Unexpected Mechanisms of Repurposed Drugs in the Pathogenic Pathways of Neurodegenerative Diseases. Discovering New Neuroprotective Therapies in Cellular Models.

Advances in biomedicine have increased life expectancy, leading to a growing prevalence of age-related neurodegenerative diseases such as Alzheimer's and Parkinson's disease, alongside disorders of genetic or environmental origin including multiple sclerosis, Huntington's disease, and amyotrophic lateral sclerosis. Despite their diverse etiologies, these conditions share convergent pathogenic mechanisms-calcium overload, neuroinflammation, and oxidative stress-that drive neuronal apoptosis and progressive neurodegeneration. Developing therapies that effectively target these interconnected pathways remains a major challenge. Here, we applied a drug-repurposing pipeline integrating computational chemistry, calcium channel affinity prediction, and in vitro validation in SH-SY5Y and HEK293 cells. Eight clinically approved CNS drugs were screened for activity against Caᵥ1, Orai1, and P2X7 channels, and subsequently evaluated in neuroprotection assays. Several compounds demonstrated significant efficacy, with chlorpromazine showing broad-spectrum activity (neuroprotection, Caᵥ1.2 and P2X7 antagonism, anti-inflammatory effects), trimipramine emerging as a potent antioxidant, and vilazodone displaying synergistic neuroprotection in combination with procyclidine. These findings reveal multi-target pharmacological profiles in well-tolerated drugs not currently used for neurodegenerative indications. By highlighting both individual and combinatorial strategies, this work provides a foundation for translational studies aimed at repurposing approved agents for complex neurological disorders, with particular relevance to Parkinson's disease.