Evaluation of the effect of Cyperus rotundus L. in scopolamine-induced learning deficit in mice.
BACKGROUND
Cyperus rotundus L. was used in traditional Iranian medicine to treat memory and cognition disorders. The present study was aimed at investigating the effect of the extract and essential oil of C. rotundus on memory dysfunction.


METHODS
Cognition was evaluated using the object recognition task that was composed of a square wooden open field box with different shape objects. The test was consisted of three sections: 15 min exploration, first trial for 12 min and second one for 5 min. In the second trial the difference in exploration between a previously seen object and novel one, was considered as an index of memory performance (recognition index). Memory deficit was induced by scopolamine (0.5 mg/kg) before injection of plant extracts and essential oil.


RESULTS
Rivastigmine at 0.6 mg/kg reversed the scopolamine induced memory dysfunction in mice (P < 0.05). On the contrary, neither the hydroalcholic extracts (100, 200, 400 mg/kg) nor the polyphenolic extract (50, 100, 200 mg/kg) and essential oil (10, 20, 40 mg/kg) of C. rotundus produced significant improvement of memory dysfunction. The fact that rivastigmine reversed the scopolamine-induced memory dysfunction confirms the validity of this memory paradigm.


CONCLUSIONS
Using the current method of the memory evaluation, none of the tested doses of the plant extract or essential oil changed the memory status of the animals, indicating either a lack of effective ingredient or unsuitable method for evaluation.
Department of Pharmacology, School of Pharmacy and Pharmaceutical Sciences and Isfahan Pharmaceutical Sciences Research Center, Isfahan University of Medical Sciences, Isfahan, Iran.
Mohammed
M
Rabbani
Department of Pharmacognosy, School of Pharmacy and Pharmaceutical Sciences, Isfahan University of Medical Sciences, Isfahan, Iran.
Alireza
A
Ghannadi
Department of Pharmacology, School of Pharmacy and Pharmaceutical Sciences and Isfahan Pharmaceutical Sciences Research Center, Isfahan University of Medical Sciences, Isfahan, Iran.
Nahid
N
Malekian
Cyperus rotundus; memory dysfunction; object recognition; scopolamine