Bioactivity of substances isolated from natural products on mollusks Biomphalaria glabrata (Say, 1818) (Planorbidae): a review / Bioatividade de substâncias isoladas de produtos naturais em moluscos Biomphalaria glabrata (Say, 1818) (Planorbidae): uma revisão

Schistosomiasis is a neglected tropical disease caused by parasitic worms of several species of the genus Schistosoma. Transmission occurs by parasitic larvae that stay in freshwater snails of the genus Biomphalaria. Thus, the search for new products that are biodegradable has increased the interest in products of plant origin. The aim of this article is to review the isolated substances from natural products that showed molluscicidal activity against the species Biomphalaria glabrata in order to reevaluate the most promising prototypes and update the progress of research to obtain a new molluscicide. We perform searches using scientific databases, such as Scientific Electronic Library Online (SciELO), Google schoolar, PUBMED, Web of Science and Latin American and Caribbean Literature on Health Sciences (LILACS). From 2000 to 2022, using the keywords "isolated substances", "molluscicidal activity" and "Biomphalaria glabrata". In the present study, it was possible to observe 19 promising molluscicidal molecules with a lethal concentration below 20 µg/mL. Of these promising isolates, only 5 isolates had the CL90 calculated and within the value recommended by WHO: Benzoic acid, 2',4',6'-Trihydroxydihydrochalcone, Divaricatic acid, Piplartine and 2-hydroxy-1,4-naphthoquinone (Lapachol). We conclude that beyond a few results in the area, the researches don't follow the methodological pattern (exposure time and measure units, toxicity test), in this way, as they don't follow a pattern on the result's exposure (LC), not following, in sum, the recommended by WHO.

A esquistossomose é uma doença tropical negligenciada causada por vermes parasitas de várias espécies do gênero Schistosoma. A transmissão ocorre por larvas parasitas que ficam em caramujos de água doce do gênero Biomphalaria. Assim, a busca por novos produtos biodegradáveis ​​tem aumentado o interesse por produtos de origem vegetal. O objetivo deste artigo é revisar as substâncias isoladas de produtos naturais que apresentaram atividade moluscicida contra a espécie Biomphalaria glabrata a fim de reavaliar os protótipos mais promissores e atualizar o progresso das pesquisas para a obtenção de um novo moluscicida. Realizamos buscas em bases de dados científicas, como Scientific Electronic Library Online (SciELO), Google acadêmico, PUBMED, Web of Science e Literatura Latina-Americana e do Caribe em Ciências da saúde (LILACS). De 2000 a 2022, utilizando as palavras-chave "substâncias isoladas", "atividade moluscicida" e "Biomphalaria glabrata". No presente estudo, foi possível observar 19 moléculas moluscicidas promissoras com concentração letal abaixo de 20 µg/mL. Destes isolados promissores, apenas 5 isolados tiveram o CL90 calculado e dentro do valor recomendado pela OMS: ácido benzóico, 2',4',6'-triidroxidihidrocalcona, ácido divaricático, piplartina e 2-hidroxi-1,4-naftoquinona (Lapachol). Concluímos que além de poucos resultados na área, as pesquisas não seguem o padrão metodológico (tempo de exposição e unidades de medida, teste de toxicidade), assim como não seguem um padrão na exposição do resultado (CL), não seguindo, em suma, o recomendado pela OMS.

Toxic, cytotoxic and genotoxic effect of plumbagin in the developmental stages of Biomphalaria glabrata (Say, 1818-intermediate host) and cercaricidal activity against the infectious agent of schistosomiasis mansoni.

BACKGROUND: Snails of the genus Biomphalaria are intermediate hosts of Schistosoma mansoni, the main etiological agent of schistosomiasis mansoni, which affects about 236.6 million people in tropical and subtropical regions of the world. The World Health Organization recommends the population control of vector snails as one of the strategies to reduce the prevalence and incidence of schistosomiasis. In this study, molluscicidal and antiparasitic activities of plumbagin, a naturally sourced naphthoquinone with a range of biological effects, were evaluated against B. glabrata and cercariae of S. mansoni. RESULTS: After 24 h of exposure, plumbagin demonstrated molluscicidal activity at low concentrations against embryos (LC50 of 0.56, 0.93, 0.68, 0.51 and 0.74 µg mL-1 for the blastula, gastrula, trochophore, veliger and hippo stage, respectively) and adult snails (LC50 of 3.56 µg mL-1 ). There were no changes in exposed snails' fecundity or fertility; however, plumbagin was able to increase the frequency of DNA damage and the number of hemocytes, with apoptosis and binucleation being the main hemocyte alterations. In addition, plumbagin showed death of S. mansoni cercariae in the concentration of 1.5 µg mL-1 in 60 min, while showing moderate toxicity to Artemia salina. CONCLUSION: Plumbagin proved to be a promising substance for the control of B. glabrata population, intermediate host of S. mansoni, as well as the cercariae, infective stage for humans (definitive host), while being moderately toxic to A. salina, a crustacean widely used in ecotoxicity tests. © 2022 Society of Chemical Industry.

Sublethal concentrations of usnic acid potassium salt impairs physiological parameters of Biomphalaria glabrata (Say, 1818) (Pulmonata: Planorbidae) infected and not infected with Schistosoma mansoni.

Schistosomiasis is a public health problem in many developing countries. The mollusc Biomphalaria glabrata is the most important vector of Schistosoma mansoni in South America. The population control of this vector to prevent the spread of schistosomiasis is currently done with the application of highly toxic molluscicide to the environment. The screening of substances in sublethal concentrations that have deleterious effects on physiological parameters is very relevant for the control of schistosomiasis, since the effectiveness of disease prevention increases if it acts on population control of the vector and on reproduction and elimination in S. mansoni cercariae. The objective of this study was to evaluate the reproductive parameters (fecundity and fertility), intra-mollusk effect (sporocysts I (72 h) and II (14 days after)) on the development of cercariae of S. mansoni and the immune cell profile of B. glabrata exposed to sublethal concentrations (LC25 - 0.5 µg/mL and LC50 - 0.92 µg/mL) of the usnic acid potassium salt (potassium usnate). LC 25 and LC 50 significantly reduced (p < 0.05) the fecundity of B. glabrata when treated infected and/or not exposed to infection, while unviable embryos were not observed in sporocyst stage I, being only significant (p < 0.05) for mollusks infected and treated with LC50 on sporocyst II. LC25 and LC50 of the potassium usnate caused significant reductions (p < 0.05) in the production and cercarial shedding when evaluated on sporocysts I and II. In addition, the mortality of infected and treated B. glabrata in the sporocyst II phase was quite marked after the 9th week of infection. Regarding the immunological cell profile of uninfected B. glabrata, both concentrations led to immunomodulatory responses, with significant morphological changes predominant of hemocytes that entered programmed cell death (apoptosis). It was concluded that the application of LC25 and LC50 from the potassium usnate could be useful in the population control of B. glabrata, since it interferes both in their biology and physiology and in the reproduction of the infectious agent of schistosomiasis mansoni.

Ecotoxicological evaluation of fruit extracts from yerba mate progenies (Ilex paraguariensis a St-Hil.): a natural biopesticide.

This study evaluated the biocidal activity of aqueous fruit extracts from Ilex paraguariensis progenies at different ripening stages in two ecotoxicity assays using Pomacea canaliculata juveniles and Danio rerio larvae. Mutagenicity was verified by the Salmonella/microsome assay (TA 98 and TA 100) in the presence and absence of hepatic metabolism in vitro. The results showed that the snails were more sensitive than the larvae to the P.1 progeny extracts in all three evaluated ripening stages. P.3 progeny extracts were the most toxic to Danio rerio larvae after 96 hours of exposure. The toxicity results indicate that the progenies' selection influenced the metabolic contents present in the fruits in all ripening stages over time, indicating high molluscicidal activity for the P.1 progeny. In the Salmonella/microsome assays, the semi-ripe and ripe extracts from progenies P.1 and P.3 showed mainly base pair substitution mutation in assays with metabolism, but at higher doses than the toxic concentrations detected for Danio rerio or Pomacea canaliculata. Therefore, the toxicological investigation of the progenies' extracts can be interesting, given the selection of plant materials influenced the response of the bioassays.

Toxicological effects of Ramalina aspera (lichen) on Biomphalaria glabrata snails and Schistosoma mansoni cercariae.

In this study, the molluscicidal activities against Biomphalaria glabrata and cercaricidal activities against Schistosoma mansoni of the ether extract of Ramalina aspera were evaluated. Additionally, toxicity parameters were evaluated at sublethal doses in terms of the influence of the extract on the fertility and fecundity of snails, as well as morphological alterations and quantification of their immunological cells. A test with Artemia salina was also carried out, in order to verify the environmental toxicity of the compound. The ether extract of R. aspera, in which divaricatic acid was identified as the major compound, demonstrated molluscicidal activity at low concentrations against both embryos (LC90 of 22.78, 24.23, 16.63 and 16.03 µg mL-1 for the gastrula, blastula, trochophore and veliger, respectively) and against adult snails (LC90 of 8.66 µg mL-1), after 24 h of exposure. At the sublethal doses, it was possible to observe a decrease in fecundity and quantitative and morphological changes in the defense cells of the exposed snails. In addition, the extract of R. aspera showed a cercaricidal effect on S. mansoni from the concentration of 5.0 µg mL-1, while showing low toxicity to Artemia salina. The ether extract of R. aspera demonstrated effective molluscicidal activity on embryos and adult snails of the species B. glabrata, cercariae of S. mansoni, and presenting low toxicity on Artemia salina. In this way, it could be considered a promising compound in the development of future molluscicidal and cercaricidal agents, thus helping to combat schistosomiasis.

Ethanol extract of Nandina domestica Thunb. leafs: effect on Pomacea canaliculata and growth of Orzya sativa seedlings / Extrato etanolico de folhas de Nandina domestica Thunb.: efeitos sobre Pomacea canaliculata e crescimento de mudas Orzya sativa

Alien species may adversely affect not only human health, agriculture, and fisheries but also the native ecosystem. Pomacea canaliculata is one of alien harmful species (IUCN). Forest residues are a kind of renewable, cheap and secure source of primary energy. Nandina domestica Thunb. is a commonly and widely cultivated plant for city landscape construction in China. After being pruned, a large of N. domestica leaves are usually abandoned. In this work, extracts of ethanol Soxhlet (SE), ethanol immerse (EE), and water immerse (WE) were obtained from leaves of N. domestica Thunb. cv. Firepower. The molluscicidal effects of the three extracts from the leaves were evaluated against black P. canaliculata. In sand pot culture condition and pot culture with paddy soil condition, SE at concentration of 4000 mg L-¹ did not affect seedlings normal growth. Plant height, seedling fresh weight (SFW), seedling dry weight (SDW) and Chlorophyll content of SE (4000 mg L-¹) were not significantly different from that in DS (distilled water + seedlings). Besides, in pot culture with paddy soil condition, the SE treatment at concentration of 4000 mg L-¹ inhibited P. canaliculata chewing rice seedlings effectively, which was not statistically different from the positive control {NSP, niclosamide (according to field dosage, 0.086 g m-²) + seedlings + P. canaliculata)}. Results from this study indicated that SE has molluscicidal effect against P. canaliculata and SE did not affect the normal growth of rice seedlings. Thus, we suggest further chemical and toxicological studies of SE.(AU)

As espécies exóticas podem afetar negativamente não apenas a saúde humana, a agricultura e a pesca, mas também o ecossistema nativo. Pomacea canaliculata é uma das espécies exóticas prejudiciais (UICN). Os resíduos florestais são um tipo de fonte renovável, barata e segura de energia primária. Nandina domestica Thunb. é uma planta comumente cultivada em paisagens urbanas na China. Depois de ser podada, uma grande quantidade de folhas de N. domestica são geralmente abandonadas. Neste trabalho, extratos, Soxhlet de etanol (SE), folhas mergulhadas em etanol (EE) e imersas em água (WE) foram obtidas a partir de folhas de N. domestica Thunb. cv. Firepower. Os efeitos moluscicidas dos três extratos das folhas foram avaliados contra P. canaliculata preta em cultivo de arroz em potes de areia e cultivo em potes com solo compactação, SE foi utilizado na concentração de 4000 mg L-¹ e não afetou o crescimento normal das mudas. A altura da planta, (o peso fresco das mudas) SFW, (peso seco das mudas) SDW e o teor de clorofila do tratamento SE (4000 mg L-¹) não foram significativamente diferentes dos observados no tratamento controle DS (água destilada + mudas). Além disso, no cultivo de arroz em pote na condição de compactação, o tratamento SE na concentração de 4000 mg L-¹ inibiu a alimentação de P. canaliculata em mudas de arroz, e não foi estatisticamente diferente do controle positivo {NSP, niclosamida (de acordo com a dosagem de campo, 0.086g m²) + mudas + P. canaliculata)}. Os resultados deste estudo indicaram que SE tem efeito moluscicida contra P. canaliculata e não afetou o crescimento normal das mudas de arroz. Assim, sugerimos outros estudos químicos e toxicológicos da SE.(AU)

Potassium usnate toxicity against embryonic stages of the snail Biomphalaria glabrata and Schistosoma mansoni cercariae.

The snail Biomphalaria glabrata is the most important vector for Schistosoma mansoni. Control of this vector to prevent the spread of schistosomiasis is currently performed with the application of a niclosamide molluscicide, which is highly toxic to the environment. Screening of substances that show embryotoxic molluscicidal potential as well as have detrimental effects on cercariae is very relevant for the control of schistosomiasis, as the efficacy of prevention of the disease is increased if it acts as a molluscicide as well as on the cercariae of S. mansoni. The aim of this work was to evaluate the effect of potassium usnate derived from usnic acid on different stages of embryonic development of B. glabrata and on S. mansoni cercariae. After 24 h of exposure, potassium usnate showed embryotoxic activity across all embryonic stages. The values obtained from the LC50 for the embryonic stages were the following: blastula 5.22 µg/mL, gastrula 3.21 µg/mL, trochophore 3.58 µg/mL, veliger 2.79, and hippo stage 2.52 µg/mL. Against S. mansoni cercariae, it had LC90 and 100% mortality at concentrations of 2.5 and 5 µg/mL in 2 h of exposure. In conclusion, this is the first report of potassium usnate toxicity on the embryonic stages of B. glabrata and cercariae of S. mansoni, and this study shows the potassium usnate as a promising agent for the control of mansoni schistosomiasis.

Toxicity of Usnic Acid from Cladonia substellata (Lichen) to embryos and adults of Biomphalaria glabrata.

This study reports the molluscicidal activity of usnic acid isolated from Cladonia substellata Vanio (lichen) on embryos at various stages of development and in adult mollusks of Biomphalaria glabrata. The toxicity of usnic acid was also evaluated through Artemia salina larvae mortality. Usnic acid was extracted with diethyl ether, isolated, purified, and its structure confirmed by analyzing the spectra of proton nuclear magnetic resonance. LC90 for 24 h of exposure were 1.62, 4.45, 5.36, and 4.49 µg mL-1 for blastula, gastrula, trocophore, and veliger embryonic stages, respectively, and 3.45 µg mL-1 for adult snails; LC50 of usnic acid against A. salina was 2.46 µg mL-1. LC90 assessed 7 days after exposure was 2.56 µg mL-1 for adult mollusks. In conclusion, these findings demonstrate that under laboratory conditions usnic acid has teratogenic and molluscicide potential to control the aquatic snail B. glabrata and may prove to be a promising candidate in the search for new molluscicide agents, but further detailed studies on its molluscicidal effect and possible environmental effects are needed.

Ethanol extract of Nandina domestica Thunb. leafs: effect on Pomacea canaliculata and growth of Orzya sativa seedlings / Extrato etanolico de folhas de Nandina domestica Thunb.: efeitos sobre Pomacea canaliculata e crescimento de mudas Orzya sativa

Alien species may adversely affect not only human health, agriculture, and fisheries but also the native ecosystem. Pomacea canaliculata is one of alien harmful species (IUCN). Forest residues are a kind of renewable, cheap and secure source of primary energy. Nandina domestica Thunb. is a commonly and widely cultivated plant for city landscape construction in China. After being pruned, a large of N. domestica leaves are usually abandoned. In this work, extracts of ethanol Soxhlet (SE), ethanol immerse (EE), and water immerse (WE) were obtained from leaves of N. domestica Thunb. cv. Firepower. The molluscicidal effects of the three extracts from the leaves were evaluated against black P. canaliculata. In sand pot culture condition and pot culture with paddy soil condition, SE at concentration of 4000 mg L-¹ did not affect seedlings normal growth. Plant height, seedling fresh weight (SFW), seedling dry weight (SDW) and Chlorophyll content of SE (4000 mg L-¹) were not significantly different from that in DS (distilled water + seedlings). Besides, in pot culture with paddy soil condition, the SE treatment at concentration of 4000 mg L-¹ inhibited P. canaliculata chewing rice seedlings effectively, which was not statistically different from the positive control {NSP, niclosamide (according to field dosage, 0.086 g m-²) + seedlings + P. canaliculata)}. Results from this study indicated that SE has molluscicidal effect against P. canaliculata and SE did not affect the normal growth of rice seedlings. Thus, we suggest further chemical and toxicological studies of SE.

As espécies exóticas podem afetar negativamente não apenas a saúde humana, a agricultura e a pesca, mas também o ecossistema nativo. Pomacea canaliculata é uma das espécies exóticas prejudiciais (UICN). Os resíduos florestais são um tipo de fonte renovável, barata e segura de energia primária. Nandina domestica Thunb. é uma planta comumente cultivada em paisagens urbanas na China. Depois de ser podada, uma grande quantidade de folhas de N. domestica são geralmente abandonadas. Neste trabalho, extratos, Soxhlet de etanol (SE), folhas mergulhadas em etanol (EE) e imersas em água (WE) foram obtidas a partir de folhas de N. domestica Thunb. cv. Firepower. Os efeitos moluscicidas dos três extratos das folhas foram avaliados contra P. canaliculata preta em cultivo de arroz em potes de areia e cultivo em potes com solo compactação, SE foi utilizado na concentração de 4000 mg L-¹ e não afetou o crescimento normal das mudas. A altura da planta, (o peso fresco das mudas) SFW, (peso seco das mudas) SDW e o teor de clorofila do tratamento SE (4000 mg L-¹) não foram significativamente diferentes dos observados no tratamento controle DS (água destilada + mudas). Além disso, no cultivo de arroz em pote na condição de compactação, o tratamento SE na concentração de 4000 mg L-¹ inibiu a alimentação de P. canaliculata em mudas de arroz, e não foi estatisticamente diferente do controle positivo {NSP, niclosamida (de acordo com a dosagem de campo, 0.086g m²) + mudas + P. canaliculata)}. Os resultados deste estudo indicaram que SE tem efeito moluscicida contra P. canaliculata e não afetou o crescimento normal das mudas de arroz. Assim, sugerimos outros estudos químicos e toxicológicos da SE.

Barbatic Acid Offers a New Possibility for Control of Biomphalaria Glabrata and Schistosomiasis.

This study evaluated the biological activity of an ether extract and barbatic acid (BAR) from Cladia aggregata on embryos and adult mollusks of Biomphalaria glabrata, cercariae of Schistosoma mansoni and the microcrustacean Artemia salina. The ether extract and BAR were obtained by successive extractions with diethyl ether. The obtained extracts were analyzed using thin-layer chromatography (TLC), high-performance liquid chromatography (HPLC), proton nuclear magnetic resonance (¹H-NMR) and infrared (IR) spectroscopy. The results demonstrated that the ether extract exerted embryotoxic effects at 50 and 100 µg/mL and molluscicidal effects at 20 and 25 µg/mL. BAR exhibited no embryotoxicity, and its molluscicidal concentration was equal to that of the ether extract. However, after 60 min of exposure, 1 µg/mL BAR presented cercaricidal activity against the parasite S. mansoni at the second larval stage. Neither substance induced toxicity against A. salina. These results indicate the potential molluscicidal activities of the ether extract and BAR against B. glabrata and S. mansoni cercariae. In addition to these effects, there was a lack of toxicity against the aquatic environment and no damage to the biota, indicating the potential of these products for large-scale control and/or eradication of schistosomiasis.

MOLLUSCICIDAL AND LARVICIDAL ACTIVITIES OF Atriplex inflata AERIAL PARTS AGAINST THE MOLLUSK Galba truncatula, INTERMEDIATE HOST OF Fasciola hepatica / Atividade moluscicida e larvicida das partes aéreas de Atriplex inflata contra o molusco Galba truncatula, hospedeiro intermediário da Fasciola hepatica

Fasciolosis is a widespread parasitosis of farm live-stock in many developing countries. For this reason, it is necessary to search for new substances against parasitic diseases caused by flukes. Indeed, a wide variety of terrestrial plants have been subjected to chemical and pharmacological screening in order to discover their potential for human medicinal use. The molluscicidal and larvicidal activities of Atriplex inflata were tested on Galba truncatula and Fasciola hepatica larval stages infecting this snail in Tunisia. Phytochemical tests were conducted on extracts in order to establish a meaningful relationship with molluscicidal and larvicidal activities. The molluscicidal activity was evaluated by subjecting snails to sample aqueous solutions. Accordingly, hexane, ethyl acetate, methanol and methanol-water (8:2, v-v) were used as extraction solvents. As a result, hexane and ethyl acetate extracts showed potent activity, according to the World Health Organization, giving LC50 = 7.59 mg/L and 6.69 mg/L for hexane extracts of leaves and fruits, respectively. Ethyl acetate extracts gave LC50 = 5.90 mg/L and 7.32 mg/L for leaves and fruits, successively. Molluscicidal activities of powders were less potent on snails, but active according to the World Health Organization. Hexane and ethyl acetate extracts from leaves and fruits gave potent larvicidal activities with a delay rate exceeding 45.50% (45.50- 98.92%). Phytochemical tests showed that these activities may be attributed to the presence of triterpenoids and/or sterols.

Fasciolose é uma parasitose generalizada que ocorre em animais de fazendas em muitos países em desenvolvimento. Por esta razão, é necessária a busca de novas substâncias contra as doenças parasitárias causadas por vermes. De fato, uma grande variedade de plantas terrestres foi objeto de testes farmacológicos e químicos a fim de descobrir o seu potencial para utilização em terapêutica humana. As atividades moluscicida e larvicida de Atriplex inflata foram testadas contra estágios larvários de Galba truncatula e Fasciola hepatica infectando este caracol na Tunísia. Testes fitoquímicos foram realizados com extratos a fim de estabelecer uma relação significativa com as atividades moluscicida e larvicida. A atividade moluscicida foi avaliada submetendo os caracóis a soluções aquosas. Conforme o caso, hexano, acetato de etilo, metanol e metanol-água (8:2, v-v) foram utilizados como solventes de extração. Como resultado, hexano e extratos de acetato apresentaram atividades potentes de acordo com a Organização Mundial de Saúde, resultando em LC50 = 7,59 mg/L e 6,69 mg/L para extratos de hexano de folhas e frutos, respectivamente. Extratos de acetato de etilo resultaram em LC50 = 5,90 mg/L e 7,32 mg/L para as folhas e frutos sucessivamente. Atividades moluscicidas das substâncias sob a forma de pó foram menos potentes em caracóis, mas ativas de acordo com a Organização Mundial de Saúde. Hexano e extratos de acetato de folhas e frutos apresentaram atividade larvicida potente, com uma taxa de atraso superior a 45,50% (45,50-98,92%). Testes fitoquímicos mostraram que estas atividades podem ser atribuídas à presença de triterpenóides e/ou esteróis.

Assessment of toxicity of Moringa oleifera flower extract to Biomphalaria glabrata, Schistosoma mansoni and Artemia salina.

This study reports the effect of an aqueous extract from Moringa oleifera Lam. flowers on Biomphalaria glabrata embryos and adults and on Schistosoma mansoni adult worms. The extract contains tannins, saponins, flavones, flavonols, xanthones, and trypsin inhibitor activity. The toxicity of the extract on Artemia salina larvae was also investigated to determine the safety of its use for schistosomiasis control. After incubation for 24h, the flower extract significantly (p<0.05) delayed the development of B. glabrata embryos and promoted mortality of adult snails (LC50: 2.37±0.5mgmL(-1)). Furthermore, treatment with the extract disrupted the development of embryos generated by snails, with most of them remaining in the blastula stage while control embryos were already in the gastrula stage. Flower extract killed A. salina larvae with a LC50 value (0.2±0.015mgmL(-1)) lower than that determined for snails. A small reduction (17%) in molluscicidal activity was detected when flower extract (2.37mgmL(-1)) was exposed to tropical environmental conditions (UVI index ranging from 1 to 14, temperature from 25 to 30°C, and 65% relative humidity). Toxicity to A. salina was also reduced (LC50 value of 0.28±0.01mgmL(-1)). In conclusion, M. oleifera flower extract had deleterious effects on B. glabrata adults and embryos. However, unrestricted use to control schistosomiasis should be avoided due to the toxicity of this extract on A. salina.

Phytochemical and molluscicidal activity of Mikania glomerata Sprengel (Asteraceae) in different lifestages of Subulina octona (Mollusca, Subulinidade)

The objective of this work was to study the molluscicidal activity of aqueous extract of Mikania glomerata on the land snail Subulina octona and to assess the changes caused on the snail's fecundity, growth, hatchability and the offspring produced after exposure. Eggs, newly hatched and 30 day old snails were exposed to the sublethal concentration of M. glomerata extract for 24 and 48 h and the observations were made for 120 days. The presence of tannins, flavonoids and saponins were shown by phytochemical tests. The extract reduced significantly the hatchability and the survival of the offspring hatched from the exposed eggs. The eggs exposed for 48 h presented lower hatchability rates. There was a reduction on survival and growth of newly hatched and 30-days old snails exposed to the extract. These results indicated that the aqueous extract of M. glomerata could be applied as an alternative molluscicide for the control of this snail species efficiently.

Characterization of the molluscicidal activity of Bauhinia variegata and Mimusops elengi plant extracts against the fasciola vector lymnaea acuminata / Caracterização da atividade moluscicida dos extratos das plantas Bauhinia variegata e Mimusops elengi contra o vetor da Fasciola, Lymnaea acuminata

The molluscicidal activity of Bauhinia variegata leaf and Mimusops elengi bark was studied against vector snail Lymnaea acuminata. The toxicity of both plants was time and concentration-dependent. Among organic extracts, ethanol extracts of both plants were more toxic. Toxicity of B. variegata leaf ethanolic extract (96h LC50- 14.4 mg/L) was more pronounced than M. elengi bark ethanolic extract (96h LC50-15.0 mg/L). The 24h LC50 of column purified fraction of B. variegata and M. elengi bark were 20.3 mg/L and 18.3 mg/L, respectively. Saponin and quercetin were characterized and identified as active molluscicidal component. Co-migration of saponin (Rf 0.48) and quercetin (Rf 0.52) with column purified bark of M. elengi and leaf of B. variegata on thin layer chromatography demonstrate same Rf value i.e. 0.48 and 0.52, respectively. The present study clearly indicates the possibility of using M. elengi and/or B. variegata as potent molluscicide.

A atividade moluscicida das folhas da Bauhinia variegata e da casca do Mimusops elengi foi testada contra o vetor caracol, Limnaea acuminata. A toxicidade de ambas as plantas é dependente do tempo e da concentração. Entre os extratos orgânicos, os extratos de etanol de ambas as plantas foi mais tóxico. A toxicidade do extrato etanólico da folha da B. variegata (96 h LC50 - 14,4 mg/L) foi mais pronunciada do que o extrato etanólico da casca do M. elengi (96h - LC50 - 15,0 mg/L). As frações purificadas em coluna durante 24 h LC50 do B. variegata e da casca do M. elengi foram 20,3 mg/L e 18,3 mg/L, respectivamente. A saponina e a quercentina foram caracterizadas e identificadas como os componentes ativos moluscicidas. A co-migração da saponina (Rf 0,48) e da quercentina (Rf 0,52) com a casca purificada por coluna do M. elengi e as folhas da B. variegata na cromatografia demonstraram o mesmo valor Rf isto é, 0,48 e 0,52 respectivamente. O presente estudo indica claramente a possibilidade de usar M. elengi e/ou B. variegata como moluscicidas potentes.

Molluscicidal activities of medicinal plants from eastern China against Oncomelania hupensis, the intermediate host of Schistosoma japonicum / Atividades moluscicida de plantas medicinais do leste da China contra Oncomelania hupensis, o hospedeiro intermediário da Schistosoma japonicum

In a search for natural products that could be used to control schistosomiasis, nineteen extracts of eleven medicinal plants from eastern China have been tested for molluscicidal activity against snail Oncomelania hupensis. The n-butanol fraction of the fresh leaf from Buddleja lindleyana Fortune, Buddlejaceae, showed significant activity against the snails. Statistical analysis revealed that the LC50 and LC90 values for the n-butanol fraction were 39.91 mg L-1 and 59.28 mg L-1 for 48 h, respectively. Otherwise, the LC50 values for the n-butanol fraction to zebrafish was 403.24 mg L-1 for 48 h. Therefore, the n-butanol fraction of the fresh leaf from B. lindleyana may be a potent and safe molluscicides.

Na busca por produtos naturais que podem ser utilizados para controle da esquistossomose, dezenove extratos de onze plantas medicinais do leste da China foram testados para atividade moluscicida contra o caramujo Oncomelania hupensis. A fração n-butanol das folhas frescas de Buddleja lindleyana Fortune, Buddlejaceae, mostrou atividade significativa contra os caracóis. A análise estatística revelou que os valores de CL50 e CL90 para a fração n-butanol foram 39,91 mg L-1 e 59,28 mg L-1 por 48 h, respectivamente. Por outro lado, a CL50 para a fração n-butanol para peixe-zebra foi 403,24 mg L-1 por 48 h. Portanto, a fração n-butanol das folhas frescas de B. lindleyana poderá vir a ser um moluscicidas potente e seguro.

Avaliação da bioatividade dos extratos de cúrcuma (Curcuma longa L., Zingiberaceae) em Artemia salina e Biomphalaria glabrata / Bioactivity evaluation of the turmeric (Curcuma longa L., Zingiberaceae) extracts in Artemia salina and Biomphalaria glabrata

A cúrcuma é o rizoma limpo, em boas condições, seco e moído da Curcuma longa L., uma planta herbácea da família Zingiberaceae. Visando novas alternativas para o controle da esquistossomose, os extratos de Curcuma longa L. foram testados para a avaliação da atividade moluscicida contra caramujos adultos da espécie Biomphalaria glabrata, e toxicidade (ensaio de letalidade com Artemia salina). A oleoresina e o óleo essencial de cúrcuma foram ativos contra Artemia salina (CL50 = 80,43 e CL50 = 319,82 μg/mL, respectivamente) e também ativos contra os indivíduos adultos de Biomphalaria glabrata (CL50 = 58,3 e CL50 = 46,73 μg/mL, respectivamente). A partir dos resultados obtidos pôde ser concluído que ambos os extratos podem constituir uma alternativa no controle da população desses caramujos e na redução da esquistossomose.

The turmeric is the clean rhizome at good conditions, dried and powdered of Curcuma longa L., an herbaceous plant of Zingiberaceae family. Aiming new alternatives for Schistosomiasis control, the Curcuma longa L. extracts were tested for molluscicidal activity evaluation against adult snails of Biomphalaria glabrata specie, and the toxicity (Brine Shrimp Lethality-BSL-bioassay). The oleoresin and the essential oil of turmeric were active against Artemia salina (CL50 = 80.43 and CL50 = 319.82 μg.mL-1, respectively) and also active against the adult snails of Biomphalaria glabrata (CL50 = 58.3 and CL50 = 46.73 μg.mL-1, respectively). From the obtained results it was concluded that both extracts can constitute an alternative to population control of these snails and in the reduction of Schistosomiasis.

Molluscicidal activity of Hammada scoparia (Pomel) Iljin leaf extracts and the principal alkaloids isolated from them against Galba truncatula

The molluscicidal activity of Hammada scoparia leaf extracts and the principal alkaloids isolated from them (carnegine and N-methylisosalsoline) were tested against the mollusc gastropod, Galba truncatula, the intermediate host of Fasciola hepatica in Tunisia. The results indicated that the molluscicidal activity was correlated with the presence of alkaloids. A significant molluscicidal value, according to the World Health Organization, was found with the methanol extract (LC50 = 28.93 ppm). Further fractionation of the methanolic extract led to the isolation of two principal alkaloids: carnegine and N-methylisosalsoline. These alkaloids are isoquinolines that have not previously been characterised for their molluscicidal activity. The N-methylisosalsoline possesses the highest molluscicidal activity (LC50 = 0.47 ìM against G. truncatula).

Molluscicidal activity of 2-hydroxy-[1, 4]naphthoquinone and derivatives

The toxic profile of lawsone (2-hydroxy-[1,4]naphthoquinone) and a series of [1,4]naphthoquinone derivatives was evaluated against the brine shrimp Artemia salina and against the mollusk Biomphalaria glabrata, the main transmitting vector of schistosomiasis in Brazil. Of the seventeen compounds tested nine fell below the threshold of 100 µg/mL set for potential molluscicidal activity by the World Health Organization. As a general rule derivatives with non-polar substituents presented the highest molluscicidal activities. These substances showed significant toxicity in A. salina lethality bioassay.

A toxicidade da lausona (2-hidroxi-1,4)-naftoquinona e de diversos derivados foi avaliada frente à Artemia salina e ao molusco Biomphalaria glabrata, o principal vetor de transmissão da esquistossomose no Brasil. Entre os dezessete compostos testados, nove apresentaram um perfil de toxicidade menor que 100 µg/mL, sendo potenciais agentes moluscicidas de acordo com as designações da Organização Mundial da Saúde. No presente estudo, os compostos contendo substituintes apolares exibiram as maiores atividades. Estes compostos também se mostraram significantemente tóxicos frente à A. salina.

Avaliação da atividade tóxica em Artemia salina e Biomphalaria glabrata de extratos de quatro espécies do gênero Eleocharis (Cyperaceae) / Toxic evaluation of four species of the genus Eleocharis (Cyperaceae) in Artemia salina and Biomphalaria glabrata

O gênero Eleocharis R. Br. compreende cerca de 200 espécies, ocorrendo em ambientes úmidos tais como brejos e margens de rios e lagos. Procurando novos agentes moluscicidas, os extratos de Eleocharis acutangula (Roxb.) Schult., Eleocharis interstincta (Vahl) Roem. & Schult., Eleocharis maculosa (Vahl) Roem. & Schult. e Eleocharis sellowiana Kunth foram testados para atividade moluscicida, contra caramujos adultos e desovas, e toxicidade (ensaio de letalidade com Artemia salina). O extrato hexânico de Eleocharis acutangula (parte subterrânea fresca) foi ativo contra Artemia salina (CL50 = 476,00 mg/mL), enquanto os demais extratos apresentaram CL50 >> 10³ mg/mL, sugerindo baixa toxicidade. O extrato hidro-etanólico de Eleocharis sellowiana (parte subterrânea fresca) foi ativo contra desovas de Biomphalaria glabrata (CL50 = 24,27 mg/mL) mas inativo contra indivíduos adultos. Os demais extratos testados não apresentaram atividade moluscicida.

The genus Eleocharis R. Br. comprises about 200 species, occurring in wet environments like swamps, lakes and river margins. In the search for new molluscicides, extracts from Eleocharis acutangula (Roxb.) Schult., Eleocharis interstincta (Vahl) Roem. & Schult., Eleocharis maculosa (Vahl) Roem. & Schult. and Eleocharis sellowiana Kunth were tested for molluscicidal activity (spawns and adult snails) and toxicity (Brine Shrimp Lethality - BSL - bioassay). The hexane extract of Eleocharis acutangula (fresh subterraneous parts) was active in the BSL bioassay (LC50 = 476 mg/mL), while the other extracts showed LC50 >> 10³ mg/mL, suggesting they have low toxicity. The aqueous ethanol extract of Eleocharis sellowiana (fresh subterraneous parts) was active against Biomphalaria glabrata spawns (LC50 = 24.27 mg/mL) but it was not lethal to adult snails. No other plant extract tested in this study showed molluscicidal activity.