Killing Effects of Mustard on the Encysted Metacercaria of Clonorchis sinensis

Objective To evaluate the in vitro killing effects of mustard on the encysted metacercaria of Clonorchis sinensis. Methods Encysted metacercarias were collected from freshwater fishes by artificial digestion method. The encysted metacercarias were then divided into various groups with 20 metacercarias per group.The effect of mustard on their activities was then evaluated under a microscope. Results Enhanced activities were observed in the first 1 to 6 minutes after incubation of encysted metacercarias with musturd.Metacercaria became less active or even killed starting at 7 minutes (11.76%) and all metacercarias were killed at 210 minutes. Morphological alteration and activity of the encysted metacercarias were not changed in the control group. Conclusion Although mustard is cytotoxic to encysted metacercaria,it can not kill the metacercaria within a short period of time. It is not advisable to kill encysted metacercaria by mustard for the purpose of preventing infection.