We carried out the Irwin's test with some different extracts of the aerial parts of Thidax procumbens L., the leaves of Neurolaena lobata (L.) R. Br., bark and leaves of Byrsonima crassifolia (L.) Kunth. and Gliricidia sepium Jacq. Walp., and root and leaves of Petiveria alliacea L. At dosage of