Hydroalcoholic extracts of plants from north east Brazil were teste in the following preparations: toad rectus abdomins, isolated duodenum of rabbits, isolated heart of amphibia and isolated uterus of rats. The following plants were considered inactíve: Marmeleirinho (Croton sp-33), Azeitona (Eugenia jambolana), Pimenta de macaco (Piper sp-06), Imburana de espinho (Bursera, leptophilococos), Espirro (Siparuna guianensis) Araticum (Annona careacea) e Hyptis sp. Several other plants showed activity such as Jurema (Mimosa acutistipula) Canafístula de boi (Pithecolobium multiflorum, Castanha de burro (Dipteryx alata), Goiabeira (Psidium guajava), Flamboyan (Delonix regia) and Capim cidreira (Cymbopogon citratus).