Colchicum Ritchii flower: a new molluscicidal plant for Biomphalaria alexandrina snails and the infective stages of Schistosoma mansoni

ABSTRACT Schistosomiasis is considered a neglected disease, but it is the cause of many social and economic problems in many developing countries. The aim of the present study was to find an alternative molluscicide of botanical origin to decrease the spread of this disease. The investigation studied the effect of the methanolic extract of Colchicum ritchii flowers on Biomphalaria alexandrina snails, larvae of Schistosoma mansoni, and the freshwater cladoceran Daphnia magna. The preliminary phytochemical screening test confirmed the presence of tannins and saponins that might be responsible for cytotoxic effects. The methanolic extract had a molluscicidal activity on B. alexandrina snails with an LC50 of 35.1 mg L−1 after 24 h of exposure. The LC50 of D. magna after 24 h was 63.5 mg L−1. The extract also had a larvicidal activity and caused alterations in the haemocytes of B. alexandrina snails. Aggregations of both hyalinocytes and granulocytes were formed after exposure for 24 h to LC25. Both the mean number of micronuclei per slide and the olive tail moment of snails exposed to LC10 and LC25 of the extract were increased compared to control snails. In conclusion, C. ritchii extract potentially could be used as a molluscicide and larvicide.