Molluscidal activity of mirazid on Biomphalaria alexandrina snails: biological and molecular studies

The growing awareness of the possible dangers from the use of molluscicides gives a great attention to the plant molluscicides for snail control. Mirazid was tested as a molluscicide against adult Biomphalaria alexandrina snails and a larvicide against S. mansoni larvae (miracidia and cercariae). LC50 and LC90 values were detected for both tests (19.19 and 41.26 mg/l, respectively). B. alexandrina, non-infected and infected with Schistosoma mansoni were exposed to 3 mg/l of Mirazid drug for 4 weeks compared to non-treated with Merazid and/or infected controls. Then the meracidea, cercariae, egg production, protein electrophoresis and DNA fragmentation analysis of B. alexandrina and organ histology were assessed. Mirazid treatment suppressed the growth rate by 11%, decreased the eggs/snail/week by 98 %, and delayed eggs hatchability to 13 days and complete cessation of cercarial shedding (100 %). Mirazid exhibited sever histological alterations at 4th week of exposure on hermaphrodite and digestive glands of infected and non-infected B. alexandrina snails. It also led to decrease in total protein intensity of the hermaphrodite-digestive glands in both treated and treated-infected snails as absence of the protein band 54.77 kDa. The previous two groups of snails also showed DNA damage in hermaphrodite-digestive glands. It is concluded that, Mirazid can be used as a promising molluscicide for B. alexandrina snails’control.