Spinelli_2026_Bioorg.Chem_171_109566

Alzheimer's disease (AD) is a multifactorial and progressive neurodegenerative disorder for which no effective treatment currently exists. The development of multitarget-directed ligands (MTDLs) capable of simultaneously modulating several pathological pathways represents a rational strategy to address its complex etiology. In this study, we report the isolation, chemical synthesis, and functional characterization of BcI-4, a short cationic peptide identified from the skin secretion of the Argentinean frog Boana cordobae. The peptide exhibited potent and reversible inhibitory activity against acetylcholinesterase (AChE), with IC50 values of 1.10 and 0.9 microM for recombinant human and Electrophorus electricus AChE, respectively, acting through a non-competitive mechanism involving the peripheral anionic site (PAS). BcI-4 also inhibited AChE-induced beta-amyloid (Abeta) aggregation, showed modest monoamine oxidase B (MAO-B) inhibition, and displayed both antioxidant and metal-chelating activities, including inhibition of lipid peroxidation. The peptide retained the multifuctional pharmacological profile previously observed for the crude extract of B. cordobae, with significantly enhanced potency and selectivity toward AChE. Moreover, BcI-4 was non-toxic in vitro (hemolysis and HeLa cell assays) and in vivo (Artemia salina test) even at the highest concentrations tested. Altogether, these findings position BcI-4 as a nature-inspired multitarget peptide with neuroprotective potential, combining reversible AChE inhibition, anti-amyloid, antioxidant, and MAO-B modulatory activities. BcI-4 represents a promising lead compound for the development of peptide-based therapeutics against AD.