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.

Phytochemical analysis of Eucalyptus camaldulensis leaves extracts and testing its antimicrobial and schistosomicidal activities

“…Indeed, exposure of B. alexandrina to 90% defatted methanol extract from Punica granatum peels reduced the infection rates of snails with S. mansoni to 20% compared to 95% in infected unexposed snails (Mossalem et al 2017). The same reduction in infection rate was obtained when snails exposed to ethyl acetate extract from E. camaldulensis leaves (Mossalem et al 2018).…”

“…E25/4/3) is kept in the herbarium of the garden. Details of extraction of E. camaldulensis leaves using organic solvents and testing the free radical scavenging activity of the obtained extracts are described in Mossalem et al (Mossalem et al 2018).…”

“…Miracidia and cercariae of S. mansoni were obtained from Schsitosome Biological Supply Center (SBSC), Theodor Bilharz Research Institute. The selected concentration was 200 mg/L (Mossalem et al 2018). A double concentration of fraction 5 n-hexane/EtOAc (20: 80 v/v) was prepared in 5 ml volume of water.…”

“…Recently, there has been an interest to control schistosomes infection within snails rather than killing these intermediate hosts. This method has many advantages including maintenance of natural biodiversity in aquatic habitats and minimizing the environmental impacts related to application of chemical molluscicides (Mossalem et al 2018). Plants rich with antioxidant molecules such as flavonoids and phenolic acids compounds are great targets for exogenous source of antioxidants that can maintain the balance between oxidative stress result from infection or other stressors and antioxidant system within organisms (Ghareeb et al 2018b).…”

“…Other plants are not toxic to snails, but due to their powerful antioxidant capacity, they were used as supplementary antioxidants to control schsitosome infection within snails (Mossalem et al 2017). Moreover, E. camaldulensis itself was shown to reduce the outcome of S. mansoni infection in Biomphalaria alexandrina (Mossalem et al 2018).…”