RESEARCH NOTE - Screening of Asteraceae (Compositae) Plant Extracts for Molluscicidal Activity

Schistosomiasis is an endemic disease caused by helminths belonging to the genus Schistosoma. According to the World Health Organization (WHO), this disease affects more than 200 million people and places other 600 million at risk of infection in more than 70 countries in the tropics (WHO 1994 O controle da Esquistossomose, Ed Fiocruz, Rio de Janeiro, Brazil). In Central and South America, S. mansoni causes intestinal schistosomiasis in 8-12 millions patients (JR Lambertucci et al. 1987 Rev Soc Bras Med Trop 20: 47-52). In view of its prevalence and morbidity this disease is a serious public health problem in Brazil and many other countries. The life cycle of this parasite involves the infection of some species of molluscs. In Brazil, snails of genus Biomphalaria, in special B. glabrata, are the most important intermediate hosts for S. mansoni. Snail's population control via mollusciciding can play an important role in an integrated approach aiming at the control of this disease if the molluscicidal agent is made available to the affected communities. Thus, the development of efficient, cheap and environmentally safe molluscicides would result in an important complementary tool to minimize the impact of schistosomiasis. This demand has stimulated the involvement of many groups worldwide in the search of new compounds from plants that can be used as molluscicide