The effect of silymarin on prevention of hippocampus neuronal damage in rats with temporal lob epilepsy

Background and Objective: 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 of silymarin (SM), this study was undertaken to evaluate the preventive effect of this agent on structural changes in hippocampus of kainate-epileptic rats. Materials and Methods: In this study, 32 male rats were divided into sham, SM-treated sham, epileptic, and SM-treated epileptic group. Rat model of epilepsy was induced by unilateral intrahippocampal administration of 0.8 ?g kainic acid per rat. Rats received SM (100 mg/kg, i.p.) daily for 3 days before the surgery. Finally, brain sections were stained with Nissl and Timm methods. Results: Induction of epilepsy was followed by a significant seizure and SM pretreatment did not lower seizure intensity. In addition, density of Nissl-stained neurons in CA3 and CA4 areas of hippocampus was significantly lower in epileptic rats versus sham (p < 0.05) and SM pretreatment did not significantly prevented it in. Regarding mossy fiber sprouting, epileptic rats showed a higher degree of sprouting as compared to sham group (p < 0.01) and SM pretreatment did not significantly lowered it. Conclusion: SM pretreatment does not reduce seizure intensity, could not preserve hippocampal neurons and could not lower mossy fiber sprouting in kainate-induced epileptic animals.