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Rodrigues DC, de Oliveira da Cunha CN, Mattos GT, Martins LHR, Nogueira TCM, de Souza MVN, da Costa de Avila LF, Ramos DF, Scaini CJ. Larvicidal activity of coumarin derivatives on Toxocara canis larvae, cytotoxicity analysis, and in silico bioavailability studies. Parasitol Res 2024; 123:246. [PMID: 38896311 DOI: 10.1007/s00436-024-08272-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2024] [Accepted: 06/13/2024] [Indexed: 06/21/2024]
Abstract
Human toxocariasis is a neglected anthropozoonosis with global distribution. Treatment is based on the administration of anthelmintics; however, their effectiveness at the tissue level is low to moderate, necessitating the discovery of new drug candidates. Several groups of synthetic compounds, including coumarin derivatives, have demonstrated bioactivity against fungi, bacteria, and even parasites, such as Dactylogyrus intermedius, Leishmania major, and Plasmodium falciparum. The aim of this study was to evaluate the effect of ten coumarin-derived compounds against Toxocara canis larvae using in vitro, cytotoxicity, and in silico tests for selecting new drug candidates for preclinical tests aimed at evaluating the treatment of visceral toxocariasis. The compounds were tested in vitro in duplicate at a concentration of 1 mg/mL, and compounds with larvicidal activity were serially diluted to obtain concentrations of 0.5 mg/mL; 0.25 mg/mL; 0.125 mg/mL; and 0.05 mg/mL. The tests were performed in a microculture plate containing 100 T. canis larvae in RPMI-1640 medium. One compound (COU 9) was selected for cytotoxicity analysis using J774.A1 murine macrophages and it was found to be non-cytotoxic at any concentration tested. The in silico analysis was performed using computational models; the compound presented adequate results of oral bioavailability. To confirm the non-viability of the larvae, the contents of the microplate wells of COU 9 were inoculated intraperitoneally (IP) into female Swiss mice at 7-8 weeks of age. This confirmed the larvicidal activity of this compound. These results show that COU 9 exhibited larvicidal activity against T. canis larvae, which, after exposure to the compound, were non-viable, and that COU 9 inhibited infection in a murine model. In addition, COU 9 did not exhibit cytotoxicity and presented adequate bioavailability in silico, similar to albendazole, an anthelmintic, which is the first choice for treatment of human toxocariasis, supporting the potential for future investigations and preclinical tests on COU 9.
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Affiliation(s)
| | | | - Gabriela Torres Mattos
- Parasitology Laboratory, Faculty of Medicine, Federal University of Rio Grande, Rio Grande, Brazil
| | | | | | | | | | - Daniela Fernandes Ramos
- New Drug Development Laboratory, Faculty of Medicine, Federal University of Rio Grande, Rio Grande, Brazil
| | - Carlos James Scaini
- Parasitology Laboratory, Faculty of Medicine, Federal University of Rio Grande, Rio Grande, Brazil
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2
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Vokřál I, Podlipná R, Matoušková P, Skálová L. Anthelmintics in the environment: Their occurrence, fate, and toxicity to non-target organisms. CHEMOSPHERE 2023; 345:140446. [PMID: 37852376 DOI: 10.1016/j.chemosphere.2023.140446] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Revised: 10/11/2023] [Accepted: 10/12/2023] [Indexed: 10/20/2023]
Abstract
Anthelmintics are drugs used for the treatment and prevention of diseases caused by parasitic worms (helminths). While the importance of anthelmintics in human as well as in veterinary medicine is evident, they represent emerging contaminants of the environment. Human anthelmintics are mainly used in tropical and sub-tropical regions, while veterinary anthelmintics have become frequently-occurring environmental pollutants worldwide due to intensive agri- and aquaculture production. In the environment, anthelmintics are distributed in water and soil in relation to their structure and physicochemical properties. Consequently, they enter various organisms directly (e.g. plants, soil invertebrates, water animals) or indirectly through food-chain. Several anthelmintics elicit toxic effects in non-target species. Although new information has been made available, anthelmintics in ecosystems should be more thoroughly investigated to obtain complex knowledge on their impact in various environments. This review summarizes available information about the occurrence, behavior, and toxic effect of anthelmintics in environment. Several reasons why anthelmintics are dangerous contaminants are highlighted along with options to reduce contamination. Negative effects are also outlined.
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Affiliation(s)
- Ivan Vokřál
- Department of Pharmacology and Toxicology, Charles University in Prague, Faculty of Pharmacy, Heyrovského 1203, Hradec Králové, CZ-500 05, Czech Republic
| | - Radka Podlipná
- Laboratory of Plant Biotechnologies, Institute of Experimental Botany, Czech Academy of Sciences, Rozvojová 263, Praha 6, CZ-165 02, Czech Republic.
| | - Petra Matoušková
- Department of Biochemical Sciences, Charles University in Prague, Faculty of Pharmacy, Heyrovského 1203, Hradec Králové, CZ-500 05, Czech Republic
| | - Lenka Skálová
- Department of Biochemical Sciences, Charles University in Prague, Faculty of Pharmacy, Heyrovského 1203, Hradec Králové, CZ-500 05, Czech Republic
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3
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Kotze AC, Hunt PW. The current status and outlook for insecticide, acaricide and anthelmintic resistances across the Australian ruminant livestock industries: assessing the threat these resistances pose to the livestock sector. Aust Vet J 2023; 101:321-333. [PMID: 37401786 DOI: 10.1111/avj.13267] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Revised: 06/06/2023] [Accepted: 06/14/2023] [Indexed: 07/05/2023]
Abstract
The Australian ruminant livestock industries are faced with the need to control parasitic infectious diseases that can seriously impact the health of animals. However, increasing levels of resistance to insecticides, anthelmintics and acaricides are substantially reducing the ability to control some of these parasites. Here we review the current situation with regard to chemical resistances in parasites across the various sectors of the Australian ruminant livestock industries and assess the level of threat that these resistances pose to the sustainability of these sectors in the short to long terms. We also look at the extent to which testing for resistance occurs across the various industry sectors, and hence how well-informed these sectors are of the extent of chemical resistance. We examine on-farm management practices, breeding of parasite-resistant animals, and non-chemical therapeutics that may act as short to long term means to reduce the current reliance on chemicals for parasite control. Finally, we look at the balance between the prevalence and magnitude of current resistances and the availability and adoption rates of management, breeding and therapeutic alternatives in order to assess the parasite control outlook for the various industry sectors.
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Affiliation(s)
- A C Kotze
- CSIRO Agriculture and Food, Brisbane, Queensland, Australia
| | - P W Hunt
- CSIRO Agriculture and Food, Armidale, New South Wales, Australia
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Canton C, Canton L, Lifschitz A, Paula Dominguez M, Alvarez L, Ceballos L, Mate L, Lanusse C, Ballent M. Monepantel-based anthelmintic combinations to optimize parasite control in cattle. Int J Parasitol 2023; 53:441-449. [PMID: 36963744 DOI: 10.1016/j.ijpara.2023.02.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2022] [Revised: 02/19/2023] [Accepted: 02/21/2023] [Indexed: 03/26/2023]
Abstract
Improvement in the use of existing anthelmintics is a high priority need for the pharmaco-parasitology research field, considering the magnitude and severity of anthelmintic resistance as an important issue in livestock production. In the work described here, monepantel (MNP) was given alone or co-administered with either macrocyclic lactone (ML) or benzimidazole (BZ) anthelmintics to calves naturally infected with ML- and BZ-resistant gastrointestinal (GI) nematodes on two different commercial cattle farms. Both pharmacokinetic (PK) and efficacy assessments were performed. On Farm A, male calves (n = 15 per group) were treated with either MNP orally (2.5 mg/kg), IVM s.c. (0.2 mg/kg), ricobendazole (RBZ) s.c. (3.75 mg/kg) or remained untreated. On Farm B, eight groups (n = 15) of male calves received treatment with either: MNP, abamectin (ABM, oral, 0.2 mg/kg), RBZ (s.c., 3.75 mg/kg), albendazole (ABZ, oral, 5 mg/kg), MNP+ABM, MNP+RBZ, MNP+ABZ (all at the above-mentioned routes and doses) or remained untreated. Seven animals from each treated group (Farm B) were randomly selected to perform the PK study. MNP and its metabolite monepantel sulphone (MNPSO2) were the main analytes recovered in plasma after HPLC analysis. The combined treatments resulted in decreased systemic exposures to MNP parent drug compared with that observed after treatment with MNP alone (P < 0.05). However, the systemic availability of the main MNP metabolite (MNPSO2) was unaffected by co-administration with either ABM, RBZ or ABZ. Efficacies of 98% (Farm A) and 99% (Farm B) demonstrated the high efficacy of MNP given alone (P < 0.05) against GI nematodes resistant to ML and BZ in cattle. While the ML (IVM, ABM) failed to control Haemonchus spp., Cooperia spp. and Ostertagia spp., MNP achieved 99% to 100% efficacy against those nematode species on both commercial farms. However, MNP alone failed to control Oesophagostomum spp. (60% efficacy) on Farm A. The co-administered treatments MNP+ABZ and MNP+RBZ reached a 100% reduction against all GI nematode genera. In conclusion, the oral treatment with MNP should be considered to deal with resistant nematode parasites in cattle. The use of MNP in combination with BZ compounds could be a valid strategy to extend its lifespan for use in cattle as well as to reverse its poor activity against Oesophagostomum spp.
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Affiliation(s)
- Candela Canton
- Laboratorio de Farmacología, Centro de Investigación Veterinaria de Tandil (CIVETAN), UNCPBA-CONICET-CICPBA, Campus Universitario, Tandil, Buenos Aires, Argentina; Universidad Nacional del Centro de la Provincia de Buenos Aires (UNCPBA), Facultad de Ciencias Veterinarias, Campus Universitario, Tandil, Buenos Aires, Argentina.
| | - Lucila Canton
- Laboratorio de Farmacología, Centro de Investigación Veterinaria de Tandil (CIVETAN), UNCPBA-CONICET-CICPBA, Campus Universitario, Tandil, Buenos Aires, Argentina; Universidad Nacional del Centro de la Provincia de Buenos Aires (UNCPBA), Facultad de Ciencias Veterinarias, Campus Universitario, Tandil, Buenos Aires, Argentina
| | - Adrian Lifschitz
- Laboratorio de Farmacología, Centro de Investigación Veterinaria de Tandil (CIVETAN), UNCPBA-CONICET-CICPBA, Campus Universitario, Tandil, Buenos Aires, Argentina; Universidad Nacional del Centro de la Provincia de Buenos Aires (UNCPBA), Facultad de Ciencias Veterinarias, Campus Universitario, Tandil, Buenos Aires, Argentina
| | - Maria Paula Dominguez
- Laboratorio de Farmacología, Centro de Investigación Veterinaria de Tandil (CIVETAN), UNCPBA-CONICET-CICPBA, Campus Universitario, Tandil, Buenos Aires, Argentina; Universidad Nacional del Centro de la Provincia de Buenos Aires (UNCPBA), Facultad de Ciencias Veterinarias, Campus Universitario, Tandil, Buenos Aires, Argentina
| | - Luis Alvarez
- Laboratorio de Farmacología, Centro de Investigación Veterinaria de Tandil (CIVETAN), UNCPBA-CONICET-CICPBA, Campus Universitario, Tandil, Buenos Aires, Argentina; Universidad Nacional del Centro de la Provincia de Buenos Aires (UNCPBA), Facultad de Ciencias Veterinarias, Campus Universitario, Tandil, Buenos Aires, Argentina
| | - Laura Ceballos
- Laboratorio de Farmacología, Centro de Investigación Veterinaria de Tandil (CIVETAN), UNCPBA-CONICET-CICPBA, Campus Universitario, Tandil, Buenos Aires, Argentina; Universidad Nacional del Centro de la Provincia de Buenos Aires (UNCPBA), Facultad de Ciencias Veterinarias, Campus Universitario, Tandil, Buenos Aires, Argentina
| | - Laura Mate
- Laboratorio de Farmacología, Centro de Investigación Veterinaria de Tandil (CIVETAN), UNCPBA-CONICET-CICPBA, Campus Universitario, Tandil, Buenos Aires, Argentina; Universidad Nacional del Centro de la Provincia de Buenos Aires (UNCPBA), Facultad de Ciencias Veterinarias, Campus Universitario, Tandil, Buenos Aires, Argentina
| | - Carlos Lanusse
- Laboratorio de Farmacología, Centro de Investigación Veterinaria de Tandil (CIVETAN), UNCPBA-CONICET-CICPBA, Campus Universitario, Tandil, Buenos Aires, Argentina; Universidad Nacional del Centro de la Provincia de Buenos Aires (UNCPBA), Facultad de Ciencias Veterinarias, Campus Universitario, Tandil, Buenos Aires, Argentina
| | - Mariana Ballent
- Laboratorio de Farmacología, Centro de Investigación Veterinaria de Tandil (CIVETAN), UNCPBA-CONICET-CICPBA, Campus Universitario, Tandil, Buenos Aires, Argentina; Universidad Nacional del Centro de la Provincia de Buenos Aires (UNCPBA), Facultad de Ciencias Veterinarias, Campus Universitario, Tandil, Buenos Aires, Argentina
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Lan T, Chen S, Zhang Y, Gan Z, Su S, Ding S, Sun W. Occurrence, ecology risk assessment and exposure evaluation of 19 anthelmintics in dust and soil from China. CHEMOSPHERE 2023; 334:138971. [PMID: 37207903 DOI: 10.1016/j.chemosphere.2023.138971] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2023] [Revised: 05/04/2023] [Accepted: 05/16/2023] [Indexed: 05/21/2023]
Abstract
In order to fill the blank of domestic research on anthelmintics in dust and soil, 159 paired dust (including indoor and outdoor dust) and soil samples were collected nationwide. All 19 kinds of the anthelmintics were detected in the samples. The total concentration of the target substances in the outdoor dust, indoor dust and soil samples ranged from 1.83 to 1.30 × 103 ng/g, from 2.99 to 6.00 × 103 ng/g and from 0.23 to 8.03 × 102 ng/g, respectively. The total concentration of the 19 anthelmintics in northern China were significantly higher than those in southern China in the outdoor dust and soil samples. No significant correlation was found in the total concentration of anthelmintics between the indoor and outdoor dust because of strong human activities interference, however, a significant correlation existed between the outdoor dust and soil samples and between the indoor dust and soil samples. High ecological risk was found at 35% and 28% of all the sampling sites to non-target organisms in the soil respectively for IVE and ABA, and merits further study. The daily anthelmintics intakes were evaluated via ingestion and dermal contact of soil and dust samples for both children and adults. Ingestion was the predominant way for anthelmintics exposure, and the anthelmintics in soil and dust did not pose a health threat to human health at present.
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Affiliation(s)
- Tianyang Lan
- College of Architecture and Environment, Sichuan University, Chengdu, 610065, China.
| | - Sibei Chen
- College of Architecture and Environment, Sichuan University, Chengdu, 610065, China
| | - Yujue Zhang
- College of Architecture and Environment, Sichuan University, Chengdu, 610065, China
| | - Zhiwei Gan
- College of Architecture and Environment, Sichuan University, Chengdu, 610065, China
| | - Shijun Su
- College of Architecture and Environment, Sichuan University, Chengdu, 610065, China
| | - Sanglan Ding
- College of Architecture and Environment, Sichuan University, Chengdu, 610065, China
| | - Weiyi Sun
- College of Architecture and Environment, Sichuan University, Chengdu, 610065, China.
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Shaver AO, Wit J, Dilks CM, Crombie TA, Li H, Aroian RV, Andersen EC. Variation in anthelmintic responses are driven by genetic differences among diverse C. elegans wild strains. PLoS Pathog 2023; 19:e1011285. [PMID: 37011090 PMCID: PMC10101645 DOI: 10.1371/journal.ppat.1011285] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Revised: 04/13/2023] [Accepted: 03/08/2023] [Indexed: 04/05/2023] Open
Abstract
Treatment of parasitic nematode infections in humans and livestock relies on a limited arsenal of anthelmintic drugs that have historically reduced parasite burdens. However, anthelmintic resistance (AR) is increasing, and little is known about the molecular and genetic causes of resistance for most drugs. The free-living roundworm Caenorhabditis elegans has proven to be a tractable model to understand AR, where studies have led to the identification of molecular targets of all major anthelmintic drug classes. Here, we used genetically diverse C. elegans strains to perform dose-response analyses across 26 anthelmintic drugs that represent the three major anthelmintic drug classes (benzimidazoles, macrocyclic lactones, and nicotinic acetylcholine receptor agonists) in addition to seven other anthelmintic classes. First, we found that C. elegans strains displayed similar anthelmintic responses within drug classes and significant variation across drug classes. Next, we compared the effective concentration estimates to induce a 10% maximal response (EC10) and slope estimates of each dose-response curve of each strain to the laboratory reference strain, which enabled the identification of anthelmintics with population-wide differences to understand how genetics contribute to AR. Because genetically diverse strains displayed differential susceptibilities within and across anthelmintics, we show that C. elegans is a useful model for screening potential nematicides before applications to helminths. Third, we quantified the levels of anthelmintic response variation caused by genetic differences among individuals (heritability) to each drug and observed a significant correlation between exposure closest to the EC10 and the exposure that exhibited the most heritable responses. These results suggest drugs to prioritize in genome-wide association studies, which will enable the identification of AR genes.
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Affiliation(s)
- Amanda O. Shaver
- Molecular Biosciences, Northwestern University, Evanston, Illinois, United States of America
| | - Janneke Wit
- Molecular Biosciences, Northwestern University, Evanston, Illinois, United States of America
| | - Clayton M. Dilks
- Molecular Biosciences, Northwestern University, Evanston, Illinois, United States of America
| | - Timothy A. Crombie
- Molecular Biosciences, Northwestern University, Evanston, Illinois, United States of America
| | - Hanchen Li
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Raffi V. Aroian
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Erik C. Andersen
- Molecular Biosciences, Northwestern University, Evanston, Illinois, United States of America
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Analysis of residual monepantel sulfone in milk using icELISA based on a monoclonal antibody developed from an easy-synthesized and low-cost hapten. J Food Compost Anal 2023. [DOI: 10.1016/j.jfca.2022.104897] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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8
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Tagboto S, Orish V. Drug development for onchocerciasis-the past, the present and the future. FRONTIERS IN TROPICAL DISEASES 2022. [DOI: 10.3389/fitd.2022.953061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Onchocerciasis affects predominantly rural communities in Africa, and with small foci in South America and the Yemen. The disease is a major cause of blindness and other significant morbidity and mortality. Control programs have achieved a major impact on the incidence and prevalence of onchocerciasis by interrupting transmission with vector control programs, and treatment with mass drug administration using the microfilaricide ivermectin. Over the last few decades, several microfilaricides have been developed. This initially included diethylcarbamazine, which had significant side effects and is no longer used as such. Ivermectin which is a safe and highly effective microfilaricide and moxidectin which is a longer acting microfilaricide are presently recognized therapies. Suramin was the first effective macrofilaricide but was prohibitively toxic. Certain antibiotics including doxycycline can help eliminate adult worms by targeting its endosymbiont bacteria, Wolbachia pipientis. However, the dosing regimens may make this difficult to use as part of a mass disease control program in endemic areas. It is now widely recognized that treatments that are able to kill or permanently sterilize adult filarial worms should help achieve the elimination of this disease. We summarize in detail the historic drug development in onchocerciasis, including prospective future candidate drugs.
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Boelow H, Krücken J, Thomas E, Mirams G, von Samson-Himmelstjerna G. Comparison of FECPAK G2, a modified Mini-FLOTAC technique and combined sedimentation and flotation for the coproscopic examination of helminth eggs in horses. Parasit Vectors 2022; 15:166. [PMID: 35549990 PMCID: PMC9097362 DOI: 10.1186/s13071-022-05266-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2021] [Accepted: 03/30/2022] [Indexed: 01/24/2023] Open
Abstract
Background Due to high prevalence of anthelmintic resistance in equine helminths, selective treatment is increasingly promoted and in some countries a positive infection diagnosis is mandatory before treatment. Selective treatment is typically recommended when the number of worm eggs per gram faeces (epg) exceeds a particular threshold. In the present study we compared the semi-quantitative sedimentation/flotation method with the quantitative methods Mini-FLOTAC and FECPAKG2 in terms of precision, sensitivity, inter-rater reliability and correlation of worm egg counts to improve the choice of optimal diagnostic tools. Methods Using sedimentation/flotation (counting raw egg numbers up to 200), we investigated 1067 horse faecal samples using a modified Mini-FLOTAC approach (multiplication factor of 5 to calculate epgs from raw egg counts) and FECPAKG2 (multiplication factor of 45). Results Five independent analyses of the same faecal sample with all three methods revealed that variance was highest for the sedimentation/flotation method while there were no significant differences between methods regarding the coefficient of variance. Sedimentation/flotation detected the highest number of samples positive for strongyle and Parascaris spp. eggs, followed by Mini-FLOTAC and FECPAKG2. Regarding Anoplocephalidae, no significant difference in frequency of positive samples was observed between Mini-FLOTAC and sedimentation/flotation. Cohen’s κ values comparing individual methods with the combined result of all three methods revealed almost perfect agreement (κ ≥ 0.94) for sedimentation/flotation and strong agreement for Mini-FLOTAC (κ ≥ 0.83) for strongyles and Parascaris spp. For FECPAKG2, moderate and weak agreements were found for the detection of strongyle (κ = 0.62) and Parascaris (κ = 0.51) eggs, respectively. Despite higher sensitivity, the Mini-FLOTAC mean epg was significantly lower than that with FECPAKG2 due to samples with > 200 raw egg counts by sedimentation/flotation, while in samples with lower egg shedding epgs were higher with Mini-FLOTAC than with FECPAKG2. Conclusions For the simple detection of parasite eggs, for example, to treat foals infected with Parascaris spp., sedimentation/flotation is sufficient and more sensitive than the other two quantitative investigared in this study. Mini-FLOTAC is predicted to deliver more precise results in faecal egg count reduction tests due to higher raw egg counts. Finally, to identify animals with a strongyle epg above a certain threshold for treatment, FECPAKG2 delivered results comparable to Mini-FLOTAC. Grpahical Abstract ![]()
Supplementary Information The online version contains supplementary material available at 10.1186/s13071-022-05266-y.
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Affiliation(s)
- Heike Boelow
- Institute for Parasitology and Tropical Veterinary Medicine, Freie Universität Berlin, Robert-von-Ostertag-Str. 7-13, 14163, Berlin, Germany
| | - Jürgen Krücken
- Institute for Parasitology and Tropical Veterinary Medicine, Freie Universität Berlin, Robert-von-Ostertag-Str. 7-13, 14163, Berlin, Germany.
| | - Eurion Thomas
- Techion UK, Peithyll Centre, Capel Dewi, Aberystwyth, SY23 3HU, Wales, UK
| | - Greg Mirams
- Techion New Zealand, Invermay Agriculture Centre, Block A, 176 Puddle Alley, Mosgiel, 9092, New Zealand
| | - Georg von Samson-Himmelstjerna
- Institute for Parasitology and Tropical Veterinary Medicine, Freie Universität Berlin, Robert-von-Ostertag-Str. 7-13, 14163, Berlin, Germany
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Rollins RL, Qader M, Gosnell WL, Wang C, Cao S, Cowie RH. A validated high-throughput method for assaying rat lungworm ( Angiostrongylus cantonensis) motility when challenged with potentially anthelmintic natural products from Hawaiian fungi. Parasitology 2022; 149:1-28. [PMID: 35236524 PMCID: PMC9440163 DOI: 10.1017/s0031182022000191] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Revised: 02/10/2022] [Accepted: 02/15/2022] [Indexed: 11/06/2022]
Abstract
Parasitic nematodes devastate human and animal health. The limited number of anthelmintics available is concerning, especially because of increasing drug resistance. Anthelmintics are commonly derived from natural products, e.g. fungi and plants. This investigation aimed to develop a high-throughput whole organism screening method based on a motility assay using the wMicroTracker system. Anthelmintic activity of extracts from Hawaiian fungi was screened against third-stage larvae of the parasitic nematode Angiostrongylus cantonensis , categorized according to the degree of motility reduction. Of the 108 crude samples and fractionated products, 48 showed some level of activity, with 13 reducing motility to 0–25% of the maximum exhibited, including two pure compounds, emethacin B and epicoccin E, neither previously known to exhibit anthelmintic properties. The process of bioassay-guided fractionation is illustrated in detail based on analysis of one of the crude extracts, which led to isolation of lamellicolic anhydride, a compound with moderate activity. This study validates the wMicroTracker system as an economical and high-throughput option for testing large suites of natural products against A. cantonensis , adds to the short list of diverse parasites for which it has been validated and highlights the value of A. cantonensis and Hawaiian fungi for discovery of new anthelmintics.
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Affiliation(s)
- Randi L. Rollins
- Pacific Biosciences Research Center, University of Hawaii, Honolulu, HI96822, USA
- School of Life Sciences, University of Hawaii at Manoa, Honolulu, HI96822, USA
| | - Mallique Qader
- Department of Pharmaceutical Sciences, Daniel K. Inouye College of Pharmacy, University of Hawaii at Hilo, Hilo, HI96720, USA
| | - William L. Gosnell
- Department of Tropical Medicine, Medical Microbiology and Pharmacology, John A. Burns School of Medicine, University of Hawaii, Honolulu, HI96813, USA
| | - Cong Wang
- Department of Pharmaceutical Sciences, Daniel K. Inouye College of Pharmacy, University of Hawaii at Hilo, Hilo, HI96720, USA
| | - Shugeng Cao
- Department of Pharmaceutical Sciences, Daniel K. Inouye College of Pharmacy, University of Hawaii at Hilo, Hilo, HI96720, USA
| | - Robert H. Cowie
- Pacific Biosciences Research Center, University of Hawaii, Honolulu, HI96822, USA
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Park KM, Kim SD, Park JB, Hong SJ, Ryu PD. Electrophysiological Properties of Ion Channels in Ascaris suum Tissue Incorporated into Planar Lipid Bilayers. THE KOREAN JOURNAL OF PARASITOLOGY 2021; 59:329-339. [PMID: 34470084 PMCID: PMC8413856 DOI: 10.3347/kjp.2021.59.4.329] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Accepted: 07/19/2021] [Indexed: 12/03/2022]
Abstract
Ion channels are important targets of anthelmintic agents. In this study, we identified 3 types of ion channels in Ascaris suum tissue incorporated into planar lipid bilayers using an electrophysiological technique. The most frequent channel was a large-conductance cation channel (209 pS), which accounted for 64.5% of channels incorporated (n=60). Its open-state probability (Po) was ~0.3 in the voltage range of −60~+60 mV. A substate was observed at 55% of the main-state. The permeability ratio of Cl− to K+ (PCl/PK) was ~0.5 and PNa/PK was 0.81 in both states. Another type of cation channel was recorded in 7.5% of channels incorporated (n=7) and discriminated from the large-conductance cation channel by its smaller conductance (55.3 pS). Its Po was low at all voltages tested (~0.1). The third type was an anion channel recorded in 27.9% of channels incorporated (n=26). Its conductance was 39.0 pS and PCl/PK was 8.6±0.8. Po was ~1.0 at all tested potentials. In summary, we identified 2 types of cation and 1 type of anion channels in Ascaris suum. Gating of these channels did not much vary with voltage and their ionic selectivity is rather low. Their molecular nature, functions, and potentials as anthelmintic drug targets remain to be studied further.
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Affiliation(s)
- Kwon Moo Park
- Department of Veterinary Pharmacology, College of Veterinary Medicine, Seoul National University, Seoul 08826, Korea.,Department of Anatomy, School of Medicine, Kyungpook National University, Daegu 41944, Korea
| | - Sun-Don Kim
- Department of Veterinary Pharmacology, College of Veterinary Medicine, Seoul National University, Seoul 08826, Korea.,ChemOn Inc., Yongin 17162, Korea
| | - Jin Bong Park
- Department of Physiology, College of Medicine, Chungnam National University, Daejeon 35015, Korea
| | - Sung-Jong Hong
- Department of Medical Environmental Biology, Chung-Ang University College of Medicine, Seoul 06974, Korea
| | - Pan Dong Ryu
- Department of Veterinary Pharmacology, College of Veterinary Medicine, Seoul National University, Seoul 08826, Korea
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12
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Wit J, Rodriguez BC, Andersen EC. Natural variation in Caenorhabditis elegans responses to the anthelmintic emodepside. Int J Parasitol Drugs Drug Resist 2021; 16:1-8. [PMID: 33878514 PMCID: PMC8079822 DOI: 10.1016/j.ijpddr.2021.04.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Revised: 04/01/2021] [Accepted: 04/06/2021] [Indexed: 11/19/2022]
Abstract
Treatment of parasitic nematode infections depends primarily on the use of anthelmintics. However, this drug arsenal is limited, and resistance against most anthelmintics is widespread. Emodepside is a new anthelmintic drug effective against gastrointestinal and filarial nematodes. Nematodes that are resistant to other anthelmintic drug classes are susceptible to emodepside, indicating that the emodepside mode of action is distinct from previous anthelmintics. The laboratory-adapted Caenorhabditis elegans strain N2 is sensitive to emodepside, and genetic selection and in vitro experiments implicated slo-1, a large K+ conductance (BK) channel gene, in emodepside mode of action. In an effort to understand how natural populations will respond to emodepside, we measured brood sizes and developmental rates of wild C. elegans strains after exposure to the drug and found natural variation across the species. Some of the observed variation in C. elegans emodepside responses correlates with amino acid substitutions in slo-1, but genetic mechanisms other than slo-1 coding variants likely underlie emodepside resistance in wild C. elegans strains. Additionally, the assayed strains have higher offspring production in low concentrations of emodepside (a hormetic effect). We find that natural variation affects emodepside sensitivity, supporting the suitability of C. elegans as a model system to study emodepside responses across natural nematode populations.
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Affiliation(s)
- Janneke Wit
- Molecular Biosciences, Northwestern University, Evanston, IL, 60208, USA
| | - Briana C Rodriguez
- Molecular Biosciences, Northwestern University, Evanston, IL, 60208, USA
| | - Erik C Andersen
- Molecular Biosciences, Northwestern University, Evanston, IL, 60208, USA.
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13
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Monepantel pharmaco-therapeutic evaluation in cattle: Pattern of efficacy against multidrug resistant nematodes. INTERNATIONAL JOURNAL FOR PARASITOLOGY-DRUGS AND DRUG RESISTANCE 2021; 15:162-167. [PMID: 33799058 PMCID: PMC8044591 DOI: 10.1016/j.ijpddr.2021.03.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Revised: 03/11/2021] [Accepted: 03/15/2021] [Indexed: 11/23/2022]
Abstract
The goal of the current work was to perform an integrated evaluation of monepantel (MNP) pharmacokinetics (PK) and pharmacodynamics, measured as anthelmintic efficacy, after its oral administration to calves naturally infected with GI nematodes resistant to ivermectin (IVM) and ricobendazole (RBZ) on three commercial farms. On each farm, forty-five calves were randomly allocated into three groups (n = 15): MNP oral administration (2.5 mg/kg); IVM subcutaneous (SC) administration (0.2 mg/kg); and RBZ SC administration (3.75 mg/kg). Eight animals from the MNP treated group (Farm 1) were selected to perform the PK study. Drug concentrations were measured by HPLC. The efficacy was determined by the faecal egg count reduction test (FECRT). MNP and MNP-sulphone (MNPSO2) were the main analytes recovered in plasma. MNPSO2 systemic exposure was markedly higher compared to that obtained for MNP. Higher Cmax and AUC values were obtained for the active MNPSO2 metabolite (96.8 ± 29.7 ng/mL and 9220 ± 1720 ng h/mL) compared to MNP (21.5 ± 4.62 ng/mL and 1709 ± 651 ng h/mL). The MNPSO2 AUC value was 6-fold higher compared to the parent drug. Efficacies of 99% (Farm 1), 96% (Farm 2) and 98% (Farm 3) demonstrated the high activity of MNP (P < 0.05) against GI nematodes resistant to IVM (reductions between 27 and 68%) and RBZ (overall efficacy of 75% on Farm 3). While IVM failed to control Haemonchus spp. and Cooperia spp., and RBZ failed to control Coooperia spp. and Ostertagia spp., MNP achieved 100% efficacy against Haemonchus spp., Cooperia spp. and Ostertagia spp. However, a low efficacy of MNP against Oesophagostomum spp. (efficacies ranging from 22 to 74%) was observed. In conclusion, oral treatment with MNP should be considered for dealing with IVM and benzimidazole resistant nematode parasites in cattle. The work described here reports for the first time an integrated assessment of MNP pharmaco-therapeutic features and highlights the need to be considered as a highly valuable tool to manage nematode resistant to other chemical families.
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14
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Bedogni GR, Pires FQ, Chaker JA, Sa-Barreto LL, Seremeta K, Okulik N, Salomon CJ, Cunha-Filho M. Elucidating the Splitting Behavior of Tablets to Optimize the Pharmacotherapy in Veterinary Medicine. AAPS PharmSciTech 2021; 22:67. [PMID: 33554316 DOI: 10.1208/s12249-021-01937-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Accepted: 01/15/2021] [Indexed: 11/30/2022] Open
Abstract
It is well known that the splitting of tablets can bring serious risks to the health of the treated animals, e.g., the possible adverse reactions caused by overdoses of fenbendazole or aspirin. In this regard, this work aimed to evaluate, for the first time, the splitting behavior of commercial veterinary tablets and identifying the technological aspects that interfere in this process. Tablets were cut in halves using a tablet splitter and were analyzed regarding mass variation, mass loss, friability, and hardness. Microstructural and morphological evaluations were also performed. For most of the tablets, organic flavor additives provided more uniformity and cohesive matrix, which preserved its hardness after the cut and led to subdivision results within acceptable limits for mass measurements and friability. Apart from the microstructure, the most critical technological aspect for a correct splitting performance in such tablets was the presence of a score. Thus, the results presented here allow us to guide the manufacturing of veterinary drug products in order to produce tablets more adapted to the splitting process.
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15
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Aderibigbe SA, Idowu SO, Olaniyi AA, Wright CW, Fatokun AA. Bioactivity and cytotoxicity profiling of vincosamide and strictosamide, anthelmintic epimers from Sarcocephalus latifolius (Smith) Bruce leaf. JOURNAL OF ETHNOPHARMACOLOGY 2021; 265:113142. [PMID: 32697959 DOI: 10.1016/j.jep.2020.113142] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2020] [Revised: 06/09/2020] [Accepted: 07/01/2020] [Indexed: 06/11/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE The leaf of Sarcocephalus latifolius is known to be used traditionally by the Fulanis in Nigeria to deworm animals. As helminthosis remains a major constraint to profitable livestock production worldwide, a precarious situation aggravated by the advent of resistant parasites, the discovery of new anthelmintics is a priority, necessitating exploration of medicinal plants for their anthelmintic principles. AIM OF THE STUDY To identify and characterise compounds with anthelmintic activity from the leaf of Sarcocephalus latifolius. MATERIALS AND METHODS Powdered S. latifolius leaves were extracted by successive maceration with n-hexane, chloroform and acetone. The dried extracts were evaluated for anthelmintic activity against Haemonchus placei adult worms, and the most active extract was subjected to bioassay-guided chromatographic separations. The isolated compounds were evaluated for cytotoxicity against the mammalian HeLa and MC3T3-E1 cell lines, using alamar blue and CellTitreGloTM to quantify cell viability. LC50 values were computed from the in vitro anthelmintic activity data by fitting to a non-linear regression equation (variable slope). Isolated compounds were characterized using spectroscopic and mass spectrometric analyses. RESULTS Anthelmintic activity LC50 values for n-hexane, chloroform and acetone extracts were 47.85, 35.76 and 5.72 (mg/mL), respectively. Chromatographic separation of acetone extract afforded two bioactive epimers, identified as vincosamide (LC50 14.7 mg/mL) and strictosamide (LC50 12.8 mg/mL). Cytotoxicity evaluation showed that, below 200 μg/mL (400 μM), neither compound was toxic to the HeLa or MC3T3-E1 cells. CONCLUSION Vincosamide and strictosamide could serve as novel scaffolds for the development of anthelmintic derivatives with improved potency and helminth selectivity.
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Affiliation(s)
- Segun A Aderibigbe
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, University of Ibadan, Ibadan, Oyo State, Nigeria; School of Pharmacy and Medical Sciences, Faculty of Life Sciences, University of Bradford, Bradford, BD7 1DP, UK
| | - Sunday O Idowu
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, University of Ibadan, Ibadan, Oyo State, Nigeria.
| | - Ajibola A Olaniyi
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, University of Ibadan, Ibadan, Oyo State, Nigeria
| | - Colin W Wright
- School of Pharmacy and Medical Sciences, Faculty of Life Sciences, University of Bradford, Bradford, BD7 1DP, UK
| | - Amos A Fatokun
- School of Pharmacy and Medical Sciences, Faculty of Life Sciences, University of Bradford, Bradford, BD7 1DP, UK.
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16
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Verma S, Kulke D, McCall JW, Martin RJ, Robertson AP. Recording drug responses from adult Dirofilaria immitis pharyngeal and somatic muscle cells. INTERNATIONAL JOURNAL FOR PARASITOLOGY-DRUGS AND DRUG RESISTANCE 2020; 15:1-8. [PMID: 33348209 PMCID: PMC7753077 DOI: 10.1016/j.ijpddr.2020.12.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Revised: 12/09/2020] [Accepted: 12/11/2020] [Indexed: 12/13/2022]
Abstract
Despite being considered one of the most pathogenic helminth infections of companion animals, members of macrocyclic lactone class are the only drugs available for the prevention of heartworm disease caused by Dirofilaria immitis. Alarmingly, heartworm prevention is at risk; several studies confirm the existence of macrocyclic lactone resistance in D. immitis populations across the United States. To safeguard the long term prevention and control of this disease, the identification and development of novel anthelmintics is urgently needed. To identify novel, resistance-breaking drugs, it is highly desirable to: Unfortunately, none of the three above statements can be answered sufficiently for D. immitis and most of our hypotheses derive from surrogate species and/or in vitro studies. Therefore, the present study aims to improve our fundamental understanding of the neuromuscular system of the canine heartworm by establishing new methods allowing the investigation of body wall and pharyngeal muscle responses and their modulation by anthelmintics. We found that the pharynx of adult D. immitis responds to both ivermectin and moxidectin with EC50s in the low micromolar range. We also demonstrate that the somatic muscle cells have robust responses to 30 μM acetylcholine, levamisole, pyrantel and nicotine. This is important preliminary data, demonstrating the feasibility of electrophysiological studies in this important parasite.
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Affiliation(s)
- S Verma
- Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA, 50011, USA
| | - D Kulke
- Drug Discovery and External Innovation, Bayer Animal Health GmbH, 51373, Leverkusen, Germany.
| | | | - R J Martin
- Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA, 50011, USA
| | - A P Robertson
- Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA, 50011, USA
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17
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El Bialy SA, Mansour B, Bayoumi WA, Taman A, Eissa HM. Novel 2-(5-Aryl)thiophen-2-yl)benzimidazoles; Design, Synthesis and In vitro Evaluation Against Cercarial Phase of Schistosoma mansoni. LETT DRUG DES DISCOV 2020. [DOI: 10.2174/1570180817999200523181211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Background:
Literature survey has pointed out that Benzimidazoles represent an interesting
class of anthelmintics, of which several potent members were developed.
Objective:
Benzimidazoles hybridized with pharmacophoric moieties possessing anthelmintic activity
were designed, synthesized to be evaluated against cercaria.
Methods:
Structural modification was achieved through 2- and 5-positions. Moreover, an in vitro
cercarial assay was adopted to evaluate target compounds.
Results and Discussion:
Biological screening revealed that compound 3h showed significant activity
with a survival index of 35% at a 100 μg/mL concentration. Whereas, compounds 3a and 3c
showed moderate activity, the rest of the tested compounds exhibited low activity.
Conclusion:
The current study evidenced that the new hybrids "benzimidazole-thiophen-aryl" are
successful as cercacidal agents. Further studies of this novel tri-ring system are suggested on adult
worms of S. mansoni.
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Affiliation(s)
- Serry Atta El Bialy
- Department of Pharmaceutical Organic Chemistry, Faculty of Pharmacy, Mansoura University, Mansoura 35516, Egypt
| | - Basem Mansour
- Department of Pharmaceutical Organic Chemistry, Faculty of Pharmacy, Mansoura University, Mansoura 35516, Egypt
| | - Waleed Abdelhakeem Bayoumi
- Department of Pharmaceutical Organic Chemistry, Faculty of Pharmacy, Mansoura University, Mansoura 35516, Egypt
| | - Amira Taman
- Department of Medical Parasitology, Faculty of Medicine, Mansoura University, Mansoura 35516, Egypt
| | - Hassan Mohammed Eissa
- Department of Pharmaceutical Organic Chemistry, Faculty of Pharmacy, Mansoura University, Mansoura 35516, Egypt
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18
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Bais S, Greenberg RM. Schistosome TRP channels: An appraisal. Int J Parasitol Drugs Drug Resist 2020; 13:1-7. [PMID: 32250774 PMCID: PMC7138929 DOI: 10.1016/j.ijpddr.2020.02.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Revised: 02/14/2020] [Accepted: 02/16/2020] [Indexed: 02/07/2023]
Abstract
Ion channels underlie electrical excitability in cells and are essential for a variety of functions, most notably neuromuscular and sensory activity. They are also validated targets for a preponderance of approved anthelmintic compounds. Transient receptor potential (TRP) channels constitute an ion channel superfamily whose members play important roles in sensory signaling, regulation of ion homeostasis, organellar trafficking, and other key cellular and organismal activities. Unlike most other ion channels, TRP channels are often polymodal, gated by a variety of mechanisms. Furthermore, TRP channels fall into several classes or subtypes based on sequence and structure. Until recently, there had been very little investigation of the properties and functions of TRP channels from parasitic helminths, including schistosomes, but that situation has changed in the past few years. Indeed, it is now clear that at least some schistosome TRP channels exhibit unusual pharmacological properties, and, intriguingly, both a mammalian and a schistosome TRP channel are activated by praziquantel, the current antischistosomal drug of choice. With the latest release of the Schistosoma mansoni genome database, several changes in predicted TRP channel sequences appeared, some of which were significant. This review updates and reassesses the TRP channel repertoire in S. mansoni, examines recent findings regarding these potential therapeutic targets, and provides guideposts for some of the physiological functions that may be mediated by these channels in schistosomes.
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Affiliation(s)
- Swarna Bais
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, 3800 Spruce Street, Philadelphia, PA, 19104, USA
| | - Robert M Greenberg
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, 3800 Spruce Street, Philadelphia, PA, 19104, USA.
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19
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Partridge FA, Forman R, Bataille CJR, Wynne GM, Nick M, Russell AJ, Else KJ, Sattelle DB. Anthelmintic drug discovery: target identification, screening methods and the role of open science. Beilstein J Org Chem 2020; 16:1203-1224. [PMID: 32550933 PMCID: PMC7277699 DOI: 10.3762/bjoc.16.105] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Accepted: 05/12/2020] [Indexed: 12/13/2022] Open
Abstract
Helminths, including cestodes, nematodes and trematodes, are a huge global health burden, infecting hundreds of millions of people. In many cases, existing drugs such as benzimidazoles, diethylcarbamazine, ivermectin and praziquantel are insufficiently efficacious, contraindicated in some populations, or at risk of the development of resistance, thereby impeding progress towards World Health Organization goals to control or eliminate these neglected tropical diseases. However, there has been limited recent progress in developing new drugs for these diseases due to lack of commercial attractiveness, leading to the introduction of novel, more efficient models for drug innovation that attempt to reduce the cost of research and development. Open science aims to achieve this by encouraging collaboration and the sharing of data and resources between organisations. In this review we discuss how open science has been applied to anthelmintic drug discovery. Open resources, including genomic information from many parasites, are enabling the identification of targets for new antiparasitic agents. Phenotypic screening remains important, and there has been much progress in open-source systems for compound screening with parasites, including motility assays but also high content assays with more detailed investigation of helminth physiology. Distributed open science compound screening programs, such as the Medicines for Malaria Venture Pathogen Box, have been successful at facilitating screening in diverse assays against many different parasite pathogens and models. Of the compounds identified so far in these screens, tolfenpyrad, a repurposed insecticide, shows significant promise and there has been much progress in creating more potent and selective derivatives. This work exemplifies how open science approaches can catalyse drug discovery against neglected diseases.
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Affiliation(s)
- Frederick A Partridge
- Centre for Respiratory Biology, UCL Respiratory, Division of Medicine, University College London, Gower Street, London, WC1E 6BT, United Kingdom
| | - Ruth Forman
- The Lydia Becker Institute for Immunology and Inflammation, Faculty of Biology, Medicine and Health, University of Manchester, Oxford Road, Manchester, M13 9PL, United Kingdom
| | - Carole J R Bataille
- Department of Chemistry, Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford, OX1 3TA United Kingdom
| | - Graham M Wynne
- Department of Chemistry, Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford, OX1 3TA United Kingdom
| | - Marina Nick
- Centre for Respiratory Biology, UCL Respiratory, Division of Medicine, University College London, Gower Street, London, WC1E 6BT, United Kingdom
| | - Angela J Russell
- Department of Chemistry, Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford, OX1 3TA United Kingdom
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford, OX1 3QT, United Kingdom
| | - Kathryn J Else
- The Lydia Becker Institute for Immunology and Inflammation, Faculty of Biology, Medicine and Health, University of Manchester, Oxford Road, Manchester, M13 9PL, United Kingdom
| | - David B Sattelle
- Centre for Respiratory Biology, UCL Respiratory, Division of Medicine, University College London, Gower Street, London, WC1E 6BT, United Kingdom
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20
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Liu M, Panda SK, Luyten W. Plant-Based Natural Products for the Discovery and Development of Novel Anthelmintics against Nematodes. Biomolecules 2020; 10:biom10030426. [PMID: 32182910 PMCID: PMC7175113 DOI: 10.3390/biom10030426] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Revised: 02/27/2020] [Accepted: 03/02/2020] [Indexed: 12/11/2022] Open
Abstract
Intestinal parasitic nematodes infect approximately two billion people worldwide. In the absence of vaccines for human intestinal nematodes, control of infections currently relies mainly on chemotherapy, but resistance is an increasing problem. Thus, there is an urgent need for the discovery and development of new anthelmintic drugs, especially ones with novel mechanisms of action. Medicinal plants hold great promise as a source of effective treatments, including anthelmintic therapy. They have been used traditionally for centuries and are mostly safe (if not, their toxicity is well-known). However, in most medicinal plants the compounds active against nematodes have not been identified thus far. The free-living nematode C. elegans was demonstrated to be an excellent model system for the discovery of new anthelmintics and for characterizing their mechanism of action or resistance. The compounds discussed in this review are of botanical origin and were published since 2002. Most of them need further studies of their toxicity, mechanisms and structure-activity relationship to assess more fully their potential as drugs.
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21
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Jiao Y, Preston S, Hofmann A, Taki A, Baell J, Chang BCH, Jabbar A, Gasser RB. A perspective on the discovery of selected compounds with anthelmintic activity against the barber's pole worm-Where to from here? ADVANCES IN PARASITOLOGY 2020; 108:1-45. [PMID: 32291083 DOI: 10.1016/bs.apar.2019.12.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Parasitic roundworms (nematodes) cause substantial morbidity and mortality in animals worldwide. Anthelmintic treatment is central to controlling these worms, but widespread resistance to most of the commercially available anthelmintics for veterinary and agricultural use is compromising control, such that there is an urgency to discover new and effective drugs. The purpose of this article is to review information on parasitic nematodes, the treatment and control of parasitic nematode infections and aspects of discovering new anthelmintics in the context of anthelmintic resistance problems, and then to discuss some progress that our group has made in identifying selected compounds with activity against nematodes. The focus of our recent work has been on discovering new chemical entities and known drugs with anthelmintic activities against Haemonchus contortus as well as other socioeconomically important parasitic nematodes for subsequent development. Using whole worm-based phenotypic assays, we have been screening compound collections obtained via product-development-partnerships and/or collaborators, and active compounds have been assessed for their potential as anthelmintic candidates. Following the screening of 15,333 chemicals from five distinct compound collections against H. contortus, we have discovered one new chemical entity (designated SN00797439), two human kinase inhibitors (SNS-032 and AG-1295), 14 tetrahydroquinoxaline analogues, one insecticide (tolfenpyrad) and two tolfenpyrad (pyrazole-5-carboxamide) derivatives (a-15 and a-17) with anthelmintic activity in vitro. Some of these 20 'hit' compounds have selectivity against H. contortus in vitro when compared to particular human cell lines. In our opinion, some of these compounds could represent starting points for 'lead' development. Accordingly, the next research steps to be pursued include: (i) chemical optimisation of representative chemicals via structure-activity relationship (SAR) evaluations; (ii) assessment of the breadth of spectrum of anthelmintic activity on a range of other parasitic nematodes, such as strongyloids, ascaridoids, enoplids and filarioids; (iii) detailed investigations of the absorption, distribution, metabolism, excretion and toxicity (ADMET) of optimised chemicals with broad nematocidal or nematostatic activity; and (iv) establishment of the modes of action of lead candidates.
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Affiliation(s)
- Yaqing Jiao
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, VIC, Australia
| | - Sarah Preston
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, VIC, Australia; Faculty of Science and Technology, Federation University, Ballarat, VIC, Australia
| | - Andreas Hofmann
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, VIC, Australia
| | - Aya Taki
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, VIC, Australia
| | - Jonathan Baell
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
| | - Bill C H Chang
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, VIC, Australia
| | - Abdul Jabbar
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, VIC, Australia.
| | - Robin B Gasser
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, VIC, Australia.
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22
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Ruan B, Zhang Y, Tadesse S, Preston S, Taki AC, Jabbar A, Hofmann A, Jiao Y, Garcia-Bustos J, Harjani J, Le TG, Varghese S, Teguh S, Xie Y, Odiba J, Hu M, Gasser RB, Baell J. Synthesis and structure-activity relationship study of pyrrolidine-oxadiazoles as anthelmintics against Haemonchus contortus. Eur J Med Chem 2020; 190:112100. [PMID: 32018095 DOI: 10.1016/j.ejmech.2020.112100] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Revised: 01/22/2020] [Accepted: 01/22/2020] [Indexed: 02/07/2023]
Abstract
Parasitic roundworms (nematodes) are significant pathogens of humans and animals and cause substantive socioeconomic losses due to the diseases that they cause. The control of nematodes in livestock animals relies heavily on the use of anthelmintic drugs. However, their extensive use has led to a widespread problem of drug resistance in these worms. Thus, the discovery and development of novel chemical entities for the treatment of parasitic worms of humans and animals is needed. Herein, we describe our medicinal chemistry optimization efforts of a phenotypic hit against Haemonchus contortus based on a pyrrolidine-oxadiazole scaffold. This led to the identification of compounds with potent inhibitory activities (IC50 = 0.78-22.4 μM) on the motility and development of parasitic stages of H. contortus, and which were found to be highly selective in a mammalian cell counter-screen. These compounds could be used as suitable chemical tools for drug target identification or as lead compounds for further optimization.
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Affiliation(s)
- Banfeng Ruan
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Melbourne, Victoria, 3052, Australia; Key Lab of Biofabrication of Anhui Higher Education, Institution Centre for Advanced Biofabrication, Hefei University, Hefei, 230601, PR China
| | - Yuezhou Zhang
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Melbourne, Victoria, 3052, Australia; Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, VIC, 3010, Australia; State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, 430070, China
| | - Solomon Tadesse
- Department of Pharmaceutical Chemistry and Pharmacognosy, School of Pharmacy, College of Health Sciences, Addis Ababa University, Addis Ababa, Ethiopia
| | - Sarah Preston
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, VIC, 3010, Australia; School of Health and Life Sciences, Federation University, Ballarat, Victoria, 3353, Australia
| | - Aya C Taki
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, VIC, 3010, Australia
| | - Abdul Jabbar
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, VIC, 3010, Australia
| | - Andreas Hofmann
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, VIC, 3010, Australia
| | - Yaqing Jiao
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, VIC, 3010, Australia
| | - Jose Garcia-Bustos
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, VIC, 3010, Australia
| | - Jitendra Harjani
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Melbourne, Victoria, 3052, Australia
| | - Thuy Giang Le
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Melbourne, Victoria, 3052, Australia
| | - Swapna Varghese
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Melbourne, Victoria, 3052, Australia
| | - Silvia Teguh
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Melbourne, Victoria, 3052, Australia
| | - Yiyue Xie
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Melbourne, Victoria, 3052, Australia
| | - Jephthah Odiba
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Melbourne, Victoria, 3052, Australia
| | - Min Hu
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, 430070, China
| | - Robin B Gasser
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, VIC, 3010, Australia
| | - Jonathan Baell
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Melbourne, Victoria, 3052, Australia; School of Pharmaceutical Sciences, Nanjing Tech University, No. 30, South Puzhu Road, Nanjing, 211816, PR China; ARC Centre for Fragment-Based Design, Monash University, Parkville, VIC, 3052, Australia; Australian Translational Medicinal Chemistry Facility (ATMCF), Monash University, Parkville, Victoria, 3052, Australia.
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Gaens D, Leithäuser C, Hamann M, Geyer J. Adverse Drug Reactions After Administration of Emodepside/Praziquantel (Profender®) in an MDR1-Mutant Australian Shepherd Dog: Case Report. Front Vet Sci 2019; 6:296. [PMID: 31555677 PMCID: PMC6743036 DOI: 10.3389/fvets.2019.00296] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Accepted: 08/19/2019] [Indexed: 11/22/2022] Open
Abstract
A 3-year-old male Australian Shepherd was presented with signs of neurological toxicity following the administration of Profender® at the recommended dosage. Unfortunately, the owner had received the product from a veterinarian without any further instructions on fasting as recommended by the manufacturer, so the dog was fed prior to Profender® administration. Neurological toxicity included generalized tremor, agitation and panting, and required hospitalization of the dog. All neurological signs resolved after symptomatic treatment within 24 h and the dog was discharged without the need for further medication. MDR1 genotyping revealed a homozygous mutation of the MDR1 gene, which is normally important to prevent brain penetration of emodepside by an efflux-based transport mechanism at the blood brain barrier. This case indicates that Profender® can lead to serious, but transient neurological toxicity in dogs with homozygous MDR1 mutation even at therapeutic dosage, in particular when fasting recommendations are disregarded. Therefore, the case report highlights both the importance of MDR1 genotyping in predisposed dog breeds as well as strict compliance with fasting recommendations around the time of Profender® administration.
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Affiliation(s)
- Daniela Gaens
- Faculty of Veterinary Medicine, Institute of Pharmacology and Toxicology, Justus Liebig University Giessen, Giessen, Germany
| | - Carola Leithäuser
- Animal Clinic Norderstedt, Evidensia Tierärztliche Klinik Für Kleintiere, Norderstedt, Germany
| | - Melanie Hamann
- Faculty of Veterinary Medicine, Institute of Pharmacology and Toxicology, Justus Liebig University Giessen, Giessen, Germany
| | - Joachim Geyer
- Faculty of Veterinary Medicine, Institute of Pharmacology and Toxicology, Justus Liebig University Giessen, Giessen, Germany
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24
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Ng B, Chanabun R, Panha S. Biological and physiological responses of Perionyx excavatus to abamectin. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2019; 26:28309-28318. [PMID: 31368070 DOI: 10.1007/s11356-019-06013-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Accepted: 07/22/2019] [Indexed: 06/10/2023]
Abstract
Biological and behavioral responses of the tropical earthworm Perionyx excavatus towards different concentrations of abamectin were evaluated. Abamectin significantly reduced the biomass and reproduction (cocoon production) of P. excavatus as well as inducing histopathological alterations in the cuticle. Biomass loss was recorded in P. excavatus exposed to abamectin at a concentration as low as 0.1 mg active ingredient (a.i.) kg-1, while atrophy, another physiological response, was observed at an abamectin concentration of 0.21 μg cm-2 in a filter paper test. Cocoon production was significantly reduced in the presence of abamectin, and no cocoons were produced at doses of 20 mg a.i. kg-1 or higher, while abamectin at 50 mg a.i. kg-1 induced extreme pathology, characterized by the loss of the integrity of the whole body wall and intestine of P. excavatus. Histopathological alterations can be used as a biomarker to evaluate the toxicological impact of exposure to abamectin.
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Affiliation(s)
- Beewah Ng
- Animal Systematics Research Unit, Department of Biology, Faculty of Science, Chulalongkorn University, 254 Phayathai Road, Pathumwan, Bangkok, 10330, Thailand
| | - Ratmanee Chanabun
- Program in Animal Science, Faculty of Agriculture Technology, Sakon Nakhon Rajabhat University, Sakon Nakhon, 47000, Thailand
| | - Somsak Panha
- Animal Systematics Research Unit, Department of Biology, Faculty of Science, Chulalongkorn University, 254 Phayathai Road, Pathumwan, Bangkok, 10330, Thailand.
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25
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An appraisal of natural products active against parasitic nematodes of animals. Parasit Vectors 2019; 12:306. [PMID: 31208455 PMCID: PMC6580475 DOI: 10.1186/s13071-019-3537-1] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Accepted: 05/27/2019] [Indexed: 12/28/2022] Open
Abstract
Here, the scientific and patent literature on the activities of purified natural compounds has been reviewed, with the aim of assessing their suitability as anthelmintic drug discovery starting points. Only compounds described as active against parasitic nematodes of animals or against the model nematode Caenorhabditis elegans have been analysed. Scientific articles published since 2010 and patents granted from 2000, both inclusive, have been included in this analysis. The results show a scarcity of novel chemical structures, a limited follow-up of compounds disclosed before 2010 and a bias towards the screening of plant products, almost to the exclusion of other sources, when microbial extracts have, historically, provided most starting points for anti-infective drugs. All plant products published in this period were previously known, alerting to the high re-discovery rates of a limited number of chemical classes from this source. The most promising compounds described in the literature reviewed here, namely the linear nemadectin-derivatives, are novel and of bacterial origin. Patented but otherwise unpublished spiroketal structures also appear as interesting scaffolds for future development. The patent literature confirmed that it is possible to patent derivatives of previously known products, making them valid starting points for translational research.
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Karpstein T, Pasche V, Häberli C, Scandale I, Neodo A, Keiser J. Evaluation of emodepside in laboratory models of human intestinal nematode and schistosome infections. Parasit Vectors 2019; 12:226. [PMID: 31088525 PMCID: PMC6515646 DOI: 10.1186/s13071-019-3476-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Accepted: 04/30/2019] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Helminthiases are very prevalent worldwide, yet their treatment and control rely on a handful of drugs. Emodepside, a marketed broad-spectrum veterinary anthelminthic with a unique mechanism of action, undergoing development for onchocerciasis is an interesting anthelmintic drug candidate. We tested the in vitro and in vivo activity of emodepside on nematode species that serve as models for human soil-transmitted helminth infection as well as on schistosomes. METHODS In vitro viability assays were performed over a time course of 72 hours for Trichuris muris, Necator americanus, Ancylostoma ceylanicum, Heligmosomoides polygyrus, Strongyloides ratti, Schistosoma mansoni and Schistosoma haematobium. The drug effect was determined by the survival rate for the larvae and by phenotypical scores for the adult worms. Additionally, mice infected with T. muris and hamsters harboring hookworm infection (N. americanus or A. ceylanicum) were administered orally with emodepside at doses ranging from 1.25 to 75 mg/kg. Expelled worms in the feces were counted until 3 days post-drug intake and worms residing in the intestines were collected and counted after dissection. RESULTS After 24 hours, emodepside was very active in vitro against both larval and adult stages of the nematodes T. muris, A. ceylanicum, N. americanus, H. polygyrus and S. ratti (IC50 < 4 µM). The good in vitro activity was confirmed in vivo. Hamsters infected with the hookworms were cured when administered orally with 2.5 mg/kg of the drug. Emodepside was also highly active in vivo against T. muris (ED50 = 1.2 mg/kg). Emodepside was moderately active on schistosomula in vitro (IC50 < 8 µM) 24 h post-drug incubation and its activity on adult S. mansoni and S. haematobium was low (IC50: 30-50 µM). CONCLUSIONS Emodepside is highly active against a broad range of nematode species both in vitro and in vivo. The development of emodepside for treating soil-transmitted helminth infections should be pursued.
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Affiliation(s)
- Tanja Karpstein
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Valérian Pasche
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Cécile Häberli
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Ivan Scandale
- Drugs for Neglected Disease initiative, Chemin Louis-Dunant 15, 1202 Geneva, Switzerland
| | - Anna Neodo
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Jennifer Keiser
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
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27
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Kumarasingha R, Young ND, Yeo TC, Lim DSL, Tu CL, Palombo EA, Shaw JM, Gasser RB, Boag PR. Transcriptional alterations in Caenorhabditis elegans following exposure to an anthelmintic fraction of the plant Picria fel-terrae Lour. Parasit Vectors 2019; 12:181. [PMID: 31023350 PMCID: PMC6485125 DOI: 10.1186/s13071-019-3429-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Accepted: 04/03/2019] [Indexed: 01/18/2023] Open
Abstract
Background Natural compounds from plants are known to provide a source of anthelmintic molecules. In previous studies, we have shown that plant extracts from the plant Picria fel-terrae Lour. and particular fractions thereof have activity against the free-living nematode Caenorhabditis elegans, causing quite pronounced stress responses in this nematode. We have also shown that a fraction, designated Pf-fraction 5, derived from this plant has a substantial adverse effect on this worm; however, nothing is known about the molecular processes affected in the worm. In the present study, we explored this aspect. Results Key biological processes linked to upregulated genes (n = 214) included ‘response to endoplasmic reticulum stress’ and ‘lipid metabolism’, and processes representing downregulated genes (n = 357) included ‘DNA-conformation change’ and ‘cellular lipid metabolism’. Conclusions Exposure of C. elegans to Pf-fraction 5 induces significant changes in the transcriptome. Gene ontology analysis suggests that Pf-fraction 5 induces endoplasmic reticulum and mitochondrial stress, and the changes in gene expression are either a direct or indirect consequence of this. Further work is required to assess specific responses to sub-fractions of Pf-fraction 5 in time-course experiments in C. elegans, to define the chemical(s) with potent anthelmintic properties, to attempt to unravel their mode(s) of action and to assess their selectivity against nematodes. Electronic supplementary material The online version of this article (10.1186/s13071-019-3429-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Rasika Kumarasingha
- Development and Stem Cells Program, Monash Biomedicine Discovery Institute, Clayton, Victoria, 3800, Australia.,Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria, 3800, Australia
| | - Neil D Young
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, Victoria, 3010, Australia
| | - Tiong-Chia Yeo
- Sarawak Biodiversity Centre, KM 20 Jalan Borneo Heights, Semengoh, Locked Bag 3032, 93990, Kuching, Sarawak, Malaysia
| | - Diana S L Lim
- Sarawak Biodiversity Centre, KM 20 Jalan Borneo Heights, Semengoh, Locked Bag 3032, 93990, Kuching, Sarawak, Malaysia
| | - Chu-Lee Tu
- Sarawak Biodiversity Centre, KM 20 Jalan Borneo Heights, Semengoh, Locked Bag 3032, 93990, Kuching, Sarawak, Malaysia
| | - Enzo A Palombo
- Department of Chemistry and Biotechnology, Faculty of Science, Engineering and Technology, Swinburne University of Technology, Hawthorn, Victoria, 3122, Australia
| | - Jillian M Shaw
- Department of Health and Medical Sciences, Faculty of Health, Arts and Design, Swinburne University of Technology, Hawthorn, Victoria, 3122, Australia
| | - Robin B Gasser
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, Victoria, 3010, Australia.
| | - Peter R Boag
- Development and Stem Cells Program, Monash Biomedicine Discovery Institute, Clayton, Victoria, 3800, Australia. .,Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria, 3800, Australia. .,Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, Victoria, 3010, Australia.
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28
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Bais S, Greenberg RM. TRP channels as potential targets for antischistosomals. Int J Parasitol Drugs Drug Resist 2018; 8:511-517. [PMID: 30224169 PMCID: PMC6287577 DOI: 10.1016/j.ijpddr.2018.08.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Revised: 08/23/2018] [Accepted: 08/28/2018] [Indexed: 01/08/2023]
Abstract
Ion channels are membrane protein complexes that underlie electrical excitability in cells, allowing ions to diffuse through cell membranes in a regulated fashion. They are essential for normal functioning of the neuromusculature and other tissues. Ion channels are also validated targets for many current anthelmintics, yet the properties of only a small subset of ion channels in parasitic helminths have been explored in any detail. Transient receptor potential (TRP) channels comprise a widely diverse superfamily of ion channels with important roles in sensory signaling, regulation of ion homeostasis, organellar trafficking, and other functions. There are several subtypes of TRP channels, including TRPA1 and TRPV1 channels, both of which are involved in, among other functions, sensory, nociceptive, and inflammatory signaling in mammals. Several lines of evidence indicate that TRPA1-like channels in schistosomes exhibit pharmacological sensitivities that differ from their mammalian counterparts and that may signify unique physiological properties as well. Thus, in addition to responding to TRPA1 modulators, schistosome TRPA1-like channels also respond to compounds that in other organisms modulate TRPV1 channels. Notably, TRPV channel genes are not found in schistosome genomes. Here, we review the evidence leading to these conclusions and examine potential implications. We also discuss recent results showing that praziquantel, the current drug of choice against schistosomiasis, selectively targets host TRP channels in addition to its likely primary targets in the parasite. The results we discuss add weight to the notion that schistosome TRP channels are worthy of investigation as candidate therapeutic targets.
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Affiliation(s)
- Swarna Bais
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, 3800 Spruce Street, Philadelphia PA 19104, USA
| | - Robert M Greenberg
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, 3800 Spruce Street, Philadelphia PA 19104, USA.
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29
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Liu M, Kipanga P, Mai AH, Dhondt I, Braeckman BP, De Borggraeve W, Luyten W. Bioassay-guided isolation of three anthelmintic compounds from Warburgia ugandensis Sprague subspecies ugandensis, and the mechanism of action of polygodial. Int J Parasitol 2018; 48:833-844. [PMID: 30031002 DOI: 10.1016/j.ijpara.2017.11.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2017] [Revised: 11/27/2017] [Accepted: 11/27/2017] [Indexed: 12/21/2022]
Abstract
Parasitic helminths continue to pose problems in human and veterinary medicine, as well as in agriculture. Resistance to current anthelmintics has prompted the search for new drugs. Anthelmintic metabolites from medicinal plants could be good anthelmintic drug candidates. However, the compounds active against nematodes have not been identified in most medicinal plants with anthelmintic activity. In this study, we aimed to identify the active compounds against helminths in Warburgia ugandensis Sprague subspecies ugandensis (Canellaceae) and study the underlying mechanism of action. A bioassay-guided isolation of anthelmintic compounds from the plant was performed using a Caenorhabditis elegans (C. elegans) test model with a WMicrotracker instrument to monitor motility. Three active compounds were purified and identified by nuclear magnetic resonance and high resolution MS: warburganal (IC50: 28.2 ± 8.6 μM), polygodial (IC50: 13.1 ± 5.3 μM) and alpha-linolenic acid (ALA, IC50: 70.1 ± 17.5 μM). A checkerboard assay for warburganal and ALA as well as polygodial and ALA showed a fractional inhibitory concentration index of 0.41 and 0.37, respectively, suggesting that polygodial and ALA, as well as warburganal and ALA, have a synergistic effect against nematodes. A preliminary structure-activity relationship study for polygodial showed that the α,β-unsaturated 1,4-dialdehyde structural motif is essential for the potent activity. None of a panel of C. elegans mutant strains, resistant against major anthelmintic drug classes, showed significant resistance to polygodial, implying that polygodial may block C. elegans motility through a mechanism which differs from that of currently marketed drugs. Further measurements showed that polygodial inhibits mitochondrial ATP synthesis of C. elegans in a dose-dependent manner (IC50: 1.8 ± 1.0 μM). Therefore, we believe that the underlying mechanism of action of polygodial is probably inhibition of mitochondrial ATP synthesis. In conclusion, polygodial could be a promising anthelmintic drug candidate worth considering for further development.
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Affiliation(s)
- Maoxuan Liu
- Faculty of Pharmaceutical Sciences, KU Leuven, Herestraat 49, 3000 Leuven, Belgium; Department of Biology, Animal Physiology and Neurobiology Section, KU Leuven, Naamsestraat 59, Box 2465, 3000 Leuven, Belgium.
| | - Purity Kipanga
- Faculty of Pharmaceutical Sciences, KU Leuven, Herestraat 49, 3000 Leuven, Belgium
| | - Anh Hung Mai
- Department of Chemistry, Molecular Design and Synthesis, KU Leuven, Celestijnenlaan 200F, Box 2404, 3000 Leuven, Belgium
| | - Ineke Dhondt
- Department of Biology, Faculty of Sciences, Ghent University, K.L. Ledeganckstraat 35, 9000 Gent, Belgium
| | - Bart P Braeckman
- Department of Biology, Faculty of Sciences, Ghent University, K.L. Ledeganckstraat 35, 9000 Gent, Belgium
| | - Wim De Borggraeve
- Department of Chemistry, Molecular Design and Synthesis, KU Leuven, Celestijnenlaan 200F, Box 2404, 3000 Leuven, Belgium
| | - Walter Luyten
- Department of Biology, Animal Physiology and Neurobiology Section, KU Leuven, Naamsestraat 59, Box 2465, 3000 Leuven, Belgium
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Abstract
Helminth infections have large negative impacts on production efficiency in ruminant farming systems worldwide, and their effective management is essential if livestock production is to increase to meet future human needs for dietary protein. The control of helminths relies heavily on routine use of chemotherapeutics, but this approach is unsustainable as resistance to anthelmintic drugs is widespread and increasing. At the same time, infection patterns are being altered by changes in climate, land-use and farming practices. Future farms will need to adopt more efficient, robust and sustainable control methods, integrating ongoing scientific advances. Here, we present a vision of helminth control in farmed ruminants by 2030, bringing to bear progress in: (1) diagnostic tools, (2) innovative control approaches based on vaccines and selective breeding, (3) anthelmintics, by sustainable use of existing products and potentially new compounds, and (4) rational integration of future control practices. In this review, we identify the technical advances that we believe will place new tools in the hands of animal health decision makers in 2030, to enhance their options for control and allow them to achieve a more integrated and sustainable approach to helminth control in support of animal welfare and production.
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31
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Molena RA, Peachey LE, Di Cesare A, Traversa D, Cantacessi C. Cyathostomine egg reappearance period following ivermectin treatment in a cohort of UK Thoroughbreds. Parasit Vectors 2018; 11:61. [PMID: 29370872 PMCID: PMC5785887 DOI: 10.1186/s13071-018-2638-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Accepted: 01/10/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND In spite of the emergence of populations of drug-resistant cyathostomines worldwide, little is known of parasite species responsible for 'early egg shedding' in cohorts of horses subjected to treatment with widely used anthelmintics, e.g. ivermectin (IVM). In this study, we determined the cyathostomine egg reappearance period (ERP) after IVM treatment in a cohort of yearlings from a large Thoroughbred (TB) stud farm in the United Kingdom, and identified species of cyathostomines with reduced ERP using a combination of fundamental parasitology techniques coupled with advanced molecular tools. METHODS Individual faecal samples were collected from TB yearlings with cyathostomine infection prior to IVM treatment, as well as at 14, 21, 28, 35, 42 and 49 days post-treatment. Faecal egg counts (FEC) were performed for each individual sample for determination of ERPs. In addition, individual larval cultures were performed and representative numbers of third-stage larvae (L3s) harvested from each culture were subjected to molecular species identification via PCR-Reverse Line Blot (RLB). RESULTS Prior to IVM treatment, 11 cyathostomine species were detected in faecal samples from TB horses enrolled in this study, i.e. Cyathostomum catinatum, Cylicostephanus longibursatus, Cylicostephanus goldi, Cylicocyclus nassatus, Cylicostephanus calicatus, Cyathostomum pateratum, Cylicocyclus radiatus, Paraposteriostomum mettami, Coronocyclus labratus, Cylicocyclus insigne and Cylicocyclus radiatus variant A. Of these, eggs of Cya. catinatum, Cys. longibursatus, Cyc. nassatus and Cyc. radiatus could be detected at 28 days post-treatment, while from day 42 onwards, cyathostomine species composition reflected data obtained pre-IVM treatment, with the exception of eggs of Cor. labratus and Cyc. insigne which could no longer be detected post-IVM administration. CONCLUSIONS This study provides valuable data on the occurrence of IVM-resistance in cyathostomines in the UK. Nevertheless, further investigations are needed to shed light on the prevalence and incidence of drug-resistance in this country, as well as other areas of the world where equine trade is substantial.
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Affiliation(s)
- Rebecca A Molena
- Department of Veterinary Medicine, University of Cambridge, Cambridge, UK
| | - Laura E Peachey
- Department of Veterinary Medicine, University of Cambridge, Cambridge, UK
| | - Angela Di Cesare
- Faculty of Veterinary Medicine, University of Teramo, Località Piano d'Accio, Teramo, Italy
| | - Donato Traversa
- Faculty of Veterinary Medicine, University of Teramo, Località Piano d'Accio, Teramo, Italy
| | - Cinzia Cantacessi
- Department of Veterinary Medicine, University of Cambridge, Cambridge, UK.
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32
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N'Guessan JPDU, Delaye PO, Pénichon M, Charvet CL, Neveu C, Ouattara M, Enguehard-Gueiffier C, Gueiffier A, Allouchi H. Discovery of imidazo[1,2-a]pyridine-based anthelmintic targeting cholinergic receptors of Haemonchus contortus. Bioorg Med Chem 2017; 25:6695-6706. [DOI: 10.1016/j.bmc.2017.11.012] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Revised: 10/26/2017] [Accepted: 11/05/2017] [Indexed: 01/25/2023]
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33
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Screening of a small, well-curated natural product-based library identifies two rotenoids with potent nematocidal activity against Haemonchus contortus. Vet Parasitol 2017; 244:172-175. [DOI: 10.1016/j.vetpar.2017.07.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Revised: 07/05/2017] [Accepted: 07/06/2017] [Indexed: 12/20/2022]
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34
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Preston S, Korhonen PK, Mouchiroud L, Cornaglia M, McGee SL, Young ND, Davis RA, Crawford S, Nowell C, Ansell BRE, Fisher GM, Andrews KT, Chang BCH, Gijs MAM, Sternberg PW, Auwerx J, Baell J, Hofmann A, Jabbar A, Gasser RB. Deguelin exerts potent nematocidal activity
via
the mitochondrial respiratory chain. FASEB J 2017; 31:4515-4532. [DOI: 10.1096/fj.201700288r] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Accepted: 06/12/2017] [Indexed: 12/14/2022]
Affiliation(s)
- Sarah Preston
- Faculty of Veterinary and Agricultural SciencesUniversity of MelbourneParkvilleVictoriaAustralia
- Faculty of Science and TechnologyFederation UniversityBallaratVictoriaAustralia
| | - Pasi K. Korhonen
- Faculty of Veterinary and Agricultural SciencesUniversity of MelbourneParkvilleVictoriaAustralia
| | - Laurent Mouchiroud
- Laboratory of Integrative and Systems PhysiologyÉcole Polytechnique Fédérale de LausanneLausanneSwitzerland
| | - Matteo Cornaglia
- Laboratory of MicrosystemsÉcole Polytechnique Fédérale de LausanneLausanneSwitzerland
| | - Sean L. McGee
- Metabolic Research UnitMetabolic Reprogramming LaboratorySchool of Medicine, Faculty of Health, Deakin UniversityWaurn PondsVictoriaAustralia
| | - Neil D. Young
- Faculty of Veterinary and Agricultural SciencesUniversity of MelbourneParkvilleVictoriaAustralia
| | - Rohan A. Davis
- Griffith Institute for Drug DiscoveryGriffith UniversityNathanQueenslandAustralia
| | - Simon Crawford
- School of Biosciences, University of MelbourneParkvilleVictoriaAustralia
| | - Cameron Nowell
- Drug Discovery BiologyMonash University Institute of Pharmaceutical SciencesMonash UniversityParkvilleVictoriaAustralia
| | - Brendan R. E. Ansell
- Faculty of Veterinary and Agricultural SciencesUniversity of MelbourneParkvilleVictoriaAustralia
| | - Gillian M. Fisher
- Griffith Institute for Drug DiscoveryGriffith UniversityNathanQueenslandAustralia
| | - Katherine T. Andrews
- Griffith Institute for Drug DiscoveryGriffith UniversityNathanQueenslandAustralia
| | - Bill C. H. Chang
- Faculty of Veterinary and Agricultural SciencesUniversity of MelbourneParkvilleVictoriaAustralia
- Yourgene BioscienceTaipeiTaiwan
| | - Martin A. M. Gijs
- Laboratory of MicrosystemsÉcole Polytechnique Fédérale de LausanneLausanneSwitzerland
| | - Paul W. Sternberg
- Division of Biology and Biological EngineeringCalifornia Institute of TechnologyPasadenaCaliforniaUSA
| | - Johan Auwerx
- Laboratory of Integrative and Systems PhysiologyÉcole Polytechnique Fédérale de LausanneLausanneSwitzerland
| | - Jonathan Baell
- Medicinal ChemistryMonash University Institute of Pharmaceutical SciencesMonash UniversityParkvilleVictoriaAustralia
| | - Andreas Hofmann
- Faculty of Veterinary and Agricultural SciencesUniversity of MelbourneParkvilleVictoriaAustralia
- Griffith Institute for Drug DiscoveryGriffith UniversityNathanQueenslandAustralia
| | - Abdul Jabbar
- Faculty of Veterinary and Agricultural SciencesUniversity of MelbourneParkvilleVictoriaAustralia
| | - Robin B. Gasser
- Faculty of Veterinary and Agricultural SciencesUniversity of MelbourneParkvilleVictoriaAustralia
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Jiao Y, Preston S, Koehler AV, Stroehlein AJ, Chang BCH, Simpson KJ, Cowley KJ, Palmer MJ, Laleu B, Wells TNC, Jabbar A, Gasser RB. Screening of the 'Stasis Box' identifies two kinase inhibitors under pharmaceutical development with activity against Haemonchus contortus. Parasit Vectors 2017; 10:323. [PMID: 28679424 PMCID: PMC5499055 DOI: 10.1186/s13071-017-2246-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2017] [Accepted: 06/13/2017] [Indexed: 01/06/2023] Open
Abstract
Background In partnership with the Medicines for Malaria Venture (MMV), we screened a collection (‘Stasis Box’) of 400 compounds (which have been in clinical development but have not been approved for illnesses other than neglected infectious diseases) for inhibitory activity against Haemonchus contortus, in order to attempt to repurpose some of the compounds to parasitic nematodes. Methods We assessed the inhibition of compounds on the motility and/or development of exsheathed third-stage (xL3s) and fourth-stage (L4) larvae of H. contortus using a whole-organism screening assay. Results In the primary screen, we identified compound MMV690767 (also known as SNS-032) that inhibited xL3 motility by ~70% at a concentration of 20 μM after 72 h as well as compound MMV079840 (also known as AG-1295), which induced a coiled xL3 phenotype, with ~50% inhibition on xL3 motility. Subsequently, we showed that SNS-032 (IC50 = 12.4 μM) and AG-1295 (IC50 = 9.92 ± 1.86 μM) had a similar potency to inhibit xL3 motility. Although neither SNS-032 nor AG-1295 had a detectable inhibitory activity on L4 motility, both compounds inhibited L4 development (IC50 values = 41.24 μM and 7.75 ± 0.94 μM for SNS-032 and AG-1295, respectively). The assessment of the two compounds for toxic effects on normal human breast epithelial (MCF10A) cells revealed that AG-1295 had limited cytotoxicity (IC50 > 100 μM), whereas SNS-032 was quite toxic to the epithelial cells (IC50 = 1.27 μM). Conclusions Although the two kinase inhibitors, SNS-032 and AG-1295, had moderate inhibitory activity on the motility or development of xL3s or L4s of H. contortus in vitro, further work needs to be undertaken to chemically alter these entities to achieve the potency and selectivity required for them to become nematocidal or nematostatic candidates. Electronic supplementary material The online version of this article (doi:10.1186/s13071-017-2246-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Yaqing Jiao
- Faculty of Veterinary and Agricultural Sciences, Melbourne Veterinary School, The University of Melbourne, Parkville, VIC, 3010, Australia
| | - Sarah Preston
- Faculty of Veterinary and Agricultural Sciences, Melbourne Veterinary School, The University of Melbourne, Parkville, VIC, 3010, Australia
| | - Anson V Koehler
- Faculty of Veterinary and Agricultural Sciences, Melbourne Veterinary School, The University of Melbourne, Parkville, VIC, 3010, Australia
| | - Andreas J Stroehlein
- Faculty of Veterinary and Agricultural Sciences, Melbourne Veterinary School, The University of Melbourne, Parkville, VIC, 3010, Australia
| | - Bill C H Chang
- Faculty of Veterinary and Agricultural Sciences, Melbourne Veterinary School, The University of Melbourne, Parkville, VIC, 3010, Australia
| | - Kaylene J Simpson
- Victorian Centre for Functional Genomics, Peter MacCallum Cancer Centre, Parkville, VIC, Australia.,The Sir Peter MacCallum Department of Oncology, University of Melbourne, Parkville, VIC, Australia
| | - Karla J Cowley
- Victorian Centre for Functional Genomics, Peter MacCallum Cancer Centre, Parkville, VIC, Australia
| | - Michael J Palmer
- Medicines for Malaria Venture (MMV), Route de Pré-Bois 20, CH-1215, Geneva, Switzerland
| | - Benoît Laleu
- Medicines for Malaria Venture (MMV), Route de Pré-Bois 20, CH-1215, Geneva, Switzerland
| | - Timothy N C Wells
- Medicines for Malaria Venture (MMV), Route de Pré-Bois 20, CH-1215, Geneva, Switzerland
| | - Abdul Jabbar
- Faculty of Veterinary and Agricultural Sciences, Melbourne Veterinary School, The University of Melbourne, Parkville, VIC, 3010, Australia.
| | - Robin B Gasser
- Faculty of Veterinary and Agricultural Sciences, Melbourne Veterinary School, The University of Melbourne, Parkville, VIC, 3010, Australia.
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Ritler D, Rufener R, Sager H, Bouvier J, Hemphill A, Lundström-Stadelmann B. Development of a movement-based in vitro screening assay for the identification of new anti-cestodal compounds. PLoS Negl Trop Dis 2017; 11:e0005618. [PMID: 28520724 PMCID: PMC5448807 DOI: 10.1371/journal.pntd.0005618] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Revised: 05/30/2017] [Accepted: 05/02/2017] [Indexed: 11/18/2022] Open
Abstract
Intestinal cestodes are infecting millions of people and livestock worldwide, but treatment is mainly based on one drug: praziquantel. The identification of new anti-cestodal compounds is hampered by the lack of suitable screening assays. It is difficult, or even impossible, to evaluate drugs against adult cestodes in vitro due to the fact that these parasites cannot be cultured in microwell plates, and adult and larval stages in most cases represent different organisms in terms of size, morphology, and metabolic requirements. We here present an in vitro-drug screening assay based on Echinococcus multilocularis protoscoleces, which represent precursors of the scolex (hence the anterior part) of the adult tapeworm. This movement-based assay can serve as a model for an adult cestode screen. Protoscoleces are produced in large numbers in Mongolian gerbils and mice, their movement is measured and quantified by image analysis, and active compounds are directly assessed in terms of morphological effects. The use of the 384-well format minimizes the amount of parasites and compounds needed and allows rapid screening of a large number of chemicals. Standard drugs showed the expected dose-dependent effect on movement and morphology of the protoscoleces. Interestingly, praziquantel inhibited movement only partially within 12 h of treatment (at concentrations as high as 100 ppm) and did thus not act parasiticidal, which was also confirmed by trypan blue staining. Enantiomers of praziquantel showed a clear difference in their minimal inhibitory concentration in the motility assay and (R)-(-)-praziquantel was 185 times more active than (S)-(-)-praziquantel. One compound named MMV665807, which was obtained from the open access MMV (Medicines for Malaria Venture) Malaria box, strongly impaired motility and viability of protoscoleces. Corresponding morphological alterations were visualized by scanning electron microscopy, and demonstrated that this compound exhibits a mode of action clearly distinct from praziquantel. Thus, MMV665807 represents an interesting lead for further evaluation. Tapeworms (cestodes) are a medically important group of helminths that infect humans and animals all around the globe. The clinical signs caused by intestinal infection with adult cestodes are mostly mild, in contrast to the more severe disease symptoms inflicted by infection with the tissue-dwelling larval stages of the same species. Praziquantel is the main drug in use against intestinal cestode infections. Development of resistance and treatment failures have been reported in trematodes, and are expected to become a problem in the future also in the case of cestode infections. Therefore, new treatment options against intestinal helminths are needed. To date, there is no in vitro-based whole-organism screening assay available that allows screening of candidate drugs with potential activity against adult cestodes. We established and characterized of a screening assay in 384-well format, which serves as a model for adult stage parasites by using Echinococcus multilocularis protoscoleces and their loss of motility as a read-out. This novel assay showed that drugs with known activity against adult cestodes inhibited motility of protoscoleces. The movement-based assay identified MMV665807 as a novel compound with profound activity against protoscoleces, and potentially also adult cestodes. Light- and electron microscopical assessments of protoscoleces treated with praziquantel and MMV665807 point towards different modes of action of the two drugs.
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Affiliation(s)
- Dominic Ritler
- Institute of Parasitology, Vetsuisse Faculty, University of Berne, Berne, Switzerland
| | - Reto Rufener
- Institute of Parasitology, Vetsuisse Faculty, University of Berne, Berne, Switzerland
| | | | | | - Andrew Hemphill
- Institute of Parasitology, Vetsuisse Faculty, University of Berne, Berne, Switzerland
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Diseases of the Nervous System. Vet Med (Auckl) 2017. [PMCID: PMC7322266 DOI: 10.1016/b978-0-7020-5246-0.00014-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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38
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Experimental and theoretical investigation of new furan and thiophene derivatives containing oxazole, isoxazole, or isothiazole subunits. Struct Chem 2016. [DOI: 10.1007/s11224-016-0863-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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39
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Hess J, Patra M, Rangasamy L, Konatschnig S, Blacque O, Jabbar A, Mac P, Jorgensen EM, Gasser RB, Gasser G. Organometallic Derivatization of the Nematocidal Drug Monepantel Leads to Promising Antiparasitic Drug Candidates. Chemistry 2016; 22:16602-16612. [DOI: 10.1002/chem.201602851] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Indexed: 12/20/2022]
Affiliation(s)
- Jeannine Hess
- Department of Chemistry University of Zurich Winterthurerstrasse 190 8057 Zurich Switzerland
| | - Malay Patra
- Department of Chemistry University of Zurich Winterthurerstrasse 190 8057 Zurich Switzerland
| | - Loganathan Rangasamy
- Department of Chemistry University of Zurich Winterthurerstrasse 190 8057 Zurich Switzerland
| | - Sandro Konatschnig
- Department of Chemistry University of Zurich Winterthurerstrasse 190 8057 Zurich Switzerland
| | - Olivier Blacque
- Department of Chemistry University of Zurich Winterthurerstrasse 190 8057 Zurich Switzerland
| | - Abdul Jabbar
- Faculty of Veterinary and Agricultural Sciences The University of Melbourne Parkville, Victoria 3010 Australia
| | - Patrick Mac
- Howard Hughes Medical Institute Department of Biology University of Utah Salt Lake City UT 84112-0840 USA
| | - Erik M. Jorgensen
- Howard Hughes Medical Institute Department of Biology University of Utah Salt Lake City UT 84112-0840 USA
| | - Robin B. Gasser
- Faculty of Veterinary and Agricultural Sciences The University of Melbourne Parkville, Victoria 3010 Australia
| | - Gilles Gasser
- Department of Chemistry University of Zurich Winterthurerstrasse 190 8057 Zurich Switzerland
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Sales N, Love S. Resistance of Haemonchus sp. to monepantel and reduced efficacy of a derquantel / abamectin combination confirmed in sheep in NSW, Australia. Vet Parasitol 2016; 228:193-196. [DOI: 10.1016/j.vetpar.2016.08.016] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Revised: 08/19/2016] [Accepted: 08/23/2016] [Indexed: 11/24/2022]
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Papaya latex supernatant has a potent effect on the free-living stages of equid cyathostomins in vitro. Vet Parasitol 2016; 228:23-29. [PMID: 27692327 DOI: 10.1016/j.vetpar.2016.07.036] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2016] [Revised: 07/28/2016] [Accepted: 07/31/2016] [Indexed: 11/21/2022]
Abstract
The control of equid gastrointestinal nematodes in developed countries, in particular the cyathostomins, is threatened by high levels of anthelmintic resistance. In recent years, there has been increasing interest in the evaluation of traditional 'ethnoveterinary' medicines as alternatives to chemical anthelmintics. The cysteine proteinases (CPs), a group of enzymes derived from fruits such as papaya (Carica papaya), pineapple (Ananas comosus) and figs (Ficus spp.), have shown good efficacy against adult stages of a range of parasitic nematodes, in vitro and in vivo. The efficacy of CPs against cyathostomins remains to be explored. In this study, the efficacy of a crude preparation of CPs, papaya latex supernatant (PLS), against the free-living stages of cyathostomins was evaluated using two in vitro tests, the egg hatch test (EHT) and the larval migration inhibition test (LMIT). It was demonstrated that PLS had a potent effect in the EHT, with EC-50 values in the range of 0.12-0.22μM. At concentrations above 6.25μM the eggs did not develop, below this concentration the L1 developed but they lost integrity of the cuticle upon hatching. These effects were inhibited by pre-incubation of PLS with the CP inhibitor L-trans-epoxysuccinyl-l-leucylamido-(4-guanidino butane) (E64), indicating that CPs were responsible for the anti-parasitic activity. A dose-dependent inhibition of migration of third stage larvae (L3) in the LMIT was demonstrated at higher concentrations of PLS, with EC-50 values in the range of 67.35-106.31μM. Incubation of PLS with E64 prior to use in the LMIT did not reverse the anti-migratory effect, suggesting that CPs were not responsible for the reduced migration of cyathostomin L3 and that PLS also contains an additional active compound. This is the first report of PLS and/or CPs showing activity against the free-living stages of a parasitic helminth. In addition, it suggests that cyathostomins are highly sensitive to the effects of CPs and further evaluation of their efficacy against parasitic stages and in vivo are strongly indicated.
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Preston S, Luo J, Zhang Y, Jabbar A, Crawford S, Baell J, Hofmann A, Hu M, Zhou HB, Gasser RB. Selenophene and thiophene-core estrogen receptor ligands that inhibit motility and development of parasitic stages of Haemonchus contortus. Parasit Vectors 2016; 9:346. [PMID: 27306029 PMCID: PMC4910235 DOI: 10.1186/s13071-016-1612-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2016] [Accepted: 05/27/2016] [Indexed: 12/17/2022] Open
Abstract
Background Parasitic worms represent a substantial disease burden in animals and humans worldwide. The control of parasitic roundworms (nematodes) relies heavily on the use of anthelmintic drugs. However, widespread drug resistance in nematodes seriously compromises the effectiveness of many anthelmintics around the world. Thus, there is a need to discover new drugs, with unique modes of action, against parasites. Methods Here, we synthesised and tested 74 selective estrogen receptor modulators (SERMs) for in vitro-activity on parasitic larvae of Haemonchus contortus (barber’s pole worm), one of the most important nematode pathogens of small ruminants (including sheep and goats) and a key representative of one of the largest groups of parasitic nematodes (the Strongylida) of animals. We also studied the morphology of treated and untreated larvae using scanning electron microscopy (SEM), and assessed the agonistic/antagonistic activity of SERMs in a human embryonic kidney cell line using a luciferase reporter assay system. Results We identified three SERMs (one selenophene and two thiophene-core compounds) with potent inhibitory activities (at 3–25 μM) on the motility and development of parasitic stages of H. contortus. An SEM examination of treated H. contortus revealed considerable damage to the cuticle of fourth- but not exsheathed, third-stage larvae; this damage appeared to be consistent with that observed upon treatment with monepantel but not moxidectin (control compounds). Conclusion The potency of the three SERMs compared favourably with commercially available anthelmintics, such that they warrant further assessment as nematocides. Future studies could focus on assessing the selectivity of these SERMs to parasites, characterising their target(s) and/or designing analogs that are parasite-specific. Electronic supplementary material The online version of this article (doi:10.1186/s13071-016-1612-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Sarah Preston
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, VIC, 3010, Australia
| | - Junjie Luo
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Wuhan University School of Pharmaceutical Sciences, Wuhan, 430072, China
| | - Yuezhou Zhang
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, VIC, 3010, Australia.,Medicinal Chemistry, Monash University Institute of Pharmaceutical Sciences (MIPS), Monash University, Parkville, VIC, 3052, Australia.,State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, 430070, China
| | - Abdul Jabbar
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, VIC, 3010, Australia
| | - Simon Crawford
- School of Biosciences, The University of Melbourne, Parkville, VIC, 3010, Australia
| | - Jonathan Baell
- Medicinal Chemistry, Monash University Institute of Pharmaceutical Sciences (MIPS), Monash University, Parkville, VIC, 3052, Australia
| | - Andreas Hofmann
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, VIC, 3010, Australia.,Structural Chemistry Program, Eskitis Institute for Drug Discovery, Griffith University, Brisbane, QLD, 4111, Australia
| | - Min Hu
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, 430070, China
| | - Hai-Bing Zhou
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Wuhan University School of Pharmaceutical Sciences, Wuhan, 430072, China.
| | - Robin B Gasser
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, VIC, 3010, Australia. .,Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Wuhan University School of Pharmaceutical Sciences, Wuhan, 430072, China.
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Kuesel AC. Research for new drugs for elimination of onchocerciasis in Africa. INTERNATIONAL JOURNAL FOR PARASITOLOGY-DRUGS AND DRUG RESISTANCE 2016; 6:272-286. [PMID: 27693536 PMCID: PMC5196484 DOI: 10.1016/j.ijpddr.2016.04.002] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/20/2016] [Accepted: 04/20/2016] [Indexed: 01/12/2023]
Abstract
Onchocerciasis is a parasitic, vector borne disease caused by the filarial nematode Onchocerca volvulus. More than 99% of the population at risk of infection live in Africa. Onchocerciasis control was initiated in West Africa in 1974 with vector control, later complemented by ivermectin mass drug administration and in the other African endemic countries in 1995 with annual community directed treatment with ivermectin (CDTI.) This has significantly reduced infection prevalence. Together with proof-of-concept for onchocerciasis elimination with annual CDTI from foci in Senegal and Mali, this has resulted in targeting onchocerciasis elimination in selected African countries by 2020 and in 80% of African countries by 2025. The challenges for meeting these targets include the number of endemic countries where conflict has delayed or interrupted control programmes, cross-border foci, potential emergence of parasite strains with low susceptibility to ivermectin and co-endemicity of loiasis, another parasitic vector borne disease, which slows down or prohibits CDTI implementation. Some of these challenges could be addressed with new drugs or drug combinations with a higher effect on Onchocerca volvulus than ivermectin. This paper reviews the path from discovery of new compounds to their qualification for large scale use and the support regulatory authorities provide for development of drugs for neglected tropical diseases. The status of research for new drugs or treatment regimens for onchocerciasis along the path to regulatory approval and qualification for large scale use is reviewed. This research includes new regimens and combinations of ivermectin and albendazole, antibiotics targeting the O. volvulus endosymbiont Wolbachia, flubendazole, moxidectin and emodepside and discovery of new compounds.
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Affiliation(s)
- Annette C Kuesel
- UNICEF/UNDP/World Bank/WHO Special Programme for Research and Training in Tropical Diseases, 20 Avenue Appia, 1211 Geneva, Switzerland.
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Gasser RB, Schwarz EM, Korhonen PK, Young ND. Understanding Haemonchus contortus Better Through Genomics and Transcriptomics. ADVANCES IN PARASITOLOGY 2016; 93:519-67. [PMID: 27238012 DOI: 10.1016/bs.apar.2016.02.015] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Parasitic roundworms (nematodes) cause substantial mortality and morbidity in animals globally. The barber's pole worm, Haemonchus contortus, is one of the most economically significant parasitic nematodes of small ruminants worldwide. Although this and related nematodes can be controlled relatively well using anthelmintics, resistance against most drugs in common use has become a major problem. Until recently, almost nothing was known about the molecular biology of H. contortus on a global scale. This chapter gives a brief background on H. contortus and haemonchosis, immune responses, vaccine research, chemotherapeutics and current problems associated with drug resistance. It also describes progress in transcriptomics before the availability of H. contortus genomes and the challenges associated with such work. It then reviews major progress on the two draft genomes and developmental transcriptomes of H. contortus, and summarizes their implications for the molecular biology of this worm in both the free-living and the parasitic stages of its life cycle. The chapter concludes by considering how genomics and transcriptomics can accelerate research on Haemonchus and related parasites, and can enable the development of new interventions against haemonchosis.
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Affiliation(s)
- R B Gasser
- The University of Melbourne, Parkville, VIC, Australia
| | - E M Schwarz
- The University of Melbourne, Parkville, VIC, Australia; Cornell University, Ithaca, NY, United States
| | - P K Korhonen
- The University of Melbourne, Parkville, VIC, Australia
| | - N D Young
- The University of Melbourne, Parkville, VIC, Australia
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45
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Practical and low cost whole-organism motility assay: A step-by-step protocol. Mol Cell Probes 2016; 30:13-7. [DOI: 10.1016/j.mcp.2015.08.005] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Revised: 08/25/2015] [Accepted: 08/25/2015] [Indexed: 01/09/2023]
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46
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Hess J, Patra M, Jabbar A, Pierroz V, Konatschnig S, Spingler B, Ferrari S, Gasser RB, Gasser G. Assessment of the nematocidal activity of metallocenyl analogues of monepantel. Dalton Trans 2016; 45:17662-17671. [DOI: 10.1039/c6dt03376h] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Ferrocenyl and ruthenocenyl analogues of the nematocidal drug monepantel show organometallic-dependent activity against Haemonchus contortus and Trichostrongylus colubriformis.
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Affiliation(s)
- Jeannine Hess
- Department of Chemistry
- University of Zurich
- CH-8057 Zurich
- Switzerland
| | - Malay Patra
- Department of Chemistry
- University of Zurich
- CH-8057 Zurich
- Switzerland
| | - Abdul Jabbar
- Faculty of Veterinary and Agricultural Sciences
- The University of Melbourne
- Parkville
- Australia
| | - Vanessa Pierroz
- Department of Chemistry
- University of Zurich
- CH-8057 Zurich
- Switzerland
- Institute of Molecular Cancer Research
| | | | - Bernhard Spingler
- Department of Chemistry
- University of Zurich
- CH-8057 Zurich
- Switzerland
| | - Stefano Ferrari
- Institute of Molecular Cancer Research
- University of Zurich
- CH-8057 Zurich
- Switzerland
| | - Robin B. Gasser
- Faculty of Veterinary and Agricultural Sciences
- The University of Melbourne
- Parkville
- Australia
| | - Gilles Gasser
- Department of Chemistry
- University of Zurich
- CH-8057 Zurich
- Switzerland
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France DJ, Stepek G, Houston DR, Williams L, McCormack G, Walkinshaw MD, Page AP. Identification and activity of inhibitors of the essential nematode-specific metalloprotease DPY-31. Bioorg Med Chem Lett 2015; 25:5752-5. [PMID: 26546217 PMCID: PMC4658336 DOI: 10.1016/j.bmcl.2015.10.077] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2015] [Revised: 10/23/2015] [Accepted: 10/25/2015] [Indexed: 11/26/2022]
Abstract
Infection by parasitic nematodes is widespread in the developing world causing extensive morbidity and mortality. Furthermore, infection of animals is a global problem, with a substantial impact on food production. Here we identify small molecule inhibitors of a nematode-specific metalloprotease, DPY-31, using both known metalloprotease inhibitors and virtual screening. This strategy successfully identified several μM inhibitors of DPY-31 from both the human filarial nematode Brugia malayi, and the parasitic gastrointestinal nematode of sheep Teladorsagia circumcincta. Further studies using both free living and parasitic nematodes show that these inhibitors elicit the severe body morphology defect 'Dumpy' (Dpy; shorter and fatter), a predominantly non-viable phenotype consistent with mutants lacking the DPY-31 gene. Taken together, these results represent a start point in developing DPY-31 inhibition as a totally novel mechanism for treating infection by parasitic nematodes in humans and animals.
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Affiliation(s)
- David J France
- WestChem School of Chemistry, University of Glasgow, University Avenue, Glasgow G12 8QQ, UK
| | - Gillian Stepek
- Institute of Biodiversity, Animal Health & Comparative Medicine, University of Glasgow, Bearsden Road, Glasgow G61 1QH, UK
| | - Douglas R Houston
- Institute of Structural & Molecular Biology, University of Edinburgh, Mayfield Road, Edinburgh EH9 3JR, UK
| | - Lewis Williams
- WestChem School of Chemistry, University of Glasgow, University Avenue, Glasgow G12 8QQ, UK
| | - Gillian McCormack
- Institute of Biodiversity, Animal Health & Comparative Medicine, University of Glasgow, Bearsden Road, Glasgow G61 1QH, UK
| | - Malcolm D Walkinshaw
- Institute of Structural & Molecular Biology, University of Edinburgh, Mayfield Road, Edinburgh EH9 3JR, UK
| | - Antony P Page
- Institute of Biodiversity, Animal Health & Comparative Medicine, University of Glasgow, Bearsden Road, Glasgow G61 1QH, UK
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Abstract
Gastrointestinal nematodes represent important sources of economic losses in farmed ruminants, and the increasing frequency of anthelmintic resistance requires an increased ability to explore alternative strategies. Theoretical approaches at the crossroads of immunology and epidemiology are valuable tools in that context. In the case of Teladorsagia circumcincta in sheep, the immunological mechanisms important for resistance are increasingly well-characterized. However, despite the existence of a wide range of theoretical models, there is no framework integrating the characteristic features of this immune response into a tractable phenomenological model. Here, we propose to bridge that gap by developing a flexible modelling framework that allows for variability in nematode larval intake which can be used to track the variations in worm burdens. We parameterize this model using data from trickle infection of sheep and show that using simple immunological assumptions, our model can capture the dynamics of both adult worm burdens and nematode fecal egg counts. In addition, our analysis reveals interesting dose-dependent effects on the immune response. Finally, we discuss potential developments of this model and highlight how an improved cross-talk between empiricists and theoreticians would facilitate important advances in the study of infectious diseases.
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An evidence-based approach to the evaluation of ethnoveterinary medicines against strongyle nematodes of equids. Vet Parasitol 2015; 210:40-52. [DOI: 10.1016/j.vetpar.2015.03.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2014] [Revised: 03/12/2015] [Accepted: 03/13/2015] [Indexed: 11/18/2022]
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