Burchellin: effects on Triatoma infestans and on Trypanosoma cruzi within this vector

Supplementation of blood with the neolignan burchellin (50 mug/ml), a compo und from the arboreous Lauraceae Aniba burchelli, affected the ingestion of blood and the course of excretion of fourth- and fifth-instar larvae of Tr iatoma infestans, the latter especially within the first 4 h after feeding. The total resultant weight loss of treated fourth instars within 24 and 48 h after feeding was only 24% and 28% vs 41% and 48%, respectively, in untr eated bugs. In fifth instars, the total weight losses of untreated bugs wit hin 24 and 48 h after feeding were 38% and 41% whereas the weight of treate d bugs decreased by 28% and 34%, respectively. In a treatment of Trypanosom a cruzi-infected fourth instars, burchellin significantly reduced the popul ation density of the established infection in the rectum at 5 and 10 days a fter feeding. This was especially due to a significant increase in the numb er of the main dividing stage, the epimastigote.