The Amyloid Beta Aggregation Inhibition Properties of New Pt (II) Complexes and Their Potential in Alzheimer's Treatment

In this study, N-phenylortho-phenylenediamine and N-phenyl ethylenediamine were utilized as amines, and two novel ligands, benzimidazole (LI) and Schiff base (LII), were synthesized through condensation reactions with 3-methoxy-4-benzyloxybenzaldehyde. Furthermore, using these same amines, LIII (benzimidazole) with 3-phenoxybenzaldehyde and LIV (Schiff base) with 4-benzyloxybenzaldehyde were synthesized in accordance with the literature. Then, Pt (II) complexes (Ia, Ib, II, III, and IV) were prepared with these ligands, and it was determined that Ia and Ib are geometric isomers. The ligands and complexes were characterized using ¹H-NMR, ¹³C-NMR, FT-IR, and elemental analysis methods. The cytotoxic effects of these complexes were evaluated on SH-SY5Y neuronal cells. Low-toxicity complexes Ia, II, and IV were then tested for their ability to inhibit amyloid beta (Aβ_1–42) aggregation. Thioflavin T fluorescence analysis, AFM imaging, and MALDI-TOF mass spectrometry demonstrated that these complexes, particularly at a 1:1 complex-to-amyloid molar ratio, effectively inhibited Aβ aggregation. These findings suggest that Pt (II) complexes containing Schiff base and benzimidazole ligands may be effective against Alzheimer's disease by alleviating Aβ toxicity.