Effects of quercetin on the learning and memory ability of temporal lobe epilepsy in rats

Abstract

Objective To explore the effects and mechanisms of quercetin on the learning and memory ability of temporal lobe epilepsy (TLE) in rats. Methods Forty-five male Sprague-Dawley rats were randomly grouped into control, TLE model and quercetin treatment group (40 mg/kg). Lithium-pilocarpine was used to establish TLE rat model by intraperitoneal injection.Morris water maze test was carried out to determine the navigation ability and space exploration ability of rats.The levels of total antioxidant capacity (T-AOC), superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) were detected by commercial kits.The Nrf2 and brain-derived neurotrophic factor (BDNF) mRNA levels were quantified with real-time PCR.Escape latency, residence time, enzymatic activities in hippocampal among groups were compared by one-way analysis of variance. Results The escape latency in the Morris water maze test was longer in TLE model group than that in the control group.After removing platform, the percentage of time in the probe quadrant was shorter in TLE group than that in control group(on the third/fourth/fifth day, F=123.49, 162.49, 98.01; P<0.05). Quercetin significantly shortened the escape latency and prolonged the time in probe quadrant of TLE rats (F=107.58, P<0.05). The levels of antioxidant indicators T-AOC, SOD, CAT and GSH-Px in quercetin treatment group were higher than those in other two groups(F=99.21, 205.37, 20.06, 92.97; P<0.05)and Nrf2 mRNA expression was down-regulated in hippocampus of TLE rats, which was reversed by quercetin (F=374.74, P<0.05). In addition, the BDNF mRNA was markedly up-regulated in TLE hippocampus, but down-regulated by quercetin (F=323.34, P<0.05). Conclusions Quercetin can increase the learning and memory ability of TEL rats, and the elevated antioxidant levels of hippocampus may contribute to this process. Key words: Epilepsy temporal lobe; Flavones; Hippocampus; Cognition Disorders; Oxidative stress