The effects of thymoquinone on spatial and non -spatial memory impairment induced by scopolamine and the brain tissues oxidative damage in rats.

Beheshti, Farimah; Hoseini, Mahmoud; sadeghi Ghuzhdi, Niloufar; Aghili, Sasan

Introduction: In the present study, we aimed to examine the potential protective effects of thymoquinone (TQ) on spatial and non -spatial memory impairment induced by scopolamine (Sco) and the brain tissues oxidative damage in rats. Methods: The rats were divided into four groups: 1) Control, 2) Scopolamine (Sco, 3) Sco- TQ 10 and 4) Sco- TQ 20. Pretreatment with 10 or 20 mg /kg of TQ (dissolved in saline supplemented by ethanol) was done before behavioral test for 2 weeks in groups 3 and 4. Scopolamine (2 mg/kg b.w., i.p.) was administered 30 min before Morris water maze (MWM) test and passive avoidance in groups 2-4. Finally the brains were removed for biochemical assessments. Results: In MWM, the escape latency in the Sco group was significantly higher while, the time spent in target quadrant lower than control group (both P<0.001). Pretreatment with 10 and 20 mg/kg TQ before scopolamine administration improved scape latency compared to Sco group (respectively P<0.01, P<0.001). Both 10 and 20 mg/ kg of TQ increased the time spent in target quadrant compare with Sco group (respectively P<0.01, P<0.001). In passive avoidance test, Sco decreased time latency for entering to dark room (P<0.01). Both doses of TQ prolonged the latency to enter the dark (P < 0.05- P < 0.001). Sco increased MDA concentration while, decreased total thiol concentration and superoxide dismutase (SOD) and catalase activity in hippocampus and the brain cortex (P<0.05). Treatment by 10 and 20 mg/kg TQ decreased MDA while, increased total thiol, SOD and catalase compared to Sco group (P<0.05). Conclusion: These results allow us to propose that pretreatment with TQ have positive effects on learning and memory. The effect might be due to the anti-oxidative effects.

OXIDATIVE stress; QUINONE; SPATIAL memory; MEMORY disorders; BRAIN physiology; LABORATORY rats; THERAPEUTICS

Medical journal of Mashhad University of Medical Sciences, 2016, Vol 59, p62

1735-4013

Academic Journal