BRINE SHRIMP LETHALITY ASSAY AS A PRESCREENING SYSTEM FOR ANTI-TRYPANOSOMA CRUZI ACTIVITY

With the aim of finding an acceptable method for selecting plant extra cts to be assayed against the infective blood form of Trypanosoma cruz i, the causative agent of Chagas' disease (American trypanosomiasis), two different strategies were compared: a) screening only medicinal sp ecies and b) pre-screening random collected species in the brine shrim p lethality assay (BSLA). Fifty-two plants belonging to the Asteraceae family, including eighteen medicinal species, were collected and thei r ethanol extracts assayed against both ?: cruzi and Artemia salina (b rine shrimp). The proportion of trypanocidal extracts among the medici nal species and among the random collection did not differ significant ly. On the other hand, the proportion of trypanocidal extracts among t hose that presented LC(50) of less than 100 ppm to A. salina was four times higher than among the medicinal species.