Introduction:
Alzheimer’s disease (AD) as the most prevalent figure of dementia, is considered as a neurodegenerative disease leading to the impairment of cognitive function and memory. In this study, we have investigated the therapeutic and preserving effects of vinpocetine (a phosphodiesterase 1 inhibitor) on the animal model of AD induced by intracerebroventricular (ICV) injection of beta-amyloid (Aβ) with using of behavioral and electrophysiological methods.in rats.Material and method: Sixty male adult Wistar rats were randomly divided into 6 groups (n = 10 rats/group): 1- control, 2- Sham, 3- Aβ, 4- Pre-treatment (Vin + Aβ): vinpocetine administration ((4 mg/kg) by gavage) for 30 days, then followed by Aβ ICV injection, 5- Treatment (Aβ + Vin): Aβ ICV injection, then treating by vinpocetine for 30 days, 6- Pre-treatment + treatment (Vin + Aβ + Vin): vinpocetine administration for 30 days before and 30 days after induction of AD. Finally, behavioral and electrophysiological studies were examined respectively and oxidative and antioxidant compounds were measured.Results: The results demonstrated that Aβ significantly enhanced escape latency and the distance traveled in the Morris water maze (MWM), decreased step-through latency and increased time spent in the dark compartment in PAL.
Vinpocetine ameliorated the Aβ infused memory failure in both MWM and passive avoidance learning (PAL) tests. In addition, administration of vinpocetine in the Aβ rats increased the discrimination index of the novel object recognition (NOR) test. Also, vinpocetine in all three forms of pretreatment, treatment and pretreatment + treatment improved LTP in granular dentate gyrus by increasing the EPSP slope and PS amplitude compared to the Aβ group. It also significantly diminished the nitric oxide and malondialdehyde (MDA) levels and restored the reduced glutathione (GSH) levels.Conclusion: According to the results, it can be suggested that vinpocetine could improve the learning and memory impairment and synaptic plasticity following Aβ induction base on the some vinpocetine properties including antioxidant effects and indicate that vinpocetine administration can lead to an amelioration of cognitive dysfunction in AD.