Anticonvulsant effect of the essential oil and methanolic extracts of Zataria multiflora Boiss.

UNLABELLED: Zataria multiflora is an Iranian endemic plant with a variety of uses. Anticonvulsant effect of the plant has not been studied yet. We aimed to evaluate the anticonvulsant effect of the essential oil and methanolic extract of the plant on chemical and electrically seizures.

METHODS: Essential oil (EO) and methanolic extract (ME) were prepared by hydrodistillation and maceration method respectively and administered for evaluating the anticonvulsant activity against pentylenetetrazole (PTZ) and maximal electroshock (MES) convulsions in mice. Different doses of the EO and ME of Zataria multiflora were administered intraperitoneally (i.p), thirty minutes before induction of chemical (PTZ, 100 mg/kg) and electrical (50 mA, 50 Hz, 1 s duration) convulsions. Neurotoxicity was evaluated using rota-rod test. Mortality was determined after 24 hours for determining LD50.

RESULTS: EO significantly increased the onset time of clonic seizures at doses of 0.2, 0.25 and 0.35ml/kg and significantly prevented tonic convulsions induced by PTZ at the same doses. No increase in onset time of tonic convulsions was observed. Methanolic extract of Z. multiflora was not effective in PTZ model. Neither EO nor ME was effective against MES convulsions; however both of them significantly reduced the time spent on rota-rod at doses of 0.6 ml/kg and 3 g/kg respectively. LD50 value of the EO was determined as 1.30 (1.0-1.5) ml/kg. No mortality was seen for the ME until dose of 5 g/kg.

CONCLUSION: EO would be a good candidate for more investigations to determine its active constituent(s) and also its mechanism against PTZ-induced seizures.