ABSTRACT
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.
Subject(s)
Animals , Female , Male , Jatropha/chemistry , Lymnaea/drug effects , Molluscacides/pharmacology , Plant Extracts/pharmacology , Molluscacides/chemistry , Plant Extracts/chemistry , Reproduction/drug effectsABSTRACT
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.
Subject(s)
Animals , Euphorbia/toxicity , Euphorbiaceae/toxicity , Latex/poisoning , Molluscacides/chemistry , Mollusca/parasitology , Gastropoda , Pest Control, BiologicalABSTRACT
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).
Subject(s)
Animals , Alkaloids , Isoquinolines , Molluscacides , Plant Extracts , Plants, Medicinal , Snails/drug effects , Alkaloids/classification , Alkaloids/isolation & purification , Isoquinolines/classification , Isoquinolines/isolation & purification , Molluscacides/chemistry , Plant Extracts/analysis , Plant Extracts/chemistry , Plant Leaves/chemistry , Plants, Medicinal/chemistryABSTRACT
Three spirostanol and two furostanol saponins have been isolated from the methanol extract of the leaves of Yucca elephantipes. The structures of these saponins were established as 3-O-beta-D-xylopyranosyl [1->2] [-beta-D-glucopyranosyl- [1->3]]- beta-D-glucopyranoside yamogenin [I], 3-O-beta-D-xylopyranosyl- [1->2] [beta-D-glucopyranosyl- [1->3]], 26-beta-D- glncopyranoside [25 S]- furost-5-ene-3,22,26-triol [II], 3-O-alpha-L- rhamnopyranosyl [1->2]- [beta-D-xylopyranosyl- [1->3]]- beta-D-glucopyranosyl- [1->4]-beta-D-galactopyranoside gitogenin [III], 3-O-beta-D-xylopyranosyl- [1-> 3]-[beta-D-glucopyranosyl- [1->2]- beta-D-glucopyranosyl- [1->4]- beta-D-galactopyranoside gitogenin [IV], and 26-O-beta-D-glucopyranosyl-22-O-methyl [25R]-5-furostan- 2,3,26-tetrol-3-O- [alpha-L-rhamnopyranosyl- [1->3]]- beta-D-glucopyranosyl- [1->2]- beta-D-glucopyranosyl [1->4]- beta-D-galactopyranoside [V]. Saponins I, III and IV showed high molluscicidal activities against Biomphalaria alexandrina snails after 24 hours exposure [LC90 = 4,9 and 7 ppm] whereas saponins II and V were inactive up to 50 ppm