Quercetin improved spatial memory dysfunctions in rat model of intracerebroventricular streptozotocin-induced sporadic Alzheimer's disease

Abstract

Background: Alzheimer's disease (AD) is one of the most common neurodegenerative syndromes characterized by a progressive decline in the spatial memory. There are convincing evidences on the neuroprotective effects of flavonoids against AD. Aims and Objective: To determine the effect of quercetin on the acquisition and retention of spatial memory in a rat model of AD. Materials and Methods: Twenty-four male Wistar rats were divided into four groups (six in each): group I: control rats receiving intracerebroventricular (ICV) injection of normal saline, group II: rats induced AD by ICV injection of streptozotocin (STZ; 3 mg/kg bilaterally; twice, on days 1 and 3), and groups III and IV: ICV-STZ AD rats treated intraperitoneally (IP) with 40 and 80 mg/kg/day quercetin, respectively, over a period of 12 days. Then, the rats were trained with four trials per day for five consecutive days in the Morris water maze (MWM). On the sixth day, the memory retention was evaluated. Result: The ICV-STZ AD groups showed a significant impairment in the acquisition and retrieval of spatial memory when compared with the control group (P o 0.001). In the AD groups, the escape latency during the training trials showed a significant decrease (P o 0.001). Meanwhile, during the MWM task, these rats spent more time in the target quadrant in probe trials when compared with the controls. Conclusion: Quercetin acted as a spatial memory enhancer in ICV-STZ-induced AD rats. Hence, this flavonoid can be considered potentially as a promising agent for developing prophylactic and therapeutic neuroprotection. This neuroprotective effect of quercetin may be attributed to its antioxidant and scavenging properties.

Everolimus, a mammalian target of rapamycin inhibitor, ameliorated streptozotocin-induced learning and memory deficits via neurochemical alterations in male rats

“…To do so, EVR was intraperitoneally (ip) injected to AD rats on days 21-28 post-STZ injection, one hour before the behavioral study. As our preliminary experiments, along with other studies, showed that learning and memory impairments were established at day 21 post-STZ administration (Ashrafpour et al, 2015[ 5 ]; Mehla et al, 2013[ 50 ]; Salkovic-Petrisic et al, 2013[ 67 ]). Experiment II was carried out to evaluate the effect of the mTORC1 inhibitor on the progress of Alzheimer's disease (groups 1, 2, 5-7).…”

Anticholinesterase and antioxidant activities of foliar extract from a tropical species: Psidium guajava L. (Myrtaceae) grown in Algeria

“…The antioxidant effect of P. guajava fruit might also be beneficial in protecting the brains of rodents against oxidative stress [50]. A previous study confirmed the effect of quercetin on the acquisition and retention of spatial memory in a rat model of Alzheimer's disease and concluded that there is convincing evidence on the neuroprotective effects of flavonoids against Alzheimer's disease [51]. According to the studies cited above, P. guajava leaves contain quercitin.…”

Nootropic and Anti-Stress Effects of Allium Cepa Bulb and Quercetin in Male Mice

“…However, quercetin (500 mg/day) administration for 12 weeks failed to exhibit a significant effect on neurocognitive functioning in humans, raising concern the clinical translation of results from in vitro and in vivo animal studies [63]. Quercetin enhanced the spatial memory in aged and ethanol intoxicated mice through it antioxidant and scavenging properties [64]. Mohammadi, et al (2014) reported that quercetin alleviated the deleterious effects of chronic stress on learning and memory in rats, improving its cognitive deficit by suppressing the oxidative stress and plasma corticosterone level.…”