An assessment of the molluscicidal potential of Cucurbita maxima seed extracts on Biomphalaria pfeifferi and Bulinus globosus snails

Abstract

Reports of snails’ resistance to niclosamide appeared recently and finding new molluscicides becomes necessary. We investigated the molluscicidal effects of Cucurbita maxima seed extracts on Biomphalaria pfeifferi, and Bulinus globosus snails under laboratory conditions. For B. pfeifferi, we tested seed extracts on juvenile and adult snails while only adult B. globosus were available for testing. Snails were exposed to water and crude ethanol extracts for 72 h and significant concentrationdependent mortality rates were observed. The number of B. pfeifferi juveniles collected was not enough for a comprehensive investigation against both solvents. We, therefore, tested them against water extracts only. A lethal concentration of 0.02 mg/mL killed 50% of the snails (LC50) for both water and ethanol extracts on adult B. pfeifferi snails. Our results suggest that pumpkin seed extracts have a significant molluscicidal effect on B. pfeifferi and B. globosus snails. The LC50 values for all the extracts in B. pfeifferi and B. globosus snails are within the threshold set for potential molluscicides by the World Health Organisation. We propose that C.maxima seed extracts be considered as potential molluscicidal agents in Schistosomiasis transmission control.