Reversal of Phenytoin-induced Cognitive Impairment by Acorus Calamus in Mice

The study deals with the investigation of the effect of methanolic extract of Acorus calamus rhizomes on phenytoin induced cognitive impairment in mice using passive-avoidance task, locomotor activity and acetylcholinesterase enzyme estimation. The regular administration of Phenytoin (75 mg/kg) showed cognitive impairment in passive avoidance task method by decreasing Step-Down Latency (SDL) and increase in Time Spent in the shock Zone (TSZ) significantly at 2 h and 24 h post-training. Acorus calamus (250 mg/kg) failed to produce any significant change in cognition. However, when given in combination with phenytoin, significantly increased SDL and decreased TSZ at 2 h and 24 h post-training when compared with phenytoin alone treated group. Acorus calamus showed significantly decreased locomotor activity unlike PHT and the combination of AC and PHT. The chronic oral administration of phenytoin significantly raised AChE level in the brain. Administration of Acorus calamus alone as well as in combination with PHT showed significant decrease in AChE level. Thus, this study provides evidence of the importance of Acorus calamus as adjuvant in antiepileptic therapy to reduce associated cognitive impairments.