chelating activity, reducing power, and ABTS •+ radical cation decolorization. Antiangiogenic activity was evaluated in vivo using the chick chorioallantoic membrane (CAM) assay. Palladium complex 1 exhibited the strongest ferrous ion-chelating ability (71.91% inhibition) and the highest ABTS •+ scavenging activity (49.79%), while Palladium complex 2 demonstrated superior reducing power (EC 50 = 1.06 mg/mL). Both complexes showed strong antiangiogenic effects, with Palladium complex 1 achieving an average inhibition score of 0.90─comparable to the positive control (±)-thalidomide─and without observable irritation or toxicity. These results indicate that both complexes possess potent biological activities; however, the overall antioxidant and antiangiogenic profile of Palladium complex 1 suggests it may be particularly promising as a redox-modulating agent targeting oxidative stress–induced angiogenesis. To the best of our knowledge, this is the first report of palladium–phosphine–benzimidazole complexes demonstrating such dual activity, highlighting their potential as multifunctional candidates in cancer-related therapeutic research.