Mem Inst Oswaldo Cruz, Rio de Janeiro, Vol. 94(3): 411-412, May/Jun. 1999 411 Thus, the development of efficient, cheap and en- RESEACH NOTE vironmentally safe molluscicides would result in an important complementary tool to minimize the impact of schistosomiasis. This demand has stimu- Screening of Asteraceae lated the involvement of many groups worldwide (Compositae) Plant Extracts in the search of new compounds from plants that can be used as molluscicide. for Molluscicidal Activity In this paper we present the screening of 66 species belonging to Asteraceae (Compositae) fam- Nelymar M Mendes, Rogério O ily against B. glabrata adult snails aiming at find- Queiroz, Telma SM Grandi*, Antônio ing molluscicidal plant extracts. The aerial parts MG dos Anjos*, Alaíde B de of the plants were collected in the vicinities of Belo Oliveira**, Carlos L Zani/+ Horizonte, State of Minas Gerais, Brazil, from March 1989 to September 1991. The following Laboratório de Química de Produtos Naturais, Centro species were identified and their exsiccates depos- de Pesquisas René Rachou-Fiocruz, Caixa Postal ited at the Federal University of Minas Gerais Her- 1743, 30190.002 Belo Horizonte, MG, Brasil barium: Acanthospermum australe* (Loef.) Kunt, *Departamento de Botânica, ICB, UFMG, Belo Achyrocline satureioides*(Lam.) D.C., Actinoseris Horizonte, MG, Brasil **Faculdade de Farmácia, angustifolia (Gardn.) Cabr., Ageratum conyzoides* UFMG, Belo Horizonte, MG, Brasil L, Alomia myriadenia Baker, Aspilia foliosa (Garder) Benth & Hook, Baccharis dracun- Key words: schistosomiasis - plant molluscicides - culifolia* D.C., Baccharis helichrysoides D.C., medicinal plants - Biomphalaria glabrata - Baccharis platypoda D.C., Baccharis serrulata Schistosoma mansoni (Lam.) Pers., Baccharis trimera* (L.) D.C., Baccharis trinervis (Lam.) Pers, Bidens pilosa* L., Bidens rubifolius H.B.K., Blainvillea biaristata Schistosomiasis is an endemic disease caused D.C., Cetratherum punctatum Cass., Chaptalia by helminths belonging to the genus Schistosoma. nutans (L.) Polak, Cosmos sulfureus* Cav., According to the World Health Organization Dasyphyllum macrocephala Baker, Eclipta (WHO), this disease affects more than 200 million paniculata Kuntz, Elephantopus mollis* H.B.K., people and places other 600 million at risk of in- Eremanthus glomerulatus (D.C.) Less., Ereman- fection in more than 70 countries in the tropics thus sphaerocephalus Baker, Erigeron bonariensis (WHO 1994 O controle da Esquistossomose, Ed L., Erigeron canadensis L., Eupatorium amphi- Fiocruz, Rio de Janeiro, Brazil). In Central and dictyum D.C., Eupatorium bupleurifolium D.C., South America, S. mansoni causes intestinal schis- Eupatorium halimifolium D.C., Eupatorium tosomiasis in 8-12 millions patients (JR laevigatum* Lam., Eupatorium squalidum D.C., Lambertucci et al. 1987 Rev Soc Bras Med Trop Gnaphalium spicatum Hook, Gochnatia 20: 47-52). In view of its prevalence and morbid- polymorpha* (Less.) Cabr, Hieracium sp., Jaegeria ity this disease is a serious public health problem hirta (Lag.) Less, Jungia floribunda* Less., in Brazil and many other countries. The life cycle Lychnophora pinaster Mart., Lychnophora of this parasite involves the infection of some spe- pseudovillosissima Semir & L.F., Mikania cies of molluscs. In Brazil, snails of genus cordifolia* (L.F.) Wild, Mikania lutzelburghii Biomphalaria, in special B. glabrata, are the most Mattf., Mikania obtusata D.C., Mikania sessilifolia important intermediate hosts for S. mansoni. Snail’s D.C., Piptocarpha rotundifolia Baker, Pluchea population control via mollusciciding can play an quitoc* L., Pseudoginonoxis pohlii (Sch. Bip.) L.F., important role in an integrated approach aiming at Pterocaulon alopecuroides (Lam.) D.C., Senecio the control of this disease if the molluscicidal agent brasiliensis Less., Senecio confusus Britten, is made available to the affected communities. Stenocline chionaea D.C., Symphyopappus polystachyus Baker, Tagetes minuta L., Taraxacum officinale* (With.)Wiggers, Tithonia rotundifolia Baker, Trixis vauthieri D.C., Vanillosmopsis erythropappa Sch. Bip., Verbesina clausseni Sch. Supported by CNPq/Pronex/Fiocruz Bip., Vernonia condensata Baker, Vernonia +Corresponding author. Fax: +55-31-295.3115. E-mail: crotonoides (D.C.) Sch. Bip., Vernonia ferruginea [email protected] Less., Vernonia herbaceae (Vell.) Rusby, Vernonia Received 16 October 1998 linearis Spreng., Vernonia pedunculata D.C., Ver- Accepeted 15 December 1998 nonia polyanthes (Spreng.) Less., Vernonia 412 Screening Asteraceae Plant Extracts for Molluscicidal Activity Nelymar M Mendes et al. remotiflora Rich., Viguiera ovatifolia Baker, to produce it in larger amounts. Therefore, the Wedelia paludosa D.C., Wulfia baccata (L.F.) above active extracts deserve further studies in Kunt. order to identify and characterize their mollusci- Among these plants, 15 (23%) are reputed as cidal components. medicinal by some populations in Brazil (CL Zani Among the plants used in our screening 17 had 1995 Phytomedicine 2: 41-44) and are indicated already been tested for their molluscicidal activity in the above list with an asterisk. Each plant mate- by other research groups and all were confirmed rial was dried in the shade, ground in a knife mill as inactive. CP Souza et al. (1984 An Acad Brasil and extracted twice (24 hr) with ethanol at room Cienc 56: 333-338) used a sequential extraction of temperature. After filtration, the ethanol was re- A. Satureioides and P. rotundifolia with hexane- moved by rotary evaporation under reduced pres- ethyl acetate followed by ethanol and showed that sure and temperature below 45oC. The resulting only the less polar extracts were active. However, crude extract was kept in the dark in a freezer at our results showed that a direct extraction with -20o C until assayed. ethanol is also effective to extract the mollusci- A preliminary screen to detect extracts with cidal component(s). Concerning the chemical com- molluscicidal activity was run using a simple bio- position of these two species, A. satureioides was assay employing 10 adult B. glabrata. They were the object of several phytochemical investigations kept submersed during 24 hr in beakers contain- that disclosed the presence of terpenoids, ing 250 ml of a 100 ppm solution of each extract phenylpropanoids and flavonoids, among other in dechlorinated water. Control without drugs and classes of compounds. On the other hand, P. with niclosamide (0.3 ppm, 100% mortality) were rotundifolia was not yet investigated for its chemi- run in parallel. Only the extracts from A. cal composition and thus is entitled for a bioassay- angustifolia, A. myriadenia, A. satureioides, V. guided fractionation to identify its molluscicidal clausseni, P. rotundifolia and V. erythropappa killed components. 100% of the snails after 24 hr exposure. Their LC90 The molluscicidal activities of A. angustifolia, were then determined according to the WHO guide- A. myriadenia, V. erythropappa and V. clausseni lines (1983 Report of Scientific Working Group are reported here for the first time. Furthermore, of Plant Molluscicide, TDRS/SCH-SWESWE4/ except for V. erythropappa, the chemical compo- 83.3) and are shown in the Table. The extracts from sition of these species is completely unknown and A. angustifolia, A. myriadenia and A. satureioides further investigations to identify the compounds were the most active, showing LC90 of 43, 33 and responsible for the observed molluscicidal activ- 33 ppm, respectively. According to WHO, crude ity is needed. Extracts of V. erythropappa were also organic extracts should present LC90 bellow 20 shown to inhibit S. mansoni cercarial penetration ppm to be considered a good molluscicide candi- in mice tails and to kill the larvae of several para- date for direct application in infested water (WHO sitic helminths (B Gilbert 1970 An Acad Bras Cienc loc. cit.). However, it is possible that extracts ac- 42: 397-400, PM Baker 1972J Pharmacol 24: 853- tive between 20 and 100 ppm could contain small 857, B Gilbert 1972 An Acad Bras Cienc 44 suppl: amounts of very active components, which could 423). Previous phytochemical study of this spe- be isolated and/or concentrated using simple pro- cies (JN Lopes 1991 An Acad Brasil Cienc 63: 21- cedures, or even obtained from other plants known 22) disclosed the presence of several terpenoids and sesquiterpene lactones that could account for the above mentioned biological activities. In conclusion, our screening revealed the mol- TABLE luscicidal activity of six plant species, four of them Molluscicidal activity of Asteraceae plant species not previously known to present such activity. against Biomphalaria glabrata snailsa Among them, A. angustifolia and A. myriadenia Plant species LC (ppm) should be prioritized for further investigations, as 90 they were the most active and their chemistry is Achyrocline satureioides (Lam.) D.C. 43 still unknown. In this respect, A. myriadenia is Actinoseris angustifolia (Gardn.) (Cabr.) 33 currently the object of a bioassay-guided fraction- Alomia myriadenia Baker 33 ation in our laboratory aiming at the isolation and Piptocarpha rotundifolia Baker 99 Vanillosmopsis erythropappa Sch. Bip. 99 structural elucidation of its molluscicidal Vanillosmopsis erythropappa Sch. Bip. 99 component(s). Verbesina clausseni Sch. Bip. 78 Acknowledgments: to Dr Cecília Pereira de Souza a: niclosamide at 0.3 ppm killed 100 % of the molluscs (Laboratório de Malacologia, René Rachou Research after 24 hr exposition. Center-Fiocruz) for providing B. glabrata snails..