Beneficial effects of levetiracetam in streptozotocin-induced rat model of Alzheimer's disease

Alzheimer's disease (AD) is the most common neurodegenerative disorder among the elderly. In the light of increasing AD prevalence and lack of effective treatment, new strategies to prevent or reverse this condition are needed. Levetiracetam (LEV) is a newer antiepileptic drug that is commonly used to treat certain types of seizures. Researches indicated that LEV has several other pharmacological activities, including improvement of cognitive function. In this study, the recovery effects of chronic (28 days) administration of LEV (50, 100, and 150 mg/kg, ip) on cognitive deficits caused by the intracerebroventricular (icv) injection of streptozotocin (STZ), as a model for sporadic AD, were evaluated in rats. We also considered the protective effects of LEV against hippocampal cell loss, oxidative damage, acetylcholinesterase (AChE) activity, neuroinflammation, and tauopathy caused by STZ. LEV (100 and 150 mg/kg) significantly attenuated the STZ-induced learning and memory impairments in the passive avoidance and Morris water maze (MWM) tasks. In addition, LEV suppressed STZ-induced hippocampal neuronal loss, while restored alterations in the redox status (lipid peroxides and glutathione), AChE activity, proinflammatory cytokines (IL-1 beta, IL-6, TNF-alpha), and hyperphosphorylation of tau linked to STZ administration. In conclusion, our study demonstrated that LEV alleviated hippocampal cell death and memory deficits in STZ-AD rats, through mitigating oxidative damage, suppression of proinflammatory cytokines expression, and inhibition of abnormal tau hyperphosphorylation.