Target animal safety testing of an oral salicylanilide suspension, oxyclozanide, for the treatment of fascioliasis in bovine in China.

The aim of this study was to determine the potential toxicity risk of an oxyclozanide suspension to the target animal, bovine. In this experiment, 32 Simmental beef cattle were fattened and fed a full-price diet without antimicrobial agents. The test cattle were divided into 4 groups, which were treated with 0, 1, 3, and 5 times the recommended dosage through continuous intermittent oral administration at intervals of 2 days. The body weight of the cattle was recorded before and after the experiment, and the weight changes were calculated. The safety of the drugs was evaluated by weight gain, observation of clinical toxicity, haematology, clinical chemistry and histopathology. The results showed that the cattle had different degrees of diarrhoea, loss of appetite and depression after administration. The results of clinicopathology had no significant effect. The results of pathological examination showed that there was a certain degree of damage in the 5 times recommended dose group. The recommended dose was safe to use. Thus, the recommended dose should be given by a single oral administration to ensure the safe use of this drug in the clinic.

Effect of mitochondrial uncouplers niclosamide ethanolamine (NEN) and oxyclozanide on hepatic metastasis of colon cancer.

Metabolism of cancer cells is characterized by aerobic glycolysis, or the Warburg effect. Aerobic glycolysis reduces pyruvate flux into mitochondria, preventing a complete oxidation of glucose and shunting glucose to anabolic pathways essential for cell proliferation. Here we tested a new strategy, mitochondrial uncoupling, for its potential of antagonizing the anabolic effect of aerobic glycolysis and for its potential anticancer activities. Mitochondrial uncoupling is a process that facilitates proton influx across the mitochondrial inner membrane without generating ATP, stimulating a futile cycle of acetyl- CoA oxidation. We tested two safe mitochondrial uncouplers, NEN (niclosamide ethanolamine) and oxyclozanide, on their metabolic effects and anti-cancer activities. We used metabolomic NMR to examine the effect of mitochondrial uncoupling on glucose metabolism in colon cancer MC38 cells. We further tested the anti-cancer effect of NEN and oxyclozanide in cultured cell models, APCmin/+ mouse model, and a metastatic colon cancer mouse model. Using a metabolomic NMR approach, we demonstrated that mitochondrial uncoupling promotes pyruvate influx to mitochondria and reduces various anabolic pathway activities. Moreover, mitochondrial uncoupling inhibits cell proliferation and reduces clonogenicity of cultured colon cancer cells. Furthermore, oral treatment with mitochondrial uncouplers reduces intestinal polyp formation in APCmin/+ mice, and diminishes hepatic metastasis of colon cancer cells transplanted intrasplenically. Our data highlight a unique approach for targeting cancer cell metabolism for cancer prevention and treatment, identified two prototype compounds, and shed light on the anti-cancer mechanism of niclosamide.

Antihelminthic potential of quinacrine and oxyclozanide against gill parasite Microcotyle sebastis in black rockfish Sebastes schlegeli.

The aim of this study was to assess the treatment potential of quinacrine and oxyclozanide against Microcotyle sebastis (Monogenea: Polyopisthocotylea) infection in cultured black rockfish Sebastes schlegeli. The oral administration of quinacrine led to a reduction in the mean abundance of M. sebastis infection in all quinacrine-treated groups, and the groups of fish administered quinacrine at 50, 100, and 200 mg kg(-1) for 3 consecutive days showed a parasite mean abundance that was 50 to 30% lower compared to that of the control group, suggesting that quinacrine has a therapeutic potential against M. sebastis. Although oxyclozanide showed a very high in vitro killing activity, in oral administration experiments, only the groups of fish administered 200 mg kg(-1) showed less than 50% mean abundance of M. sebastis compared to the control groups, suggesting that the absorption efficiency of orally administered oxyclozanide might be low in black rockfish and/or that M. sebastis might be less sensitive to orally ingested oxyclozanide. As praziquantel has been the sole therapeutic against M. sebastis infection in Korea for a long time, a broadening of available control measures is advisable in order to reduce the possible emergence of praziquantel-resistant M. sebastis. In our study, although quinacrine and oxyclozanide showed a therapeutic potential against M. sebastis, the treatment efficacy was not high enough to replace praziquantel. Thus, after investigations on the pathological effects and pharmacodynamics, use of quinacrine or oxyclozanide in combination with praziquantel may be considered as a way to prevent praziquantel resistance in M. sebastis.

Efficacy of oxyclozanide against the rumen fluke Calicophoron daubneyi in experimentally infected goats.

Paramphistome infections are very common in ruminants and may induce clinical signs, but little is known about effective treatments. In this study, the efficacy of oxyclozanide against Calicophoron daubneyi was studied in goats and its activity tested against immature stages (10 days post-infection) at a dose of 22.5mg/kg bodyweight (BW) and against adult stages using two doses (15 and 22.5mg/kg BW). There was a reduction (82%) in the number of immature worms (compared to controls) but the result was not statistically significant. When tested against adult stages, however, oxyclozanide reduced the worm burdens by 95.6% and 95.9% at doses of 15 and 22.5mg/kg BW, respectively, with no significant difference between the two doses. The experiment demonstrated that oxyclozanide is highly effective in reducing the number of adult paramphistomes in goats.

[The investigation of short term efficiency of oxfendazole + oxyclozanide paste and tablet formulations against gastrointestinal nematodes in sheep]. / Koyunlarda Mide-Bagirsak Nematodlarina Karsi Oxfendazole + Oxyclozanide'nin Tablet ve Pasta Formülasyonlarinin Kisa Süreli Etkinliginin Arastirilmasi.

The aim of this study was to investigate the effectiveness of tablet and paste formulations of Oxfendazole and Oxyclozanide combinations against subclinical gastrointestinal nematode infections and to compare the advantages and/or disadvantages of their use. Seventy-five infected sheep were selected from an enterprise located in Kayseri in 2006. The sheep were divided into 3 equal groups as paste, tablet and control groups. Fecal samples were collected from each group before drug administration. While the paste and tablet groups were administered drugs orally, no drugs were given to the controls. Fecal samples were collected on the 7th, 14th, 21st, and 28th days after drug application and the EPG values were determined. The parasitological examination revealed that the most prevalent species was Ostertagia spp., followed by Nematodirus spp. and Trichostrongylus spp. While the mean EPG value of the control group increased up to a ratio of 7.8% at day 28, the mean EPG values of drug groups decreased to 0%. Although the unit dose of paste formulation is more expensive, it was found that it could be an alternative to tablet formulation and has some advantages such as being easier to give, effective utilizing, shorter application period, fewer complications and death risk, no application failure and requires fewer personnel.

The use of monoclonal antibody for the immunodiagnosis of Fasciola gigantica infection in cattle.

Antigens that were specific to Fasciola gigantica were obtained from the whole worm homogenate of the parasite by immunoaffinity chromatography in cyanogen bromide-activated sepharose 4B columns and used for the production of monoclonal antibodies. The F. gigantica-specific monoclonal antibody was labelled with horseradish peroxidase and used for the detection of circulating antigen by the direct ELISA method in the sera of cattle experimentally infected with the parasite. Circulating antigens were detectable in the sera of the animals as from the third week after infection while negative absorbance values were obtained 2 weeks after the termination of the infection by chemotherapy with oxyclozanide. This immunodiagnostic method offers an attractive alternative as a supplement to the conventional coprological diagnosis of fasciolosis.

The isolation of Fasciola gigantica-specific antigens and their use in the serodiagnosis of fasciolosis in sheep by the detection of circulating antigens.

The 17kDa and 69kDa polypeptide antigens which are specific to Fasciola gigantica were excised from polyacrylamide gels and used for the immunization of rabbits to raise monospecific antisera against these polypeptides. These sera were labelled with horseradish peroxidase and used for the detection of circulating 17 kDa and 69 kDa antigens by a direct enzyme-linked immunosorbent assay in the sera of sheep that were experimentally or naturally infected with F. gigantica. The 17 kDa antigen was detected in the sera of infected sheep as early as 1 week after infection and, following chemotherapy with oxyclozanide, negative seroconversion occurred 2 weeks later. The 69 kDa antigen was detectable as from the fourth week of infection and its detection ceased 3 weeks after chemotherapy. The serodiagnosis of F. gigantica, based on the detection of the 17 kDa antigen in sheep sera, was more specific and sensitive than that based on the detection of the 69 kDa antigen.

Responses in milk production to control of gastrointestinal nematode and paramphistome parasites in dairy cattle.

OBJECTIVE: To determine the effect of treating naturally acquired gastrointestinal nematode and paramphistome infections on milk production in dairy cattle. DESIGN: A field trial. ANIMALS: One thousand two hundred and thirty nine dairy cows. PROCEDURE: Cows were either not treated or treated with 4.5 mg/kg oxfendazole, 16.6 mg/kg oxyclozanide or 4.5 mg/kg oxfendazole and 16.6 mg/kg oxyclozanide in March, May and August. RESULTS: A significant increase in milk production, averaging 0.4 L (SE 0.2) per day, was seen when dairy cows infected with gastrointestinal nematodes and paramphistomes were treated with oxfendazole or oxfendazole and oxyclozanide in March, May and August. Cows treated with oxyclozanide alone at these times produced no more milk than untreated cows. Faecal egg counts confirmed that oxyclozanide treatment reduced paramphistome populations and oxfendazole treatment reduced nematode populations in cows over the 7-month monitoring period. CONCLUSION: When dairy cows infested with gastrointestinal nematodes and paramphistomes were treated with oxfendazole alone or oxfendazole and oxyclozanide in March, May and August milk production increased.

Antibody and circulating antigen profiles before and after chemotherapy in goats infected with Fasciola gigantica.

The profiles of antibody response and circulating antigen levels in goats infected with Fasciola gigantica were studied by enzyme-linked immunoelectrotransfer blot (EITB) and enzyme-linked immunosorbent assay (ELISA). In the antibody assay, sera from goats experimentally infected with F. gigantica were reacted with whole worm antigen of the worm before and after chemotherapy with oxyclozanide. In ELISA, there was a significant increase in antibody level 2 weeks after infection. After chemotherapy, there was a gradual decrease in antibody within 3 weeks followed by a rapid decline by the 4th week after treatment. By EITB, the infected goat sera recognized three polypeptides in the range of 42-80 kDa as early as 2 weeks after infection. Recognition of the complete components of F. gigantica antigen repertoire occurred as early as the 4th week after infection. By the 8th week after chemotherapy, distinct polypeptide band recognition was no longer possible. Comparative immunoblotting with goat anti-Paramphistomum, anti-Dicrocoelium and anti-Fasciola sera revealed that the 14 kDa, 17 kDa, 21 kDa, 28 kDa and 30 kDa proteins are specific to F. gigantica. In the antigen assay, circulating antigen was detectable by the direct ELISA method one week after infection and negative absorbance values were observed 4 weeks after chemotherapy.

Worm kinetics and serum IgE in hooded lister rats infected with the acanthocephalan Moniliformis moniliformis and the nematode Nippostrongylus brasiliensis.

After infection with the intestinal helminths Moniliformis moniliformis or Nippostrongylus brasiliensis, worm-specific IgE first appeared in the serum rats between days 10 and 24 p.i., varying with host age, worm species and worm dose used. The rate of increase in specific IgE was comparable regardless of the worm species, infection dose or host age and a peak response was observed about 1 month after the sera turned positive. In the M. moniliformis infections, these events took place long before the beginning of worm expulsion on day 63 in high-dose (50 worms) infections, and potentiation of heterologous IgE was not observed. In contrast, IgE stimulation by N. brasiliensis infections was detected as potentiation of anti-ovalbumin IgE, anti-M. moniliformis IgE and total IgE. Most of the total IgE in the serum of M. moniliformis-infected rats was likely to be the worm-specific IgE. Anthelminthic removal of M. moniliformis revealed that the presence of residual worms was necessary to maintain worm-specific IgE production.

Immunological detection of chemotherapeutic success in bovine fasciolosis using the specific antigen f2.

An improved hemagglutination (HA) test using the purified specific f2 antigen of Fasciola hepatica has been evaluated with regard to its potential use for the prediction of chemotherapeutic success in natural bovine infections with F. hepatica. Lactating cows (n = 16) from a herd naturally infected with F. hepatica were successively treated with nitroxynil (Dovenix, Specia) and with oxyclozanide (Zanil, ICI) 1 month later. Their f2-specific antibodies were significantly lower than those of a non-treated control group (n = 15) from the second month after the first treatment, and continued to decline thereafter to negative values 5-6 months post-treatment. In a second experiment, culled and fattened cows (n = 32) of unknown fasciolosis history were treated with closantel (Janssen Pharmaceutica). Three months after treatment, f2-specific antibodies of the serologically positive animals (n = 24) were reduced nine-fold. In contrast, in the control group (n = 28), the titers of f2-specific antibodies of the serologically positive animals (n = 21) were not modified significantly. The results show that the f2-HA test is useful for the prediction of chemotherapeutic success in bovine fascioliasis.

Production responses to internal parasite control in dairy cattle.

A significant increase in milk production, averaging 164 litres per cow per lactation (a 4.8% increase), was seen after cows infected with gastrointestinal nematodes, paramphistomes and Fasciola hepatica were treated with broad-spectrum anthelmintics. Three hundred and ninety pairs of cows from eight herds with year-round calving were studied. One cow in each matched pair was given 7.5 mg/kg fenbendazole, 7.5 mg/kg levamisole hydrochloride and 15 mg/kg oxyclozanide in March, May and August of one year; the other cow in the pair received no anthelmintic. The number of nematode and trematode eggs was significantly decreased in the faeces of treated cows.

Chemotherapy of paramphistomosis in cattle.

Controlled tests were used to assess the efficacy of anthelmintics against immature paramphistomes, predominantly Calicophoron calicophorum, in 127 calves which were exposed to contaminated pasture for 7 weeks, treated and slaughtered. When a combination product of oxyclozanide and levamisole was used, oxyclozanide at 18.7 mg/kg reduced parasite numbers in the small intestine, abomasum and rumen-reticulum by 61 to 96.1%, 50.0 to 92.6% and 56.5 to 98.1%, respectively. When 2 doses were given 3 days apart, oxyclozanide was 99.9%, 100% and 100% effective, respectively, in the above organs, and produced improvement in clinically affected calves. This treatment elicited transient diarrhoea. Hexachlorophene at 20 mg/kg as a single dose was 99.5%, 100% and 100% effective against the fluke in the small intestine, abomasum and rumen respectively but severe neurological signs were seen in some calves. Niclosamide at 160 mg/kg given as single or 2 doses 3 days apart was 91.1% and 92.6% effective, respectively, against the parasites in the small intestine. No toxicity was noted. Closantel, at 7.5 mg/kg was not effective. Oxyclozanide and niclosamide when given as a single treatment had varying activity. Two doses of oxyclozanide and a single dose of hexachlorophene gave consistent results. Further tests based on reduction of faecal egg counts, 10 to 14 days after treatment were conducted with oxyclozanide and hexachlorophene against mature paramphistomes in 207 cattle. Oxyclozanide as a single dose or 2 doses 3 days apart at 12.8 to 18.7 mg/kg was 93.6 to 97.5% effective in reducing egg counts. Hexachlorophene at 20 mg/kg was 83.0% effective.(ABSTRACT TRUNCATED AT 250 WORDS)

Decrease in hepatic microsomal UDP-glucuronosyl-transferase activity in rats and cattle with fascioliasis: impaired in vitro glucuronidation of oxyclozanide.

The effects of liver fluke infection (Fasciola hepatica) on hepatic microsomal UDP-glucuronosyl-transferase activity have been studied in microsomes from experimentally infected rats and naturally infected cattle to see if they explain the toxic episodes observed in parasite-infected animals subjected to intensive chemotherapy with the flukicidal drug oxyclozanide. Dramatic decreases in the activity of this enzyme system with the typical substrate p-nitrophenol were observed in both animal species, even when little or no degenerative lesions could be seen in the liver parenchyma. In vitro there was a similar loss of glucuronic acid conjugation of oxyclozanide by hepatic microsomes from infected cattle. In vivo this would result in slower elimination of the drug and in drug accumulation.

[Effectiveness of levamisole and oxyclozanide in paramphistomiasis in sheep and cattle]. / Efektivnost na levamizole i oxyclozanide sreshtu paramfistomatozata po ovtsete i govedata.

The antiparasitic effectiveness of Levamizole and Oxyclozamide in the control of paramphistomatosis in sheep and cattle was studied. Experiments were performed in the 1975--1978 period with 1880 sheep and 132 cattle naturally invaded by P. microbothrium. The two drugs were administered orally in the following doses: Levamizole -- 7.5 mg/kg, Oxyclozanide -- 15 mg/kg for sheep and 10 mg/kg for cattle. A part of the experimental animals were treated by the combined drug Nilzan and received the above mentioned doses of both chemico-therapeutic means. Results were scored by ovoscopic investigation on the 10th and 15th day post treatment and by helminthological investigation on a part of the animals. Egg deposition was followed on 1415 sheep in the course of 4 months. A comparatively low effectiveness of Levamizole was established, namely U = 15--50%, IU = 81.56--99.40% and a good effectiveness of Oxyclozanide application, namely -- U = 30--80%, IU = 73.94-- 99.40% for sheep, and U = 0--50%, IU = 74.84--89.97% for cattle. Highest effectiveness was observed following the application of the combined drug Nilzan -- U = 47.7--92.0%, IU = 89.07--99.98% for sheep, and U = 20--73.20%, IU = 99.32--99.96% for cattle. The enhanced effectiveness of Nilzan application is considered by the authors as a result of synergism of the two chemico-therapeutic means.

Liver fluke infection in horses and ponies.

Thirty eight cases of Fasciola hepatica infection in horses with associated clinical signs are reported. A method of examining large amounts of faeces for fluke is described. A safe method of treatment for infected horses is given which involves oral medication with oxyclozanide at a dose rate of 15 ml/50 kg body weight.