The wormicidal substances of fresh water fishes on Clonorchis sinensis VII. The effect of linoleic acid and ethyl linoleate on parasite viability

In an attempt to analyze the clonorchicidal activity of linoleic acid and ethyl linoleate in vitro, the wormicidal effects on Clonorchis sinensis were chronologically monitored in dose titration experiments. Excysted metacercariae were killed within a period of 31.0+-4.0 min, 149.3+-4.l min and 207.0+-13.5 min with 100.0 mg, 0.1 mg and 0.001 mg linoleic acid, respectively. The time required for the linoleic acid to kill adult worms was 167.0+-0.8 min with 100.0 mg, 253.0+-0.8 min with 0.1 mg, and 277.0+-0.8 min at 0.001 mg titration. Clonorchicidal activity of ethyl linoleate was relatively delayed as death was observed within 263.3+-2.9 min, 286.0+-0.5 min, and 318.0+-0.8 min for 100.0 mg/ml, 0.1 mg/ml and 0.001 mg/ml concentrations, respectively. The wormicidal effects observed with these pure anticlonorchal substances were found to be similar to the biological activity of native products derived from the mucus of the fresh water fish.

Experimental Infection of Clonorchis sinensis to Cyprinus carpio nudus

As a part of observation on the suitability as a second intermediate host of Clonorchis sinensis, various infection experiments were tried to Cyprinus carpio nudus. The results obtained were summarized as follows: The cercariae which attempted to contact with Cyprinus carpio nudus in the water were observed under the stereomicroscope. After contact, cercariae began to separate its tails from the bodies at 4 minutes increasingly, and then the number ranged to 80 percent at 13 minutes after the encounter. But very few cercariae could actually invade into the epidermis of the fish. When Cyprinus carpio nudus were exposed to a number of cercariae in the beaker, only a few cercariae could invade through the epidermis. Most of the invaded cercariae were killed before forming the cyst. Also rare encysted cercariae were found to be dead within 48 hours. Cyprinus carpio nudus were reared with Parafossarulus manchouricus shedding numerous cercariae in the indoor aquarium. When observed after 12 days, to determine the susceptibility, no metacercaria was found infected. Cyprinus carpio nudus were reared with Parafossarulus manchouricus shedding numerous cercariae in Kimhae lake for 2 months in summer of 1982, in order to check the natural infection. No metacercaria of Clonorchis sinensis was found from the fish. In the cases of control fish, Pseudorasbora parva, numerous cercariae were inspected on the course of invasion through epidermis of the fish under the stereomicroscope. And many metacercariae were also found from the fish whenever they were kept in beaker, indoor aquarium, or the lake for natural infection. The results suggested that Cyprinus carpio nudus might not be proper intermediate host of Clonorchis sinensis.

The wormicidal substance of fresh water fishes on Clonorchis sinensis IV. Preliminary research on the wormicidal substance from mucus of Cyprinus carpio nudus

As a series of studies on the suitability as a second intermediate host of Clonorchis sinensis, the wormicidal effects of mucus from epidermis of Cyprinus carpio nudus were observed. The results obtained were summarized as follows: On the silica gel thin layer chromatography with the greenish yellow supernatant in acetone:benzene/10:90 as carrier, seven spots were observed in iodine chamber. The spot of Rf. 0.225 value among them disclosed the strongest wormicidal effect on the cercaria, the excysted metacercaria, and the adult of C. sinensis. Meanwhile, no seasonal variations were found in Rf. values and effect of the wormicidal fractions. The wormicidal materials in epidermal mucus of C. carpio nudus and Carassius carassius were compared in their effect, and the former was more effective killing substance than the latter. It seemed that C. carpio nudus could not be proper intermediate host of C. sinensis according to results of the present study, in addition to our previous observation results.

Survey on encysted cercariae of trematodes from fresh-water fishes in Mangyeong riverside area

In order to clarify infestation pattern for the encysted larvae of digenetic trematodes from fresh-water fishes, this survey was carried out from March to September, 1983. A total of 380 fishes of 32 species were collected with netting at the three reaches, upper, middle and lower in Mangyeong riverside area. After the fishes were dissected into small scraps, they were pressed under cover glass and examined for the presence of those of digenetic trematodes with a microscope. The results obtained were as follows: Out of a total of 380 fishes inspected, 320 fishes (84 percent) from 31 species were found positive with digenetic trematode metacercariae; more than 10 species of the metacercariae were detected in Pseudorasbora parva; Gnathopogon majimae, Microphysogobio yaluensis, Cultriculus eigenmanni and Gnathopogon coreanus (more than 8 species); Aphyocypris chinensis(8 species) and etc. respectively. Clonorchis sinensis metacercariae were found positive from 93 fishes (25 percent) from 12 species detection rates in other species of digenetic trematode metacercariae from various fishes were; Exorchis oviformis, 261 fishes (57 percent) from 28 species; Cyathocotyle orientalis, 47 fishes (12 percent) from 12 species; Metorchis orientalis, 21 fishes (6 percent) from 12 species; Metagonimus yokogawai, 164 fishes (43 percent) from 26 species; Pseudexorchis major, 71 fishes (19 percent) from 18 species; Metacercaria hasegawai, 77 fishes (20 percent) from 25 species; Centrocestus armatus, 24 fishes (6 percent) from 7 species; Echinochasmus japonicus, 2 fishes (0.5 percent) from 2 species, and unidentified species, 34 fishes (9 percent) from 15 species respectively. The sums of average number of the encysted larvae of all species found in fish body/gram showed 83 in P. parva, Cobitis taenia (74.2), A. chinensis (28.5), Pseudoperilampus uyekii (26.6), G. majimae (19.6) and etc. respectively and the average peak number of each metacercaria in fish body/gram showed 21.7 C. sinensis, 24 E. oviformis , 15.3 M. orientalis and 6.1 E. japonicus in P. parva ; 42.7 C. orientalis and 25.1 M. yokogawai in C. taenia; 8.3 C. armatus and 8.3 M. hasegawai in P. uyekii; 6.3 P. major in Carassius carassius, and 2.9 unidentified species in G. majimae respectively.

Isolation of anthelmintic substance on Clonorchis sinensis from tuber of Bletilla striata

The present work was done to isolate the anthelmintic substance from the tuber of Bletilla striata which grows Gangweon-do of the Korea peninsula. The dried B. striata tuber was extracted with ethyl ether by a Soxhlet extractor at 40C for 24 hours, and then the extract was separated into insoluble material (negative wormicidal) and soluble material (positive wormicidal) by petroleum ether solvent. The wormicidal substance was separated in the silica gel column chromatography from the petroleum ether extract, using benzene (90 percent) and acetone (10 percent) as a solvent. The anthelmintic activity was observed in vitro on the cercaria, the excysted metacercaria and the adult of Clonorchis sinensis. On the silica gel thin layer chromatography with the wormicidal substance in benzene:acetone/90:10, five spots were observed in iodine chamber and the spot of Rf. 0.18 value of them appeared the most strong wormicidal effect on the cercaria of C. sinensis. Afterward, a substance which was equivalent to the Rf. 0.18 value spot was isolated from the wormicidal substance by means of silica gel column chromatography using 1 part of ethyl acetate and 6 parts of chloroform carrier, and the excysted matacercaria and the adult of C. sinensis were killed within 14 minutes and 128 minutes in the substance.

Clavate Cells Of Epidermis In Cyprinus Carpio Nudus With Reference To Its Defence Activity To Clonorchis Sinensis

No abstract available.