Fisetin and Neurodegeneration: From Preclinical Studies to Potential Clinical Applications

Neurodegenerative diseases (NDs), like Alzheimer's disease, Parkinson's disease, Huntington's disease, amyotrophic lateral sclerosis, and multiple sclerosis, pose significant challenges due to their gradual deterioration and limited available treatments. Fisetin, a naturally occurring flavonoid, has gained attention for its neuroprotective properties. This review explores the therapeutic potential of fisetin in NDs, focusing on its molecular processes and signaling pathways. Additionally, fisetin exhibits significant protective properties, particularly in reducing oxidative stress, neuroinflammation, and apoptosis. It enhances neuronal survival and reduces neuroinflammation by regulating key pathways, such as Nrf2/ARE, PI3K/Akt, and NF-κB. It also has anti-inflammatory, anti-apoptotic, and antioxidant actions. It stimulates autophagic processes, aiding in the removal of harmful protein aggregates, like tau tangles and amyloid plaques, which are hallmarks of NDs. Fisetin, as demonstrated through behavioral evaluations in animal models, has been found to improve motor coordination, synaptic plasticity, and cognitive function. Furthermore, fisetin's potential as a neuroprotective drug is emphasized by its role in enhancing autophagy and reducing tau and amyloid pathology. Research has shown its efficacy in enhancing neural resilience, synaptic plasticity, and cognitive function in both preclinical and in vitro settings. However, clinical translation remains limited due to challenges in pharmacokinetics and bioavailability, despite robust experimental evidence. Further clinical trials are needed to evaluate the safety and efficacy of fisetin, especially in early-stage NDs, explore potential synergistic effects, and understand the molecular interactions. The review demonstrates fisetin's therapeutic potential, recent research, and future strategies for NDs, highlighting bioavailability limitations and the need for new formulations or delivery systems.