The amebicidal activity of traditional anitiamoebic drug (emetine, carbasone, diodoquin, chloroquine, atabrine, chloramphenicol and tertracycline) and newly appeared chemicals(niridazole, metronidazole and No. 8603 substance) were assayed by in vitro experiment using five strains of human originated E, histolytica. The variety of amebicidal activity of drugs by the strains were discussed. Ranges of amoebicidal activity of traditional antiamoebic drugs kept almost similar titers of previous reports at the concentration; 1:5,000 to 1:20,000 with emetine hydrochloride, 1:10.000 to 1:20,000 with carbarsone, 1:8,000 to 1:16,000 with diodoquin, 1:50,000 with chloroquine, 1:1,000 to 1: 4,000 with atabrine ,1:1,000 to 1:2,000 with chloramphencol and 1:5,000 to 1:8,000 with tetracycline. The newly appeared chemicals showed higher amebicidal titres at the concentration; 1:500,000 to 1:5,000,000 with niridazole, 1:50,000 to 1:100,000 with metronidazol and 1:100,000 to 1:500,000 with No.8603 substance. Emetine, chloramphenicol and No. 8603 substance showed amebicidal activities at lower concentration to intestine originated amebae (YS 14, YS 15 and NAMRU II strain) than to liver originated amebae (YS 24 and YS 25 strain ), while carbarsone, chloroquine and metronidazole showed the activity at higher concentrations. Diodoquin showed lower amebicidal titres to trophozoite borne amebae (NAMRU II, YS 24 and YS 25 strain) than to cyst borne amebae(YS 14 and YS 15 strain), but niridazole showed converse results. The concentration of atabrine for amebicidal activity was not constant according to strains of the amoeba, but tetracycline showed almost settled titers.
parasitology-protozoa ; Entamoeba histolytica ; virulence ; in-vitro ; chemotherapy ; emetine ; carbasone ; diodoquin ; chloroquine ; atabrine ; chloramphenicol ; tertracycline ; niridazole ; metronidazole ; No. 8603 substance

The present study was undertaken to evaluate in vitro activities of following drugs against adult worms of Clororchis sinensis: i.e., stibnal, chloroquine diphosphate, Hetol (1,4-bis-trichloromethylbenzol), dehydroemetine 'Roche' (Ro 1-9334), niridazole (Ambilhar), bisbendazole, gentian violet, dithiazanine iodide, hexachlorophene, bithionol, niclofolan (Bilevon, Bayer 9015) and praziquantel (Embay 8440, Biltricide). After isolation from bile ducts of experimentally infected rabbits (3 months infection), the parasites were rinsed in sterilized Tyrode's solution and incubated for 24 hours at 37 C in TC 199 medium with Earle's balanced salt solution containing 0, 0.01, 0.1, 1.0, 10 and 100 microgram/ml concentrations of each above drugs. The activities of each concentrations with each drugs were evaluated by the motility of the worms in culture tubes observing at 15, 30, 60 minutes and 2, 4, 6, 12, 18 and 24 hours by stereomicroscope. In the results, no effect was found at the adult worms of C. sinensis in all concentrations with stibnal, chloroquine diphosphate, Hetol, dehydroemetine, niridazole and bisbendazole. However, moderate activities were observed in the concentrations of 1.0 and 0.1 microgram/ml of gentian violet, dithiazanine iodide, hexachlorophene and bithionol. The highest activities were observed in all concentrations of niclofolan and praziquantel.
parasitology-helminth-trematoda ; Clonorchis sinensis ; chemotherapy ; in vitro ; stibnal ; chloroquine diphosphate ; Hetol(1,4-bis-trichloromethylbenzol) ; dehydroemetine ; 'Roche'(Ro 1-9334) ; niridazole(Ambilhar) ; bisbendazole ; gentian violet ; dithiazanine iodide ; hexachlorophene ; bithionol ; niclofolan ; praziquantel

In order to find a highly efficient compound against Clonorchis infection, the anthelmintic activity of disophenol, Tremerad (SYD-230), dithiazanine iodide, dehydroemetine-late-release tablets(RO 1-9334/20), niridazole (Ambilhar), hexachlorophene (G-11), Hetol(1, 4-bis-trichloromethylbenzol) and Bilevon (niclofolan) was tested against Clonorchis sinensis experimentally infected rabbits. All drugs showed a progressive increase in efficacy as the dose rate. They were highly efficient against Clonorchis infection if sufficiently high, potentially toxic doses were given. The efficacy was evaluated by the number of detected worms with vital condition at autopsy after the treatment with above drugs. The high efficacy was observed at the following dose rates of each drugs, i.e. disophenol at a single dose of 30 mg/kg, Tremerad at the daily dose of 200 mg/kg for 10 consecutive days, dithiazanine iodide at the daily dose of 50 mg/kg for 6 consecutive days, dehydroemetine at the daily dose of 10 mg/kg for 10 consecutive days, hexachlorophene at the daily dose of 20 mg/kg for 10 to 15 consecutive days, Hetol at the daily doses from 50 to 100 mg/kg for 5 to 10 consecutive days, and Bilevon at a single dose of 8 mg/kg. Moderate effectiveness was shown in niridazole at the dose of 25 mg/kg for 10 days medication. The use of these anthelmintics for the clinical treatment of Clonorchis sinensis infection is discussed.
parasitology-helminth-trematoda ; chemotherapy-Clonorchis sinensis ; clonorchiasis-rabbit ; disophenol ; Tremerad (SYD-230) ; dithiazanine iodide ; dehydroemetine-late-release tablets(RO 1-9334/20) ; niridazole (Ambilhar) ; hexachlorophene (G-11) ; Hetol(1, 4-bis-trichloromethylbenxol) ; Bilevon (niclofolan)