Screening for molluscicidal activity in medicinal plant

Abstract Thirty-two extracts of medicinal plants were screened for activity against Oncomelania hupensis , the intermediate host of schistosomiasis due to Schistosoma japonicum . Strong molluscicidal activities were found in the n-Butyl alcohol extracts of rhizomae of Dioscorea zingiberensis and Anemarrhena asphodeloides , flower of Liriope gramnifolia . Further studies showed that the major molluscicidal constituents of Dioscorea zingiberensis were gracillin and zingiberenin A, which had a snail mortality of 98% and 96% at 5mg/l in 72 hours respectively.