Background and Objective: Pathologically, temporal lobe epilepsy is hallmarked with neuronal degeneration in some areas of hippocampus and mossy fiber sprouting in dentate area. Considering some evidences on neuroprotective and antioxidant activity Nigella sativa (NS), this study was undertaken to evaluate the preventive effect of NS on structural changes in hippocampus of kainate-epileptic rats.
Materials and Methods: In this study, 28 male rats were divided into sham, NS-treated sham, epileptic, and NS-treated epileptic group. Rat model of epilepsy was induced intrahippocampal administration of 0.8 μg kainic acid per rat. Rats treated by intraperitoneal administration of alcoholic extract of NS daily for 1 week before surgery. Finally, brain sections were stained with Nissl and Timm methods.
Results: Induction of epilepsy by kainic acid was followed by a significant seizure and NS pretreatment significantly attenuated seizure intensity. Density of Nissl-stained neurons in CA1, CA3, and CA4 of hippocampus was significantly lower in epileptic rats versus sham (P < 0.05-0.01) and NS extract pretreatment significantly increased it only in CA3 zone (p < 0.05). Regarding mossy fiber sprouting, epileptic rats showed a higher degree of sprouting as compared to sham group (p < 0.005) and NS pretreatment significantly lowered it (p < 0.05).
Conclusion: Pretreatment with alcoholic extract of Nigella sativa reduces seizure intensity and could preserve neurons in some area of hippocampus and could lower mossy fiber sprouting.
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