Efficiency of Citrus limon extract on biological and molecular activities of Biomphalaria alexandrina snails

Abstract

Molluscicides have gained a great attention in recent years and proved to be a good way of snailcontrol. C. limon was tested as a molluscicide against adult Biomophalaria alexandrina snailsand a larvicide against Schistosoma mansoni larvae (miracidia and cercariae). Lethalconcentrations, LC50 and LC90 values were detected for both tests (744.17 and 1821.25 ppm,respectively). B. alexandrina snails, non-infected and infected with S. mansoni were exposed toCitrus limon peel extract concentration of 150 ppm for 4 weeks compared to non expoed with C.limon and/or infected controls. The meracidea, cercariae, egg production, protein electrophoresisand DNA fragmentation analysis and organ histology of B. alexandrina were assessed. C. limonexposure stimulated the growth rate, increased the number of eggs/snail/week (59.31 ± 5.71),inhibited reproductive rate by 20.6 %, hatchability rate (57.7 %) and stimulation of cercarialproduction. Histological investigation of C. limon extract exhibited necrosis and deformation ofhermaphrodite and digestive glands of infected and non-infected B. alexandrina snails. C. limonexposure led to increase in total protein intensity of the hermaphrodite-digestive glands in bothexposed/exposed-infected snails. RNA intensity was increased in C. limon exposed andexposed-infected snails during the experimental period. Necrotic DNA form was a characteristicof C. limon and/or infection.