Effect of CNS depressant drugs on acute intoxication from Palicourea marcgravii St Hill in rats.

Palicourea marcgravii (Pm) is a highly toxic plant to cattle in Brazil. Previous experiments showed that Pm intoxication in rats is similar to that reported for cattle. The present study was undertaken to determine if central nervous system depressant drugs protected animals against Pm-induced seizures. Doses of 30.0 mg diazepan/kg or 2.5 or 5.0 mg xyalzine/kg increased the ET50 for seizures. Only 4.0 mg chloral hydrate/kg + 10.0 mg xylazine/kg protected animals from death. Rats treated with sodium pentobarbital, diazepan or chlorpromazine died in depression after acute Pm intoxication. The combination of 2.0 choral hydrate/kg + 10.0 mg xylazine/kg protected rats against the Pm toxic effect, since all treated animal survived.