Re-purposing 5-Nonyloxytryptamine and Epirubicin as Polysialic Acid Mimetics for Protection from MPP⁺-induced Cytotoxicity in Human Neuronal Cells

Despite significant advances in Parkinson’s disease (PD) treatment, it remains incurable, with limited therapeutic options. Currently, repurposing already tested, safe drugs has emerged as an effective therapeutic strategy against various neurodegenerative diseases, including PD. Using a drug-repurposing approach, the current study investigated the neuroregenerative potential of polysialic acid mimicking compounds, 5-nonyloxytryptamine oxalate (5-NOT) and Epirubicin (Epi), an anti-cancer drug, in 1-methyl-4-phenylpyridinium (MPP+)-treated human neuroblastoma SH-SY5Y cells as a PD model.