Covalent inhibitors in Parkinson's disease: Molecular targeting strategies for neuroprotective intervention

Parkinson's disease (PD) is a complex neurodegenerative disorder characterized by dopaminergic neuronal loss, protein aggregation, and neuroinflammation. Current symptomatic therapies have not demonstrated disease-modifying effects. Covalent inhibitors represent a promising multifactorial therapeutic approach due to their ability to form irreversible and specific bonds with target proteins. This narrative review incorporates recent experimental and computational findings on emerging covalent inhibitors that target key molecular mechanisms implicated in PD. This includes α-synuclein aggregation, LRRK2 kinase hyperactivity, monoamine oxidase B (MAO-B) dysfunction, glutathione S-transferase Pi 1 (GSTP1)-mediated oxidative stress, and modulation of the Nrf2 signaling pathway. We discuss structure-guided drug design strategies, warhead chemistry, and unique inhibition modalities that contribute to improved pharmacological profiles and neuroprotective potential. In addition to classical covalent inhibition, the review explores emerging targeted covalent degrader strategies that expand therapeutic possibilities by promoting selective protein degradation rather than mere functional suppression. Furthermore, recent preclinical advances and clinical translation challenges are evaluated, positioning covalent approaches as leading candidates for targeted and sustained PD interventions. Lastly, we address developmental obstacles, such as enhancing selectivity and blood-brain barrier penetration while minimizing off-target effects, highlighting the role of activity-based protein profiling, covalent PROTACs, and bifunctional covalent degraders as next-generation strategies to optimize therapeutic efficacy in PD treatment.