Ação moluscicida de Moringa oleifera LAM sobre o molusco BIomphalaria glabrata (SAY, 1818) hospedeiro intermediário do Schistosoma mansoni (SAMBON, 1907) e efeitos ecotoxicológicos em organismos aquáticos não alvo

Submitted by Ana Paula Macedo ([email protected]) on 2013-10-01T00:36:14Z No. of bitstreams: 1 Cesar Luiz Pinto Ayres Coelho da Silva.pdf: 2032867 bytes, checksum: 8f69ccba120ff9211202cd483b7fc68d (MD5)Made available in DSpace on 2013-10-01T00:36:14Z (GMT). No. of bitstreams: 1 Cesar Luiz Pinto Ayres Coelho da Silva.pdf: 2032867 bytes, checksum: 8f69ccba120ff9211202cd483b7fc68d (MD5) Previous issue date: 2013Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Rio de Janeiro, RJ, Brasil.A esquistossomose é uma doença parasitária de veiculação hídrica causada pelo trematódeo Schistosoma mansoni, que afeta mais de 200 milhões de pessoas. Nas áreas de maior endemismo, o acesso ao suprimento de água é precário sendo obtida em poços, cacimbas e pequenos açudes, que se tornam também “criadouros artificiais” de caramujos infectados pelo S. mansoni. A doença é de profilaxia complexa, já que os moluscos aquáticos são de difícil controle, e pela parasitose incidir em zonas que favorecem um maior contato do homem com a água. No Brasil ocorrem dez espécies e uma sub-espécie do gênero Biomphalaria, sendo três espécies hospedeiras naturais do S. mansoni: Biomphalaria glabrata, Biomphalaria straminea e Biomphalaria tenagophila. O controle químico é utilizado para reduzir as populações destes hospedeiros intermediários sendo a Niclosamida o moluscicida recomendado pela OMS, porém com alta toxicidade para muitos organismos aquáticos. Moluscicidas derivados de plantas têm provado sua efetividade, porém exigem cuidados no manuseio, pois muitas espécies são tóxicas a humanos e organismos não alvo. Iniciativas no passado para o uso de plantas como moluscicida foram pouco promissoras ou desencorajadas em programas em larga escala devido ao pequeno valor agregado que possuem para as comunidades ou gestores públicos. A planta Moringa oleifera não é tóxica sendo utilizada na alimentação humana e animal, com vários estudos realizados para testar seu múltiplo uso, principalmente quanto à sua vi propriedade purificadora de águas. No presente estudo a semente moída de M. oleifera (ESSMol) foi avaliada pela primeira vez quanto à sua atividade moluscicida contra os moluscos B. glabrata, Physa marmorata e Melanoides tuberculatus. Sua ação ecotoxicológica também foi avaliada com o microcrustáceo Ceriodaphnia dubia e o peixe Danio rerio. Os resultados mostraram que o ESSMol foi eficaz como moluscicida para B. glabrata (CL50 = 0,419 g/L; CL90=1,021 g/L e P. marmorata (CL50=0,339 g/L; CL90=0,789 g/L) mas sem atividade moluscicida para M. tuberculatus. Para os organismos não alvo os valores foram: CL50 = 0,12 g/L (χ2 = 14,99; gl = 3; p0,05) para D. rerio. O efeito tóxico apresentado nos testes ecotoxicológicos com organismos não alvo ocorreu em concentrações que permitem a manutenção de populações naturais. O ESSMol demonstrou ser um produto ecologicamente menos agressivo ao ambiente e seguro para manipulação e utilização pelo homem. A grande inovação do uso da M. oleifera como moluscicida, é apresentar um potencial para agregação de valor também como alimento para humanos e animais e na prestação de serviço ecossistêmico como purificador da qualidade da água. O multi-uso da M. oleifera integrando a relação do homem, planta e ecossistemas, compõem uma cadeia na estrutura ecossistêmica que fortalece os processos ecológicos, envolvendo mais que apenas a ação sobre o ciclo de transmissão da esquistossomose.Schistosomiasis is a waterborne parasitic disease caused by the trematode Schistosoma mansoni which affects more than 200 milion people. In the most endemic areas, access to water supply, especially in rural areas, is poor and is obtained from wells, ponds and small reservoirs, which also potentially end up turning into "artificial breeding" of snails infected by S. mansoni. The disease prophylaxis is complex, since their hosts, aquatic snails are difficult to control, and since this parasitosis occurs in very hot and irrigated areas favoring an increased human contact with the water. In Brazil there are 10 species and one subspecies of the genus Biomphalaria, three of which are natural hosts of S. mansoni: Biomphalaria glabrata, Biomphalaria straminea and Biomphalaria tenagophila. Chemical control is used to reduce populations of vector snails being Niclosamide the only recommended by the WHO, demonstrating, however, severe toxicity to some aquatic organisms. Plant derived molluscicides have proven their effectiveness requiring, however, care in handling because some species possess toxic properties to humans and non-target organisms. Past initiatives to make effective the practice of use of plants with molluscicidal property have been unpromising or not carried forward in large scale programs due to the small value such plants have to target communities or public managers. The plant Moringa oleifera is non toxic to humans and used as food for humans and other animals with several studies having been done to test the multiple uses of this plant, particularly with respect viii to its water purifying property. In this study the ground seed of M. oleifera (GSEMol) was first evaluated for its molluscicidal activity against the snails B. glabrata, Physa marmorata and Melanoides tuberculatus. Its ecotoxicological action was also evaluated for the microcrustacean Ceriodaphnia dubia and the fish Danio rerio. The results demonstrated that the GSEMol was an effective molluscicide for B. glabrata (LC50 = 0.419 g/L; LC90 = 1.021 g/L) and P. marmorata (LC50 = 0.339 g/L; LC90 = 0.789 g/L) but had no molluscicidal activity against M. tuberculatus. For the non-target organisms the values were: LC50 = 0.12 g/L (χ2 = 14.99, df = 3, p 0.05) for D. rerio. The toxic effects shown in the ecotoxicity tests against non-target organisms however, occurred at concentrations which enable the maintenance of natural populations. The GSEMol proved to be a product environmentally less aggressive and safe for handling and use by man. The great innovation of the use of M. oleifera, besides being non toxic to humans, is to present the potential to add value as food for humans and animals as well as the provision of ecosystem services such as water purifier. The multi-potential use of M. oleifera integrating the relationship between man, plants and ecosystems, make up a chain in the ecosystem structure, strengthening the ecological processes involving more than just action on the transmission cycle of schistosomiasis

Molluscicidal activity of Moringa oleiferaon Biomphalaria glabrata: integrated dynamics to the control of the snail host of Schistosoma mansoni

The ground seed of Moringa oleifera Lam., Moringaceae, has been evaluated for its molluscicidal activity against the snails Biomphalaria glabrata, Physa marmorata and Melanoides tuberculatus. The results show that M. oleifera is active against B. glabrata (LC50 0.419 g/l; LC90 1.021 g/l and P. marmorata (LC50 0.339 g/l; LC90 0.789 g/l) but has no effect against M. tuberculatus. The great innovation of the use of M. oleifera, in addition to being innocuous to humans, is the present nutritional potential for humans and animals as well as providing an ecosystemic service as water purifier

Interaction between the Intermediate Host of Schistosomiasis in Brazil Biomphalaria glabrata (Planorbidae) and a Possible Competitor Melanoides tuberculata (Thiaridae): I. Laboratory Experiments

The biological control of Biomphalaria glabrata, intermediate host of Schistosoma mansoni, is one the accepted options to fight schistosomiasis. One of the most promising candidates to control B. glabrata is the snail Melanoides tuberculata, a potential competitor. However, the mechanisms of interaction between the two species are not clear. Our objective is to determine if M. tuberculata indeed compete with B. glabrata, using two laboratory experiments. In Experiment 1, we tested the effect of the presence of M. tuberculata on the fecundity and mortality rates of B. glabrata. In Experiment 2, we tested if there was a direct or indirect interaction between the two species. In Experiment 1, M. tuberculata was eliminated after the peak in reproductive activity of B. glabrata. In Experiment 2, B. glabrata produced more egg masses when raised with M. tuberculata. The conditions leading to this unexpected positive effect of M. tuberculata on the fecundity of B. glabrata need further clarification, but emphasize that detailed studies of the interaction between these species in the conditions of the local environment should be considered

SHORT COMMUNICATION - Apparent Competition Through Facilitation between Melanoides tuberculata and Biomphalaria glabrata and the Control of Schistosomiasis

Interactions between two species that result in reduced growth rates for both and extinction of one of the species are generally considered cases of asymmetric interspecific competition. Exploitative or interference competition is the usual mechanism invoked. Here we describe another mechanism producing the same result, named apparent competition through facilitation (ACF), observed between Melanoides tuberculata and Biomphalaria glabrata populations. The superior competitor actually gives some benefit to the other species, whose population becomes unstable with progressively increasing oscillations, leading to extinction. A model of ACF using difference equations suggests initial dynamics distinct from traditional interspecific competition. The dynamics of two freshwater snails in the field and in laboratory experiments suggest ACF, and these relations should be considered in studies of schistosomiasis control. ACF could occur in natural populations, but might have gone undetected because the final result is similar to traditional interspecific competition

The Molluscicidal Activity of Niclosamide (Bayluscide WP70®) on Melanoides tuberculata (Thiaridae), a Snail Associated with Habitats of Biomphalaria glabrata (Planorbidae)

The aim of this study was to determine the toxicity of niclosamide (Bayluscide ®) on Melanoides tuberculata   and Biomphalaria glabrata   under laboratory conditions. The latter species is the intermediate host of Schistosoma mansoni   (Sambon 1917). M. tuberculata was successfully used as competitor of B. glabrata in biological control programs in French West Indies. Both molluscicide and biological control using M. tuberculata have proved to be successful in reducing the population density of B. glabrata . The associated use of molluscicide in this area would be an effective measure if M. tuberculata were less susceptibility to the molluscicide than B. glabrata . Three hundreds individuals each of B. glabrata and of M. tuberculata , collected in Sumidouro, State of Rio de Janeiro, were used in the experiment. The molluscs were exposed to 14 different concentrations of niclosamide as recommended by the World Health Organization. Probit analysis was used to determine the LC 50 and LC 90. The LC 50 and LC 90 values for B. glabrata were 0.077 mg/l and 0.175 mg/l, respectively and the LC 50 and LC 90 values for M. tuberculata were 0.082 mg/l and 0.221 mg/l respectively. As the lethal concentrations of niclosamide were approximately the same to both species, this could be a disadvantage when controlling B. glabrata with niclosamide in an area of M. tuberculata occurrence. It migth therefore be preferable to utilize the latex extracted from the Euphorbia splendens, which presented a much higher efficiency for B. glabrata than to M. tuberculata