naphthoquinones and buparvaquone

The parenteral administration of pentavalent antimonials for the treatment of all forms of leishmaniasis, including cutaneous leishamniasis (CL), has several limitations. Therapy is long, requiring repeated doses and the adverse reactions are frequent. Topical treatment is an attractive alternative for CL, offering significant advantages over systemic therapy: fewer adverse effects, ease of administration, and lower costs.. This review covers, from 1984 to the present, the progress achieved for the development of topical treatment for CL, using different drugs such as paromomycin (PA), imiquimod, amphotericin B (AmB), miltefosine, and buparvaquone. PA is the most commonly studied drug, followed by AmB and Imiquimod. These drugs were incorporated in conventional dosage forms or loaded in lipid nanocarries, which have been used mainly for improved skin delivery and antileishmanial activity.. Developing an effective topical treatment for CL using these antileishmanial drugs still remains a great challenge. Insights into the most promising delivery strategies to improve treatment of CL with PA and AmB using conventional dosage forms, lipid nanocarriers, and combined therapy are presented and discussed. The results obtained with combined therapy and alternative delivery systems are promising perspectives for improving topical treatment of CL.

Topics: Administration, Cutaneous; Aminoquinolines; Amphotericin B; Animals; Antiprotozoal Agents; Drug Delivery Systems; Humans; Imiquimod; Leishmaniasis, Cutaneous; Naphthoquinones; Paromomycin; Phosphorylcholine; Skin Absorption

Thirty buffaloes naturally infected with Theileria annulata and 10 parasitologically free controls were used to determine the potential clinical, haematological and therapeutic impact of tropical theileriosis in Egypt. The clinical signs in the infected buffaloes were pyrexia (40.5-41.5 degrees C), enlargement of superficial lymph nodes, slight nasal and ocular discharges, salivation, anaemia and respiratory distress. Eye lesions also were recorded. There was a significant decrease in erythrocyte counts and haemoglobin content and a significant decrease in total leucocyte counts in infected buffaloes compared to controls. Early treatment with buparvaquone was 100% effective in eliminating the protozoan parasites from the blood and lymph nodes and led to an improvement in the clinical state whereas treatment in the later stages of the disease whilst eliminating the parasites failed to improve the clinical condition of the animal.

Topics: Animals; Antiprotozoal Agents; Buffaloes; Cattle; Cattle Diseases; Egypt; Naphthoquinones; Theileriasis

East Coast fever, caused by the protozoan parasite Theileria parva, kills about 600,000 cattle annually in Africa. The hydroxynaphthoquinone compound buparvaquone (BPQ) is curative. Sixteen calves were infected with T. parva. On manifestation of disease symptoms, eight were injected with the original (pioneer) BPQ product and eight with a test product containing BPQ. All 16 calves were cured by one injection of 2.5 mg BPQ/kg bodyweight. The concentration of BPQ in blood plasma was monitored by HPLC. The mean observed C(max) of BPQ was 0.229 and 0.253 microg/mL of plasma, the mean observed time to reach this concentration (T(max)) was 2.62 and 2.12 h and the AUC (area under curve) was 4.785 and 4.156 microg h/mL, respectively, for the pioneer and test product. Considerable variations occurred in the plasma concentration of BPQ within each group. They showed no relationship with either clinical or parasitological parameters following treatment.

Topics: Animals; Antiprotozoal Agents; Area Under Curve; Cattle; Cattle Diseases; Male; Naphthoquinones; Theileriasis

The therapeutic efficacy of imidocarb, artesunate, arteether, buparvaquone and arteether+buparvaquone combination was evaluated against Babesia equi of Indian origin in splenectomised donkeys with experimentally induced acute infection. Efficacies of these drugs were tested by administering each drug or drug combination to groups of donkeys (having three donkeys each group). One group of donkey was kept as untreated control for comparing the results. Parasitaemia, haematology (WBC, RBC, PCV, granulocytes and haemoglobin), biochemical parameters (SAST, SALT, alkaline phosphatase, albumin/globulin ratio) were monitored at regular intervals. Individually, arteether and buparvaquone were found to have no parasite clearing efficacy and the treated animals died within 5-6 days after showing high parasitaemia and clinical symptoms of the disease. However, artesunate treated animals were able to restrict the parasite multiplication but only during the treatment period. Animals treated with imidocarb and arteether+buparvaquone combination were able to clear the parasite from the blood circulation after 2-5 days post-treatment (PT). After 55-58 days PT, recrudescence of B. equi parasite was observed in both these groups and a mean survival period of 66 days and 69 days, respectively, was recorded in these groups. Results of haemato-biochemical parameters had shown that imidocarb had deleterious effect on the liver function while on the other hand arteether+buparvaquone combination was found to be safe. This limited study indicates that arteether+buparvaquone combination could be a better choice than imidocarb for treating B. equi infection, but further trials are required in detail.

Topics: Animals; Antiprotozoal Agents; Artemisinins; Babesiosis; Blood Cell Count; Drug Therapy, Combination; Equidae; Imidocarb; India; Naphthoquinones; Sesquiterpenes; Splenectomy

An in vitro method for testing activity of buparvaquone in serum on the infection and development of Theileria in its bovine host mononuclear cells is described and results compared with the effect exhibited in vivo. Serum samples were collected over a time course from calves in a clinical trial of 5 mg kg(-1) buparvaquone prophylaxis on Theileria annulata or T. parva experimental infection. To evaluate drug levels and persistence in each animal for a period of 14 days and its effect on the early infection stages, the sera were tested on established macroschizont infected cell lines and against the in vitro infection and development process of the sporozoite and trophozoite stages of the two Theileria species. Results from the in vitro assays show that buparvaquone in serum can completely prevent the establishment of Theileria infection during the first 48 h after administration at 5 mg kg(-1). After seven days, levels are sufficient to delay the establishment of infection. The drug is more effective in the prevention of the de novo development of the parasite in cells than against established macroschizont infected cell culture. At low concentrations, it is more effective against T. parva than against T. annulata. Drug effect peaks during the first 24 h but residual effect persists for 14 days, particularly against T. parva infection. These novel findings demonstrate how high doses of buparvaquone could over-protect calves if used in the 'infection-and-treatment' method of immunisation when drug is administered prophylactically at the same time as infection with live sporozoites. It is suggested that in certain high Theileria risk situations there may be potential for the immunoprophylactic use of buparvaquone without simultaneous infection. The in vitro assay itself has been shown to be of value as a model for Theileria establishment in cattle.

Topics: Animals; Antiprotozoal Agents; Biological Assay; Cattle; Cell Line; Naphthoquinones; Theileria annulata; Theileria parva; Theileriasis; Time Factors

A clinical trial was conducted to test buparvaquone (Butalex; Coopers Pitman-Moore) in the treatment of East Coast fever under field conditions in Kenya. Data from 229 cases were analysed following treatment with one (69), two (142) or three (18) doses at 2.5 mg/kg. The majority of cattle (95.2 per cent) were exotic (Bos taurus) or improved (Bos taurus cross Bos indicus) and 39.3 per cent were infected with Anaplasma marginale. There was an overall recovery rate of 85.6 per cent, with 90.1 per cent recovering following one treatment and 75.4 per cent recovering following two treatments. At a follow-up visit three to six months after completion of the trial data was obtained on 224 cases. Thirty had died, 13 of which were reported to have been from East Coast fever, nine had been sold and six slaughtered. Of the remaining 146, 86.3 per cent were in good condition, 13.7 per cent fair and 2.0 per cent in poor condition. A two dose regimen was most effective and should be recommended except in very early cases or those under direct veterinary supervision.

Topics: Anaplasmosis; Animals; Antiprotozoal Agents; Cattle; Injections, Intramuscular; Kenya; Naphthoquinones; Theileria parva; Theileriasis

Leishmaniasis, a neglected tropical disease, is prevalent in 98 countries with the occurrence of 1.3 million new cases annually. The conventional therapy for visceral leishmaniasis requires hospitalization due to the severe adverse effects of the drugs, which are administered parenterally. Buparvaquone (BPQ) showed in vitro activity against leishmania parasites; nevertheless, it has failed in vivo tests due to its low aqueous solubility. Though, lipid nanoparticles can overcome this holdback. In this study we tested the hypothesis whether BPQ-NLC shows in vivo activity against L. infantum. Two optimized formulations were prepared (V1: 173.9 ± 1.6 nm, 0.5 mg of BPQ/mL; V2: 232.4 ± 1.6 nm, 1.3 mg of BPQ/mL), both showed increased solubility up to 73.00-fold, and dissolution up to 83.29%, while for the free drug it was only 2.89%. Cytotoxicity test showed their biocompatibility (CC50 >554.4 µM). Besides, the V1 dose of 0.3 mg/kg/day for 10 days reduced the parasite burden in 83.4% ±18.2% (p <0.05) in the liver. BPQ-NLC showed similar leishmanicidal activity compared to miltefosine. Therefore, BPQ-NLC is a promising addition to the limited therapeutic arsenal suitable for leishmaniasis oral administration treatment.

Topics: Administration, Oral; Antiprotozoal Agents; Leishmania infantum; Lipids; Liposomes; Nanoparticles; Naphthoquinones

When Theileria annulata infects host cells, it undertakes unlimited proliferation as tumor cells. Although the transformed cells will recover their limited reproductive characteristics and enter the apoptosis process after treatment with buparvaquone (BW720c), the metabolites and metabolic pathways involved are not clear.. The transformed cells of T. annulata were used as experimental materials, and the buparvaquone treatment group and DMSO control group were used. Qualitative and quantitative analysis was undertaken of 36 cell samples based on the LC-QTOF platform in positive and negative ion modes. The metabolites of the cell samples after 72 h of drug treatment were analyzed, as were the different metabolites and metabolic pathways involved in the BW720c treatment. Finally, the differential metabolites and metabolic pathways in the transformed cells were found.. A total of 1425 metabolites were detected in the negative ion mode and 1298 metabolites were detected in the positive ion mode. After drug treatment for 24 h, 48 h, and 72 h, there were 56, 162, and 243 differential metabolites in negative ion mode, and 35, 121, and 177 differential metabolites in positive ion mode, respectively. These differential metabolites are mainly concentrated on various essential amino acids.. BW720c treatment induces metabolic disturbances in T. annulata-infected cells by regulating the metabolism of leucine, arginine, and L-carnitine, and induces host cell apoptosis.

Topics: Animals; Arginine; Carnitine; Cattle; Dimethyl Sulfoxide; Leucine; Naphthoquinones; Theileria; Theileria annulata; Theileriasis

Visceral leishmaniasis is a vector-borne protozoan infection that is fatal if untreated. There is no vaccination against the disease, and the current chemotherapeutic agents are ineffective due to increased resistance and severe side effects. Buparvaquone is a potential drug against the leishmaniases, but it is highly hydrophobic resulting in poor bioavailability and low therapeutic efficacy. Herein, we loaded the drug into silicon nanoparticles produced from barley husk, which is an agricultural residue and widely available. The buparvaquone-loaded nanoparticles were several times more selective to kill the intracellular parasites being non-toxic to macrophages compared to the pure buparvaquone and other conventionally used anti-leishmanial agents. Furthermore, the in vivo results revealed that the intraperitoneally injected buparvaquone-loaded nanoparticles suppressed the parasite burden close to 100%. By contrast, pure buparvaquone suppressed the burden only by 50% with corresponding doses. As the conclusion, the biogenic silicon nanoparticles are promising carriers to significantly improve the therapeutic efficacy and selectivity of buparvaquone against resistant visceral leishmaniasis opening a new avenue for low-cost treatment against this neglected tropical disease threatening especially the poor people in developing nations.

Topics: Animals; Antiprotozoal Agents; Drug Carriers; Female; Hordeum; Injections, Intraperitoneal; Leishmania donovani; Leishmaniasis, Visceral; Macrophages; Mice, Inbred BALB C; Nanoparticles; Naphthoquinones; Silicon

Topics: Administration, Intravenous; Animals; Chemical Precipitation; Drug Delivery Systems; Female; Lipids; Mice; Microscopy, Electron, Scanning; Nanoparticles; Naphthoquinones; Particle Size; Spleen

Leishmaniasis is a neglected disease presenting cutaneous, mucosal and visceral forms and affecting an estimated 12 million mostly low-income people. Treatment of cutaneous leishmaniasis (CL) is recommended to expedite healing, reduce risk of scarring, prevent parasite dissemination to other mucocutaneous (common with New World species) or visceral forms and reduce the chance of relapse, but remains an unmet need. Available treatments are painful, prolonged (>20 days) and require hospitalisation, which increases the cost of therapy. Here we present the development of optimised topical self-nanoemulsifying drug delivery systems (SNEDDS) loaded with buparvaquone (BPQ, a hydroxynapthoquinone from the open Malaria Box) for the treatment of CL from New World species. The administration of topical BPQ-SNEDDS gels for 7 days resulted in a reduction of parasite load of 99.989 ± 0.019% similar to the decrease achieved with intralesionally administered Glucantime® (99.873 ± 0.204%) in a L. amazonensis BALB/c model. In vivo efficacy was supported by ex vivo permeability and in vivo tape stripping studies. BPQ-SNEDDS and their hydrogels demonstrated linear flux across non-infected CD-1 mouse skin ex vivo of 182.4 ± 63.0 μg cm

Topics: Animals; Antiprotozoal Agents; Hydrogels; Leishmaniasis, Cutaneous; Mice; Mice, Inbred BALB C; Naphthoquinones

The aims of this study were to monitor the change in Theileria orientalis Ikeda type infection intensity, haematocrit, milk production and reproduction on three New Zealand spring calving dairy herds, over the 2014-2015 milking season. Three spring calving dairy farms, A, B and C, from high risk (endemically stable), low risk (endemically unstable), and zero risk (disease-free) tick areas respectively were followed through the 2014-2015 milking season. On Farms, A and B, 100 cows were randomly selected at the first visit, and the same cows blood sampled every month thereafter, whilst on Farm C, the whole herd was blood sampled bimonthly (140 cows). Blood samples were tested for haematocrit, by centrifugation, and Ikeda infection intensity, using qPCR. Animals that were Ikeda type PCR positive at the first sampling were described as prevalence cases and cows that were negative at the first sampling and became PCR positive during the sampling period were described as incidence cases. Production and reproduction data were accessed through LIC MINDA® and milk production data was standardised to energy corrected milk (ECM). In addition, the effect of buparvaquone (BPQ) treatment on milk production was estimated on Farm B. The prevalence of infection at the first sampling was 100 % on Farm A, 57 % on Farm B and 26 % on Farm C. The incidence risk of infection over the sampling period on Farms B and C was 25 % and 2 % and the incident rate was 0.026 and 0.002 cases per cow-month respectively. The average infection intensity for prevalence cases on all farms was low throughout the milking season, <7000 Ikeda organisms/μL however, cases of anaemia still occurred. There was no direct effect of infection intensity on milk production or from being a prevalence case compared to an uninfected cow on milk production, across all farms. However, on Farm B there was a loss of 266 kg (95 % CI 82 ̶ 450) ECM (∼20 kg milk solids) for incidence cases and a loss of 458 kg (95 % CI 211 ̶ 710) of ECM for buparvaquone treated cows, compared to uninfected cows. No significant effect of Ikeda infection on reproduction could be shown for Farms B and C, reproductive data for Farm A was not available. The effect of T. orientalis Ikeda type infection on production and reproduction appears to be minimal once animals have passed through the acute phase of infection and reached the chronic, asymptomatic carrier phase of infection.

Topics: Animals; Antiprotozoal Agents; Cattle; Dairying; DNA, Protozoan; Female; Gene Dosage; Hematocrit; Incidence; Lactation; Longitudinal Studies; Naphthoquinones; Prevalence; Prospective Studies; Real-Time Polymerase Chain Reaction; Reproduction; Theileria; Theileriasis

The tick-borne parasite Theileria annulata is the causative agent of tropical theileriosis or Mediterranean theileriosis. Infection of bovine leukocytes by the obligate intracellular parasites induces proliferative and invasive phenotypes associated with activated signaling pathways. The transformed phenotypes of infected cells are reversible by treatment with the theilericidal drug buparvaquone. Recent reports of resistance to buparvaquone in Africa and Asia highlight the need to investigate the mechanisms and prevalence of drug resistance. We screened 67 T. annulata isolates from Sudan to investigate mutations in the T. annulata prolyl isomerase I gene (TaPIN1). The secreted TaPin1 interacts with host proteins to induce pathways driving oncogenic transformation and metabolic reprogramming. We found an Alanine-to-Proline mutation at position 53 (A53P) in the catalytic loop that was previously found in Tunisian drug-resistant samples. This is the first study reporting independent confirmation of the A53P mutation in geographically isolated samples. We found several additional mutations in the predicted N-terminal signal peptide that might affect TaPin1 processing or targeting. We found that many parasites also share mutations in both the TaPIN1 and the cytochrome b genes, suggesting that these two genes represent important biomarkers to follow the spread of resistance in Africa, the Middle East and Asia.

Topics: Animals; Antiprotozoal Agents; Cattle; Drug Resistance; Naphthoquinones; Peptidylprolyl Isomerase; Phenotype; Point Mutation; Sudan; Theileria annulata; Theileriasis

We here assessed the in vitro efficacy of the naptho-quinone buparvaquone (BPQ) against Besnoitia besnoiti tachyzoites in vitro. BPQ is currently licensed for the treatment of theileriosis in cattle in many countries, but not in the EU. In 4-day treatment assays, BPQ massively impaired tachyzoite proliferation with an IC50 of 10 ± 3 nm, and virtually complete inhibition was obtained in the presence of nm BPQ. Exposure to 1 µm BPQ leads to ultrastructural changes affecting initially the mitochondrial matrix and the cristae. After 96 h, most parasites were largely distorted, filled with cytoplasmic amylopectin granules and vacuoles containing components of unknown composition. Host cell mitochondria did not appear to be notably affected by the drug. However, upon prolonged exposure (14-16 days) to increased BPQ concentrations, B. besnoiti tachyzoites exhibited the capacity to adapt, and they resumed proliferation at dosages of up to 10 µm BPQ, albeit at a lower rate. These BPQ-adapted parasites maintained this lower susceptibility to BPQ treatment after freeze-thawing, and inspection by the transmission electron microscopy revealed that they underwent proliferation in the absence of structurally intact mitochondria.

Topics: Animals; Antiprotozoal Agents; Cell Line; Chlorocebus aethiops; Drug Resistance; Fibroblasts; Inhibitory Concentration 50; Microscopy, Electron, Transmission; Mitochondria; Naphthoquinones; Sarcocystidae; Vero Cells

Drug resistance is one of the emerging and re-emerging epidemics affecting both veterinary and public health sectors. Buparvaquone provides the most satisfactory means in the treatment of bovine tropical theileriosis. However, recently there has been widespread reports of development of resistance of Theileria annulata to buparvaquone. To investigate the situation in Sudan where bovine tropical theileriosis is endemic, fifty blood samples from T. annulata-positive cattle. were used for DNA extraction, PCR and cytochrome b gene nucleotide sequencing. Analysis of the two buparvaquone binding site regions Q

Topics: Animals; Antiprotozoal Agents; Cattle; Cytochromes b; Drug Resistance; Naphthoquinones; Point Mutation; Sudan; Theileria annulata; Theileriasis; Treatment Failure

Chemotherapy of East Coast fever, a lymphoproliferative cancer-like disease of cattle causing significant economic losses in Africa, is largely dependent on the use of buparvaquone, a drug that was developed in the late 1980's. The disease is caused by the tick-borne protozoan pathogen Theileria parva. Buparvaquone can be used prophylactically and it is also active against tropical theileriosis, caused by the related parasite Theileria annulata. Recently, drug resistance was reported in T. annulata, and could occur in T. parva. Using a

Topics: Animals; Antimalarials; Antiprotozoal Agents; Cattle; Cell Line; Cell Proliferation; Dasatinib; Drug Repositioning; High-Throughput Screening Assays; Inhibitory Concentration 50; Leukocytes, Mononuclear; Naphthoquinones; Small Molecule Libraries; Theileria parva; Theileriasis

Metabolic reprogramming is an important feature of host-pathogen interactions and a hallmark of tumorigenesis. The intracellular apicomplexa parasite

Topics: Animals; Antiprotozoal Agents; Biological Transport; Carrier Proteins; Cattle; Cell Line, Transformed; Cell Transformation, Neoplastic; Enzyme Inhibitors; Gene Expression Regulation; Glucose; Host-Pathogen Interactions; Hypoxia-Inducible Factor 1, alpha Subunit; Lymphocytes; Membrane Proteins; Metabolic Networks and Pathways; Naphthoquinones; NIMA-Interacting Peptidylprolyl Isomerase; Protozoan Proteins; RNA, Small Interfering; Signal Transduction; Theileria; Thyroid Hormone-Binding Proteins; Thyroid Hormones

This study aimed to establish a pure single-cell

Topics: Animals; Antigens; B-Lymphocytes; Cattle; Cytokines; Flow Cytometry; Gene Expression Regulation; Lipopolysaccharides; Macrophages; Naphthoquinones; Single-Cell Analysis; Theileria annulata; Theileriasis

This study aimed to describe the preparation and in vitro evaluation of a surface-modified nanostructured lipid carrier (NLC) using chitosan and dextran for co-delivery of buparvaquone (BPQ) and polymyxin B (PB) against leishmaniasis.. The NLC was prepared using high-pressure homogenisation. Polymyxin B binding and surface modification with biopolymers were achieved by electrostatic interaction. In vitro cytotoxicity was assessed in mouse peritoneal macrophages, and leishmanicidal activity in amastigotes of Leishmania infantum.. The developed NLC proved to be a promising formulation with which to overcome the drawbacks of current leishmaniasis treatment by the co-delivery of two alternative drugs and a macrophage targeting modified surface.

Topics: Anti-Bacterial Agents; Biopolymers; Chitosan; Dextrans; Drug Combinations; Drug Delivery Systems; Leishmania infantum; Leishmaniasis; Lipids; Nanostructures; Naphthoquinones; Particle Size; Polymyxin B; Thermogravimetry

Mountain bongo (

Topics: Animals; Antelopes; Antiprotozoal Agents; Conservation of Natural Resources; Disease Outbreaks; Female; Kenya; Male; Naphthoquinones; Oxytetracycline; Theileria; Theileriasis

The present study was designed to assess the deleterious effects of bovine tropical theileriosis on the cardiovascular system and the consequent myocardial involvement in young calves. Myocardial effects in parasitic diseases are often neglected. Hemolytic anemia, associated secondary hypoxia, and vasculitis are cardinal features of bovine theileriosis. In the present study, electrocardiogram (ECG) alongside serum cardiac troponin I (cTnI) and creatinine phosphokinase-myocardial band (CPK-MB) concentrations were analyzed in infected, treated, and control groups of young calves. Non-significant alterations were noticed in ECG. However, certain signs like sinus tachycardia, first-degree AV block, atrial premature complex, left atrial hypertrophy, and right atrial hypertrophy were found on consistent basis in infected calves. A significant increase in the serum concentration levels of cTnI and CPK-MB was noticed in infected calves followed by significant fall in both these biomarkers post treatment. cTnI and CPK-MB can definitely be used as myocardial markers in theileriosis-affected animals.

Topics: Animals; Antiprotozoal Agents; Biomarkers; Cattle; Creatine Kinase, MB Form; Electrocardiography; Heart; Naphthoquinones; Theileriasis; Troponin I

Nanoenabled lipid-based drug delivery systems offer a platform to overcome challenges encountered with current failed leads in the treatment of parasitic and infectious diseases. When prepared with FDA or EMA approved excipients, they can be readily translated without the need for further toxicological studies, while they remain affordable and amenable to scale-up. Buparvaquone (BPQ), a hydroxynapthoquinone with in vitro activity in the nanomolar range, failed to clinically translate as a viable treatment for visceral leishmaniasis due to its poor oral bioavailability limited by its poor aqueous solubility (BCS Class II drug). Here we describe a self-nanoemulsifying system (SNEDDS) with high loading and thermal stability up to 6 months in tropical conditions and the ability to enhance the solubilization capacity of BPQ in gastrointestinal media as demonstrated by flow-through cell and dynamic in vitro lipolysis studies. BPQ SNEDDS demonstrated an enhanced oral bioavailability compared to aqueous BPQ dispersions (probe-sonicated), resulting in an increased plasma AUC

Topics: Administration, Oral; Animals; Antiprotozoal Agents; Biological Availability; Cell Line; Disease Models, Animal; Drug Carriers; Drug Compounding; Drug Liberation; Drug Stability; Emulsions; Excipients; Feasibility Studies; Humans; Leishmania infantum; Leishmaniasis, Visceral; Lipids; Male; Mice; Mice, Inbred BALB C; Nanoparticles; Naphthoquinones; Solubility; Treatment Outcome

Topics: Albendazole; Animals; Anthelmintics; Antiprotozoal Agents; Drug Evaluation, Preclinical; Drug Repositioning; Echinococcosis; Echinococcus multilocularis; Electron Transport Complex III; Glucose-6-Phosphate Isomerase; Inhibitory Concentration 50; Life Cycle Stages; Mice; Microscopy, Electron, Transmission; Naphthoquinones; Parasite Load; Phenyl Ethers; Quinolones

Establishment of a mouse model for congenital toxoplasmosis based on oral infection with oocysts from Toxoplasma gondii ME49 and its application for investigating chemotherapeutic options against congenital toxoplasmosis.. CD1 mice were mated, orally infected with 5, 25, 100, 500 or 2000 oocysts and monitored for clinical signs and survival of dams and pups until 4 weeks post partum . The parasite burden in infected mice was quantified by real-time PCR in lungs, brains and, in the case of surviving pups, also in eyes. Seroconversion was assessed by ELISA. T. gondii cysts in brain were identified by immunofluorescence. In a second experiment, pregnant CD1 mice challenged with 20 oocysts/mouse were treated with buparvaquone or the calcium-dependent protein kinase 1 inhibitor bumped kinase inhibitor (BKI)-1294 and the outcome of infection was analysed.. T. gondii DNA was detected in the brain of all infected animals, irrespective of the infection dose. Seroconversion occurred at 3 weeks post-infection. Most pups born to infected dams died within 1 week post partum , but a small fraction survived until the end of the experiment. T. gondii DNA was detected in the brain of all survivors and half of them exhibited ocular infection. Chemotherapy with both compounds led to dramatically increased numbers of surviving pups and reduced cerebral infection. Most efficient were treatments with BKI-1294, with 100% survivors and only 7% brain-positive pups.. BKI-1294 and buparvaquone exert excellent activities against transplacental transmission in pregnant mice.

Topics: Animals; Antiprotozoal Agents; Disease Models, Animal; Female; Infectious Disease Transmission, Vertical; Male; Mice; Naphthalenes; Naphthoquinones; Piperidines; Pyrazoles; Toxoplasmosis, Animal; Toxoplasmosis, Congenital; Treatment Outcome

Topics: Animals; Chromatography, High Pressure Liquid; Etomidate; Naphthoquinones; Nystatin; Swine; Tandem Mass Spectrometry

Piroplasmosis caused by the Babesia microti-like piroplasm (Bml) is increasingly being detected in dogs in Europe. Sick dogs show acute disease with severe anaemia associated with thrombocytopenia with a poor response to current available drugs. This study assesses the safety and tolerance of three treatments and compares their efficacy over a full year of follow up in dogs naturally infected with Bml.. Fifty-nine dogs naturally infected with Bml were randomly assigned to a treatment group: imidocarb dipropionate (5 mg/kg SC, 2 doses 14 d apart) (IMI); atovaquone (13.3 mg/kg PO q 8 h, 10 d)/azithromycin (10 mg/kg PO q 24 h, 10 d) (ATO); or buparvaquone (5 mg/kg IM, 2 d apart)/azithromycin (same dosage) (BUP). Before and after treatment (days 15, 45, 90 and 360), all dogs underwent a physical exam, blood tests and parasite detection (blood cytology and PCR). Clinical efficacy was assessed by grading 24 clinical and 8 clinicopathological signs from low to high severity.. Before treatment, most dogs had severe regenerative anaemia (88.13%) and thrombocytopenia (71.4%). On treatment Day 45, clinical signs were mostly reduced in all dogs, and by Day 90, practically all dogs under the ATO or BUP regimen were clinically healthy (76.4 and 88%, respectively). Highest percentage reductions in laboratory abnormalities (82.04%) were detected in animals treated with ATO. Over the year, clinical relapse of Bml was observed in 8 dogs (8/17) treated with IMI. However, on Day 360, these animals had recovered clinically, though clinicopathological abnormalities were still present in some of them. Parasitaemia was PCR-confirmed on Days 90 and 360 in 47.05 and 50% of dogs treated with ATO, 68 and 60.08% with BUP, and 94.1 and 73.3% with IMI, respectively. Even after 360 days, 13.3% of the dogs treated with IMI returned a positive blood cytology result.. IMI showed the worse clinical and parasitological, efficacy such that its use to treat Bml infection in dogs is not recommended. The treatments ATO and BUP showed better efficacy, though they were still incapable to completely eliminate PCR-proven infection at the recommended dose. All three treatments showed good tolerance and safety with scarce adverse events observed.

Topics: Animals; Antiprotozoal Agents; Atovaquone; Azithromycin; Babesia microti; Babesiosis; Dog Diseases; Dogs; Drug Therapy, Combination; Europe; Female; Imidocarb; Male; Naphthoquinones; Parasitemia; Polymerase Chain Reaction

The three anti-malarial drugs artemiside, artemisone, and mefloquine, and the naphthoquinone buparvaquone known to be active against theileriosis in cattle and Leishmania infections in rodents, were assessed for activity against Neospora caninum infection. All four compounds inhibited the proliferation of N. caninum tachyzoites in vitro with IC50 in the sub-micromolar range, but artemisone and buparvaquone were most effective (IC50 = 3 and 4.9 nM, respectively). However, in a neosporosis mouse model for cerebral infection comprising Balb/c mice experimentally infected with the virulent isolate Nc-Spain7, the three anti-malarial compounds failed to exhibit any activity, since treatment did not reduce the parasite burden in brains and lungs compared to untreated controls. Thus, these compounds were not further evaluated in pregnant mice. On the other hand, buparvaquone, shown earlier to be effective in reducing the parasite load in the lungs in an acute neosporosis disease model, was further assessed in the pregnant mouse model. Buparvaquone efficiently inhibited vertical transmission in Balb/c mice experimentally infected at day 7 of pregnancy, reduced clinical signs in the pups, but had no effect on cerebral infection in the dams. This demonstrates proof-of-concept that drug repurposing may lead to the discovery of an effective compound against neosporosis that can protect offspring from vertical transmission and disease.

Topics: Animals; Antiparasitic Agents; Coccidiosis; Female; Infectious Disease Transmission, Vertical; Male; Mice, Inbred BALB C; Naphthoquinones; Neospora; Pregnancy

To determine the concentration of the anti-theilerial drug buparvaquone in the milk and tissue of dairy cattle following treatment with two different formulations, and to assess the effect of clinical theileriosis on the concentration of buparvaquone in milk.. Healthy lactating dairy cows (n=25) were injected once (Day 0) I/M with 2.5 mg/kg of one of two formulations of buparvaquone (Butalex; n=12 or Bupaject; n=13). Milk samples were collected from all cows daily until Day 35. Five cows were slaughtered on each of Days 56, 119, 147, 203 and 328, and samples of liver, muscle and injection site tissue collected. Milk samples were also collected from cows (n=14) clinically affected with theileriosis for up to 21 days after treatment with buparvaquone. Milk and tissue samples were analysed by liquid chromatography-mass spectrometry; limits of detection (LOD) were 0.00018 mg/kg for muscle and 0.00023 mg/L for milk. Concentrations of buparvaquone in milk and tissues were log10-transformed for analysis using multivariate models.. In healthy cows, concentrations of buparvaquone in milk declined with time post-treatment (p<0.001), but were above the LOD in 11 of 25 cows at Day 35. Concentration in milk was higher one day after treatment in cows treated with Butalex than in cows treated with Bupaject, but not different thereafter (p=0.007). Concentrations of buparvaquone in muscle were below the LOD for four of five animals at Day 119 and for all animals by Day 147, but were above the LOD at the injection site of one cow, and in the liver of three cows at Day 328. Tissue concentrations did not differ with formulation nor was there a formulation by time interaction (p>0.3). Concentrations of buparvaquone in the milk of clinically affected animals were not different from those of healthy animals at 1 and 21 days post-treatment (p=0.72). Between 21 and 25 days post-treatment concentrations were below the LOD in 9/14 milk samples from clinically affected cows.. Detectable concentrations of buparvaquone were found in the milk of some cows for at least 35 days and in the liver and injection site of some cows until at least 328 days after injection. There were no biologically meaningful differences in milk or tissue concentrations between the formulations, or in the milk concentrations for cows that were clinically affected compared with those that were healthy at the time of treatment.

Topics: Animals; Antiprotozoal Agents; Cattle; Female; Injections, Intramuscular; Liver; Milk; Muscle, Skeletal; Naphthoquinones; Theileriasis

Infectious agents develop intricate mechanisms to interact with host cell pathways and hijack their genetic and epigenetic machinery to change host cell phenotypic states. Among the Apicomplexa phylum of obligate intracellular parasites, which cause veterinary and human diseases, Theileria is the only genus that transforms its mammalian host cells. Theileria infection of bovine leukocytes induces proliferative and invasive phenotypes associated with activated signalling pathways, notably JNK and AP-1 (ref. 2). The transformed phenotypes are reversed by treatment with the theilericidal drug buparvaquone. We used comparative genomics to identify a homologue of the peptidyl-prolyl isomerase PIN1 in T. annulata (TaPIN1) that is secreted into the host cell and modulates oncogenic signalling pathways. Here we show that TaPIN1 is a bona fide prolyl isomerase and that it interacts with the host ubiquitin ligase FBW7, leading to its degradation and subsequent stabilization of c-JUN, which promotes transformation. We performed in vitro and in silico analysis and in vivo zebrafish xenograft experiments to demonstrate that TaPIN1 is directly inhibited by the anti-parasite drug buparvaquone (and other known PIN1 inhibitors) and is mutated in a drug-resistant strain. Prolyl isomerization is thus a conserved mechanism that is important in cancer and is used by Theileria parasites to manipulate host oncogenic signalling.

Topics: Animals; Cattle; Cell Line; Cell Transformation, Neoplastic; Drug Resistance; Host-Parasite Interactions; Humans; Leukocytes; Naphthoquinones; NIMA-Interacting Peptidylprolyl Isomerase; Parasites; Peptidylprolyl Isomerase; Protein Stability; Proto-Oncogene Proteins c-jun; Signal Transduction; SKP Cullin F-Box Protein Ligases; Theileria; Transcription Factor AP-1; Ubiquitination; Xenograft Model Antitumor Assays; Zebrafish

In this study, in vitro anti-leishmanial activity of buparvaquone was evaluated against promastigotes and intracellular amastigotes of Pakistani Leishmania tropica isolate KWH23 in relation to the current standard chemotherapy for leishmaniasis (sodium stibogluconate, sodium stibogluconate, amphotericin B and miltefosine). For buparvaquone, mean % inhibition in intracellular amastigotes at four different concentrations (1.35 µM, 0.51 µM, 0.17 µM and 0.057 µM) was 78%, 44%, 20% and 14% respectively, whereas, against promastigotes it was 89%, 77%, 45% and 35% respectively. IC50 values calculated to estimate the anti-leishmanial activity of buparvaquone against intra-cellular amastigotes and promastigotes was 0.53 µM (95% C.I. = 0.32-0.89) and 0.15 µM (95% C.I. = 0.01-1.84) respectively. Amphotericin B was the most potent in-vitro drug tested, with an IC50 of 0.075 µM (95% C.I. = 0.006-0.907) against promastigotes, and 0.065 µM (95% C.I. = 0.048-0.089) against intra-cellular amastigotes. Amphotericin B was more cytotoxic against THP1 cells, with an IC50 of 0.15 µM (95% C.I. = 0.01-0.95) and an apparent in-vitro therapeutic index of 2.0, than was buparvaquone, with an IC50 of 12.03 µM (95% C.I. = 5.36-26.96) against THP1 cells and a therapeutic index of 80.2. The study proposes that buparvaquone may be further investigated as a candidate drug for treatment of cutaneous leishmaniasis.

Topics: Amphotericin B; Antimony Sodium Gluconate; Antiprotozoal Agents; Cell Line, Tumor; Child; Humans; Inhibitory Concentration 50; Leishmania tropica; Leishmaniasis, Cutaneous; Macrophages; Male; Meglumine; Meglumine Antimoniate; Naphthoquinones; Organometallic Compounds; Pakistan; Parasitic Sensitivity Tests

The naphthoquinone buparvaquone is currently the only drug used against theileriosis. Here, the effects of buparvaquone were investigated in vitro and in an experimental mouse model for Neospora caninum infection. In 4-day proliferation assays, buparvaquone efficiently inhibited N. caninum tachyzoite replication (IC50 = 4.9 nM; IC100 = 100 nM). However, in the long term tachyzoites adapted and resumed proliferation in the presence of 100 nM buparvaquone after 20 days of cultivation. Parasiticidal activity was noted after 9 days of culture in 0.5 µM or 6 days in 1 µM buparvaquone. TEM of N. caninum infected fibroblasts treated with 1 µM buparvaquone showed that the drug acted rather slowly, and ultrastructural changes were evident only after 3-5 days of treatment, including severe alterations in the parasite cytoplasm, changes in the composition of the parasitophorous vacuole matrix and a diminished integrity of the vacuole membrane. Treatment of N. caninum infected mice with buparvaquone (100 mg/kg) either by intraperitoneal injection or gavage prevented neosporosis symptoms in 4 out of 6 mice in the intraperitoneally treated group, and in 6 out of 7 mice in the group receiving oral treatment. In the corresponding controls, all 6 mice injected intraperitoneally with corn oil alone died of acute neosporosis, and 4 out of 6 mice died in the orally treated control group. Assessment of infection intensities in the treatment groups showed that, compared to the drug treated groups, the controls showed a significantly higher parasite load in the lungs while cerebral parasite load was higher in the buparvaquone-treated groups. Thus, although buparvaquone did not eliminate the parasites infecting the CNS, the drug represents an interesting lead with the potential to eliminate, or at least diminish, fetal infection during pregnancy.

Topics: Animals; Antiprotozoal Agents; Cells, Cultured; Coccidiosis; Female; Fibroblasts; Humans; Mice; Mice, Inbred BALB C; Naphthoquinones; Neospora

Buparvaquone (BW 720C) is the major hydroxynaphtoquinone active against tropical theileriosis (Theileria annulata infection). Previous studies showed that buparvaquone, similarly to others hydroxynaphtoquinone, probably acts by binding to cytochrome b (cyt b) inhibiting the electron transport chain in the parasite. Several observations suggested that T. annulata is becoming resistant to buparvaquone in many endemic regions (Tunisia, Turkey and Iran), which may hinder the development of bovine livestock in these areas.. In the present study we sought to determine whether point mutations in T. annulata cytochrome b gene could be associated to buparvaquone resistance. A total of 28 clones were studied in this work, 19 of which were obtained from 3 resistant isolates (ST2/12, ST2/13 and ST2/19) collected at different time after treatment, from a field treatment failure and nine clones isolated from 4 sensitive stocks of T. annulata (Beja, Battan, Jed4 and Sousse). The cytochrome b gene was amplified and sequenced. We identified five point mutations at the protein sequences (114, 129, 253, 262 and 347) specific for the clones isolated from resistant stocks. Two of them affecting 68% (13/19) of resistant clones, are present in the drug-binding site Q02 region at the position 253 in three resistant clones and at the position 262 in 11 out of 19 resistant clones. These two mutations substitute a neutral and hydrophobic amino acids by polar and hydrophilic ones which could interfere with the drug binding capabilities. When we compared our sequences to the Iranian ones, the phylogenetic tree analyses show the presence of a geographical sub-structuring in the population of T. annulata.. Taken together, our results suggest that the cytochrome b gene may be used as a tool to discriminate between different T. annulata genotypes and also as a genetic marker to characterize resistant isolates of T. annulata.

Topics: Animals; Antiprotozoal Agents; Cattle; Cytochromes b; Drug Resistance; Naphthoquinones; Point Mutation; Polymorphism, Single Nucleotide; Protozoan Proteins; Theileria annulata; Theileriasis; Treatment Failure

Theileria annulata, an intracellular parasite of bovine lymphoid cells, induces substantial phenotypic alterations to its host cell including continuous proliferation, cytoskeletal changes and resistance to apoptosis. While parasite induced modulation of host cell signal transduction pathways and NFκB activation are established, there remains considerable speculation on the complexities of the parasite directed control mechanisms that govern these radical changes to the host cell. Our objectives in this study were to provide a comprehensive analysis of the global changes to host cell gene expression with emphasis on those that result from direct intervention by the parasite. By using comparative microarray analysis of an uninfected bovine cell line and its Theileria infected counterpart, in conjunction with use of the specific parasitacidal agent, buparvaquone, we have identified a large number of host cell gene expression changes that result from parasite infection. Our results indicate that the viable parasite can irreversibly modify the transformed phenotype of a bovine cell line. Fifty percent of genes with altered expression failed to show a reversible response to parasite death, a possible contributing factor to initiation of host cell apoptosis. The genes that did show an early predicted response to loss of parasite viability highlighted a sub-group of genes that are likely to be under direct control by parasite infection. Network and pathway analysis demonstrated that this sub-group is significantly enriched for genes involved in regulation of chromatin modification and gene expression. The results provide evidence that the Theileria parasite has the regulatory capacity to generate widespread change to host cell gene expression in a complex and largely irreversible manner.

Topics: Animals; Cattle; Cell Differentiation; Cell Line, Tumor; Cell Proliferation; Cell Survival; Gene Expression Regulation; Host-Parasite Interactions; Leukocytes; Lymphoma, Non-Hodgkin; Naphthoquinones; Theileria annulata; Transcription, Genetic

Our efforts are concerned with identifying features of incomplete malignant transformation caused by non viral pathogens. Theileria parva (T. parva) is a tick-transmitted protozoan parasite that can cause a fatal lymphoproliferative disease in cattle. The T. parva-infected lymphocytes display a transformed phenotype and proliferate in culture media like the other tumor cells, however those cells will return to normal after antiprotozoal treatment reflecting the incomplete nature of transformation. To identify signaling pathways involved in this form of transformation of T. parva-infected cells, we screened a library of anticancer compounds. Among these, TIBC, a specific inhibitor of MDM2, markedly inhibited proliferation of T. parva-infected lymphocytes and promoted apoptosis. Therefore we analyzed MDM2 function in T. parva-infected cells. Several T. parva-infected cell lines showed increased expression level of MDM2 with alternatively spliced isoforms compared to the lymphoma cells or ConA blasts. In addition, buparvaquone affected MDM2 expression in T. parva transformed cells. Moreover, p53 protein accumulation and function were impaired in T. parva-infected cells after cisplatin induced DNA damage despite the increased p53 transcription level. Finally, the treatment of T. parva-infected cells with boronic-chalcone derivatives TIBC restored p53 protein accumulation and induced Bax expression. These results suggest that the overexpression of MDM2 is closely linked to the inhibition of p53-dependent apoptosis of T. parva-infected lymphocytes. Aberrant expression of host lymphocyte MDM2 induced by cytoplasmic existence of T. parva, directly and/or indirectly, is associated with aspects of this type of transformation of T. parva-infected lymphocytes. This form of transformation shares features of oncogene induced malignant phenotype acquisition.

Topics: Amino Acid Sequence; Animals; Apoptosis; bcl-2-Associated X Protein; Cattle; Cell Line; Cell Transformation, Neoplastic; Cisplatin; DNA Damage; Enzyme Activation; Lymphocyte Activation; Molecular Sequence Data; Naphthoquinones; NF-kappa B; Protein Isoforms; Proto-Oncogene Proteins c-mdm2; Signal Transduction; T-Lymphocytes; Theileria parva; Tumor Suppressor Protein p53

The objective of this study was to develop a novel liposomal formulation, containing phosphatidylserine (PS), of buparvaquone (BPQ) and to evaluate its in vivo effectiveness in Leishmania (L.) infantum chagasi-infected hamsters. The activity of BPQ was evaluated against both the promastigote forms of different Leishmania species and the intracellular amastigotes of L. (L.) infantum chagasi. Buparvaquone was entrapped in PS-liposomes (BPQ-PS-LP), and the drug was quantified by ultra-high-performance liquid chromatography. The treatment was quantified by detecting the RNA of the living amastigotes in the spleen and the liver by real-time PCR. In vitro assays with L. (L.) infantum chagasi intracellular amastigotes were performed in peritoneal macrophages for the evaluation of the 50% inhibitory concentration (IC(50)). BPQ-PS-LP at 0.33 mg/kg/day for eight consecutive days reduced the number of amastigotes by 89.4% (P<0.05) in the spleen and by 67.2% (P>0.05) in the liver, compared to 84.3% (P<0.05) and 99.7% (P<0.05), respectively, following Glucantime® treatment at 50 mg/kg/day. Free BPQ at 20 mg/kg/day failed to treat the hamsters when compared to the untreated group. BPQ was significantly (P<0.05) selective against L. (L.) infantum chagasi intracellular amastigotes, with an IC(50) value of 1.5 μM; no in vitro mammalian cytotoxicity could be detected. Other cutaneous species were also susceptible to BPQ, with IC(50) values in the range 1-4 μM. BPQ-PS-LP caused a significant reduction in the parasite burden at a 60-fold lower dose than did the free BPQ. These results show the potential of PS-liposome formulations for the successful targeted delivery of BPQ in visceral leishmaniasis.

Topics: Animals; Antiprotozoal Agents; Cell Line; Cells, Cultured; Cricetinae; Disease Models, Animal; Humans; Inhibitory Concentration 50; Leishmania infantum; Leishmaniasis, Visceral; Liposomes; Macaca mulatta; Macrophages, Peritoneal; Male; Mesocricetus; Mice; Mice, Inbred BALB C; Naphthoquinones; Phosphatidylserines

Theileriosis is an economically important haemoprotozoal disease with high morbidity and mortality in cattle. Buparvaquone is very effective in the treatment of Theileria infections in cattle. The present study reported an outbreak of bovine tropical theileriosis in Fars Province, southern Iran with buparvaquone treatment failure associated with mutations in drug-binding sites of its causative agent. The infected animals (n=8) exhibited poor condition, fever, anemia, rough coat and superficial lymph node enlargement. Both blood smears and lymph nodes punctures were positive and further molecular examination revealed that these animals were infected with Theileria annulata. Death occurred in seven of the eight infected animals in spite of the buparvaquone treatment. At molecular study, two types of important single-base mutations were observed in the cytochrome b gene of the parasite. These changes resulted in amino acid mutations in the parasite cytochrome b from serine (AGT) 109 to glycine (GGT) for the six dead cases and proline (CCT) 233 to serine (TCT) for one dead case within strongly Q(o) drug-binding sites. In contrast, neither of these mutations was found in the parasite cytochrome b for the buvarvaquone-treated animal. It seems that these mutation sites are associated with resistance to buparvaquone, a hydroxynaphthoquinone compound.

Topics: Animals; Antiprotozoal Agents; Cattle; Cytochromes b; Dairying; Drug Resistance; Female; Gene Expression Regulation; Naphthoquinones; Point Mutation; Theileria annulata; Theileriasis

Four hand-reared, naïve roan antelope, 4 months of age, were exposed to naturally infected pasture on a game farm in Mpumalanga Province, South Africa, where roan are known to die from theileriosis. Various clinical parameters were recorded during this period. The predominant ticks parasitising these animals at the time (January to February), were Rhipicephalus appendiculatus and Rhipicephalus evertsi evertsi adults. After a period of 5 weeks the animals developed signs of clinical theileriosis and were treated with buparvaquone to prevent mortality. Primary hyperplasia of the local draining lymph nodes (Lnn. anorectales) near the feeding site of adult R. evertsi evertsi indicated possible transmission of Theileria sp. (sable) by this tick species. After recovery from theileriosis, these animals were confirmed carriers of Theileria sp. (sable) by PCR (polymerase chain reaction) and DNA probe analysis. Laboratory-bred larvae and nymphs of R. evertsi evertsi and R. appendiculatus respectively, were fed on the ears of these roan antelope. Salivary glands from moulted and prefed adult ticks of each species were dissected and stained for Theileria spp., and the PCR and DNA probe applied to a representative batch of dissected glands. R. appendiculatus adults collected from grass in infected camps were also dissected after prefeeding them on rabbits. Salivary glands of both tick species showed infected acini on staining and were also positive for Theileria sp. (sable) only, on multiprotozoal PCR-screening analysis. There was no statistical significant difference between the infection rate and the intensity of infection between the two tick species. R. appendiculatus ticks collected from grass were also PCR-positive for Theileria sp. (sable).

Topics: Animals; Animals, Wild; Antelopes; Antiprotozoal Agents; DNA, Protozoan; Male; Naphthoquinones; Polymerase Chain Reaction; Rhipicephalus; Salivary Glands; South Africa; Theileria; Theileriasis; Tick Infestations

The aim of this study was to prepare a lipid-based self-microemulsifying drug delivery system (SMEDDS) to increase the solubility and oral bioavailability of a poorly water-soluble compound, buparvaquone (BPQ).. The solubility of BPQ was determined in various vehicles, and pseudo-ternary phase diagrams were constructed to determine the microemulsion region. A series of formulations with different compositions were selected in the microemulsion region for assessment of self-emulsification time and droplet size. The optimized SMEDDS formulation was used for in vitro dissolution and pharmacokinetic studies in rabbits.. The optimum formulation of SMEDDS consisted of Capryol 90 (9.82%), Cremophor EL (70.72%), Labrasol (17.68%), and BPQ (1.78%). Emulsification time and the mean droplet size were found to be 1 minute and 18.0 +/- 0.25 nm, respectively, for the optimum formulation. The cumulative percentage of drug released in 90 minutes was 100% in both SGF and SIF. The calculated absolute oral bioavailability for BPQ was found to be 40.10%.. The optimum SMEDDS formulation was increased the rate and extent of absorption of BPQ. The formulation is suitable for oral administration of BPQ. It would be useful to conduct efficacy studies of BPQ in diseased animal models and subsequently for toxicokinetics studies.

Topics: Animals; Chemistry, Pharmaceutical; Drug Delivery Systems; Drug Evaluation, Preclinical; Emulsifying Agents; Male; Naphthoquinones; Rabbits

The present study describes an outbreak of tropical theileriosis cases refractory to buparvaquone treatment, which occurred in a small-size dairy farm in Tunisia. Out of seven treated cows, four died in spite of repeated buparvaquone injections (2.5 and 5 mg kg(-1)) and the monitoring of the affected cows showed no improvement of the course of the disease with a consistent decrease in the haematocrit, the persistence of fever and an increased parasitaemia after treatment. Ticks were fed on a calf experimentally infected with one isolate established in culture from one of the cases and the resultant infected ticks ground up to generate a supernatant infected with the potentially resistant stock. This was used to experimentally infect three calves, and the clinical observations, post-buparvaquone treatment, showed an absence of the usual effect of buparvaquone treatment on the parasite Theileria annulata, such as the rapid decline of schizont index and parasitaemia and a rapid recovery from the disease. These results confirmed for the first time the occurrence of resistance to buparvaquone in the protozoan T. annulata.

Topics: Animals; Antiprotozoal Agents; Cattle; Dairying; Disease Outbreaks; Drug Resistance; Hematocrit; Naphthoquinones; Parasitemia; Schizonts; Theileria annulata; Theileriasis; Treatment Failure; Tunisia

The function of the p53 protein as the central effector molecule of the p53 apoptotic pathway was investigated in a reversible model of epigenetic transformation. The infection of bovine leukocytes by the intracellular protozoan parasite Theileria annulata results in parasite-dependent transformation and proliferation of the host cells. We found p53 to be largely localized in the host cell cytoplasm and associated with the parasite membrane of isolated schizonts. Curing infected cells of the parasite with the theilericidal drug buparvaquone resulted in a time-dependent translocation of p53 into the host cell nucleus and the upregulation of the proapoptotic Bax and Apaf-1 and the downregulation of the anti-apoptotic Bcl-2 proteins. Although buparvaquone treatment led to apoptosis of the host cell, inhibition of either p53 or Bax significantly reduced buparvaquone-induced apoptosis of the transformed cells. Thus, the p53 apoptotic pathway of host cells is not induced by infection and transformation with Theileria by a mechanism involving cytoplasmic sequestration of p53. The close association of host cell p53 with the parasite membrane implies that the parasite either interacts directly with p53 or mediates cytoplasmic sequestration of p53 by interacting with other host cell proteins regulating p53 localization.

Topics: Animals; Antiprotozoal Agents; bcl-2-Associated X Protein; Cattle; Cell Nucleus; Cell Survival; Concanavalin A; DNA, Complementary; Gene Amplification; Kinetics; Leukocytes; Naphthoquinones; Theileria annulata; Theileriasis; Transcription, Genetic; Tumor Suppressor Protein p53

The acute toxicities of five naphthoquinone compounds to Photobacterium phosphoreum were determined. We evaluated the mechanism of toxicity using the structure-activity relationship technique. The results showed that some factors, including the species of substituents, shape/size of molecule and oil-water partition coefficient (log P) played the important roles in the interaction between the naphthoquinones and the target. Among of these, the toxicities of Atovaquone and Buparvaquone were lower than the other naphthoquinones we tested because of the alkyl-substitution with the bigger volume and strong hydrophobicity. Conversely, Menadione had the highest toxicity because of the appropriate log P and shape/size of molecule resulting in the easier interaction with the target.

Topics: Antiprotozoal Agents; Atovaquone; Microbial Sensitivity Tests; Naphthoquinones; Photobacterium; Structure-Activity Relationship; Toxicity Tests, Acute

The tick-borne protozoan parasite Theileria annulata causes a debilitating disease of cattle called Tropical Theileriosis. The parasite predominantly invades bovine macrophages (m phi) and induces host cell transformation by a mechanism that has not been fully elucidated. Infection is associated with loss of characteristic m phi functions and phenotypic markers, indicative of host cell de-differentiation. We have investigated the effect of T. annulata infection on the expression of the m phi differentiation marker c-maf. The up-regulation of c-maf mRNA levels observed during bovine monocyte differentiation to m phi was suppressed by T. annulata infection. Furthermore, mRNA levels for c-maf and the closely related transcription factor mafB were significantly lower in established T. annulata-infected cell-lines than in bovine monocyte-derived m phi. Treatment of T. annulata-infected cells with the theileriacidal drug buparvaquone induced up-regulation of c-maf and mafB, which correlated with altered expression of down-stream target genes, e.g. up-regulation of integrin B7 and down-regulation of IL12A. Furthermore, T. annulata infection is associated with the suppression of the transcription factors, Pu.1 and RUNX1, and colony stimulating factor 1 receptor (CSF1R) which are also involved in the regulation of monocyte/m phi differentiation. We believe these results provide the first direct evidence that T. annulata modulates the host m phi differentiation state, which may diminish the defence capabilities of the infected cell and/or promote cell proliferation. Musculoaponeurotic fibrosarcoma oncogene (MAF) transcription factors play an important role in cell proliferation, differentiation and survival; therefore, regulation of these genes may be a major mechanism employed by T. annulata to survive within the infected m phi.

Topics: Animals; Antiprotozoal Agents; Cattle; Cattle Diseases; Cell Dedifferentiation; Cell Differentiation; Host-Parasite Interactions; Macrophages; Maf Transcription Factors; Naphthoquinones; Phenotype; Theileria annulata; Theileriasis

The aim of this study was to examine the efficacy of buparvaquone (Buparvon, ALKE, Istanbul) in the treatment of theileriosis in cattle. The causative agent T. annulata causes direct and indirect gross economical loss in Turkey. Theileriosis was microscopically diagnosed by determining the presence of piroplasms in erythrocytes in thin blood smears stained with Giemsa stain. Buparvaquone was administered intramuscularly to the cattle with theileriosis using a single dose of 2.5 mg/kg. Clinical and laboratory examinations in cattle with theileriosis were carried out before and on the first, third and seventh days after treatment. As a result, it was concluded that a single deep intramuscular dose of 2.5 mg/kg buparvaquone was effective in the treatment of cattle which are naturally infected with T. annulata. However, further studies are needed using control groups of the same breed and age including suitable numbers of naturally infected and experimentally infected cattle.

Topics: Animals; Antiprotozoal Agents; Cattle; Erythrocytes; Injections, Intramuscular; Naphthoquinones; Theileriasis; Treatment Outcome

A simple, sensitive and specific reversed-phase high-performance liquid chromatographic method with UV detection at 251 nm was developed for quantitation of buparvaquone (BPQ) in human and rabbit plasma. The method utilizes 250 microL of plasma and sample preparation involves protein precipitation followed by solid-phase extraction. The method was validated on a C18 column with mobile phase consisting of ammonium acetate buffer (0.02 m, pH 3.0) and acetonitrile in the ratio of 18:82 (v/v) at a flow rate of 1.1 mL/min. The calibration curves were linear (correlation coefficient>or=0.998) in the selected range. The method is specific and sensitive with limit of quantitation of 50 ng/mL for BPQ. The validated method was found to be accurate and precise in the working calibration range. Stability studies were carried out at different storage conditions and BPQ was found to be stable. Partial validation studies were carried out using rabbit plasma and intra- and inter-day precision and accuracy were within 7%. This method is simple, reliable and can be routinely used for preclinical pharmacokinetic studies for BPQ.

Topics: Animals; Antiprotozoal Agents; Chromatography, High Pressure Liquid; Humans; Molecular Structure; Naphthoquinones; Rabbits; Reproducibility of Results; Solid Phase Extraction; Spectrophotometry, Ultraviolet

A simple, sensitive and specific reversed phase high performance liquid chromatographic (RP-HPLC) method with UV detection at 251 nm was developed for simultaneous quantitation of buparvaquone (BPQ), atenolol, propranolol, quinidine and verapamil. The method was applicable in rat in situ intestinal permeability study to assess intestinal permeability of BPQ, a promising lead compound for Leishmania donovani infections. The method was validated on a C-4 column with mobile phase comprising ammonium acetate buffer (0.02 M, pH 3.5) and acetonitrile in the ratio of 30:70 (v/v) at a flow rate of 1.0 ml/min. The retention times for atenolol, quinidine, propranolol, verapamil and BPQ were 4.30, 5.96, 6.55, 7.98 and 8.54 min, respectively. The calibration curves were linear (correlation coefficient > or =0.996) in the selected range of each analyte. The method is specific and sensitive with limit of quantitation of 15 microg/ml for atenolol, 0.8 microg/ml for quinidine, 5 microg/ml for propranolol, 10 microg/ml for verapamil and 200 ng/ml for BPQ. The validated method was found to be accurate and precise in the working calibration range. Stability studies were carried out at different storage conditions and all the analytes were found to be stable. This method is simple, reliable and can be routinely used for accurate permeability characterization.

Topics: Animals; Antiprotozoal Agents; Atenolol; Buffers; Chromatography, High Pressure Liquid; Drug Stability; Hydrogen-Ion Concentration; Intestinal Mucosa; Male; Molecular Structure; Naphthoquinones; Perfusion; Permeability; Propranolol; Quinidine; Rats; Rats, Sprague-Dawley; Reproducibility of Results; Sensitivity and Specificity; Spectrophotometry, Ultraviolet; Verapamil

As the part of a study to develop buparvaquone (BPQ) formulations for the treatment of cutaneous leishmaniasis, the topical delivery of BPQ and one of its prodrugs from a range of formulations was evaluated. In previous studies, BPQ and its prodrugs were shown to be potent antileishmanials in-vitro, with ED50 values in the nanomolar range. 3-Phosphono-oxymethyl-buparvaquone (3-POM-BPQ) was the most potent antileishmanial and was chosen, together with the parent drug, for further investigation. The ability of the parent and prodrug formulations to cross human and murine skin was tested in-vitro using the Franz diffusion cells. Formulations intended for topical application containing either BPQ or 3-POM-BPQ were developed using excipients that were either acceptable for topical use (GRAS or FDA inactive ingredients) or currently going through the regulatory process. BPQ was shown to penetrate both human epidermal membranes and full thickness BALB/c skin from a range of formulations (gels, emulsions). Similarly, 3-POM-BPQ penetrated full-thickness BALB/c skin from several gel formulations. In-vitro binding studies showed that BPQ bound melanin in a dose-dependent manner and preferably bound to delipidized skin over untreated BALB/c skin (on a weight to weight basis). The results confirm that BPQ and its prodrug 3-POM-BPQ can penetrate the skin from several formulations, making them potentially interesting candidates for further investigation of topical formulations using in-vivo models of cutaneous leishmaniasis.

Topics: Administration, Cutaneous; Animals; Antiprotozoal Agents; Chemistry, Pharmaceutical; Ethanol; Female; Humans; In Vitro Techniques; Leishmaniasis, Cutaneous; Melanins; Mice; Mice, Inbred BALB C; Myristates; Naphthoquinones; Organophosphates; Polyethylene Glycols; Prodrugs; Propylene Glycol; Skin; Skin Absorption

The efficacy of different formulations of the naphthoquinone buparvaquone and two phosphate prodrugs in in vivo models of both visceral and cutaneous leishmaniasis is described.. Several topical formulations of buparvaquone containing acceptable excipients were tested in vivo against Leishmania major cutaneous lesions in BALB/c mice. In vivo studies against Leishmania donovani investigated whether the prodrugs had improved efficacy when compared with buparvaquone.. Both a hydrous gel and water-in-oil emulsion of buparvaquone significantly reduced cutaneous parasite burden (P < 0.05, 22 days post-infection) and lesion size, compared with the untreated control (P < 0.0001, 16 days post-infection). The prodrug 3-phosphonooxymethyl-buparvaquone was formulated into an anhydrous gel and this also significantly reduced parasite burden and lesion size (P < 0.0001, 16 days post-infection). Histology confirmed this efficacy. In the visceral model, both prodrugs were significantly more effective at reducing liver parasite burden than the parent drug, buparvaquone. Buparvaquone-3-phosphate was shown to be the most effective antileishmanial (P = 0.0003, 50 mg buparvaquone molar equivalent/kg/day five times), reducing the liver parasite burden by approximately 34% when compared with the untreated control.. The introduction of a topical formulation, such as buparvaquone (or its prodrug), would be a significant advance for the treatment of simple cutaneous lesions. In particular, the avoidance of the parenteral antimonials would greatly increase patient compliance and reduce treatment costs.

Topics: Animals; Antiprotozoal Agents; Chemistry, Pharmaceutical; Female; Leishmania donovani; Leishmania major; Leishmaniasis, Cutaneous; Leishmaniasis, Visceral; Liver; Mice; Mice, Inbred BALB C; Naphthoquinones; Prodrugs; Skin

Evaluation trials of the efficacy of buparvaquone (BUTA-kel KELA Laboratoria, N.V. Belgium), as a treatment of field cases of Theileria parva infection (East Coast fever - ECF) were carried out on 63 cattle in the peri-urban of Dar Es Salaam city, Tanzania, during the period November 2004 to August 2005. Thirty-two cattle (56%) received single-dose treatment (2.5 mg buparvaquone per kg body weight), while two and three-dose treatment with interval(s) of 48 h was given to 33% and 11% of total treated cattle, respectively; 38 cattle (60.3%) were treated at an early stage of the disease, while 25 cattle (39.7%) were treated at an advanced stage of the disease. The rectal body temperature of 90.5% of buparvaquone-treated cattle dropped to normal values (37.5-39.5 degrees C) by day 7 of treatment, and by day 15 of treatment 96.8% of treated cattle showed normal values. Pulmonary signs were observed in 8/68 (11.8%) of total ECF diagnosed cattle and were successfully treated, albeit with parvaquone plus frusemide (Fruvexon); were not included in final evaluation of the efficacy of BUTA-kel. The present evaluation trials record a recovery rate of 95.2%. Buparvaquone (BUTA-kel KELA Laboratoria, N.V. Belgium), therefore, records another efficacious and valuable alternative treatment against East Coast fever in Tanzania.

Topics: Animals; Antiprotozoal Agents; Cattle; Cattle Diseases; Female; Male; Naphthoquinones; Tanzania; Theileria parva; Theileriasis; Treatment Outcome

Water-soluble phosphate prodrugs of buparvaquone (1), containing a hydroxynaphthoquinone structure, were synthesized and evaluated in vitro for improved topical and oral drug delivery against cutaneous and visceral leishmaniasis. The successful prodrug synthesis involved a strong base; e.g., sodium hydride. Buparvaquone-3-phosphate (4a) and 3-phosphonooxymethyl-buparvaquone (4b) prodrugs possessed significantly higher aqueous solubilities (>3.5 mg/mL) than the parent drug (

Topics: Administration, Oral; Administration, Topical; Alkaline Phosphatase; Animals; Antiprotozoal Agents; Cricetinae; Female; Humans; Hydrolysis; In Vitro Techniques; Leishmania; Leishmaniasis, Cutaneous; Leishmaniasis, Visceral; Macrophages, Peritoneal; Mice; Naphthoquinones; Organophosphates; Permeability; Prodrugs; Skin; Solubility; Water

Topics: Animals; Anti-Bacterial Agents; Antiprotozoal Agents; Brain Diseases; Cattle; Cattle Diseases; Erythrocytes; Injections, Intramuscular; Male; Naphthoquinones; Oxytetracycline; Polymerase Chain Reaction; Theileria; Theileriasis; Treatment Outcome

Novel oxime derivatives (2, 3 and 5) of buparvaquone (1) and O-methyl-buparvaquone (4) were synthesized and their in vitro activities against Leishmania donovani, the causative agent of visceral leishmaniasis (VL), were determined. Buparvaquone-oxime (2) was also studied as a bioreversible prodrug structure of buparvaquone (1). Buparvaquone-oxime (2) released buparvaquone (1) in vitro when it was incubated with induced rat liver microsomes, which suggests that the oxime-structure is a useful prodrug template for developing novel prodrugs of buparvaquone and other hydroxynaphthoquinones. Moreover, the formation of NO(2)(-) , formed via oxidation of NO, was confirmed during the bioconversion. The release of NO from buparvaquone-oxime (2) may provide an additional therapeutic effect in the treatment of leishmaniasis. Buparvaquone-oxime (2) and buparvaquone-O-methyloxime (3) demonstrated moderate activity against amastigotes of the Leishmania species that causes VL. However, the studied oximes (2, 3) most probably did not release buparvaquone (1) and NO during the present in vitro experiment. Further in vivo studies are needed to verify the biological activity of buparvaquone-oximes in the treatment of leishmaniasis.

Topics: Animals; Antiprotozoal Agents; Leishmania donovani; Leishmaniasis, Visceral; Macrophages; Magnetic Resonance Spectroscopy; Microsomes, Liver; Molecular Structure; Naphthoquinones; Oximes; Rats; Rats, Wistar

The effects of dexamethasone and promethazine on the amelioration of pulmonary oedema in East Coast fever were investigated. The clinical effects of these drugs were further investigated when used in conjunction with the antitheilerial drug, buparvaquone. In the first experiment, 15 crossbred (Friesian x Zebu) steers were divided into four groups. With the exception of the animals in group IV, that served as a control group all the others were infected with Theileria parva sporozoites. On the second day of the febrile reaction, the steers in groups I and II were treated with dexamethasone (0.1 mg/kg) and promethazine (1 mg/kg), respectively. Group III steers served as the infected untreated controls. On the fifth day of the febrile reaction the animals in groups I, II and III were infused intravenously with tattoo ink suspension and 1 h later sacrificed for post-mortem examination and tissue sampling. The clinical picture indicated that both drugs significantly mitigated dyspnoea and the post mortem examination revealed a significant reduction in morphological changes. Tattoo ink particle count reflected a significant (P< 0.01) reduction in vascular leakage in the treated animals, with promethazine being significantly (P < 0.05) more effective than dexamethasone in this respect. In the second experiment, 18 steers were infected with T. parva sporozoites, and then were randomly allotted into three groups each of which contained six animals. After the onset of ECF clinical signs, the animals in the first two groups were treated with buparvaquone in combination with either dexamethasone (group I) or promethazine (group II), and the third group was treated with buparvaquone alone. The results indicated that all the animals in groups I, II and III recovered well and no significant differences were observed in clinical disposition between the groups. Two months later, serum samples were collected from the refractory animals and demonstrated the presence of antibodies against T. parva. When the animals were subsequently artificially challenged with T. parva, none of them succumbed to clinical disease. The same T. parva stabilate stock was used in both experiments and it proved to be infective in a separate batch of steers.

Topics: Animals; Antiprotozoal Agents; Cattle; Cattle Diseases; Dexamethasone; Drug Therapy, Combination; Glucocorticoids; Histamine H1 Antagonists; Male; Naphthoquinones; Promethazine; Pulmonary Edema; Random Allocation; Theileria; Theileriasis; Treatment Outcome

Novel water-soluble phosphate prodrugs (2b-5b) of buparvaquone-oxime (1a) and buparvaquone-O-methyloxime (1b) were synthesized and evaluated in vitro as potential oral prodrugs against leishmaniasis. Buparvaquone-oxime (1a), and most probably also buparvaquone-O-methyloxime (1b), released the parent buparvaquone via a cytochrome P450-catalysed reaction. The prodrugs 2b-5b showed significantly higher aqueous solubilities (>4 mg/ml) than buparvaquone (< or = 0.03 microg/ml) over a pH range of 3.0-7.4. The prodrugs 2b, 3b and 5b rapidly released (t1/2 = 7 min) the corresponding oximes of buparvaquone (1a and 1b), and prodrug 4b at a moderate rate (t1/2 = 22.5 min) in alkaline phosphatase solution in vitro. Prodrug 3b was the most chemically stable in the aqueous solutions over a pH range of 3.0-7.4 (t1/2 > 8 days). Although buparvaquone-oxime (1a) has been shown to undergo a cytochrome P450-catalysed oxidation in liver microsomes to the parent buparvaquone and behave as a novel bioreversible prodrug, its usefulness is limited in oral drug delivery due to its poor aqueous solubility, like buparvaquone itself. Further phosphorylation of an oxime form of buparvaquone significantly increased water solubility, and this novel approach is therefore useful to improve physicochemical properties of drugs containing a ketone functional group.

Topics: Alkaline Phosphatase; Antiprotozoal Agents; Buffers; Drug Design; Hydrolysis; Indicators and Reagents; Lipids; Magnetic Resonance Spectroscopy; Naphthoquinones; Prodrugs; Solubility

Infection of bovine T cells and B cells with the intracellular protozoan parasite Theileria parva induces a transformed phenotype with characteristics comparable to leukemic cells. The transformed phenotype reverts on drug-induced parasite death, and the cured lymphocytes acquire a resting phenotype and eventually die by apoptosis if not further stimulated. Here, we show that both lymphocyte proliferation and activation of the transcription factor AP-1 are mediated by Src-family protein tyrosine kinases (PTKs) in a parasite-dependent fashion. Src-family PTKs are known to be present in glycolipid-enriched microdomains (GEMs), also called lipid rafts, and to be negatively regulated by PTK Csk complexed to tyrosine-phosphorylated transmembrane adapter protein PAG (phosphoprotein associated with GEMs) also called Cbp (Csk-binding protein). We, therefore, purified GEMs from proliferating infected B cells and from growth-arrested cells that had been drug-cured of parasites. Proliferation arrest led to a striking increase of PAG/Cbp expression; correspondingly, the amount of Csk associated with PAG/Cbp in GEMs increased markedly, whereas PTK Hck accumulation in GEM fractions did not alter on growth arrest. We propose that Theileria-induced lymphocyte proliferation and permanent activation of Hck stems from down-regulation of PAG/Cbp and the concomitant constitutive loss of the negative regulator Csk from the GEMs of transformed B cells.

Topics: Animals; Antiprotozoal Agents; B-Lymphocytes; Cattle; Cell Division; Cell Transformation, Neoplastic; CSK Tyrosine-Protein Kinase; Enzyme Activation; Enzyme Inhibitors; Lymphocyte Activation; Membrane Microdomains; Membrane Proteins; Naphthoquinones; Phenotype; Phosphatidylinositol 3-Kinases; Phosphoproteins; Protein-Tyrosine Kinases; Proto-Oncogene Proteins; Proto-Oncogene Proteins c-hck; Pyrimidines; Signal Transduction; src-Family Kinases; Theileria parva; Transcription Factor AP-1

New Cu(II), Ni(II), Co(II), Fe(II), and Mn(II) metal complexes of buparvaquone [3-trans(4-tert.-butylcyclohexyl)methyl-2-hydroxy-1,4-naphthoquione] (L1H) have been synthesized and characterized using IR, electron paramagnetic resonance (EPR) spectroscopy, microanalytical methods and single crystal X-ray diffraction methods. The single crystal structures were determined for ligand L1H [space group P-1 with a=6.2072(14) A, b=10.379 (2) A, c=13.840 (3) A, V=878.7(3) A(3), Z=2, D(calcd.)=1.234 mg/m(3)] and copper complex [Cu(L1)(2)(C(2)H(5)OH)(2)] C1 [space group I2/a with a=17.149(14) A, b=9.4492(8) A, c=26.946(3) A, V=4335.3(7)A(3), Z=4, D(calcd.)=1.233 mg/m(3)]. All the metal complexes along with the parent ligand have been studied for their electrochemical properties using cyclic voltammetric techniques. The compounds were tested for their in vitro antimalarial activity against Plasmodium falciparum strains. A correlation between the antimalarial activity and the redox property of these complexes is presented. The copper complex C1 exhibits significantly higher growth inhibitory activity both in vitro and in vivo than the parent ligand.

Topics: Animals; Antimalarials; Crystallography, X-Ray; Electrochemistry; Metals; Models, Molecular; Naphthoquinones; Oxidation-Reduction; Plasmodium falciparum; Spectrophotometry, Infrared

Lymphocyte homeostasis is regulated by mechanisms that control lymphocyte proliferation and apoptosis. Activation-induced cell death is mediated by the expression of death ligands and receptors, which, when triggered, activate an apoptotic cascade. Bovine T cells transformed by the intracellular parasite Theileria parva proliferate in an uncontrolled manner and undergo clonal expansion. They constitutively express the death receptor Fas and its ligand, FasL but do not undergo apoptosis. Upon elimination of the parasite from the host cell by treatment with a theilericidal drug, cells become increasingly sensitive to Fas/FasL-induced apoptosis. In normal T cells, the sensitivity to death receptor killing is regulated by specific inhibitor proteins. We found that anti-apoptotic proteins such as cellular (c)-FLIP, which functions as a catalytically inactive form of caspase-8, and X-chromosome-linked inhibitor of apoptosis protein (IAP) as well as c-IAP, which can block downstream executioner caspases, are constitutively expressed in T. parva-transformed T cells. Expression of these proteins is rapidly down-regulated upon parasite elimination. Antiapoptotic proteins of the Bcl-2 family such as Bcl-2 and Bcl-x(L) are also expressed but, in contrast to c-FLIP, c-IAP, and X-chromosome-linked IAP, do not appear to be tightly regulated by the presence of the parasite. Finally, we show that, in contrast to the situation in tumor cells, the phosphoinositide 3-kinase/Akt pathway is not essential for c-FLIP expression. Our findings indicate that by inducing the expression of antiapoptotic proteins, T. parva allows the host cell to escape destruction by homeostatic mechanisms that would normally be activated to limit the continuous expansion of a T cell population.

Topics: Animals; Antiprotozoal Agents; Apoptosis; Carrier Proteins; CASP8 and FADD-Like Apoptosis Regulating Protein; Caspases; Cattle; Cell Line, Transformed; Enzyme Activation; Fas Ligand Protein; fas Receptor; Homeostasis; Host-Parasite Interactions; Immunity, Innate; Inhibitor of Apoptosis Proteins; Intracellular Signaling Peptides and Proteins; Ligands; Membrane Glycoproteins; Naphthoquinones; Protein Biosynthesis; Proteins; T-Lymphocyte Subsets; Theileria parva; Up-Regulation; X-Linked Inhibitor of Apoptosis Protein

The intracellular parasite Theileria parva (T. parva) can infect bovine B and T-lymphocytes. T. parva-infected cells become transformed, and they survive and proliferate independently of exogenous growth factors. In vivo the uncontrolled cellular proliferation associated with lymphocyte transformation underlies the pathogenesis of the disease called East Coast Fever. The transformed state of parasitised cells can be reversed upon elimination of the parasite by specific theilericide drugs. In this study we found that elimination of the parasite by buparvaquone induces apoptosis of transformed B and CD8(+) T-lymphocytes. Apoptosis is accompanied by the activation of caspase 9 and caspase 3 and processing of poly(ADP ribose) polymerase and is inhibited by Z-VAD a general caspase inhibitor. Based on these observations, we propose that the lack of activation of a caspase 9 > caspase 3 > poly(ADP ribose) polymerase pathway is important and protects T. parva-transformed cells from spontaneous apoptosis.

Topics: Amino Acid Chloromethyl Ketones; Animals; Antiprotozoal Agents; Apoptosis; Caspase 3; Caspase 9; Caspase Inhibitors; Caspases; Cattle; Cell Death; Cysteine Proteinase Inhibitors; Enzyme Activation; Naphthoquinones; Poly(ADP-ribose) Polymerases; T-Lymphocytes; Theileria parva; Theileriasis

Parasites have evolved a plethora of mechanisms to ensure their propagation and evade antagonistic host responses. The intracellular protozoan parasite Theileria is the only eukaryote known to induce uncontrolled host cell proliferation. Survival of Theileria-transformed leukocytes depends strictly on constitutive nuclear factor kappa B (NF-kappaB) activity. We found that this was mediated by recruitment of the multisubunit IkappaB kinase (IKK) into large, activated foci on the parasite surface. IKK signalosome assembly was specific for the transforming schizont stage of the parasite and was down-regulated upon differentiation into the nontransforming merozoite stage. Our findings provide insights into IKK activation and how pathogens subvert host-cell signaling pathways.

Topics: Active Transport, Cell Nucleus; Animals; Antiprotozoal Agents; Apoptosis; Cattle; Cell Cycle; Cell Division; Cell Line, Transformed; Cell Nucleus; Down-Regulation; I-kappa B Kinase; I-kappa B Proteins; Leukocytes; Microscopy, Confocal; Naphthoquinones; NF-kappa B; Phosphorylation; Protein Serine-Threonine Kinases; Signal Transduction; Theileria

The poorly soluble drug buparvaquone is used in experimental clinics against the gastrointestinal persisting parasite Cryptosporidium parvum. It was produced as nanosuspension by high pressure homogenisation. Main advantages of nanosuspensions (amongst others) are their increase of saturation solubility and dissolution velocity, improving the bioavailability of drugs. The buparvaquone nanosuspension had a bulk population of about 600 nm (analysed by photon correlation spectroscopy (PCS)). The additional analysis performed with laser diffraction showed that only a very small content of microparticles occurred, which is, for the special features of nanosuspensions, negligible because they were still below 3 microm. Another feature of nanosuspensions is the adhesion properties to surfaces, e.g. mucosa. To further increase the adhesion time of the buparvaquone nanosuspension to C. parvum, the nanosuspension was formulated with hydrogels made from mucoadhesive polymers, e.g. different types of Carbopol and chitosan. Only a small increase of the particle size of the bulk population occurred directly after the incorporation of buparvaquone nanosuspension into the hydrogels. The nanosuspension/hydrogel systems were physically long-term stable over a period of 6 months as indicated by the unchanged particle sizes.

Topics: Adhesives; Antiprotozoal Agents; Drug Stability; Hydrogels; Microscopy, Electron; Nanotechnology; Naphthoquinones; Particle Size; Technology, Pharmaceutical

A method for the rapid screening of drugs targeting the bioenergetic metabolism of Leishmania spp. was developed. The system is based on the monitoring of changes in the intracellular ATP levels of Leishmania donovani promastigotes that occur in vivo, as assessed by the luminescence produced by parasites transfected with a cytoplasmic form of Phothinus pyralis luciferase and incubated with free-membrane permeable D-luciferin analogue D-luciferin-[1-(4,5-dimethoxy-2-nitrophenyl) ethyl ester]. A significant correlation was obtained between the rapid inhibition of luminescence with parasite proliferation and the dissipation of changes in mitochondrial membrane potential (DeltaPsi(m)) produced by buparvaquone or plumbagin, two leishmanicidal inhibitors of oxidative phosphorylation. To further validate this test, a screen of 14 standard leishmanicidal drugs, using a 50 microM cutoff, was carried out. Despite its semiquantitative properties and restriction to the promastigote stage, this test compares favorably with other bioenergetic parameters with respect to time and cell number requirements for the screening of drugs that affect mitochondrial activity.

Topics: Adenosine Triphosphate; Animals; Antiprotozoal Agents; Cell Division; Cell Line; Dose-Response Relationship, Drug; Energy Metabolism; Firefly Luciferin; Kinetics; Leishmania donovani; Luciferases; Luminescent Measurements; Membrane Potentials; Mitochondria; Naphthoquinones; Parasitic Sensitivity Tests; Transfection

Bupravaquone is a new naphthoquinone antibiotic against Cryptosporidium parvum and other parasites. It has attracted interest for the treatment of C. parvum infections, because of the lack of a drug in the treatment of mostly AIDS patients. The bioavailability of bupravaquone is limited when given orally. To overcome the problem of the high elimination rate caused by diarrhoea, typical for C. parvum infections, bupravaquone was formulated as a mucoadhesive nanosuspension, i.e. combining the properties of mucoadhesive drug delivery systems, in this case hydro gels, with nanosuspensions. In this study different polymers/hydro gels were employed to create a prolonged retention time for the drug in the infected gastrointestinal tract (GIT). The second step to improve the bioavailability of bupravaquone was the formulation as nanosuspension. Therefore various concentrations of bupravaquone with different surfactants were tested. The production of these nanosuspensions was carried out by high pressure homogenisation. In addition to the classical stepwise production, about a new one step production method is described.

Topics: Animals; Antiprotozoal Agents; Chemistry, Pharmaceutical; Chitin; Chitosan; Cryptosporidium parvum; Drug Delivery Systems; Drug Stability; Gels; Naphthoquinones; Particle Size; Suspensions

The efficacy of 5 drugs was tested against experimental Babesia felis infection in domestic cats. Two of the drugs, rifampicin and a sulphadiazine-trimethoprim combination, appeared to have an anti-parasitic effect, but were inferior to primaquine. The other 3 drugs, buparvaquone, enrofloxacin and danofloxacin, had no significant anti-babesial effect.

Topics: Animals; Anti-Infective Agents; Antiprotozoal Agents; Babesiosis; Cat Diseases; Cats; Drug Combinations; Enrofloxacin; Fluoroquinolones; Hematocrit; Naphthoquinones; Parasitemia; Primaquine; Quinolones; Rifampin; Sulfadiazine; Trimethoprim

Three antihaematozoal drugs were tested for the treatment of pigeons naturally infected with Haemoproteus columbae. Butalex (Buparvaquone) was found effective against the parasite either by using the recommended dose (R. D.) or the double (D. D.) dosis. The R. D. of Berenil (Diminazene aceturate) was not effective while the D. D. reduced the number of gametocytes circulating in the infected blood. Triquine was found very toxic to the pigeons both the R. D. and the D. D.

Topics: Animals; Animals, Domestic; Antiprotozoal Agents; Bird Diseases; Coccidiosis; Columbidae; Diminazene; Haemosporida; Naphthoquinones; Quinolinium Compounds

Plasma levels of vitamins A, E, beta carotene, both plasma and erythrocyte glutathione peroxidase (GSHPx), lipid peroxidation (LPO) and reduced glutathione (GSH) were investigated in cattle naturally infected with Theileria annulata and treated with buparvaquone. There were two groups each containing 30 cattle. Naturally infected cattle were used in the second group. Buparvaquone (2.5 mg/kg body weight) was administered to animals in the second group. Blood samples were taken from control animals, and immediately before treatment, and from animals 10 days after the injection of buparvaquone. Detection of the infected animals was carried out by blood smears. Plasma vitamins A, E, beta carotene, both plasma and erythrocyte GSHPx, LPO and GSH levels were determined. The levels of LPO in plasma and erythrocyte samples were significantly (P < 0.05, P < 0.01) higher after treatment than in either control animals or before treatment. Plasma levels of antioxidant vitamins, vitamin E and beta carotene were significantly (P < 0.05, P < 0.01) lower after treatment than in either control animals or before treatment, while the vitamin E level was found to be higher before treatment than in either the control group or animals after treatment (P < 0.05, P < 0.01). The levels of vitamin A in plasma and the activity of GSHPx and GSH in both plasma and erythrocytes in control animals after and before treatment did not differ significantly. In conclusion, we observed that there was a decreased plasma level of vitamin E and beta carotene and an increased level of LPO in cattle treated with buparvaquone. Buparvaquone might function in the treatment of Theileria annulata by forming free radicals.

Topics: Animals; Antiprotozoal Agents; beta Carotene; Cattle; Cattle Diseases; Erythrocytes; Glutathione; Glutathione Peroxidase; Lipid Peroxidation; Naphthoquinones; Reference Values; Theileriasis; Vitamin A; Vitamin E; Vitamins

Two trials were conducted to compare the efficacy of parvaquone and buparvaquone for the treatment of naturally acquired East Coast fever (ECF, Theileria parva infection) which, if untreated, is almost invariably fatal in European breeds of cattle. In the first trial 28 naive cattle were exposed in a paddock infested with ticks carrying a virulent form of the disease. Twelve were treated with each drug when they developed clinical ECF. All 24 cattle were cured. In the second study, 100 cases of ECF occurring naturally on farms in Kenya were treated, 50 with each drug. Parvaquone cured 44 (88%) buparvaquone cured 45 (90%). Intercurrent infections, predominantly anaplasmosis and bacterial pneumonia or scour, were treated specifically. It is concluded that parvaquone and buparvaquone are similarly effective in curing ECF and cure rates are maximised by accurate diagnosis and prompt treatment of both ECF and intercurrent infections.

Topics: Administration, Topical; Animals; Antimalarials; Biopsy; Cattle; Female; Fever; Injections, Intramuscular; Insecticides; Kenya; Male; Naphthoquinones; Nitriles; Parasitemia; Pyrethrins; Random Allocation; Theileriasis; Tick Infestations

Buparvaquone (Butalex), a therapeutic for theileriosis, has been shown to have anti-leishmanial activity in vitro. Seven dogs with symptomatic, parasitologically positive, canine visceral leishmaniosis were treated with Butalex at 5 mg kg(-1) body weight using four doses over 12 days. Two animals showed minor clinical improvement (growth of healthy hair) but all remained parasitologically positive and disease progression was not halted.

Topics: Animals; Antiprotozoal Agents; Dog Diseases; Dogs; Female; Injections, Intramuscular; Leishmaniasis, Visceral; Male; Naphthoquinones

Recovery from primary infection of Theileria annulata results in the development of a persistent carrier state in the vertebrate host. The carrier state is of great importance in the maintenance of the life cycle by alternate tick/cattle challenge and both contributes to and may be necessary for maintenance of immunity. Therefore, an accurate determination of carrier animals could be useful in determining immune status and may allow the necessary control measures to be implemented. Detailed information on the carrier state of animals following immunization with attenuated cell lines is lacking. In this study, relationship between immune response, persistence of the parasite, and the antibody response has been investigated. Calves were infected with T. annulata sporozoites, low passage (non-attenuated) or high passage (attenuated, vaccine) cell lines and later challenged with a lethal dose of heterologous sporozoites. The presence and persistence of the parasite were monitored by PCR using primers derived from genes coding for ssrRNA and a 30 kDa major merozoite surface protein, by Giemsa stained blood smears to detect the presence of piroplasms and also by attempting to establish infected mononuclear cell cultures from venous blood. Antibody responses were measured by indirect ELISA using a merozoite recombinant antigen and IFAT using piroplasm and macroschizont antigens. Results showed that there was an evident relationship between the persistence of carrier status, antibody response in ELISA and immune response to challenge.

Topics: Animals; Antibodies, Protozoan; Antibody Formation; Antigens, Protozoan; Antigens, Surface; Antiprotozoal Agents; Carrier State; Cattle; Cell Line; Enzyme-Linked Immunosorbent Assay; Fluorescent Antibody Technique, Indirect; Life Cycle Stages; Male; Naphthoquinones; Polymerase Chain Reaction; RNA, Protozoan; RNA, Ribosomal; Sensitivity and Specificity; Theileria annulata; Theileriasis; Ticks

A clinical trial testing the prophylactic effect of a 5 mg kg-1 dose of buparvaquone on either Theileria annulata or Theileria parva experimental infections of calves demonstrated its efficacy for periods of at least seven days. The drug given 1 h or seven days before 50% lethal T. annulata sporozoite infection protected all eight calves, but prophylaxis was insufficient after 14 days to protect two out of four calves from severe reaction. When immunity was challenged by a lethal second parasite dose a month after the first, all these calves were immune. In the T. parva trial, calves given drug 1 h or seven days before a 25% lethal infection underwent minimal reaction, but some were over-protected and were susceptible to a similar challenge sporozoite dose. Although drug levels remaining 14 days after prophylaxis protected these calves from the mild challenge, some parameters measured were within the range of the 'no drug' control group. These results indicated the effectiveness of a single 5 mg kg-1 dose of buparvaquone for more than seven days but also the potential risk of its use in the infection and treatment method of immunisation. It is suggested that there may be circumstances where simple field prophylactic treatment with buparvaquone may be beneficial.

Topics: Animals; Antibodies, Protozoan; Antiprotozoal Agents; Cattle; Fluorescent Antibody Technique, Indirect; Naphthoquinones; Parasitemia; Theileria annulata; Theileria parva; Theileriasis

After infection with sporozoites of the protozoon Theileria parva (Tp) bovine T cells are readily transformed to permanent growth in vivo and in vitro. Their transformed state depends on the constant presence of the parasite but membrane signals remain important. Non-receptor tyrosine kinases play a critical role in the transduction of membrane signals in haematopoietic cells. We have investigated Src-family kinases in bovine T cells transformed by Tp. The T cell receptor-associated tyrosine kinase p60fyn had high activity in all cell lines tested. In addition, weak phosphorylation of 2 novel bands was observed associated with Fyn. In contrast to Fyn, enzymatic activity of p56lck, which in T cells has an essential role in signalling, was low. Furthermore, 1 of 3 Tp transformed cell lines was completely devoid of p56lck indicating that the enzyme is not necessary for the Tp dependent growth of the T cells. In addition to p60fyn and p56lck weak enzymatic activity of 1 splice variant of p53/56lyn was observed after infection of T cells with Tp. These data show that growth transformation by Tp influences kinase activity in bovine T cells. However, they also prove that p56lck does not play an essential role in the transformation mechanism.

Topics: Animals; Antiprotozoal Agents; Cattle; Cell Line, Transformed; Herpesvirus 2, Saimiriine; Humans; Jurkat Cells; Naphthoquinones; Phosphorylation; Precipitin Tests; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Signal Transduction; src-Family Kinases; T-Lymphocytes; Theileria parva; Tyrosine

The susceptibility/immune status to tropical theileriosis of calves born of immunized dams was evaluated. Six cows were vaccinated with the Theileria annulata cell culture vaccine in the eighth month of pregnancy. Sera from the immunized dams exhibited very high post-vaccination antibody titres as determined by the indirect fluorescent antibody (IFA) test. The calves born to these dams did not show antibodies against T. annulata at the time of birth (IFA titres of < 1:20). The new-born calves were fed colostrum from their mothers and were challenged with T. annulata-infected ground tick supernate at 5-7 days of age. All the calves developed fever (from day 5-6 onwards) and parasitological reactions (from day 8-9 onwards) after challenge. There was a significant decrease in the haemoglobin and packed cell volume of the calves after challenge. All the calves showed signs of acute theileriosis by day 9-10 after challenge and had to be treated with buparvaquone in order to save their lives. The study indicated that detectable levels of anti-theilerial antibodies were not transferred from immune dams to their offspring. All the calves born to immunized dams were fully susceptible to theileriosis and thus themselves needed vaccination.

Topics: Animals; Animals, Newborn; Antibodies, Protozoan; Antigens, Protozoan; Antiprotozoal Agents; Arachnid Vectors; Body Temperature; Cattle; Disease Susceptibility; Female; Fluorescent Antibody Technique, Indirect; Hematocrit; Hemoglobins; Immunity, Maternally-Acquired; India; Naphthoquinones; Protozoan Vaccines; Theileria annulata; Theileriasis; Ticks; Vaccination

Theileria annulata is a tick-transmitted protozoan parasite of cattle, which transforms cells of macrophage (Mphi) or B cell lineage. Bone marrow cells, bone marrow cell-derived, and monocyte-derived Mphi were infected with T. annulata sporozoites, and the resulting cell lines were assessed for surface marker expression and function. Transformed lines expressed histocompatibility complex (MHC) class-I and II, CD44, CD45, and the myeloid marker DH598-surface markers CD14, CD11b, M-M7, TH57A, and to a lesser extent CD11a/CD18, CD11c, and ACT(B), were down-regulated. Likewise, transformed cells failed to express Mphi functions (Fc-receptor-mediated phagocytosis, phorbol myristate acetate-induced oxidative burst, lipopolysaccharide-induced tumor necrosis factor alpha, and nitric oxide generation and procoagulant activity up-regulation). Mphi origin was assured by homogeneity of the starting population, cloning of cells by limiting dilution, and repeated microscopic and flow cytometric monitoring of the cell lines. Elimination of the parasite by treatment with BW720c resulted in the re-acquisition of monocyte lineage properties, as evidenced by up-regulation of CD14, and by re-acquisition of the capacity to ingest opsonized sheep red blood cells and bacteria. Thus, Mphi transformed by T. annulata appear to undergo a process of parasite-induced dedifferentiation but reassume the differentiated phenotype upon elimination of the parasite.

Topics: Animals; Antigens, Surface; Antiprotozoal Agents; Cattle; Cell Differentiation; Cell Line, Transformed; Down-Regulation; Female; Flow Cytometry; Host-Parasite Interactions; Lipopolysaccharides; Macrophages; Naphthoquinones; Phenotype; Sensitivity and Specificity; Theileria annulata; Theileriasis

When T cells become infected by the parasite Theileria parva, they acquire a transformed phenotype and no longer require antigen-specific stimulation or exogenous growth factors. This is accompanied by constitutive interleukin 2 (IL-2) and IL-2 receptor expression. Transformation can be reversed entirely by elimination of the parasites using the specific drug BW720c. Extracellular signal-regulated kinase and jun NH2-terminal kinase (JNK) are members of the mitogen-activated protein kinase family, which play a central role in the regulation of cellular differentiation and proliferation and also participate in the regulation of IL-2 and IL-2 receptor gene expression. T. parva was found to induce an unorthodox pattern of mitogen-activated protein kinase expression in infected T cells. JNK-1 and JNK-2 are constitutively active in a parasite-dependent manner, but have altered properties. In contrast, extracellular signal-regulated kinase-2 is not activated even though its activation pathway is functionally intact. Different components of the T cell receptor (TCR)-dependent signal transduction pathways also were examined. The TCRzeta or CD3epsilon chains were found not to be phosphorylated and T. parva-transformed T cells were resistant to inhibitors that block the early steps of T cell activation. Compounds that inhibit the progression of T cells to proliferation, however, were inhibitory. Our data provide the first example, to our knowledge, for parasite-mediated JNK activation, and our findings strongly suggest that T. parva not only lifts the requirement for antigenic stimulation but also entirely bypasses early TCR-dependent signal transduction pathways to induce continuous proliferation.

Topics: 8-Bromo Cyclic Adenosine Monophosphate; Animals; Antiprotozoal Agents; Calcium-Calmodulin-Dependent Protein Kinases; Cell Line; Enzyme Activation; Enzyme Inhibitors; Humans; Immunosuppressive Agents; Indoles; JNK Mitogen-Activated Protein Kinases; Kinetics; Lymph Nodes; Lymphocyte Activation; Maleimides; Mitogen-Activated Protein Kinase 9; Mitogen-Activated Protein Kinases; Naphthoquinones; Polyenes; Protein Kinase C; Protein Kinases; Receptor-CD3 Complex, Antigen, T-Cell; Sirolimus; T-Lymphocytes; Tacrolimus; Theileria parva

Theileria-infected cells are induced to undergo a transformation that is reversible, since their proliferation is inhibited after elimination of the schizonts by the theilericidal drug buparvaquone. The molecular mechanisms of the transformation remain unknown. The experiments described in the present report deal with the role of casein kinase (CK) II, a serine/threonine protein kinase, in the permanent proliferation of the parasitized cells and show that the CK II-alpha subunit is expressed in both T. annulata- and T. parva-infected cells and that its expression is closely related to the presence of the parasites in the host-cell cytoplasm. Thus, elimination of the schizonts by buparvaquone leads to the inhibition of CK II-alpha subunit mRNA expression without affecting the expression of actin. Cells treated with 5,6-dichloro-1-beta-D-ribofuranosylbenzimidazole (DRB) are inhibited in a dose-dependent manner from under-going DNA synthesis as measured by [3H]-thymidine incorporation and from expressing CK II. Furthermore, a host-cell-specific CK II-alpha antisense inhibits DNA synthesis in a dose-dependent manner. In the present study, 6 microM antisense reduced [3H]-thymidine incorporation by Theileria-infected bovine cells to about 50%. Using a primer derived from T. parva CK II, we detected a parasite-specific CK II mRNA in T. parva-infected cell lines. Interestingly. DRB also inhibited the expression of the parasite-specific CK II. However, to date we have not detected a target sequence for this primer in T. annulata schizonts.

Topics: Animals; Antiprotozoal Agents; Casein Kinase II; Cattle; Cell Division; Cell Line; Concanavalin A; Dichlororibofuranosylbenzimidazole; DNA; Gene Expression Regulation; Lymphocytes; Mitogens; Naphthoquinones; Nucleic Acid Synthesis Inhibitors; Protein Serine-Threonine Kinases; RNA, Messenger; Theileria annulata; Theileria parva; Ticks

Twenty-three Friesian cattle were inoculated subcutaneously anterior to the left prescapular lymph node with 1 ml of a mild isolate of Theileria parva. The cattle developed low macroschizont parasitosis but no clinical reaction was observed. Thirty-five days later the cattle were grouped into five groups and challenged with five different Theileria parva isolates (four cattle-derived Theileria and one buffalo-derived Theileria). The cattle were all solidly immune to challenge with the cattle-derived Theileria isolates but three out of five of the cattle challenged with the buffalo-derived parasite died of theileriosis. All ten non-immunised control cattle developed severe theileriosis and were treated with buparvaquone (Butalex; Pitman-Moore).

Topics: Animals; Antiprotozoal Agents; Cattle; Immunization; Naphthoquinones; Protozoan Vaccines; Theileria parva; Theileriasis; Time Factors

Lactating cows, heifers, calves and young bulls suffering from naturally occurring bovine tropical theileriosis were treated with Butalex (buparvaquone). As a result of treatment, the clinical signs disappeared and the previously depressed milk yield of cows increased. No mortality was recorded and all the animals recovered.

Topics: Animals; Antiprotozoal Agents; Cattle; Female; Male; Naphthoquinones; Theileriasis; Treatment Outcome

One hundred and nine cases of bovine tropical theileriosis (Theileria annulata infection) in Punjab State, India, were treated with oxytetracycline (23 cases) or buparvaquone (86 cases). Ages of affected cattle ranged from 6 days to 3 years. Oxytetracycline cured only 7 animals (30.4%), all of them calves below 15 days old, while buparvaquone cured all but one (98.8%), a severely affected 10 day old calf. Cured cattle remained theileriosis-free for 12 to 18 months following recovery. Theileriosis in Punjab is predominantly a disease of young calves that cannot be protected by available cell-culture vaccines. It is suggested that the most economical way to control theileriosis in India would be to immunise calves by infection with sporozoite stabilate and simultaneous treatment with tetracycline, and to reserve buparvaquone for the treatment of clinical cases, in cattle of all ages.

Topics: Age Factors; Animals; Antiprotozoal Agents; Cattle; India; Naphthoquinones; Oxytetracycline; Protozoan Vaccines; Theileria; Theileriasis; Vaccination

The clinical efficacy of albendazole (ABZ) in the treatment of chronic uncomplicated strongyloidiasis has been reported to be highly variable. In our murine model of strongyloidiasis a single oral dose of 5 and 10 mg kg-1 ABZ reduced (at day 4 post infection) the faecal larval count (FLC) by 54.2 +/- 12.5% and 81.5 +/- 10.2%, respectively. 100 mg kg-1 ABZ reduced the FLC by 100%. Two inhibitors of protozoan and filarial electron transport (720C80 and 993C76) inhibited the endogenous O2 consumption of intact infective (L3) larvae of S. ratti by > 50% at 2 x 10(-5) M in vitro, and reduced the FLC by 72 +/- 9.3% and 62.0 +/- 10.3% respectively in vivo, at a dose of 70 mg kg-1. These results suggest that compounds designed as selective inhibitors of protozoan electron transport have significant efficacy against murine strongyloidiasis and may prove useful in the management of human strongyloidiasis.

Topics: Albendazole; Animals; Antiprotozoal Agents; Female; Naphthoquinones; Rats; Rats, Sprague-Dawley; Strongyloidiasis

Groups of calves were infected by the injection of ground-up-tick supernatant from ticks infected with ODE-Anand stock of Theileria annulata, the causative agent of tropical theileriosis. Treatment with long-acting oxytetracycline, at 20 mg kg-1, injected intramuscularly, had no effect against severe Theileria annulata infection when administered either as a single injection on the day of infection or as three injections given on days 8, 10 and 12 after infection. Halofuginone lactate, given orally at 1.2 mg kg-1 was effective but caused anorexia, diarrhoea and debility. Parvaquone at 20 mg kg-1 intramuscularly given on day 11 after infection, had a marked suppressive effect, while buparvaquone was highly effective. A single treatment with buparvaquone, either at 5 mg kg-1 or 2.5 mg kg-1 intramuscularly, rapidly eliminated schizonts and piroplasms of T annulata. At 5 mg kg-1 it resulted in rapid recovery of all the treated calves.

Topics: Animals; Antiprotozoal Agents; Cattle; Male; Naphthoquinones; Oxytetracycline; Quinazolines; Quinazolinones; Theileria annulata; Theileriasis

We have previously developed a mouse model which allowed the proliferation of Theileria sergenti in severe combined immunodeficiency (SCID) mice with circulating bovine erythrocytes (Bo-RBC). In the present study, this model was utilized to test the efficacy of anti-theilerial drugs. Bo-RBC-SCID mice were created by giving periodic transfusions of T. sergenti-free Bo-RBC, and subsequently infecting with T. sergenti. Three anti-protozoal compounds, Pamaquine (Yamanouchi Pharmaceutical Co. Ltd), Ganaseg (Japan CIBA-GEIGY Ltd) and Buparvaquone (Coopers Animal Health Ltd), were subcutaneously administered into the mice at doses recommended for cattle therapy. Blood examinations demonstrated that all three drugs significantly reduced the level of parasitemia although Ganaseg was effective only at a dose five times higher than that recommended for cattle therapy. Administration of the drugs neither caused any sign of acute toxicity nor changed the rate of Bo-RBC in the SCID mice's circulating blood cells. The results indicate that the Bo-RBC-SCID mouse model may offer a useful in vivo system for evaluating the efficacy of anti-protozoal drugs against T. sergenti.

Topics: Aminoquinolines; Animals; Antiprotozoal Agents; Cattle; Diminazene; Drug Evaluation, Preclinical; Erythrocyte Transfusion; Female; Mice; Mice, SCID; Models, Biological; Naphthoquinones; Theileria

Theileria annulata-infected cells were cultured in the presence or absence of human recombinant interleukin 2 (hrIL-2). This growth factor proved to be capable of enhancing the growth of the infected cells: its effect was marked, particularly when the cells were seeded at low densities, and it varied from cell line to cell line. The infected cells produced a factor that possessed the biological activities of IL-2, since their supernatants could enhance the proliferation of concanvalin A-stimulated (Con A) blasts. The reactivity of the parasitized cells to hrIL-2 was abolished following their treatment with the antitheilerial drug buparvaquone. In addition, the drug inhibited the binding of 125I-IL-2 to T. annulata-infected cells but failed to suppress its binding to Con A blasts. Northern blot analysis revealed that the drug had no effect on the expression of the alpha chain of the IL-2 receptor (IL-2R). Therefore, it is possible that buparvaquone interferes with the expression of the beta chain of the IL-2R. The role of IL-2 and the IL2R in the permanent proliferation of T. annulata-infected cells is discussed.

Topics: Animals; Cattle; Cells, Cultured; Gene Expression Regulation; Humans; Interleukin-2; Lymphocyte Activation; Lymphocytes; Naphthoquinones; Receptors, Interleukin-2; Recombinant Proteins; RNA, Messenger; Theileria annulata

Three experiments were undertaken to determine the efficacy of different doses of buparvaquone in the infection and treatment immunization of cattle against Theileria parva derived from African buffalo (Syncerus caffer). Two of these experiments also compared buparvaquone with standard doses of long- and short-acting formulations of oxytetracycline. In addition, different dilutions of stabilates were used in the experiments. In the first experiment, a 10(-1.0) dilution of stabilate was used to infect groups of cattle treated with buparvaquone at doses of between 5 and 0.625 mg kg-1 body weight (bwt) on Day 0 after infection. All control cattle developed severe theileriosis and none of the treatment regimes (including those utilizing long-acting oxytetracycline) prevented the development of theileriosis. Treatment with buparvaquone at 2.5 mg kg-1 bwt or oxytetracycline gave the most satisfactory results. In the second experiment when the sporozoite dose was reduced to 10(-2.0) dilution, buparvaquone treatment at 5 and 2.5 mg kg-1 bwt and short- and long-acting formulations of oxytetracycline reduced reactions greatly. While all the oxytetracycline treated animals produced a serological response and were immune to a 50-fold higher challenge with the immunizing stabilate, several animals in the buparvaquone groups did not show a serological response and were not immune to challenge. In the third experiment, groups of cattle were infected with 10(-1.2), 10(-1.4) and 10(-1.6) dilutions of stabilate and were treated with 2.5 mg kg-1 bwt of buparvaquone. No animals developed severe theileriosis and all seroconverted. On homologous challenge, however, two out of 14 cattle showed severe reactions. It was concluded that further work on immunization using buparvaquone treatment at 2.5 mg kg-1 bwt and 10(-1.6) dilution of the stabilate would have to be carried out before such a system could be used in the field.

Topics: Animals; Antibodies, Protozoan; Antiprotozoal Agents; Buffaloes; Cattle; Evaluation Studies as Topic; Immunization; Naphthoquinones; Oxytetracycline; Theileria parva; Theileriasis

We evaluated the efficacy of buparvaquone in eliminating infection with Babesia equi of European origin in carrier horses and in splenectomized horses with experimentally induced acute infection. When administered at the rate of 5 mg/kg of body weight, IV, 4 times at 48-hour intervals, buparvaquone prompted rapid abatement of parasitemia. However, secondary and tertiary recrudescent parasitemias invariably returned with establishment of the carrier state. Buparvaquone, at the dosage evaluated, had transitory therapeutic efficacy against acute B equi infection in splenectomized horses, but was unable alone to clear carrier infection.

Topics: Acute Disease; Animals; Antibodies, Protozoan; Antiprotozoal Agents; Babesia; Babesiosis; Carrier State; Complement Fixation Tests; Female; Fluorescent Antibody Technique; Horse Diseases; Horses; Injections, Intravenous; Male; Naphthoquinones; Splenectomy

Topics: Animals; Antiprotozoal Agents; Cattle; Immunization; Naphthoquinones; Theileriasis; Tick Control

Lymphocytes infected with the intracellular parasite Theileria parva proliferate continuously as lymphoblastoid cell lines. We have previously shown that the continuous proliferation of the T. parva-infected (Tpi) cell line TpM(803) is mediated in part by an autocrine mechanism (Dobbelaere, D. A. E. et al., Proc. Natl. Acad. Sci. USA 1988. 85:4730). We now report that continuous proliferation also requires surface stimulation through cell-cell contact. Under standard culture conditions this surface stimulus is provided by the infected cells themselves, but it can also be provided by uninfected lymphocytes or macrophages. The ability to respond to surface stimulation is critically dependent on the presence of the parasite in the host cell and is lost within 48 h after the elimination of the parasite from the host cell cytoplasm by treatment with the theilericidal drug BW720c. Tpi cells also secrete a growth factor which is able to support the proliferation of diluted Tpi cells. Growth factor secretion is rapidly lost upon elimination of the parasite. Moreover, inhibition experiments using anti-interleukin 2 (IL 2) antibodies show that IL 2 is involved in the proliferation of the Tpi cell lines TpM(803) and IN10. T cell proliferation is dependent on a number of costimulatory signals which are normally provided by accessory cells. The finding that Tpi cells can mutually stimulate each other to grow in the absence of conventional accessory cells helps to explain how they can escape the normal constraints on T cell growth, allowing them to invade and multiply in non-lymphoid as well as lymphoid tissues.

Topics: Animals; Apicomplexa; Cattle; Cell Adhesion; Cell Communication; Cell Division; Growth Substances; In Vitro Techniques; Interleukin-2; Lymphocytes; Lymphokines; Naphthoquinones; Theileriasis

Buparvaquone, a naphthoquinone with known efficacy against Theileria parva parva in cattle, was tested for activity against Theileria cervi piroplasms in both an in vitro culture system and in vivo in experimentally infected white-tailed deer. The in vitro data showed a significant decrease in the incorporation of 3H-hypoxanthine by infected red blood cells treated with buparvaquone when compared to that seen with imidocarb and chloroquine treatment. In both intact and splenectomized deer treated with buparvaquone (2.5 mg kg-1) a gradual decrease in piroplasm parasitaemia was observed following treatment. However, in the splenectomized deer, parasitaemia levels returned to near pretreatment values after approximately 2 weeks.

Topics: Animals; Antiprotozoal Agents; Apicomplexa; Cells, Cultured; Chloroquine; Deer; Erythrocytes; Hypoxanthine; Hypoxanthines; Imidocarb; Naphthoquinones; Theileriasis

Thirty-seven high grade cattle were immunised against Corridor disease (Theileria parva lawrencei infection) on a farm with a history of heavy and often lethal theilerial challenge. Nineteen cattle were immunised by treating with two doses of long-acting oxytetracyclines given at 20 mg/kg on days 0 and 4 after sporozoite stabilate inoculation, while the other 18 were treated with naphthoquinone buparvaquone, given as a single dose of 2.5 mg/kg simultaneously with stabilate inoculation. All the cattle underwent subclinical theilerial reactions with all but two developing high antibody titres on the IFAT test against T. parva schizont antigen by day 35 after the immunisation. Both buparvaquone and long-acting oxytetracycline appeared equally effective in the immunisation. To date, 26 months later, only two cases of theileriosis parasitologically characteristic of T. p. parva have been reported in the immunised cattle. Following the two cases, investigations showed that when uninfected Rhipicephalus appendiculatus nymphal ticks were deliberately fed on healthy resident cattle on the farm, the resultant adult ticks transmitted acute and lethal theilerial infections to five out of five susceptible cattle. The resultant infections were parasitologically characteristic of T. p. parva infections. Furthermore, the monoclonal antibody profiles of schizont infected cell lines from these infections appeared to be characteristic of T. p. parva. It was thus concluded that resident cattle on the farm could be a potential source of T.p. parva infection which had broken through the immunity of T.p. lawrencei immunised cattle and could constitute a reservoir of theilerial infection for ticks and hence to susceptible stock on the farm.

Topics: Animals; Antibodies, Protozoan; Antiprotozoal Agents; Apicomplexa; Arachnid Vectors; Carrier State; Cattle; Disease Reservoirs; Female; Fluorescent Antibody Technique; Immunization; Male; Naphthoquinones; Nymph; Oxytetracycline; Pregnancy; Pregnancy Complications, Infectious; Theileriasis; Ticks

Parvaquone (BW993C), 2-cyclohexyl-3-hydroxy-1,4-naphthoquinone, and buparvaquone (BW720C) 2-(trans-4-t-butylcyclohexyl-methyl)-3-hydroxy-1,4-naphthoquinone, were evaluated to determine their therapeutic efficacy in the treatment of theileriosis caused by Theileria annulata infection in cattle in Iran. One hundred and fifty-nine pure and crossbred Bos taurus cattle, experimentally or naturally infected with T annulata, were treated. Parvaquone was injected into 86 animals with up to three doses of 20 mg kg-1 or 10 mg kg-1 at intervals of 48 hours between doses. Buparvaquone was injected into 73 animals. Up to three doses of 2.5 mg kg-1 were injected with an interval of 48 hours between doses. The recovery rate of animals treated with parvaquone was 60.7 per cent and with buparvaquone it was 88.7 per cent. No significant side effects of relapse of disease were observed following the use of either compound. It is concluded that buparvaquone at a dose of 2.5 mg kg-1 has a satisfactory therapeutic index and is a more effective treatment of T annulata infection than parvaquone. The prophylactic use of schizont tissue culture vaccine and chemotherapy with buparvaquone could be the most promising means of controlling theileriosis in Iran.

Topics: Animals; Antimalarials; Antiprotozoal Agents; Cattle; Iran; Naphthoquinones; Theileriasis

The efficacy of parvaquone (Clexon) and buparvaquone (Butalex) in treating experimentally induced feline cytauxzoonosis was explored. Domestic cats were inoculated subcutaneously with blood from a cat infected with Cytauxzoon felis and treated daily with either 20 or 30 mg kg-1 parvaquone, or 5 or 10 mg kg-1 buparvaquone, beginning on either the first day parasites were detected in peripheral blood, or 2 days after the onset of parasitemia. Fifteen cats were treated and all but one died due to the infection. Unexpectedly, one of two non-treated, infected control cats survived. Although parvaquone and buparvaquone are the treatments of choice for a related hemoprotozoan parasite causing theileriosis in African cattle, wer concluded that at the dosages and regimes tested, these drugs are not effective treatments for feline cytauxzoonosis. Blood from the two surviving cats was inoculated into naive cats and in these animals clinical disease or death were not observed. The latter two naive recipient cats were then inoculated with a lethal dose of viable, frozen C. felis and both died, thereby indicating that blood from surviving cats did not induce an infectious state that resulted in immunity. The two cats that survived the acute infection were subsequently challenged with a lethal inoculum of C. felis; they showed no clinical signs of cytauxzoonosis and were obviously immune to reinfection.

Topics: Animals; Antiprotozoal Agents; Apicomplexa; Cat Diseases; Cats; Female; Male; Naphthoquinones; Protozoan Infections; Protozoan Infections, Animal

Attempts (some successful) were made to eliminate Theileria buffeli infections from 23 naturally or experimentally infected, splenectomised calves. The anti-theilerial hydroxynaphthoquinone derivative buparvaquone was used either alone or in combination with primaquine phosphate. After treatment the calves were monitored for infection for up to 26 weeks. Blood films were examined for piroplasms and serum antibody levels were measured using an immunofluorescence technique. Buparvaquone alone failed to eliminate infections. Infections were eliminated from 11 of 16 calves treated twice with buparvaquone and three or six times with primaquine phosphate. Theilerial parasites were not subsequently seen in these 11 calves nor were antibodies detected beyond the eighth week after treatment.

Topics: Animals; Antibodies, Protozoan; Antiprotozoal Agents; Apicomplexa; Cattle; Drug Therapy, Combination; Naphthoquinones; Primaquine; Random Allocation; Theileriasis

The influence of Buparvaquone on the morphology, proliferation, and stimulation with T and B cell mitogens of Theileria annulata-infected cells was studied. In addition, the stimulatory capacity of the infected cells before and after treatment with Buparvaquone or cyclosporin A (CsA) was also examined and compared to that of ConA-stimulated bovine peripheral blood cells (PBL). After incubation of the cells for 4 days with Buparvaquone only few schizonts were detectable in the cells. Prolongation of the incubation time to 8, 12, or 14 days eliminated completely the parasites. Despite the elimination of the parasites, the cells were still unable to undergo a proliferative response to Con A or PWM. However, the drug did not interfere with the response of normal PBL to these mitogens. Furthermore, Buparvaquone but not CsA inhibits the generation of mixed lymphocyte reaction (MLR). None of the drugs could prevent ConA-blasts from stimulating autologous PBL. These results suggest that the antigen expressed by the infected cells and recognised by the responder PBL was induced by the schizonts.

Topics: Animals; Antiprotozoal Agents; Apicomplexa; Cattle; Cells, Cultured; Cyclosporins; Host-Parasite Interactions; Lymphocyte Activation; Lymphocytes; Naphthoquinones; Theileriasis

The antitheilerial activity of buparvaquone in crossbred male calves, experimentally infected with Theileria annulata (Izatnagar isolate) has been tested. Animals were treated intramuscularly at the dose rate of 2.5 mg/kg1 body weight. A single dose of the drug administered during the phase of ascending parasitaemia cured all the infected calves while all the untreated infected control calves died.

Topics: Animals; Antiprotozoal Agents; Cattle; Injections, Intramuscular; Male; Naphthoquinones; Theileriasis

Eighteen seven to 21-day-old crossbred (Bos taurus cross Bos indicus) calves were allocated to four groups (A to D). Groups A and B each consisted of six calves and groups C and D three calves each. Each calf in groups A, B and C was inoculated with ground-up tick supernate (GUTS) equivalent to two infected acini prepared from Theileria annulata-infected Hyalomma anatolicum anatolicum. Each calf in group A was also given a single intramuscular injection of buparvaquone, 2.5 mg kg-1 bodyweight simultaneously with GUTS, whereas each calf in group B was given a single intramuscular injection of long-acting oxytetracycline, 20 mg kg-1 bodyweight following inoculation of GUTS. In calves of group A clinicopathological reactions were negligible, whereas in calves of group B mild to severe reactions were observed resulting in the death of three of the six calves. All the calves of group C (infected, untreated controls) died of acute theileriosis. All the surviving calves of groups A and B withstood a lethal homologous challenge given on day 30 after immunisation, indicating no difference in the immune status of the surviving calves of the two groups. Group D, challenge control, all calves died of theileriosis within 18 days of challenge.

Topics: Animals; Cattle; Naphthoquinones; Oxytetracycline; Random Allocation; Theileriasis; Ticks

Chronic, undulating Theileria annulata infection was diagnosed as the cause of severely depressed milk yields in a herd of 44 Friesian cows in Egypt. The herd was divided at random into two groups of 22; one group was injected intramuscularly with a single dose of the experimental antitheilerial drug, buparvaquone, while the other remained untreated. Over the subsequent seven weeks milk yield in the treated group increased to double that of the untreated group (P less than 0.05). Pyrexia was controlled within two days of injection of buparvaquone and piroplasm parasitaemia was eliminated in one week. It is suggested that treatment of dairy cattle chronically infected with T. annulata using buparvaquone may have the dual beneficial effect of reducing the pathogenic effects of theileriosis, thereby permitting restoration of an impaired immune system, thus increasing resistance to other infections. If a similar effect could be produced in Bos indicus cattle in T. annulata endemic areas, treatment of indigenous cattle with buparvaquone could be a useful alternative to the introduction of Bos taurus blood as a way of boosting milk production.

Topics: Animals; Antiprotozoal Agents; Body Temperature; Cattle; Female; Lactation; Naphthoquinones; Pregnancy; Random Allocation; Theileriasis

We evaluated the efficacy of buparvaquone in eliminating Babesia equi of European origin in carrier horses and in experimentally infected splenectomized ponies. When administered at the rate of 2.5 mg/kg of body weight, IM, 4 times at 96-hour intervals, buparvaquone was effective in eliminating B equi carrier infection in 1 horse. Such results could not be repeated at the same dosage or at 3.5 or 5 mg/kg, IM. Buparvaquone given at the rate of 4 to 6 mg/kg IV and/or IM was therapeutically effective in 4 of 5 acute B equi infections in splenectomized ponies. The treated ponies became carriers.

Topics: Animals; Antiprotozoal Agents; Babesiosis; Carrier State; Horse Diseases; Horses; Male; Naphthoquinones; Splenectomy; Time Factors

The antitheilerial activity of buparvaquone (BW 720C) was evaluated in experimentally induced Theileria annulata infections in cross-bred male calves. T. annulata infections were induced by injecting a suspension of infected ground tick tissue suspension (GUTTS) equivalent to two ticks subcutaneously into each calf. Buparvaquone at a dose of 2.5 mg kg-1 body weight was given as a single injection (intramuscularly) on Day 0 (Group 1), Day 8 (Group 2) and Day 12 (Group 3) post-infection. The animals in Groups 4 and 5 were untreated and challenged controls, respectively. All of the recovered animals from Groups 1-4 were challenged with a lethal dose of T. annulata at 6 weeks post-infection. The immunized animals were resistant to the homologous challenge, which killed three of four control animals (Group 5); the controls showed typical antemortem and post-mortem lesions of theileriosis.

Topics: Animals; Antiprotozoal Agents; Cattle; Male; Naphthoquinones; Random Allocation; Theileriasis

A high performance liquid chromatographic (HPLC) method for the determination of the antitheilerial drugs parvaquone and buparvaquone in plasma was developed. Both compounds were extracted from plasma with ether. After evaporating the extracts to dryness the residue was dissolved in methanol and an aliquot was injected onto a column (10 cm X 5 mm, i.d.) of ODS-Hypersil (5 mu) with a mobile phase of 0.05 M-Na acetate buffer (pH 3.6)-methanol (15:85, v/v). Detection was at 252 nm. The mean recovery for both compounds was about 92%. This method was used to elucidate their pharmacokinetics in 6 calves after intramuscular administration. The maximum plasma concentration for parvaquone was 6.36 +/- 0.58 micrograms/ml after 0.84 +/- 0.08 h. The corresponding values for buparvaquone were 0.102 +/- 0.030 microgram/ml and 3.17 +/- 0.39 h, respectively. The decay in plasma concentrations for the two drugs was biexponential and the terminal elimination half lives were 11.12 +/- 1.63 h and 26.44 +/- 2.81 h for parvaquone and buparvaquone, respectively.

Topics: Animals; Antiprotozoal Agents; Cattle; Chromatography, High Pressure Liquid; Naphthoquinones

A Theileria parva lawrencei isolate in the form of a sporozoite stabilate, derived by feeding clean Rhipicephalus appendiculatus nymphal ticks on an African buffalo (Syncerus caffer) captured in the Laikipia District, Kenya, was inoculated into groups of cattle at dilutions between 10(0) and 10(-3). Groups of 3 cattle infected with 1 ml inocula at 10(0), 10(-1) and 10(-2) dilutions were treated with 2.5 mg/kg body weight of buparvaquone on day 0 and similar groups were left untreated to act as controls. An additional group, given 10(0) dilution of the stabilate, was treated with buparvaquone on day 8 post-inoculation. It was found that all control cattle inoculated with the stabilate at dilutions between 10(0) and 10(-2) became infected, but only 2 out of 3 cattle developed patent infections at 10(-3) dilution. All 3 control cattle receiving 10(0) dilution died of theileriosis, 2 at 10(-1) and 10(-2) dilutions, and 1 at 10(-3) dilution died. Buparvaquone treatment on day 0 at 10(0) dilution resulted in the survival of 2 of 3 cattle and all the cattle at 10(-1) and 10(-2) dilutions. All the surviving cattle eventually developed a significant serological response against T. parva in the indirect fluorescent antibody test, except 1 in the 10(-3) dilution group, and were immune to homologous challenge when tested 3 months later with a lethal inoculum of stabilate, except 2 cattle in the 10(-3) dilution group. As a result of a theileriosis problem at about day 60 after inoculation in 2 cattle given 10(-2) dilution of stabilate and buparvaquone treatment on day 0, an additional 5 cattle were given 10(-2) dilution of stabilate and developed a good immunity after buparaquone treatment. None was shown to develop the carrier state. Treatment with buparvaquone on day 8 after infection with 10(0) dilution of stabilate was not successful since 2 died. The stabilate used was shown to produce reproducible infection in cattle at different dilutions.

Topics: Animals; Antiprotozoal Agents; Apicomplexa; Buffaloes; Carrier State; Cattle; Dose-Response Relationship, Immunologic; Immunization; Naphthoquinones; Oxytetracycline; Theileriasis; Thelazioidea

Twenty cross-bred (Bos taurus X Bos indicus) calves, 7-21 days old, were infected by a ground-up tick supernate of Hyalomma anatolicum anatolicum infected with the Hisar isolate of Theileria annulata. Six calves acted as untreated controls and they all died of theileriosis within 17 days of infection. The remaining 14 calves were divided into Group A and B, each consisting of seven calves. All the calves of Groups A and B were treated intramuscularly with buparvaquone (BW 720C) on Day 11 post-infection, when clinical signs of theileriosis were apparent. Each calf received 2.5 mg BW 720 C kg-1 body weight as a single injection. In addition, each calf of Group B was given proprietary haematinics by intramuscular injection, daily for 12 days. In Group A, two calves died of cerebral theileriosis and five were clinically cured. However, four of these five calves later died of anaemia. In Group B, all the calves were clinically cured and none died during the observation period of 1 month. The parasitaemia declined to less than 1% within a fortnight of treatment. The initial declines in haemoglobin concentration and packed cell volume were halted and preinfection values were soon restored. No toxic signs attributable to treatment with buparvaquone were observed.

Topics: Acute Disease; Animals; Antiprotozoal Agents; Body Temperature; Cattle; Erythrocytes; Hematocrit; Hemoglobins; Injections, Intramuscular; Lymph Nodes; Naphthoquinones; Random Allocation; Theileriasis; Ticks

Topics: Animals; Antiprotozoal Agents; Cattle; Naphthoquinones; Theileriasis

A series of hydroxynaphthoquinones, all derivatives of the antitheilerial hydroxynaphthoquinone parvaquone (993C, Clexon; Wellcome) was tested for antitheilerial activity against Theileria parva (Muguga) in vitro. BW720C (buparvaquone) was 20 times more active than parvaquone. When tested in vivo BW720C cured all 13 cattle infected with T parva and all six infected with T annulata treated at a dose rate of 2.5 mg (kg bodyweight)-1 while parvaquone at 20 mg kg-1 cured nine of 10 cattle. All 16 untreated control cattle died of theileriosis.

Topics: Animals; Antimalarials; Antiprotozoal Agents; Apicomplexa; Cattle; Chemical Phenomena; Chemistry; Kenya; Naphthoquinones; Species Specificity; Theileriasis