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Biomphalaria alexandrina
About: Biomphalaria alexandrina is a research topic. Over the lifetime, 413 publications have been published within this topic receiving 3781 citations.
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TL;DR: The molluscicidal activity of the synthesized compounds towards Biomphalaria alexandrina snails, the intermediate host of Schistosoma mansoni, was investigated and most of them showed weak to moderate activity.
Abstract: 2-(3-Hydroxy-5,5-dimethylcyclohexylidene)malononitrile 5 undergoes an azo coupling reaction with aryldiazonium salts to afford 3-amino-2-aryl-6,6-dimethyl-8-oxo-2,6,7,8-tetrahydrocinnoline-4-carbonitriles 7. Upon reflux in acetic acid, these compounds were acetylated to give the cinnoline derivatives 9. The pyrazolones 10a, b react with 3-furfurylidene- and 3-thienylidene-malononitrile derivatives 11a, b to afford the pyrano[2,3-c]pyrazole derivatives 13a-d. These newly synthesized compounds show generally a moderate molluscicidal activity to Biomphalaria alexandrina snails.
35 citations
TL;DR: Schistosome infection of the snails Biomphalaria alexandrina and Bulinus truncatus affected their citric acid cycle pathways; especially those concerned with succinic and cytochrome oxidases as mentioned in this paper.
Abstract: 1. 1. Schistosome infection of the snails Biomphalaria alexandrina and Bulinus truncatus affected their citric acid cycle pathways; especially those concerned with succinic and cytochrome oxidases. 2. 2. The rate of gluconeogenesis was decreased in schistosome-infected snails to 62 per cent for Bulinus truncatus and to 45 per cent for Biomphalaria alexandrina. 3. 3. Lactic acid production was increased in schistosome-infected snails to 52 and 73 per cent that of uninfected B. alexandrina and B. truncatus respectively. 4. 4. Schistosome infection caused a marked decrease in the glycogen content of the tissues of both snail species. 5. 5. The effect of schistosome infection on the intermediary metabolism of both snails is discussed.
35 citations
TL;DR: In this article, a phytochemical analysis of chloroform: ethanol extract was performed to search for active toxic ingredient for snails' molluscicides control, and the maximum (P <.05) mortality was recorded at a concentration of 90 ppm of S. nigrum extract.
Abstract: Background. Snails' species are associated with transmission parasitic disease as intermediate host. Biological control stands to be a better alternative to the chemical controls aimed against snails. The search of herbal preparations that do not produce any adverse effects in the non-target organisms and are easily biodegradable remains a top research issue for scientists associated with alternative molluscicides control. Method. Solvent extracts of fresh mature leaves of S. nigrum, S. villosum, and S. sinaicum were tested against Biomphalaria alexandrina, a common intermediate host of schistosoma mansoni. A phytochemical analysis of chloroform: ethanol extract was performed to search for active toxic ingredient. The lethal concentration was determined. Results. Extracts isolated from mature leaves of Solanum species were found to be having molluscicidal properties. S. nigrum extract was recorded as the highest mortality rate. When the mortality of different solvent extracts was compared, the maximum (P < .05) mortality was recorded at a concentration of 90 ppm of ethanol extract of S. nigrum. Conclusion. Extract of mature leaves of S. nigrum exhibited molluscicidal activity followed by S. sinaicum and the less one was S. villosum. The study provides considerable scope in exploiting local indigenous resources for snails' molluscicidal agents.
35 citations
TL;DR: The findings indicate that the cercaria is the target stage for the activity of chlorpyrifos on the intramolluscan larval development and it is suggested that S. mansoni cercarial production in B. alexandrina may be a useful system for monitoring the effect of low concentrations of pesticides on the aquatic environment.
Abstract: Exposure of Biomphalaria alexandrina to sublethal concentrations (0·125, 0·25 and 0·05 ppm) of the organophosporous insecticide, chlorpyrifos (Dursban), induced a reduction in egg production and egg hatchability. Exposure of Schistosoma mansoni miracidia to the insecticide (60 min, 0·05 ppm) prior to infection of B. alexandrina did not affect the subsequent production of cercariae. However, exposure of S. mansoni—infected snails to the insecticide until day 55, from day 20 to day 62 and from day 35 to 62 following infection resulted in blockage of cercarial shedding. cercarial shedding commenced in some snails when the treatement stopped. Exposure to the insecticide in concentrations of 0·125 and 0·25 ppm during the first 20 days following infection did not affect the subsequent production of cercariae, but exposure to 0·5 ppm during the first 20 days affected markedly the production of cercariae due to a high snail mortality. The findings indicate that the cercaria is the target stage for the activity of chlorpyrifos on the intramolluscan larval development. It is suggested that S. mansoni cercarial production in B. alexandrina may he a useful system for monitoring the effect of low concentrations of pesticides on the aquatic environment, and that the ability by chemical means to interrupt the cercarial production might be a useful tool in further analyses of important aspects of the snail/parasite relationship.
34 citations
TL;DR: Snails that are produced from snails previously exposed to low doses were more sensitive to the tested extracts, which may give primary indication of no possibility of inherited resistance.
34 citations