AN EXPERIMENTAL STUDY ON THE EFFECT OF NITHIOCYAMINE AGAINST SCHISTOSOMA JAPONICUM

In order to observe preventive and therapeutie activity of nithiocyamine on schistosomiasis japonicum, we have performed some experiments. Nithiocyamine was used both in gross crystalline powder and in fine crystalline powder. The drug was made into an aqueous suspension. Both mice and rabbits were used in these experiments. They were inoculated with cercariae of schistosome japonicum liberated from infected oncomelania hupensis through the shaved abdominal wall. The experiment on prevention showed that the action of nithiocyamine against various stage of development of the worm was very different. It is less effective against the worm of the age of 14 days or less (juvenile worm),When the worms developed up to the age of 21 days, Therapeutic effects increased as the worm reduction rate rised to 91.5% and about half of the infected mice were cured. When the worms developed to 28 days or more (adult worm), the worm reduction rate was up to 95.3～99.8%, and the cure rate up to 93.3～100%. The results showed that the activity of nithiocyamine was related to the age of the worms and its primary action was directed to adult worm. Nithiocyamine could cause a pronounced hepatic shift of the worms after the mice given a single dose of fine crystalline powder of the drug at the dosage of 40 mg/kg. When the infected animals were treated with oral drug at about the same dosage calculated by the area of body surface for 3 days, the worm reduction rate in the mice was 84.4%, and in rabbits it increased to 100%. Our experiments confirmed that nithiocyamine was more effective against adult schistosoma japonicum.