[Preliminary study on molluscicidal effect of Euphorbia helioscopia L ethanol extracts against Oncomelania hupensis].

Objective: To study the influences of Euphorbia helioscopia L. on glycogen contents of Oncomelania hupensis so as to explore its molluscicidal mechanism.

Methods: The different polar factions of Euphorbia helioscopia L. were separated by using the systemic solvent segregation method, and then its molluscicidal activity was detected according to the Laboratory Final Milluscicides Screening Method issued by WHO. The glycogen contents of soft tissues of Oncomelania hupensis snails treated by Euphorbia helioscopia L. ethanol extracts were determined by the anthrone method.

Results: After being immersed for 48 h with Euphorbia helioscopia L. ethanol extracts, the death rates of the snails at the concentrations of 400 mg/L and 800 mg/L were 50.43% and 77.50% respectively, while after 96 h, the death rates at the above concentrations were both 100%. The glycogen contents of the snails gradually reduced with the increase of the drug concentrations, the glycogen content decreased to the lowest while the concentration was 800 mg/L, and the glycogen content decreased by 69.49% compared with that of the control group.

Conclusion: The Euphorbia helioscopia L. ethanol extracts can significantly decrease the glycogen content of Oncomelania snails and the extracts have an adequate molluscicidal activity.