Anticonvulsant effect of aqueous extract of Valeriana officinalis in amygdala-kindled rats: possible involvement of adenosine.
BACKGROUND
Valeriana officinalis L. (valerian) root extract has been used as an antiepileptic herbal medicine in Iran.


OBJECTIVE
In the present study the effect of valerian extracts on an experimental model of temporal lobe epilepsy (TLE) was evaluated. Moreover, the involvement of adenosine system in the actions of aqueous extract of valerian was evaluated.


METHODS
Bipolar stimulating and monopolar recording electrodes were implanted stereotaxically in the right basolateral amygdala of male Sprague-Dawley rats. After kindling, the effect of aqueous (200, 500 and 800 mg/kg; intraperitoneal) and petroleum ether (PE; 50 and 100mg/kg; intraperitoneal) extracts of valerian and CPT (selective A(1) receptor antagonist; 10 and 20 microM; intracerebroventricular) on afterdischarge duration (ADD), duration of stage 5 seizure (S5D) and latency to the onset of bilateral forelimb clonuses (S4L) were measured. The effect of CPT (10 microM) on the response of aqueous extract of valerian (500 mg/kg) was also determined.


RESULTS
The results showed that aqueous extract of valerian had anticonvulsant effect. However, PE extract and CPT (20 microM) had proconvulsant effect. Administration of CPT (10 microM) before the administration of aqueous extract decreased the anticonvulsant effect of valerian.


CONCLUSIONS
The results showed significant anticonvulsant effect for aqueous but not PE extract of valerian. Moreover, CPT as a selective adenosine A(1) receptor antagonist decreased the anticonvulsant effect of valerian aqueous extract. Therefore, we concluded that part of anticonvulsant effect of valerian probably is mediated through activation of adenosine system.
Rezvani
Mohammad Ebrahim
ME
Department of Physiology and Pharmacology, School of Medicine, Rafsanjan University of Medical Sciences, Rafsanjan, Iran. erezvani@rums.ac.ir
Roohbakhsh
Ali
A
Allahtavakoli
Mohammad
M
Shamsizadeh
Ali
A
D000241:Adenosine / Q000502:physiology*; D000679:Amygdala / Q000187:drug effects* / Q000502:physiology*; D000818:Animals; D000927:Anticonvulsants / Q000302:isolation & purification / Q000494:pharmacology / Q000627:therapeutic use*; D004833:Epilepsy, Temporal Lobe / Q000188:drug therapy / Q000503:physiopathology; D007696:Kindling, Neurologic / Q000187:drug effects* / Q000502:physiology*; D008297:Male; D010936:Plant Extracts / Q000302:isolation & purification / Q000494:pharmacology / Q000627:therapeutic use*; D051381:Rats; D017207:Rats, Sprague-Dawley; D014632:Valerian; D014867:Water / Q000494:pharmacology
D000927:Anticonvulsants; D010936:Plant Extracts; D014867:Water; D000241:Adenosine