Molluscicidal activity of the secondary metabolites from Streptomyces nigrogriseolus XD 2-7 against Oncomelania hupensis and its preliminary mechanisms of molluscicidal actions / 中国血吸虫病防治杂志

OBJECTIVE@#To evaluate the storage stability of metabolites from actinomycetes Streptomyces nigrogriseolus XD 2-7 and the mollcuscicidal activity against Oncomelania hupensis in the laboratory, and to preliminarily explore the mechanisms of the molluscicidal activity.@*METHODS@#The fermentation supernatant of S. nigrogriseolus XD 2-7 was prepared and stored at -20, 4 °C and 28 °C without light for 10 d; then, the molluscicidal effect was tested against O. hupensis following immersion for 72 h. The fermentation supernatant was boiled in a 100 °C water bath for 30 min and recovered to room temperature, and then the molluscicidal effect was tested against O. hupensis following immersion for 72 h. The pH values of the fermentation supernatant were adjusted to 4.0, 6.0 and 9.0 with concentrated hydrochloric acid and sodium hydroxide, and the fermentation supernatant was stilled at room temperature for 12 h, with its pH adjusted to 7.0; then, the molluscicidal effect was tested against O. hupensis following immersion for 72 h. The fermentation product of S. nigrogriseolus XD 2-7was isolated and purified four times with macroporous resin, silica gel and octadecylsilane bonded silica gel. The final products were prepared into solutions at concentrations of 10.00, 5.00, 2.50, 1.25 mg/L and 0.63 mg/L, and the molluscicidal effect of the final productswas tested against O. hupensis following immersion for 72 h, while dechlorination water served as blank controls, and 0.10 mg/L niclosamide served as positive control. The adenosine triphosphate (ATP) and adenosine diphosphate (ADP) levels were measured in in O. hupensis soft tissues using high performance liquid chromatography (HPLC) following exposure to the final purified fermentation products of S. nigrogriseolus XD 2-7.@*RESULTS@#After the fermentation supernatant of S. nigrogriseolus XD 2-7 was placed at -20, 4 °C and 28 °C without light for 10 d, immersion in the stock solution and solutions at 10- and 50-fold dilutions for 72 h resulted in a 100% (30/30) O. hupensis mortality. Following boiling at 100 °C for 30 min, immersion in the stock solution and solutions at 10- and 50-fold dilutions for 72 h resulted in a 100.00% (30/30) O. hupensis mortality. Following storage at pH values of 4.0 and 6.0 for 12 h, immersion in the fermentation supernatant of S. nigrogriseolus XD 2-7 for 72 h resulted in a 100.00% (30/30) O. hupensis mortality, and following storage at a pH value of 9.0 for 12 h, immersion in the fermentation supernatant of S. nigrogriseolus XD 2-7 for 72 h resulted in a 33.33% (10/30) O. hupensis mortality (χ2 = 30.000, P < 0.05). The minimum concentration of the final purified fermentation products of S. nigrogriseolus XD 2-7 was 1.25 mg/L for achieving a 100% (30/30) O. hupensis mortality. The ATP level was significantly lower in O. hupensis soft tissues exposed to 0.10 mg/L and 1.00 mg/L of the final purified fermentation products of S. nigrogriseolus XD 2-7 than in controls (F = 7.274, P < 0.05), while no significant difference was detected in the ADP level between the treatment group and controls (F = 2.485, P > 0.05).@*CONCLUSIONS@#The active mollcuscicidal ingredients of the S. nigrogriseolus XD 2-7 metabolites are maintained stably at -20, 4 °C and 28 °C for 10 d, and are heat and acid resistant but not alkali resistant. The metabolites from S. nigrogriseolus XD 2-7 may cause energy metabolism disorders in O. hupensis, leading to O. hupensis death.

Development of a natural molluscicide prototype kit (MoluSchall) for the control of schistosomiasis mansoni transmission

Abstract INTRODUCTION In Brazil, Biomphalaria glabrata, B. tenagophila, and B. straminea are intermediate hosts of Schistosoma mansoni, the etiological agent of schistosomiasis mansoni. Molluscicide use is recommended by the WHO for controlling the transmission of this parasite. Euphorbia milii latex has shown promising results as an alternative molluscicide. Thus, a natural molluscicide prototype kit based on freeze-dried E. milii latex was developed and evaluated against Biomphalaria spp. METHODS E. milii latex was collected, processed, and lyophilized. Two diluents were defined for freeze-dried latex rehydration, and a prototype kit, called MoluSchall, was produced. A stability test was conducted using prototype kits stored at different temperatures, and a toxicity assay was performed using Danio rerio. Additionally, MoluSchall was tested against B. glabrata under semi-natural conditions according to defined conditions in the laboratory. RESULTS MoluSchall was lethal to three Brazilian snail species while exhibiting low toxicity to D. rerio. Regardless of storage temperature, MoluSchall was stable for 24 months and was effective against B. glabrata under semi-natural conditions, with the same LD100 as observed under laboratory conditions. CONCLUSIONS MoluSchall is a natural, effective, and inexpensive molluscicide with lower environmental toxicity than existing molluscicides. Its production offers a possible alternative strategy for controlling S. mansoni transmission.

Histopathological and ultrastructural studies on biomphalaria alexandrina snails infected with schistosoma mansoni miracidia and treated with plant extracts

Background: Biomphalaria alexandrina snails are the intermediate host of Schistosoma mansoni in Egypt

Aim of the work: this study aimed to evaluate the molluscicidal activity of the methanol extract of the plants Anagallis arvensis and Viburnum tinus against B. alexandrina [Normal and S. mansoni infected]

Results: the present results proved high activity for both plant extracts [LC[50] and LC[90] which reached 45and 60 ppm and 38 and 59 ppm for A. arvensis and V. tinus, respectively]. The effect of sub-lethal concentration, 1/2 LC[5], of the two plant extracts [26 and 11 ppm, respectively] affected B. alexandrina survival rate to be in the following order, control > V. tinus treated > A. arvensis treated > infected > infected-A. arvensis treated > infected- V. tinus treated. On the other hand, exposure to those sub-lethal doses caused considerable reduction in the infection percentages. In addition, the histopathological effects of the examined sub-lethal concentrations on hepatopancreatic tubules of the treated snails showed cells vacuolation, presence of hyaline substances filled the lumens of the tubules and necrotic focal areas in case of A. arvnsis and vacuolar degeneration with the necrotic changes in case of V. tinus. While, alterations in the hermaphrodite glands of the treated snails included: degeneration and necrotic changes in the acini. The severity of lesions was progressed with infection as a result of invading of snail tissue by developmental stages of the S. mansoni cercariae. The ultrastructural micrographs were used to explain and confirm the recorded histopathological alterations in the hermaphrodite glands of the infected-treated snails. In comparison with the control and infected snail groups, infected-treated snails showed degeneration with severe deformation and destruction in their reproductive units, degeneration in developmental stages tissues of S. mansoni cercariae and accumulation of the toxic agents

Conclusion: the two examined plants, A. arvensis and V. tinus plant extracts showed high activity against B. alexandrina and provide a considerable scope in exploiting local indigenous resources for snail's molluscicidal agents. The sub-letal concentrations, 1/2 LC[5], of the two plant extracts caused a considerable reduction in survival rate and infection rate among S. mansoni infected snails. Histopathological changes in the digestive glands showed cells vacuolation, hyaline substance filled lumens of the tubules and necrotic focal areas in the digestive glands. Histopathological effects explained and confirmed by TEM images showed degeneration with severe deformation and destruction in the reproductive units

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.

EVALUATION OF THE MOLLUSCICIDAL POTENTIAL OF HYDROALCOHOLIC EXTRACTS OF Jatropha gossypiifolia Linnaeus, 1753 ON Biomphalaria glabrata (Say, 1818) / Avaliação do potencial moluscicida de extratos hidroalcoólicos do caule, folhas e frutos de Jatropha gossypiifolia Linnaeus, 1753 em Biomphalaria glabrata (Say, 1818)

The action of extracts from the stem, leaves, and fruit of Jatropha gossypiifolia on Biomphalaria glabrata was studied by analyzing survival, feeding capacity and oviposition ability. The extracts were obtained by macerating the plant parts in 92% ethanol, which were then evaporated until a dry residue was obtained and phytochemically studied. The molluscicidal activity on B. glabrata was investigated using the procedures recommended by WHO (1965). The amount of food ingested and oviposition were measured during each experiment. The extract of leaves from J. gossypiifolia was shown to be a strong molluscicidal agent, causing 100% mortality of B. glabrata, even in the lowest concentration tested, of 25 ppm. Regarding the fruit extract, there was variation in the mortality, depending on the concentration used (100, 75, 50 and 25 ppm). The snails that were in contact with the fruit extract had significant reduction in feeding and number of embryos in comparison to the control. The stem extract did not present molluscicidal activity nor had any influence on the feeding and oviposition abilities of B. glabrata, in the concentrations tested. In conclusion, the extracts of leaves and fruits of J. gossypiifolia investigated in this work show molluscicidal effect and may be sources of useful compounds for the schistosomiasis control.

Estudou-se a ação dos extratos do caule, folhas e frutos de Jatropha gossypiifolia (Pinhão-roxo) sobre Biomphalaria glabrata analisando a sobrevivência, capacidade alimentar e de oviposição. Os extratos foram obtidos pela maceração das partes do vegetal em álcool etílico 92%, evaporados até obter-se um resíduo seco e estudados fitoquimicamente. A atividade moluscicida em B. glabrata seguiu os procedimentos recomendados pela WHO (1965). A medida de quantidade de alimento ingerido e a oviposição foi realizada durante cada experimento. O extrato das folhas de J. gossypiifolia mostrou-se um forte agente moluscicida, promovendo 100% de mortalidade de B. glabrata mesmo na menor concentração testada, 25 ppm. Com o extrato dos frutos houve variação na mortalidade, de acordo com a concentração utilizada (100, 75, 50 e 25 ppm). Os caramujos em contato com o extrato dos frutos apresentaram quando comparado ao controle uma diminuição significativa nos comportamentos alimentares e de número de embriões. O extrato do caule não apresentou atividade moluscicida e nenhuma influência sobre a capacidade alimentar e de oviposição de B. glabrata nas concentrações testadas. Em conclusão, os extratos de folhas e frutos de J. gossypiifolia investigados neste trabalho apresentam efeito moluscicida e possivelmente podem ser fontes de compostos no controle da esquistossomose.

EFFECTS OF SINGLE, BINARY AND TERTIARY COMBINATIONS WITH Jatropha gossypifolia AND OTHER PLANT-DERIVED MOLLUSCICIDES ON REPRODUCTION AND SURVIVAL OF THE SNAIL Lymnaea acuminata / Efeitos de combinações unitárias, binárias e terciárias de Jatropha gossypifolia e outros muluscicidas derivados de plantas na reprodução e sobrevivência do caramujo Lymnaea acuminata

The effect of sub-lethal doses (40% and 80% of LC50/24h) of plant derived molluscicides of singly, binary (1:1) and tertiary (1:1:1) combinations of the Rutin, Ellagic acid, Betulin and taraxerol with J. gossypifolia latex, leaf and stem bark powder extracts and their active component on the reproduction of freshwater snail Lymnaea acuminata have been studied. It was observed that the J. gossypifolia latex, stem bark, individual leaf and their combinations with other plant derived active molluscicidal components caused a significant reduction in fecundity, hatchability and survival of young snails. It is believed that sub-lethal exposure of these molluscicides on snail reproduction is a complex process involving more than one factor in reducing the reproductive capacity.

O efeito de doses sub-letais (40% e 80% de LC50/24h) de moluscicidas derivados de plantas com combinações unitárias, binárias (1:1) e terciárias (1:1:1) de Rutin, ácido Elágico, Betulin e taraxerol com látex da J. gossypifolia, folhas e extrato em pó de casca de caule e seus componentes ativos foram estudados na reprodução do caramujo de água fresca Lymnaea acuminata. Foi observado que o látex da J. gossypifolia, casca do caule, folhas individualmente e suas combinações com componentes moluscicidas ativos derivados de outras plantas causaram redução significante na fecundidade, incubação e sobrevivência dos caramujos jovens. Acredita-se que a exposição sub-letal destes moluscicidas sobre a reprodução dos caramujos é processo complexo envolvendo mais de um fator na redução da capacidade reprodutiva.

OVICIDAL EFFECT OF PIPERACEAE SPECIES ON Biomphalaria glabrata, Schistosoma mansoni HOST / Efeito ovicida de espécies de Piperaceae em Biomphalaria glabrata, hospedeiro do Schistosoma mansoni

SUMMARY Schistosomiasis is a neglected disease with public health importance in tropical and subtropical regions. An alternative to the disease control is the use of molluscicides to eliminate or reduce the intermediate host snail population causing a reduction of transmission in endemic regions. In this study nine extracts from eight Piperaceae species were evaluated against Biomphalaria glabrata embryos at blastula stage. The extracts were evaluated in concentrations ranging from 100 to 10 mg/L. Piper crassinervium and Piper tuberculatum extracts were the most active (100% of mortality at 20 mg/L and 30 mg/L respectively). .

RESUMO A esquistossomose é uma doença negligenciada de importância para a saúde pública em regiões tropicais e subtropicais. Uma alternativa para o controle da doença é o uso de moluscicidas para eliminar ou reduzir a população de caramujo hospedeiro, acarretando uma redução da transmissão da doença nas regiões endemicas. Neste estudo, nove extratos vegetais provenientes de oito espécies de Piperaceae foram expostos a embriões de Biomphalaria glabrata no estágio de blástula. Os extratos foram avaliados em concentrações que variaram entre 100 e 10 mg/L, sendo Piper crassinervium e Piper tuberculatum os extratos mais ativos (100% de mortalidade a 20 mg/L e 30 mg/L respectivamente). .

Molluscicidal and Mosquitocidal Activities of the Essential oils of Thymus capitatus Hoff. et Link. and Marrubium vulgare L. / Atividades moluscicida e mosquitocida de óleos essenciais de Thymus capitatus Hoff. et Link. e de Marrubium vulgare L

Steam distillation of essential oils of aerial parts of Thymus capitatus and Marrubium vulgare L. collected at North cost of Egypt yielded 0.5% and 0.2%, respectively. Results of Gas chromatography-mass spectrometry analyses of the two samples identified 96.27% and 90.19% of the total oil composition for T. capitatus and M. vulgare, respectively. The two oil samples appeared dominated by the oxygenated constituents (88.22% for T. capitatus and 57.50% for M. vulgare), composed of phenols, mainly carvacrol (32.98%) and thymol (32.82%) in essential oil of T. capitatus, and thymol (34.55%) in essential oil of M. vulgare. It was evaluated the molluscicidal activity of T. capitatus and M. vulgare essential oils on adult and eggs of Biomphalaria alexandrina as well as their mosquitocidal activity on Culex pipiens. The LC50 and LC90 of T. capitatus essential oil against adult snails was 200 and 400 ppm/3hrs, respectively, while for M. vulgare it was 50 and 100 ppm/3hrs, respectively. Moreover, M. vulgare showed LC100 ovicidal activity at 200 ppm/24 hrs while T. capitatus oil showed no ovicidal activity. It was verified mosquitocidal activity, with LC50 and LC90 of 100 and 200 ppm/12hrs respectively for larvae, and 200 and 400 ppm/12hrs respectively for pupae of C. pipiens.

A destilação por arraste a vapor dos óleos essenciais de partes aéreas de Thymus capitatus Hoff. et Link. e de Marrubium vulgare L. coletadas na costa norte do Egito resultaram em rendimento de 0,5% e 0,2%, respectivamente. Resultados de análises por cromatografia gasosa acoplada à espectrometria de massas de ambas as amostras possibilitaram a identificação de 96,27% e 90,19% dos constituintes químicos respectivamente de T. capitatus e M. vulgare. Verificou-se predomínio de constituintes oxigenados (88,22% para T. capitatus e 57,50% para M. vulgare, principalmente fenóis, como carvacrol (32,98%) e timol (32,82%) no óleo essencial de T. capitatus, e timol (34,55%) no óleo essencial de M. vulgare. Avaliou-se a atividade dos óleos essenciais obtidos contra adultos e ovos de Biomphalaria alexandrina, bem como em larvas e pupas de Culex pipiens. A CL50 e CL90 do óleo essencial de T. capitatus em moluscos adultos foi respectivamente 200 e 400 ppm/3hrs, enquanto para o óles essencial de M. vulgare verificou-se CL50 e CL90 de 50 e 100 ppm/3hrs, respectivamente. Além disso, M. vulgare apresentou atividade ovicida, com CL 100 de 200 ppm/24 horas, enquanto o óleo essencial de T. capitatus não demonstrou atividade ovicida. Verificou-se ainda atividade mosquitocida, com CL50 e CL90 de 100 e 200 ppm/12hrs respectivamente para larvas, e 200 e 400 ppm/12hrs contra pupas de C. pipiens.

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.

Laboratory evaluation of the molluscicidal activity of Pulsatilla chinensis (Bunge) Regel saponins against the snail Oncomelania hupensis / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To observe the toxicity of Pulsatilla chinensis (Bunge) Regel saponins (PRS) against Oncomelania hupensis (O. hupensis).</p><p><b>METHODS</b>O. hupensis snails were exposed to 40% and 80% of 24 h LC50 of PRS for 24 h, and then choline esterase (CHE), alanine aminotransferase (ALT), alkaline phosphatase (ALP), lactate dehydrogenase (LDH) activities in cephalopodium and liver of snails were determined. Niclosamide (NIC) was used as the reference molluscicide. Zebra fish lethality test was evaluated to non-target aquatic species of PRS.</p><p><b>RESULTS</b>The molluscicidal activity of PRS (LC50 at 24 h: 0.48 mg/L) was similar to that of NIC (LC50 at 24 h: 0.16 mg/L). Significant alterations about CHE, ALP, and ALT activities both in the cephalopodium and the liver of snails were observed when O. hupensis was exposed to 40% and 80% LC50 of PRS or NIC for 24 h. PRS and NIC could not affect LDH activity in the cephalopodium and the liver. Lower toxicity to fish of PRS was observed up to the highest concentration tested than NIC.</p><p><b>CONCLUSION</b>PRS, as compared with the reference molluscicide NIC, is thought to be used for the control of harmful vector snails safely.</p>

Impact of Taraxerol in combination with extract of Euphorbia tirucalli plant on biological parameters of Lymnaea acuminata / Impacto do Taraxerol em combinação com o extrato da planta de Euphorbia tirucalli nos parâmetros biológicos da Lymnaea acuminata

The present work was carried out to evaluate the molluscicidal activity of active ingredient Taraxerol with the acetone extract of Euphorbia tirucalli against Lymnaea acuminata snail. The (fecundity, hatchability and survivability) of snail L. acuminata exposed to this extract was studied. The effects of the tested extracts on life-history traits of harmful snail L. acuminata have also been evaluated, and this study also expounds the inhibitory effects of these extracts singly as well as in binary combination (1:1 ratio). It concluded that these herbal products act as a potential source of molluscicides, and that they would also have the advantage of easy availability, low cost, biodegradability and greater acceptance amongst users than synthetic pesticide.

O presente trabalho foi levado a efeito para avaliar a atividade moluscicida do ingrediente ativo Taraxerol junto com o extrato de acetona da Euphorbia tirucalli contra o caramujo Lymnaea acuminata. Foram estudados a fecundidade, o desenvolvimento e sobrevivência do caramujo Lymnaea acuminata exposto a estes extratos. Os efeitos danosos destes extratos testados na vida do caramujo L. acuminata foram também avaliados e este estudo demonstra os efeitos inibidores destes extratos isolados ou em combinação binária (relação l:1). Concluiu-se que estes produtos vegetais agem como fontes potenciais de moluscicidas e que eles também têm a vantagem de obtenção fácil, baixo custo, biodegradabilidade e maior aceitação entre os usuários do que os pesticidas sintéticos.

Bait formulations of molluscicides and their effects on biochemical changes in the ovotestis of snail Lymnaea acuminata (Mollusca; Gastropoda:Lymnaeidae) / Formulações de iscas de moluscicidas e seus efeitos sobre as alterações bioquímicas no ovoteste do caramujo Lymnaea acuminata (Mollusca;Gastropoda:Lymnaeidae)

The effect of sub-lethal feeding of bait formulations containing molluscicidal component of Ferula asafoetida (ferulic acid, umbelliferone), Syzygium aromaticum (eugenol) and Carum carvi (limonene) on biochemical changes in the ovotestis of snail Lymnaea acuminata were studied. Bait formulations feeding to L. acuminata were studied in clear glass aquaria having diameter of 30 cm. Baits were prepared from different binary combinations of attractant amino acid (valine, aspartic acid, lysine and alanine 10 mM) in 100 mL of 2 percent agar solution + sub-lethal (20 percent and 60 percent of 24h LC50) doses of different molluscicides (ferulic acid, umbelliferone, eugenol and limonene). These baits caused maximum significant reduction in free amino acid, protein, DNA, RNA levels i.e. 41.37, 23.56, 48.36 and 14.29 percent of control in the ovotestis of the snail, respectively. Discontinuation of feeding after treatment of 60 percent of 96h LC50 of molluscicide containing bait for next 72h caused a significant recovery in free amino acid, protein, DNA and RNA levels in the ovotestis of L. acuminata.

Foi estudado o efeito subletal das iscas usadas para alimentação contendo componentes moluscicidas de Ferula asafoetida (ácido ferúlico, umbeliferone), Syzygium aromaticum (eugenol) e Carum carvi (limonene) nas alterações bioquímicas do ovoteste do caramujo Lymnaea acuminata. A formulação das iscas usadas para alimentar L. acuminata foi estudada em aquários de vidros transparentes de diâmetro de 30 cm. As iscas foram preparadas por combinações diferentes binárias de aminoácidos (valina, ácido aspártico, lisina e alanina 10 mM) em 100 mL de solução de agar a 2 por cento + doses subletais (20 por cento e 60 por cento durante 24 horas LC50) de diferentes moluscicidas (ácido ferúlico, umbeliferone, eugenol e limonene). Estas iscas causaram redução significante máxima em aminoácidos livres, proteínas, níveis de DNA e RNA isto é 41,37 por cento, 23,56 por cento, 48,36 por cento e 14,29 por cento de controle no ovoteste do caramujo, respectivamente. Discontinuação da alimentação depois do tratamento de 60 por cento de 96 horas de LC50 do moluscicida contendo a isca para as subsequentes 72 horas causou significante recuperação dos níveis de aminoácidos livres, proteína, DNA e RNA no ovoteste da L. acuminata.

Efficacy of euphorbia hirta latex as plant derived molluscicides against freshwater snails / Eficácia do látex da Euphorbia hirta como moluscicida vegetal contra caramujos de água doce

The toxic effect of binary and tertiary combinations of Euphorbia hirta Linn latex powder with other plant molluscicidal compounds, were evaluated against the freshwater snails Lymnaea (Radix) acuminata and Indoplanorbis exustus in pond. These combinations showed significant time and dose dependent effect against both the snails. These compounds at higher doses were also lethal to freshwater fish Channa punctatus (Bloch) (Channidae {Ophicephalidae}), which shares the habitat with these snails, but the LC90 (24h) doses of snails have no apparent killing properties in fish populations when treated in mixed population of snails and fish.

Os efeitos tóxicos das combinações binárias e terciárias do pó de látex da Euphorbia hirta Linn assim como outros compostos vegetais moluscicidas foram avaliados em sua ação sobre caramujos de água doce Lymnaea (Radix) acuminata e Indoplanorbis exustus em represas. Estas combinações mostraram significante efeito dose e tempo dependente contra ambos os caramujos. Estes compostos em doses altas foram também letais para peixes de água doce Channa punctatus (Bloch) (Channidae {Ophicephalidae}), que compartilham o ambiente com estes caramujos mas a dose LC90 (24h) para caramujos aparentemente não tem propriedade de matar as populações de peixes quando uma população mista de peixes e caramujos são tratadas.

Efeitos de Piperaceae em Biomphalaria glabrata (Say, 1818)(Mollusca: Planorbidae) / Effects of Piperaceae on Biomphalaria glabrata (Say, 1818) (Mollusca: Plaorbidae)

A esquistossomose é uma doença grave e de evolução crônica, com importante papel sócio-econômico, cuja profilaxia inclui medidas que envolvem saneamento básico, educação sanitária, tratamento de indivíduos infectados e o controle dos caramujos hospedeiros intermediários do Schistosoma mansoni. Uma das medidas mais eficientes para o controle dos caramujos é a aplicação de moluscicidas, sendo os extratos vegetais os mais indicados. As vantagens do uso de extratos vegetais são devidas, principalmente, ao seu baixo custo e baixa ação tóxica para o ambiente. O objetivo deste trabalho foi avaliar a ação de extratos brutos de Piper cubataonum, Piper caldense, Piper cernuum, Peperomia trineura, Peperomia rubricaulis, Peperomia blanda e da substância ativa, ácido caldensínico de Piperaceae em embriões e adultos de Biomphalaria glabrata. Os extratos brutos e a substância ativa foram obtidos de folhas das plantas. Inicialmente todos os extratos e a substância ativa foram testados nas concentrações de 100 ppm e 20 ppm, respectivamente. Procurou-se determinar para cada extrato as concentrações responsáveis pela mortalidade de no mínimo 50% dos espécimes expostos. Os dados de mortalidade de adultos foram submetidos à análise de probito com intuito de estimar a concentração letal para 50% e 90% (CL50 e CL90) da população. Os extratos que apresentaram efeito tóxico em adultos foram P. trineura a 100, 80 e 60 ppm e P. caldense a 100, 80 e 50 ppm. O ácido caldensínico, quando testado em adultos, apresentou efeito tóxico a 20 e 10 ppm. Nas desovas os extratos que demonstraram efeito toxico foram P. trineura a 100, 80, 60 e 50 ppm, P. rubricaulis a 100 e 80 ppm e P. caldense a 100 ppm, apenas para os estádios de blástula, gástrula, e trocófora. Este último extrato apresentou efeito tóxico a 80 ppm somente para blástula e gástrula. P. caldense mostrou-se mais eficiente que P. trineura para causar a mortalidade em B. glabrata a 50 ppm. Os extratos de P. caldense...

Avaliação das atividades antimicrobiana, citotóxica, moluscicida e antioxidante de Bromelia antiacantha Bertol: (Bromeliaceae) / Evaluation of antimicrobial, cytotoxic, molluscicidal and antioxidant activities of Bromelia antiacantha Bertol: (Bromeliaceae)

A Bromelia antiacantha Bertol. (Bromeliaceae), conhecida como gravatá ou caraguatá, apresenta características medicinais, alimentícias e ornamentais. Neste trabalho foram avaliadas as atividades antifúngica, antibacteriana, citotóxica, moluscicida e antioxidante de extratos alcoólicos das folhas e frutos desta espécie. Na avaliação da atividade antimicrobiana pelo método de microdiluição os extratos alcoólicos não foram eficientes frente à cepa referência do fungo Candida albicans (ATCC 90028), cepas clínicas de C. albicans e C. glabrata, e frente às bactérias S. aureus (ATCC 6538), P. aeruginosa (ATCC 9027) e E. coli (ATCC 8739). A atividade citotóxica, avaliada pelo bioensaio de toxicidade sobre náuplios de Artemia salina Leach (TAS), foi positiva para ambos extratos, com valores de DL50 variando em torno de 620 µg mL-1 e 360 µg mL-1, para os extratos alcoólicos dos frutos e das folhas, respectivamente. A atividade moluscicida, avaliada frente a caramujos da espécie Biomphalaria glabrata (Molusca, Gastropoda), não mostrou toxicidade aguda para soluções de 400 µg mL-1. As propriedades antioxidantes dos extratos investigadas in vitro mediante o método de DPPH• foram consideradas modestas (~ 35 por cento de inibição na concentração de 1000 µg mL-1). Dentre as atividades biológicas que foram testadas a atividade citotóxica foi a mais pronunciada.

Bromelia antiacantha Bertol. (Bromeliaceae), popularly known as "gravatá" or "caraguatá", shows medicinal, nutritional and ornamental properties. In the present study, the alcoholic extracts of leaves and fruits of this species were evaluated for antifungal, antibacterial, cytotoxic, molluscicidal and antioxidant activities. The alcoholic extracts evaluated by microdilution method were not efficient against the standard strain of Candida albicans (ATCC 90028), clinical strains of C. albicans and C. glabrata, and S. aureus (ATCC 6538), P. aeruginosa (ATCC 9027) and E. coli (ATCC 8739). The cytotoxic activity evaluated by toxicity bioassay on nauplii of Artemia salina Leach (TAS) was positive for both extracts, with LD50 values ranging around 620 µg mL-1 and 360 µg mL-1 for alcoholic extracts from leaves and fruits, respectively. The molluscicidal activity evaluated against Biomphalaria glabrata (Mollusca, Gastropoda) did not present acute toxicity for 400 µg mL-1 solutions. The antioxidant properties of the extracts investigated in vitro using the DPPH• method were considered modest (~ 35 percent of inhibition at 1000 µg mL-1). Among the evaluated biological activities, cytotoxic activity was the most marked.

Avaliação da atividade moluscicida do látex de três espécies de Euphorbia (Euphorbiaceae) sobre Leptinaria unilamellata d'Orbigny, 1835 (Gastropoda - Subulinidae) / Assessment of moluscicidal activity of the latex of three Euphorbia (Euphorbiaceae) species on Leptinaria unilamellata d'Obigny 1835 (Gastropoda - Subulinidae)

Gastrópodes pulmonados terrestres podem atuar como hospedeiros intermediários de helmintos. Os primeiros registros do controle químico desses invertebrados datam do início do século XX e as substâncias utilizadas eram toxinas inespecíficas já empregadas no controle de outras pragas. Moluscicidas sintéticos apresentam limitações técnicas que estimularam a busca de substitutos naturais. Dentre as várias espécies vegetais com atividade moluscicida, Euphorbia cotinifolia L., Euphorbia milii des Moul. var. splendens (Bojer ex Hook) Ursch & Leandri e Euphorbia tirucalli L. despertam atenção pelos excelentes resultados obtidos sobre moluscos aquáticos. Contudo, estudos sobre a atividade de plantas moluscicidas em moluscos terrestres são pouco comuns, apesar de sua grande importância parasitológica e agrícola. As semelhanças anatomo-fisiológicas entre espécies de moluscos aquáticos e terrestres sugerem que estratégias de controle químico possam ter eficiência semelhante para os dois grupos de invertebrados. Com base nessa hipótese, o presente trabalho teve como objetivo avaliar a atividade moluscicida do látex de três espécies do gênero Euphorbia sobre Leptinaria unilamellata d'Orbigny, 1835, gastrópode terrestre descrito como hospedeiro intermediário de helmintos trematódeos digenéticos que parasitam animais domésticos. Destas E. milii var. splendens apresentou efeito moluscicida elevado sobre L. unilamellata, 100 por cento até uma diluição de 1:800, já nos primeiros minutos após a aplicação. Embora citadas na literatura como tóxicas para moluscos aquáticos, E. cotinifolia e E. tirucalli não exibiram atividade moluscicida sobre L. unilamellata. Os resultados do presente estudo indicam que o látex de E. milii var. splendens pode se constituir em uma estratégia viável de controle químico de moluscos terrestres.

Pulmonate terrestrial gastropods can be intermediate hosts for helminthes. The first records of chemically controlling these invertebrates date back to the beginning of the 20th century. The substances used were unspecific toxins which were already used for controlling other pests. Synthetic molluscicides have technical limitations that stimulated a search for natural substitutes. Among the many vegetal species that have molluscicidal activity, Euphorbia cotinifolia L., Euphorbia milii des Moul. var. splendens (Bojer ex Hook) Ursch & Leandri and Euphorbia tirucalli L. call attention because of the excellent results that have been obtained when they are used on aquatic mollusks. However, studies on the activity of molluscicidal plants on terrestrial mollusks are rare, in spite of its great importance in controlling parasites and to agriculture. Anatomical and physiological similarities among species of aquatic and terrestrial mollusks suggest that chemical control strategies can be effective on both groups of invertebrates. Based on this hypothesis, we assessed the molluscicidal activity of the latex of three species of the genus Euphorbia on the terrestrial gastropod Leptinaria unilamellata d'Orbigny, 1835, described as an intermediate host of digenetic trematode helminths that parasitize domestic animals. E. milii var. splendens had the highest molluscicidal effect on L. unilamellata, being 100 percent lethal in concentrations up to 1:1800 in the first minutes after application. Although E. cotinifolia and E. tirucalli have been cited in the literature as toxic to aquatic mollusks, they did not have molluscicidal activity on L. unilamellata. The results of our study indicate that the latex of E. milii var. splendens may be a viable strategy for the chemical control of terrestrial mollusks.

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 methanol extracts of Jatropha curcas leaves against Ampullaria gigas / 南方医科大学学报

<p><b>OBJECTIVE</b>To evaluate the molluscicidal activities of methanol extract of Jatropha curcas leaves against Ampullaria gigas.</p><p><b>METHODS</b>Young snails, adult snails and eggs of Ampullaria gigas were treated with the methanol extract of J. curcas leaves at different doses for different time lengths and the molluscicidal effects of the extract were evaluated.</p><p><b>RESULTS</b>The methanol extract showed a significant molluscicidal effect on the young snails at a low concentration, and treatment with 75 mg/L extract for more than 3 days resulted in a 100% mortality rate of the young snails. The Jatropha leaf methanol extract also showed toxicity to adult snails and eggs.</p><p><b>CONCLUSION</b>Jatropha leaves have a great potential for developing green pesticides to control Ampullaria gigas, but its biochemical mechanism needs further research.</p>

study on biological control of six fresh water snails of medical and veterinary importance

This study evaluated the molluscicidal effect of Commiphora molmol oil extract [Myrrh], on control of six fresh water snails [Lymnaea natalensis, Bilinus truncatus, Biomphalaria alexandrina, Physa acuta, Melania tuberculata and Cleopatra bulimoides]. Also, the extract effect on the egg masses of L. natalensis, B. truncatus, B. alexandrina and Ph. acuta was evaluated. Snails and egg masses were exposed at 16-20°C to various concentrations [conc.]- LD[50] after 24 hours exposure were 264/132, 283/195, 230/252, 200/224, 241/246 and 241/246 ppm for young/adult of L natalensis, B. truncatus, B. alexandrina, Ph. acuta, M. tuberculata and C. bulimoides respectively. LD[100] after 24 hours exposure were 400/400 for L. natalensis, B. truncatus, B. alexandrina, M. tuberculata and C. bulimoides, and 300/300 for Ph. acuta. Also, complete mortality [100%] was achieved for the egg masses of L. natalensis, B. truncatus, B. alexandrina and Ph. acuta at concentrations of 300, 200, 300 and 400 ppm respectively. Lower concentrations gave the same results after longer exposure. LD[100] of C. molmol oil extract [Myrrh] had a rapid lethal effect on the six snail species and their egg masses in high conc, of 300 and 400 ppm. Commiphora molmol is a promising plant to be included with the candidate plant molluscicides. The oil extract of this plant showed a remarkable molluscicidal activity against used snail species

Estudios de laboratorio sobre la acción molusquicida de la resina de pino, colofonia, sobre Biomphalaria havanensis / Lab studies on the mollusk action of pine tree resin, collophonia, on Biomphalaria havanensis

Introducción: la ausencia de poblaciones de moluscos en el entorno ecológico y natural de las pináceas, observada en estudios de campo, conllevó a estudiar la resina de pino, colofonia, como control del molusco Biomphalaria havanensis, hospedero intermediario de Schistosoma mansoni. Objetivo: determinar la acción molusquicida de la colofonia para su posible utilización en el control de Biomphalaria havanensis. Métodos: se utilizaron 7 concentraciones diferentes para determinar las dosis letales y los datos fueron analizados por un probit-log. Resultados: las dosis letales encontradas fueron: DL50= 44,33 mg/L y DL90= 141,76 mg/L. Conclusiones: con estos resultados se demostró el poder molusquicida de 2 de las pináceas cubanas, a través de la resina de colofonia, sobre Biomphalaria havanensis.

Background: Field studies have previously demonstrated that freshwater mollusk populations did not exist in the ecological and natural environment of pine trees, which led to study pine resin, colophony, as a controlling agent for Biomphalaria havanensis mollusk, an intermediate host of Schistosoma mansoni. Objective: to determine the molluscicidical action of colophony as possible use as a controlling agent for Biomphalaria havanensis. Methods: Seven different concentrations were used to determinate the lethal doses. Data were analyzed by probit-log program. Results: The lethal doses found were as follows: LD50 = 443.3 mg/L and LD90 = 1417.6 mg/L. Conclusions: These experiments showed the molluscicidical activity of the two Cuban pinaceas, through the colophony resin, on Biomphalaria havanensis.