The Effects of Nigella Sativa Hydro-alcoholic Extract on Memory and Brain Tissues Oxidative Damage after Repeated Seizures in Rats

Regarding the therapeutic properties of Nigella sativa (NS), the effects of the plant hydro – alcoholic extract on learning, memory and brain tissues oxidative damage were investigated in penthylenetetrazole (PTZ) - induced repeated seizures. There were 4 experimental groups including: 1- control group; received saline, 2- PTZ group ; received saline and PTZ (50 mg/Kg, i.p) , 3-PTZ- NS 200 and 4- PTZ- NS 400 ; received 200 and 400 mg/Kg of NS extract respectively, before PTZ injection in 5 consecutive days. Seizure scores were lower in PTZ – NS 200 and 400, furthermore the seizure onset latencies were higher in these groups than PTZ group (P<0.05 and P<0.01 ). In Morris water maze, the time spent in target quadrant by PTZ group was lower than control group (P<0.05); while, 400 mg/Kg of the extract increased it (P<0.01). In the passive avoidance test, delay time to enter the dark by PTZ group was lower than control at 1 and 24 hours after training (P<0.01- P<0.001); while, 400 mg/Kg of the extract increased it (P<0.05). The total thiol concentration in hippocampal and cortical tissues of PTZ group was reduced while, MDA concentration was higher than control (p<0.05 - p<0.001). Administration of the extract increased the total thiol and decreased the MDA concentrations (p<0.01- p<0.001). It is concluded that the hydro-alcoholic extract of NS possess beneficial effects on learning and memory impairments in repeated seizures model which is accompanied by antioxidant effects in the brain.