Antiaris toxicaria (Moraceae) was evaluated for
anticonvulsant activity in rodents. Animal models used include maximal electroshock test (MEST);
pentylenetetrazole-induced (PTZ) convulsions;
picrotoxin-induced (PCT) convulsions;
strychnine- (STR-) and 4-aminopyridine-induced convulsions. Increase in latency to
seizures as well as reduction in duration and frequency of
seizures indicated
anticonvulsant activity. The extract was more effective in all models used except the maximal electroshock test and
strychnine-induced convulsions. Antiaris toxicaria aqueous extract (200, 400, and 800 mg kg(-1)) significantly (P < 0.05 - 0.01) shortened the duration of convulsions in PTZ- and PCT-induced
seizures. Delay in the onset of convulsions in the two tests was significant (P < 0.001). Reduction in the frequency of
seizures was also significant (P < 0.05 - 0.001) in both tests. Antiaris further delayed the onset of
seizures in
4-aminopyridine model while producing 75% protection against death in mice.
Diazepam (0.1, 0.3, and 1 mg kg(-1)),
carbamazepine (3, 10, and 30 mg kg(-1)), and
sodium valproate (100-400 mg kg(-1)) were used as reference
anticonvulsant drugs for various models.
Flumazenil blocked the effect of the extract in the PTZ test significantly suggesting that Antiaris toxicaria may be acting by enhancing the effects of the GABAergic system. Antiaris toxicaria aqueous extract therefore possesses
anticonvulsant activity.