Molluscicidal Activity On Oncomelania Hupensis Of Euphorbia Helioscopia L. And Sodium Abietate, And Study On Toxicity Of Euphorbia Helioscopia L. Against Oncomelania Hupensis

Part1Observation on the killing effect of Euphorbia helioscopia L.and sodium abietate upon Oncomelania hupensisObjective: To observe the killing effect of Euphorbia helioscopia L. ethanolextracts and sodium abietate upon Oncomelania hupensis.Method: Euphorbia helioscopia L. ethanol extracts and sodium abietate wereprepared for four different concentration solutions (100、200、400、800mg/L) withde-chlorinous water respectively, and then the molluscicidal activity was detectedaccording to the Laboratory Final Milluscicides Screening Method issued by WHO.Meanwhile niclosamide and de-chlorinated water served as positive and negativecontrols respectively. The snails were immersed in different concentrations of the abovesolution for1,2,3and4days to observe the death rate of snails.Result: It was found that the mortality of snails was increased along with theincreasing concentrations and the prolonging time after the two drugs’ treatment. At thesame time and the same concentration, sodium abietate’s killing effect on Oncomelaniahupensis were significantly better than Euphorbia helioscopia L. ethanol extracts.Afterthe snails treated with different concentrations of Euphorbia helioscopia L. ethanolextracts for one day, the highest death rate of snails was only10%, and after treatmentwith the concentration of100mg/L for4d, the mortality rate was nearly50%. Thelowest mortality rate of the snails was45.5%and the highest up to100%, after thesnails soaked in the sodium abietate solution for one day.4d later, the mortality werealmost up to100%. However, no snails were died away in the de-chlorinous watercontrol group.Conclusion: To speculate from the result, Euphorbia helioscopia L. ethanol extracts and sodium abietate could kill the snails and sodium abietate’s killing effectwas better than Euphorbia helioscopia L. ethanol extracts.Part2Influence of Euphorbia helioscopia L. ethanol extracts onthe effect of glycogen and protein content of OncomelaniahupensisObjective: To identify the influences of Euphorbia helioscopia L. on glycogenand protein content of Oncomelania hupensis in order to explore the molluscicidalmechanism of Euphorbia helioscopia L..Method: After the snails soaked by the different concentrations of Euphorbiahelioscopia L. ethanol extracts for2d, weigh wet weight and dry weight of snails, andcalculate the rate of wet and dry; The glycogen and protein content of soft tissues ofOncomelania hupensis were determined using Anthrone Method and Bradford standardcurve method; Glucose and BSA were for the standard curve respectively.Result: The soft tissue weight of the snails were no significant changes, and itsdry weight was approximately between30%and35%of the wet weight; The glycogencontent was significantly reducted, decreasing from18.64%to69.49%; The proteincontent also declined, dropping from3.06%to20.44%, after the snails treated withdifferent concentrations of helioscopia ethanol extract.Conclusion: The glycogen content was significantly decreased, and the proteincontent also declined, and its weight did not change markedly after treatment.Part3Influence of Euphorbia helioscopia L. ethanol extracts onthe effect to the liver tissue and esterase of snails.Objective: To anlysis pathological section and SDS-PAGE electrophoresis patternof snails and study its molluscicidal mechanism.Method: The snails immersed in Euphorbia helioscopia L. ethanol extracts weresoaked for2days, followed by fixation, decalcification, washing, gradient dehydration,transparent, dip wax, encasement, slicing, drying, deparaffinage, HE staining, mounting,and finally observation and photographed under the light microscope. Moreover, theesterase isoenzyme activity of snails homogenated was detected with phosphate buffersolution using polyacrylamide gel electrophoresis technique.Result: No significant change of morphology was observed at the100mg/L concentration group, while when the concentration was up to200mg/L, the edges beganto swell and fluff grew downwards; while to800mg/L, the hepatic duct wall and lumenno longer exists, morphogenesis were changed obviously after treatment; the higher thedrug concentration was, the greater the morphology changed and esterase isozymesactivities firstly increased and then decreased.Conclusion: Euphorbia helioscopia L. could change the morphology andaffect the activity of the esterase isozyme of the snails.