From glycemic control to neuroprotection: alogliptin as a repurposed candidate for Huntington's disease

Huntington's disease (HD) is a progressive, autosomal dominant neurodegenerative disorder characterized by motor dysfunction, cognitive decline, and psychiatric disturbances, for which no disease-modifying therapies are currently available. Emerging evidence implicates metabolic impairment, mitochondrial dysfunction, oxidative stress, and neuroinflammation as central contributors to HD pathogenesis, thereby highlighting novel avenues for therapeutic intervention beyond conventional strategies. In this context, drug repurposing has gained considerable attention as an efficient approach to accelerate therapeutic development. Alogliptin has multiple complementary mechanisms of action that exert neuroprotective effects through inhibition of DPP-4 to boost endogenous incretin signaling (especially GLP-1), inhibition of inflammatory pathways, inhibition of oxidative stress, preservation of mitochondrial function, and modulation of neuronal survival signaling. The review summarizes existing data on the contribution of the incretin signaling to neuroprotection and critically analyzes the mechanism through which alogliptin might regulate important pathological events in HD, such as apoptosis, oxidative stress, and neuroinflammation. Additionally, preclinical results and pharmacological properties in favor of its translational potential are presented, as well as the reflection on its clinical usage and additional research perspectives. Even though direct evidence in HD is not extensive, the overlap of metabolic and neurodegenerative pathways offers a strong argument to study. This review identifies alogliptin as a potent repurposable agent and the necessity to conduct specific experimental and clinical research to determine its effectiveness in refining symptoms and changing the disease course in HD. This narrative review critically evaluates the available experimental evidence supporting the repurposing potential of Alogliptin for HD.