Methyl jasmonate (MJ) is one of the most well-studied plant stress hormones belonging to the jasmonate family. Previous studies have shown that MJ potentiated pentobarbitone sleeping time and enhanced GABA-mediated inhibitory neurotransmission, suggesting potential benefits in disorders associated with hyperactivity of the brain. This study was carried out to evaluate whether MJ has anticonvulsant and anxiolytic properties in mice. The anticonvulsant effect was assessed based on the prevention of tonic-clonic seizures induced by chemoconvulsant agents in mice. The anxiolytic property was evaluated utilizing the elevated plus maze (EPM) and light/dark transition paradigms. The effect of MJ on spontaneous locomotor activity (SMA) was also assessed. Mice received intraperitoneal (i.p.) injections of MJ 30 min before the tests were carried out and diazepam (2 mg/kg, i.p.) was used as the reference drug. MJ (50-400 mg/kg) did not protect the mice against tonic-clonic convulsions induced by picrotoxin (10 mg/kg, i.p.) or strychnine (3 mg/kg, i.p.). However, MJ (100, 200, and 400 mg/kg) offered 20, 60, and 100% protection against pentylenetetrazole (100 mg/kg, i.p.)-induced convulsions. In a similar manner to diazepam (2 mg/kg), MJ (400 mg/kg) produced a marked sedative effect as shown by decreases in the number of lines crossed and the duration of ambulation in the open field test. In contrast to diazepam (2 mg/kg), MJ (5-50 mg/kg) did not show anxiolytic effects in the EPM and light/dark transition paradigms. These findings suggest that methyl jasmonate at high doses possessed anticonvulsant properties in the pentylenetetrazole animal model of epilepsy, but did not produce anxiolytic activity in mice.
Keywords: Anxiolytic; Convulsions; Methyl jasmonate; Pentylenetetrazole; Picrotoxin; Strychnine.