Biomphalaria alexandrina

About: Biomphalaria alexandrina is a research topic. Over the lifetime, 413 publications have been published within this topic receiving 3781 citations.

Biomphalaria alexandrina: a model organism for assessing the endocrine disrupting effect of 17β-estradiol.

Abstract: A wide range of endocrine disruptor compounds are routinely discharged to the ecosystem. Water contaminated with these compounds has a potential effect on the reproductive physiology of aquatic organisms as well as humans. In the present study, we tested the effect of the steroid estrogen, 17β-estradiol, on Biomphalaria alexandrina, a snail species that is widely distributed in Egypt and that acts as an intermediate host for the human blood fluke, Schistosoma mansoni. The effects of exposure to 0.3 mg/L and 1 mg/L 17β-estradiol on fecundity (MX) and reproductive rate (R0) of B. alexandrina were recorded. In addition, levels of steroid sex hormones and antioxidants in the hemolymph and ovotestis (OT) of exposed snails were measured. Histopathological changes in the OT of B. alexandrina were also investigated. Exposure to 0.3 mg/L and 1 mg/L 17β-estradiol caused a significant increase in the number of egg masses per snail after 3 weeks and 1 week of exposure for the two tested concentrations compared with unexposed controls. An increase in the levels of progesterone hormone was recorded in the hemolymph of exposed snails in comparison with unexposed controls. Additionally, levels of the antioxidant enzyme glutathione (GSH) were increased in the hemolymph and OT tissues of snails after 2 and 4 weeks of exposure. Histopathological sections in the OT revealed an increase in the oocyte and a decrease in the sperm densities after 2 weeks and this effect was restored to normal conditions after 4 weeks of exposure to both tested concentrations. The current results indicate that B. alexandrina is sensitive to 17β-estradiol and can therefore be used as bioindicator and model organism for the assessment of water pollution with endocrine disruptor compounds.

Alterations in the fatty acid profile, antioxidant enzymes and protein pattern of Biomphalaria alexandrina snails exposed to the pesticides diazinon and profenofos.

Abstract: The use of pesticides is widespread in agricultural activities. These pesticides may contaminate the irrigation and drainage systems during agricultural activities and pests’ control and then negatively affect the biotic and abiotic component of the polluted water courses. The present study aimed to evaluate the effect of the pesticides diazinon and profenofos on some biological activities of Biomphalaria alexandrina snails such as fatty acid profile, some antioxidant enzymes like thioredoxin reductase (TrxR), sorbitol dehydrogenase (SDH), superoxide dismutase (SOD), catalase (CAT) as well as glutathione reductase (GR) and lipid peroxidation (LP) and protein patterns in snails' tissues exposed for 4 weeks to LC10 of diazinon and profenofos. The results showed that the two pesticides caused considerable reduction in survival rates and egg production of treated snails. Identification of fatty acids composition in snails' tissues treated with diazinon and profenofos pesticides was carried out using gas liquid chromatography (GLC). The results declared alteration in fatty acid profile, fluctuation in percent of long chain and short chain fatty acid contributions either saturated or unsaturated ones and a decrease in total lipid content in tissues of snails treated with these pesticides. The data demonstrate that, there was a significant inhibition in the activities of tissues SOD, CAT, GR, TrxR and SDH in tissues of treated snails while a significant elevation was detected in lipid peroxidation as compared to the normal control. On the other hand, the electrophoretic pattern of total protein showed differences in number and molecular weights of protein bands due to snails' treatment. It was concluded that the residues of diazinon and profenofos pesticides in aquatic environments have toxic effects on B. alexandrina snails. Key words: Snails, pesticides, antioxidants, enzymes, fatty acids, proteins, biochemistry.

Control of infection of Biomphalaria alexandrina (Ehrenberg, 1831) with Schistosoma mansoni Sambon, 1907 using Eucalyptus camaldulensis

Abstract: Schistosomiasis infection can be interrupted if the development of miracidia to cercariae in Biomphalaria alexandrina (Ehrenberg) is blocked. This requires an efficient snail’s antioxidant system which can be complemented with an exogenous antioxidant source to alleviate the oxidative stress of infection. For this purpose, leaves of Eucalyptus camaldulensis were air-dried, extracted with aqueous methanol (85%) and defatted with petroleum ether. The obtained defatted extract was used to prepare extracts with different solvents. Among these, ethyl acetate showed the highest antioxidant activity and was chosen for the experiments. The effect of ethyl acetate extract on the infection, survivorship, as well as levels of malondialdehyde (MDA), catalase (CAT) and reduced glutathione (GSH) in B. alexandrina were measured in control, untreated infected and treated infected snails on 1, 10, and 30 days post infection (dpi). The snails exposed to ethyl acetate extract showed a significant reduction in the infection rate compared to those infected and untreated. Moreover, the extract decreased the level of MDA and increased CAT and GSH activities in the haemolymph and tissues of the treated snails. The results suggest that ethyl acetate extract from leaves of E. camaldulensis can be used as an antiparasitic compound against the intramolluscan phase of S. mansoni Sambon, 1907. Key woRdS: ethyl acetate extract, Eucalyptus camaldulensis, Biomphalaria alexandrina, Schistosoma mansoni, oxidative stress, antioxidant activity

Effect of Cestrum diurnum and Casimiroa edulis plants on the digestive gland and its related enzymes in the freshwater snail Biomphalaria alexandrina

Abstract: Biomphalaria alexandrina snails play a central role in transmission of schistosomiasis. The present study evaluates the molluscicidal effect of two plants as aqueous suspensions, Cestrum diurnum and Casimiroa edulis. LC50 values were 66 and 195 ppm, respectively after 24 hours. Exposure of snails to sub-lethal concentrations of C. diurnum and C. edulis resulted in significant alterations in the activities of some haemolymph enzymes (alanine aminotransferase, aspartate aminotransferase and alkaline phosphatase). The digestive gland cells were highly vacuolated in all tested concentrations. The secretory cells were atrophied and degenerated at LC25 of C. diurnum, while in snails treated with LC0 of C. edulis; they were densely colored without differentiation between nucleus and nucleolus.