A Novel Oral Edaravone Formulation Partially Alleviates Tau Pathology and Motor Deficits in an Animal Model of Frontotemporal Dementia

Abstract Oxidative stress (OS) is a key factor in the pathogenesis of several neurodegenerative disorders and is involved in the accumulation of amyloid beta plaques and Tau inclusions. Edaravone (EDR) is a free radical scavenger that is approved for motor neuron disease and acute ischemic stroke. EDR alleviates pathologies and cognitive impairment of AD via targeting multiple key pathways in transgenic mice. Herein, we aimed to study the effect of EDR on Tau pathology in an animal model (P301L mice) of frontotemporal dementia (FTD) at two age time points representing the early and late stages of the disease. A novel EDR formulation was utilized in the study and the drug was delivered orally in drinking water for 3 months. Then, behavioral tests were conducted followed by animal sacrifice and brain dissection. Treatment with EDR improved the cognitive deficits as evaluated in Morris water maze, novel object recognition and significantly alleviated motor deficits in these mice. EDR also reduced the levels of 4-hydroxy-2-nonenal (4-HNE) and 3-nitrotyrosine (3-NT) adducts. In addition, immunohistochemistry showed that EDR reduced tau phosphorylation and neuroinflammation and partially rescued neurons against oxidative neurotoxicity. Moreover, EDR attenuated downstream pathologies involved in Tau hyperphosphorylation. These results suggest that EDR may be a potential therapeutic agent for the treatment of FTD.