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Periferakis AT, Periferakis A, Periferakis K, Caruntu A, Badarau IA, Savulescu-Fiedler I, Scheau C, Caruntu C. Antimicrobial Properties of Capsaicin: Available Data and Future Research Perspectives. Nutrients 2023; 15:4097. [PMID: 37836381 PMCID: PMC10574431 DOI: 10.3390/nu15194097] [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: 08/26/2023] [Revised: 09/13/2023] [Accepted: 09/20/2023] [Indexed: 10/15/2023] Open
Abstract
Capsaicin is a phytochemical derived from plants of the genus Capsicum and subject of intensive phytochemical research due to its numerous physiological and therapeutical effects, including its important antimicrobial properties. Depending on the concentration and the strain of the bacterium, capsaicin can exert either bacteriostatic or even bactericidal effects against a wide range of both Gram-positive and Gram-negative bacteria, while in certain cases it can reduce their pathogenicity by a variety of mechanisms such as mitigating the release of toxins or inhibiting biofilm formation. Likewise, capsaicin has been shown to be effective against fungal pathogens, particularly Candida spp., where it once again interferes with biofilm formation. The parasites Toxoplasma gondi and Trypanosoma cruzi have been found to be susceptible to the action of this compound too while there are also viruses whose invasiveness is significantly dampened by it. Among the most encouraging findings are the prospects for future development, especially using new formulations and drug delivery mechanisms. Finally, the influence of capsaicin in somatostatin and substance P secretion and action, offers an interesting array of possibilities given that these physiologically secreted compounds modulate inflammation and immune response to a significant extent.
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Affiliation(s)
- Aristodemos-Theodoros Periferakis
- Department of Physiology, The “Carol Davila” University of Medicine and Pharmacy, 050474 Bucharest, Romania
- Elkyda, Research & Education Centre of Charismatheia, 17675 Athens, Greece
| | - Argyrios Periferakis
- Department of Physiology, The “Carol Davila” University of Medicine and Pharmacy, 050474 Bucharest, Romania
- Elkyda, Research & Education Centre of Charismatheia, 17675 Athens, Greece
- Akadimia of Ancient Greek and Traditional Chinese Medicine, 16675 Athens, Greece
| | - Konstantinos Periferakis
- Akadimia of Ancient Greek and Traditional Chinese Medicine, 16675 Athens, Greece
- Pan-Hellenic Organization of Educational Programs (P.O.E.P), 17236 Athens, Greece
| | - Ana Caruntu
- Department of Oral and Maxillofacial Surgery, “Carol Davila” Central Military Emergency Hospital, 010825 Bucharest, Romania
- Department of Oral and Maxillofacial Surgery, Faculty of Dental Medicine, “Titu Maiorescu” University, 031593 Bucharest, Romania
| | - Ioana Anca Badarau
- Department of Physiology, The “Carol Davila” University of Medicine and Pharmacy, 050474 Bucharest, Romania
| | - Ilinca Savulescu-Fiedler
- Department of Internal Medicine and Cardiology, Coltea Clinical Hospital, 030167 Bucharest, Romania
- Department of Internal Medicine, The “Carol Davila” University of Medicine and Pharmacy, 050474 Bucharest, Romania
| | - Cristian Scheau
- Department of Physiology, The “Carol Davila” University of Medicine and Pharmacy, 050474 Bucharest, Romania
- Department of Radiology and Medical Imaging, “Foisor” Clinical Hospital of Orthopaedics, Traumatology and Osteoarticular TB, 021382 Bucharest, Romania
| | - Constantin Caruntu
- Department of Physiology, The “Carol Davila” University of Medicine and Pharmacy, 050474 Bucharest, Romania
- Department of Dermatology, ‘Prof. N.C. Paulescu’ National Institute of Diabetes, Nutrition and Metabolic Diseases, 011233 Bucharest, Romania
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Dube M, Raphane B, Sethebe B, Seputhe N, Tiroyakgosi T, Imming P, Häberli C, Keiser J, Arnold N, Andrae-Marobela K. Medicinal Plant Preparations Administered by Botswana Traditional Health Practitioners for Treatment of Worm Infections Show Anthelmintic Activities. PLANTS (BASEL, SWITZERLAND) 2022; 11:2945. [PMID: 36365400 PMCID: PMC9658373 DOI: 10.3390/plants11212945] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Revised: 10/26/2022] [Accepted: 10/26/2022] [Indexed: 06/16/2023]
Abstract
Schistosomiasis and soil-transmitted helminths are some of the priority neglected tropical diseases (NTDs) targeted for elimination by the World Health Organization (WHO). They are prevalent in Botswana and although Botswana has begun mass drug administration with the hope of eliminating soil-transmitted helminths as a public health problem, the prevalence of schistosomiasis does not meet the threshold required to warrant large-scale interventions. Although Botswana has a modern healthcare system, many people in Botswana rely on traditional medicine to treat worm infections and schistosomiasis. In this study, ten plant species used by traditional health practitioners against worm infections were collected and tested against Ancylostoma ceylanicum (zoonotic hookworm), Heligmosomoides polygyrus (roundworm of rodents), Necator americanus (New World hookworm), Schistosoma mansoni (blood fluke) [adult and newly transformed schistosomula (NTS)], Strongyloides ratti (threadworm) and Trichuris muris (nematode parasite of mice) in vitro. Extracts of two plants, Laphangium luteoalbum and Commiphora pyaracanthoides, displayed promising anthelmintic activity against NTS and adult S. mansoni, respectively. L. luteoalbum displayed 85.4% activity at 1 μg/mL against NTS, while C. pyracanthoides displayed 78.5% activity against adult S. mansoni at 10 μg/mL.
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Affiliation(s)
- Mthandazo Dube
- Department of Bioorganic Chemistry, Leibniz Institute of Plant Biochemistry, Weinberg 3, D-06120 Halle (Saale), Germany
| | - Boingotlo Raphane
- Department of Biological Sciences, Faculty of Science, University of Botswana, Gaborone P.O. Box 0022, Botswana
| | - Bongani Sethebe
- Department of Biological Sciences, Faculty of Science, University of Botswana, Gaborone P.O. Box 0022, Botswana
| | | | | | - Peter Imming
- Institute of Pharmacy, Faculty of Natural Sciences, Martin-Luther-University Halle-Wittenberg, D-06120 Halle (Saale), Germany
| | - Cécile Häberli
- Swiss Tropical and Public Health Institute, Kreuzstrasse 2, CH-4123 Allschwil, Switzerland
- University of Basel, CH-4051 Basel, Switzerland
| | - Jennifer Keiser
- Swiss Tropical and Public Health Institute, Kreuzstrasse 2, CH-4123 Allschwil, Switzerland
- University of Basel, CH-4051 Basel, Switzerland
| | - Norbert Arnold
- Department of Bioorganic Chemistry, Leibniz Institute of Plant Biochemistry, Weinberg 3, D-06120 Halle (Saale), Germany
| | - Kerstin Andrae-Marobela
- Department of Biological Sciences, Faculty of Science, University of Botswana, Gaborone P.O. Box 0022, Botswana
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Herath HMPD, Taki AC, Rostami A, Jabbar A, Keiser J, Geary TG, Gasser RB. Whole-organism phenotypic screening methods used in early-phase anthelmintic drug discovery. Biotechnol Adv 2022; 57:107937. [PMID: 35271946 DOI: 10.1016/j.biotechadv.2022.107937] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Revised: 02/24/2022] [Accepted: 03/03/2022] [Indexed: 01/17/2023]
Abstract
Diseases caused by parasitic helminths (worms) represent a major global health burden in both humans and animals. As vaccines against helminths have yet to achieve a prominent role in worm control, anthelmintics are the primary tool to limit production losses and disease due to helminth infections in both human and veterinary medicine. However, the excessive and often uncontrolled use of these drugs has led to widespread anthelmintic resistance in these worms - particularly of animals - to almost all commercially available anthelmintics, severely compromising control. Thus, there is a major demand for the discovery and development of new classes of anthelmintics. A key component of the discovery process is screening libraries of compounds for anthelmintic activity. Given the need for, and major interest by the pharmaceutical industry in, novel anthelmintics, we considered it both timely and appropriate to re-examine screening methods used for anthelmintic discovery. Thus, we reviewed current literature (1977-2021) on whole-worm phenotypic screening assays developed and used in academic laboratories, with a particular focus on those employed to discover nematocides. This review reveals that at least 50 distinct phenotypic assays with low-, medium- or high-throughput capacity were developed over this period, with more recently developed methods being quantitative, semi-automated and higher throughput. The main features assessed or measured in these assays include worm motility, growth/development, morphological changes, viability/lethality, pharyngeal pumping, egg hatching, larval migration, CO2- or ATP-production and/or enzyme activity. Recent progress in assay development has led to the routine application of practical, cost-effective, medium- to high-throughput whole-worm screening assays in academic or public-private partnership (PPP) contexts, and major potential for novel high-content, high-throughput platforms in the near future. Complementing this progress are major advances in the molecular data sciences, computational biology and informatics, which are likely to further enable and accelerate anthelmintic drug discovery and development.
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Affiliation(s)
- H M P Dilrukshi Herath
- Department of Veterinary Biosciences, Melbourne Veterinary School, The University of Melbourne, Parkville, Victoria, Australia
| | - Aya C Taki
- Department of Veterinary Biosciences, Melbourne Veterinary School, The University of Melbourne, Parkville, Victoria, Australia
| | - Ali Rostami
- Infectious Diseases and Tropical Medicine Research Center, Health Research Institute, Babol University of Medical Sciences, Babol, Iran
| | - Abdul Jabbar
- Department of Veterinary Biosciences, Melbourne Veterinary School, The University of Melbourne, Parkville, Victoria, Australia
| | - Jennifer Keiser
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, CH-4051 Basel, Switzerland
| | - Timothy G Geary
- Institute of Parasitology, McGill University, Sainte Anne-de-Bellevue, Quebec H9X3V9, Canada; School of Biological Sciences, Queen's University-Belfast, Belfast, Ireland
| | - Robin B Gasser
- Department of Veterinary Biosciences, Melbourne Veterinary School, The University of Melbourne, Parkville, Victoria, Australia.
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Jayawardene KLTD, Palombo EA, Boag PR. Natural Products Are a Promising Source for Anthelmintic Drug Discovery. Biomolecules 2021; 11:1457. [PMID: 34680090 PMCID: PMC8533416 DOI: 10.3390/biom11101457] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Revised: 09/23/2021] [Accepted: 09/28/2021] [Indexed: 12/23/2022] Open
Abstract
Parasitic nematodes infect almost all forms of life. In the human context, parasites are one of the major causative factors for physical and intellectual growth retardation in the developing world. In the agricultural setting, parasites have a great economic impact through a reduction in livestock performance or control cost. The main method of controlling these devastating conditions is the use of anthelmintic drugs. Unfortunately, there are only a few anthelmintic drug classes available in the market and significant resistance has developed in most of the parasitic species of livestock. Therefore, development of new anthelmintics with different modes of action is critical for sustainable parasitic control in the future. The drug development pipeline is broadly limited to two types of molecules, namely synthetic compounds and natural plant products. Compared to synthetic compounds, natural products are highly diverse, and many have historically proven valuable in folk medicine to treat various gastrointestinal ailments. This review focus on the use of traditional knowledge-based plant extracts in the development of new therapeutic leads, the approaches used as screening techniques, and common bottlenecks and opportunities in plant-based anthelmintic drug discovery.
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Affiliation(s)
- K. L. T. Dilrukshi Jayawardene
- Development and Stem Cells Program, Monash Biomedicine Discovery Institute, Monash University, Melbourne, VIC 3800, Australia;
- Development and Stem Cells Program, Department of Biochemistry and Molecular Biology, Monash University, Melbourne, VIC 3800, Australia
| | - Enzo A. Palombo
- Department of Chemistry and Biotechnology, School of Science, Computing and Engineering Technologies, Swinburne University of Technology, Melbourne, VIC 3122, Australia
| | - Peter R. Boag
- Development and Stem Cells Program, Monash Biomedicine Discovery Institute, Monash University, Melbourne, VIC 3800, Australia;
- Development and Stem Cells Program, Department of Biochemistry and Molecular Biology, Monash University, Melbourne, VIC 3800, Australia
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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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Herath HMPD, Taki AC, Sleebs BE, Hofmann A, Nguyen N, Preston S, Davis RA, Jabbar A, Gasser RB. Advances in the discovery and development of anthelmintics by harnessing natural product scaffolds. ADVANCES IN PARASITOLOGY 2021; 111:203-251. [PMID: 33482975 DOI: 10.1016/bs.apar.2020.10.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Widespread resistance to currently-used anthelmintics represents a major obstacle to controlling parasitic nematodes of livestock animals. Given the reliance on anthelmintics in many control regimens, there is a need for the continued discovery and development of new nematocides. Enabling such a focus are: (i) the major chemical diversity of natural products; (ii) the availability of curated, drug-like extract-, fraction- and/or compound-libraries from natural sources; (iii) the utility and practicality of well-established whole-worm bioassays for Haemonchus contortus-an important parasitic nematodes of livestock-to screen natural product libraries; and (iv) the availability of advanced chromatographic (HPLC), spectroscopic (NMR) and spectrometric (MS) techniques for bioassay-guided fractionation and structural elucidation. This context provides a sound basis for the identification and characterisation of anthelmintic candidates from natural sources. This chapter provides a background on the importance and impact of helminth infections/diseases, parasite control and aspects of drug discovery, and reviews recent work focused on (i) screening well-defined compound libraries to establish the methods needed for large-scale screening of natural extract libraries; (ii) discovering plant and marine extracts with nematocidal or nematostatic activity, and purifying bioactive compounds and assessing their potential for further development; and (iii) synthesising analogues of selected purified natural compounds for the identification of possible 'lead' candidates. The chapter describes some lessons learned from this work and proposes future areas of focus for drug discovery. Collectively, the findings from this recent work show potential for selected natural product scaffolds as candidates for future development. Developing such candidates via future chemical optimisation, efficacy and safety evaluations, broad spectrum activity assessments, and target identification represents an exciting prospect and, if successful, could pave the way to subsequent pre-clinical and clinical evaluations.
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Affiliation(s)
- H M P Dilrukshi Herath
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Aya C Taki
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Brad E Sleebs
- Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia; Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Andreas Hofmann
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, Victoria, Australia; Griffith Institute for Drug Discovery, Griffith University, Brisbane, Queensland, Australia
| | - Nghi Nguyen
- Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia; Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Sarah Preston
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, Victoria, Australia; Faculty of Science and Technology, Federation University, Ballarat, Victoria, Australia
| | - Rohan A Davis
- Griffith Institute for Drug Discovery, Griffith University, Brisbane, Queensland, Australia
| | - Abdul Jabbar
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Robin B Gasser
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, Victoria, Australia.
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Fairweather I, Brennan GP, Hanna REB, Robinson MW, Skuce PJ. Drug resistance in liver flukes. Int J Parasitol Drugs Drug Resist 2020; 12:39-59. [PMID: 32179499 PMCID: PMC7078123 DOI: 10.1016/j.ijpddr.2019.11.003] [Citation(s) in RCA: 84] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Revised: 11/19/2019] [Accepted: 11/20/2019] [Indexed: 02/07/2023]
Abstract
Liver flukes include Fasciola hepatica, Fasciola gigantica, Clonorchis sinensis, Opisthorchis spp., Fascioloides magna, Gigantocotyle explanatum and Dicrocoelium spp. The two main species, F. hepatica and F. gigantica, are major parasites of livestock and infections result in huge economic losses. As with C. sinensis, Opisthorchis spp. and Dicrocoelium spp., they affect millions of people worldwide, causing severe health problems. Collectively, the group is referred to as the Food-Borne Trematodes and their true significance is now being more widely recognised. However, reports of resistance to triclabendazole (TCBZ), the most widely used anti-Fasciola drug, and to other current drugs are increasing. This is a worrying scenario. In this review, progress in understanding the mechanism(s) of resistance to TCBZ is discussed, focusing on tubulin mutations, altered drug uptake and changes in drug metabolism. There is much interest in the development of new drugs and drug combinations, the re-purposing of non-flukicidal drugs, and the development of new drug formulations and delivery systems; all this work will be reviewed. Sound farm management practices also need to be put in place, with effective treatment programmes, so that drugs can be used wisely and their efficacy conserved as much as is possible. This depends on reliable advice being given by veterinarians and other advisors. Accurate diagnosis and identification of drug-resistant fluke populations is central to effective control: to determine the actual extent of the problem and to determine how well or otherwise a treatment has worked; for research on establishing the mechanism of resistance (and identifying molecular markers of resistance); for informing treatment options; and for testing the efficacy of new drug candidates. Several diagnostic methods are available, but there are no recommended guidelines or standardised protocols in place and this is an issue that needs to be addressed.
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Affiliation(s)
- I Fairweather
- School of Biological Sciences, The Queen's University of Belfast, 19 Chlorine Gardens, Belfast, BT9 5DL, UK.
| | - G P Brennan
- School of Biological Sciences, The Queen's University of Belfast, 19 Chlorine Gardens, Belfast, BT9 5DL, UK
| | - R E B Hanna
- Veterinary Sciences Division, Agri-Food and Biosciences Institute (AFBI), Stormont, Belfast, BT4 3SD, UK
| | - M W Robinson
- School of Biological Sciences, The Queen's University of Belfast, 19 Chlorine Gardens, Belfast, BT9 5DL, UK
| | - P J Skuce
- Disease Control, Moredun Research Institute, Pentlands Science Park, Bush Loan, Penicuik, Edinburgh, EH26 0PZ, UK
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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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Nicolao MC, Rodriguez Rodrigues C, Cumino AC. Extracellular vesicles from Echinococcus granulosus larval stage: Isolation, characterization and uptake by dendritic cells. PLoS Negl Trop Dis 2019; 13:e0007032. [PMID: 30615613 PMCID: PMC6344059 DOI: 10.1371/journal.pntd.0007032] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Revised: 01/23/2019] [Accepted: 11/28/2018] [Indexed: 12/20/2022] Open
Abstract
The secretion of extracellular vesicles (EVs) in helminth parasites is a constitutive mechanism that promotes survival by improving their colonization and adaptation in the host tissue. In the present study, we analyzed the production of EVs from supernatants of cultures of Echinococcus granulosus protoscoleces and metacestodes and their interaction with dendritic cells, which have the ability to efficiently uptake and process microbial antigens, activating T lymphocytes. To experimentally increase the release of EVs, we used loperamide, a calcium channel blocker that increases the cytosolic calcium level in protoscoleces and EV secretion. An exosome-like enriched EV fraction isolated from the parasite culture medium was characterized by dynamic light scattering, transmission electron microscopy, proteomic analysis and immunoblot. This allowed identifying many proteins including: small EV markers such as TSG101, SDCBP, ALIX, tetraspanins and 14-3-3 proteins; proteins involved in vesicle-related transport; orthologs of mammalian proteins involved in the immune response, such as basigin, Bp29 and maspardin; and parasite antigens such as antigen 5, P29 and endophilin-1, which are of special interest due to their role in the parasite-host relationship. Finally, studies on the EVs-host cell interaction demonstrated that E. granulosus exosome-like vesicles were internalized by murine dendritic cells, inducing their maturation with increase of CD86 and with a slight down-regulation in the expression of MHCII molecules. These data suggest that E. granulosus EVs could interfere with the antigen presentation pathway of murine dendritic cells inducing immunoregulation in the host. Further studies are needed to better understand the role of these vesicles in parasite survival and as diagnostic markers and new vaccines. Human cystic echinococcosis, caused by chronic infection with the larval stage of Echinococcus granulosus, affects over 1 million people worldwide. This helminth parasite secretes numerous excretory/secretory products that are in contact with host tissues where it establishes hydatid cysts. In this study, we comprehensively characterized extracellular vesicles (EVs) from E. granulosus protoscoleces and metacestodes, and demonstrated for the first time that the exosome-like vesicles from helminths can interact with host dendritic cells and carry several immunoregulatory proteins. This study provides valuable data on cestode-host immune communication. Nevertheless, further research on EVs is needed to fully understand their role in the parasite-host interface and obtain new data concerning their function as therapeutic markers and diagnostic tools.
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Affiliation(s)
- María Celeste Nicolao
- Laboratorio de Zoonosis Parasitarias, Departamento de Biología, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata (UNMdP), Funes, Nivel Cero, Mar del Plata, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina
| | - Christian Rodriguez Rodrigues
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina
- Departamento de Química, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata (UNMdP), Funes, Nivel 2, Mar del Plata, Argentina
| | - Andrea C. Cumino
- Laboratorio de Zoonosis Parasitarias, Departamento de Biología, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata (UNMdP), Funes, Nivel Cero, Mar del Plata, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina
- Departamento de Química, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata (UNMdP), Funes, Nivel 2, Mar del Plata, Argentina
- * E-mail:
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Geary TG, Sakanari JA, Caffrey CR. Anthelmintic drug discovery: into the future. J Parasitol 2015; 101:125-33. [PMID: 25584662 DOI: 10.1645/14-703.1] [Citation(s) in RCA: 74] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
The last half-century has provided all of the (few) drugs currently used to treat human helminthiases. Concern regarding the long-term utility of these drugs, given how readily resistance evolves in the veterinary-agricultural sector, spurs the discovery of new chemical entities. We review the approaches and technologies in use to identify anthelmintics and discuss a number of drug discovery paradigms that may prove pivotal to the next half-century of anthelmintic development.
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Affiliation(s)
- Timothy G Geary
- Institute of Parasitology, McGill University, 21,111 Lakeshore Road, Ste. Anne de Bellevue, Quebec, Canada H9X 3V9
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Woods DJ, Lauret C, Geary T. Anthelmintic discovery and development in the animal health industry. Expert Opin Drug Discov 2013; 2:S25-33. [PMID: 23489029 DOI: 10.1517/17460441.2.s1.s25] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Most modern anthelmintics used against human pathogens have come from the animal health (AH) industry. Historically, new molecules were discovered empirically, but recent developments in genomic and screening technologies have significantly enhanced the opportunities for target-based identification of novel therapies. However, drug discovery and development is still a complicated and costly process with high attrition. Absence of a return in investment for tropical parasitic diseases makes it difficult for large pharmaceutical companies to justify seeking antiparasitics for less developed countries in isolation. A partnership in which there is a sharing of costs and leveraging of resources is one way forward and is reflected in the new paradigm of 'integrated drug discovery', where collaborations and networks of academic institutions and industry are working together towards the discovery of new treatments for tropical parasitic diseases.
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Affiliation(s)
- Debra J Woods
- Pfizer Animal Health, Veterinary Medicine R & D, Ramsgate Road, Sandwich, Kent CT13 9NJ, UK +44 1304 646473 ; +44 1304 656691 ;
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12
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Animal Health Markets and Opportunities: Companion Animal Landscape. ADVANCES IN DELIVERY SCIENCE AND TECHNOLOGY 2013. [DOI: 10.1007/978-1-4614-4439-8_2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
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13
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Lima WC, Athayde AC, Medeiros GR, Lima DA, Borburema JB, Santos EM, Vilela VL, Azevedo SS. Nematóides resistentes a alguns anti-helmínticos em rebanhos caprinos no Cariri Paraibano. PESQUISA VETERINARIA BRASILEIRA 2010. [DOI: 10.1590/s0100-736x2010001200001] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Objetivou-se avaliar a resistência de nematódeos a alguns anti-helmínticos em rebanhos caprinos no Cariri Paraibano. Foram utilizados 144 animais no período seco e 120 animais no período chuvoso, fêmeas com idade acima de oito meses de vida e lactantes, distribuídos em 4 grupos: Grupo I não tratado, Grupo II tratado com albendazole a 10%, Grupo III tratado com ivermectina a 1% e Grupo IV tratado com fosfato de levamisole a 18,8%, nas doses recomendadas pelos fabricantes. Para avaliar a resistência, aplicou-se o teste de redução na contagem de ovos por grama de fezes (RCOF) e o cultivo de larvas de helmintos. As amostras fecais foram coletadas no dia do tratamento (dia base) e 7, 14 e 21 dias após o tratamento. No grupo tratado com Albendazole, observaram-se eficácias de 61%, 11% e 24% no período seco e de 55%, 14% e 12% no período chuvoso, aos 7, 14, e 21 dias, respectivamente. No grupo tratado com Ivermectina, a eficácia foi de 14%, 70% e 66% para o período seco, e de 76%, 34% e 71% para o período chuvoso, aos 7, 14 e 21 dias, respectivamente. O grupo tratado com fosfato de Levamisole apresentou percentuais de eficácia de 89%, 79% e 73% no período seco e de 76%, 69% e 67% no período chuvoso, aos 7, 14 e 21 dias, respectivamente. Os resultados obtidos indicam que os nematódeos gastrintestinais de alguns rebanhos caprinos no Cariri Paraibano não são sensíveis aos princípios ativos Albendazole, Levamisole e Ivermectina. Durante o período de estudo foi identificada a presença de parasitas dos gêneros Haemonchus, Trichostrongylus, Oesophagostomum e Strongyloides.
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Kaewintajuk K, Cho PY, Kim SY, Lee ES, Lee HK, Choi EB, Park H. Anthelmintic activity of KSI-4088 against Caenorhabditis elegans. Parasitol Res 2010; 107:27-30. [DOI: 10.1007/s00436-010-1828-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2010] [Accepted: 03/03/2010] [Indexed: 10/19/2022]
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Campbell WC, Conder GA, Marchiondo AA. Future of the animal health industry at a time of food crisis. Vet Parasitol 2009; 163:188-95. [DOI: 10.1016/j.vetpar.2009.05.025] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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16
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Zhao WJ, Zhang H, Bo X, Li Y, Fu X. Generation and analysis of expressed sequence tags from a cDNA library of Moniezia expansa. Mol Biochem Parasitol 2008; 164:80-5. [PMID: 19118581 DOI: 10.1016/j.molbiopara.2008.11.009] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2008] [Revised: 11/19/2008] [Accepted: 11/20/2008] [Indexed: 10/21/2022]
Abstract
The Moniezia expansa is a parasite of sheep that causes diarrhea and fleshless leading to stockbreeding losses. A genomic resource for large-scale molecular studies in this parasite is lacking. To study the gene expression including development, digestion and reproduction organs of M. expansa, a cDNA library had been constructed and expressed sequence tags (ESTs) had been analyzed, which were helpful for the development of a powerful microarray platform which are used to analyze gene expression in this species. cDNAs are useful resources in annotating genes and providing functional analysis of genes. In this study, a cDNA library from adult cestode of M. expansa was created and 2642 ESTs from 5'-ends of the cDNA clones representing 1081 unigenes were obtained. Cluster analysis of these ESTs allowed identification of 1081 unique sequences containing 351 contigs and 730 singletons. BLASTX searches identified 780 significant (E-value<10(-5)) hits and further Gene Ontology (GO) analysis was used to annotate these genes. All the EST sequences were deposited under dbEST in GenBank (GenBank: FE905224-FE905315, FE942104-FE942773, FE969189-FE969190, FF677548-FF677734, FF848124-FF848253). Although we only obtained 1081 unigenes, the set of ESTs identified represents a significant proportion of the M. expansa and provides molecular resource for the development of microarrays for gene expression studies concerning development, metabolism and reproduction.
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Affiliation(s)
- Wen Juan Zhao
- Genetic Engineering Laboratory, The Breed & Biotechnology Key Laboratory of Sheep in XinJiang, Bingtuan 832000, PR China
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17
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Jeschke P, Harder A, Etzel W, Schindler M, Thielking G. Synthesis and anthelmintic activity of cyclohexadepsipeptides with cyclohexylmethyl side chains. Bioorg Med Chem Lett 2007; 17:3690-5. [DOI: 10.1016/j.bmcl.2007.04.037] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2007] [Revised: 04/11/2007] [Accepted: 04/12/2007] [Indexed: 11/28/2022]
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18
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Borges FA, Cho HS, Santos E, Oliveira GP, Costa AJ. Pharmacokinetics of a new long acting endectocide formulation containing 2.25% ivermectin and 1.25% abamectin in cattle. J Vet Pharmacol Ther 2007; 30:62-7. [PMID: 17217403 DOI: 10.1111/j.1365-2885.2007.00816.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The objective of this study was to determine the kinetic parameters of a new formulation that contained 2.25% ivermectin combined with 1.25% abamectin in bovine plasma. The results for 2.25% ivermectin: Cmax (37.11 ng/mL +/- 7.42), Tmax (16 days +/- 5.29), T(1/2) (44.62 days +/- 53.89), AUC (928.2 ng x day/mL +/- 153.83) and MRT (36.73 days +/- 33.64), and for 1.25% abamectin: Cmax (28.70 ng/mL +/- 9.54), Tmax (14 days +/- 4.04), T(1/2) (15.40 days +/- 11.43), AUC (618.05 ng x day/mL +/- 80.27) and MRT (20.79 days +/- 8.43) suggest that this combination of 2.25% ivermectin + 1.25% abamectin possesses properties that give this pharmaceutical formula a longer activity time than two of the commercial products tested (1% ivermectin and 1% abamectin), and showed similarity to 3.15% ivermectin.
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Affiliation(s)
- F A Borges
- CPPAR/UNESP-São Paulo State University, FCAV, Jaboticabal, SP, Brazil
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19
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Bull K, Cook A, Hopper NA, Harder A, Holden-Dye L, Walker RJ. Effects of the novel anthelmintic emodepside on the locomotion, egg-laying behaviour and development of Caenorhabditis elegans. Int J Parasitol 2006; 37:627-36. [PMID: 17157854 DOI: 10.1016/j.ijpara.2006.10.013] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2006] [Revised: 10/20/2006] [Accepted: 10/23/2006] [Indexed: 11/18/2022]
Abstract
Emodepside, a cyclooctadepsipeptide, is a broad-spectrum anthelmintic previously shown to paralyse body wall muscle and pharyngeal muscle in the model nematode Caenorhabditis elegans. We demonstrate that wild-type C. elegans L4 are less sensitive than adults to emodepside in two independent assays of locomotor behaviour: body bend generation on agar (adult IC(50) 3.7 nM, L4 IC(50) 13.4 nM) and thrashing behaviour in liquid (thrashing behaviour as a % of controls after 1h in 10 microM emodepside: adults 16%, L4 worms 48%). We also show that continuous exposure of wild-type C. elegans to emodepside throughout the life-cycle from egg onwards, slows worm development, an effect that is emodepside concentration-dependent. The rate of worm-hatching from eggs on agar plates containing emodepside was not significantly different from controls, suggesting that it is development post-hatching rather than hatching itself that is affected by the drug. Emodepside also inhibits wild-type C. elegans egg-laying, with acute exposure to the drug at 500 nM resulting in an almost total inhibition within the first hour. However, the rate of egg production was not inhibited and therefore emodepside-treated worms became bloated with eggs, eventually rupturing. This suggests that the effect of emodepside on reproduction is not due to an inhibition of egg production but rather a paralytic effect on the egg-laying muscles. These results, when coupled with previous research, suggest that emodepside interferes with signalling at the neuromuscular junction on the body-wall muscles (Willson et al., 2003), pharynx (Willson et al., 2004) and egg-laying muscles and thus inhibits three important physiological functions: locomotion, feeding and reproduction.
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Affiliation(s)
- Kathryn Bull
- Neuroscience Research Group, School of Biological Sciences, University of Southampton, Southampton SO16 7PX, UK
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20
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Besier B. New anthelmintics for livestock: the time is right. Trends Parasitol 2006; 23:21-4. [PMID: 17118708 DOI: 10.1016/j.pt.2006.11.004] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2006] [Revised: 10/17/2006] [Accepted: 11/13/2006] [Indexed: 10/23/2022]
Abstract
The viability of small-ruminant enterprises is under threat in some locations because anthelmintic resistance continues to increase in prevalence and severity. Despite this, no new anthelmintic group has been developed for many years, and animal health companies seem unconvinced of the commercial justification for new compounds for the ruminant market. It is now argued, however, that market conditions are becoming favourable because of increases in multiple-drug resistance in nematodes of ruminants and other hosts and because few non-chemical options exist. A new anthelmintic is urgently needed and will find ready acceptance in an increasing market, and with better knowledge of resistance management, greater product longevity can be achieved.
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Affiliation(s)
- Brown Besier
- Animal Health Laboratories, Department of Agriculture and Food Western Australia, Albany, WA 6330, Australia.
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21
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van Wyk JA, Hoste H, Kaplan RM, Besier RB. Targeted selective treatment for worm management—How do we sell rational programs to farmers? Vet Parasitol 2006; 139:336-46. [PMID: 16774807 DOI: 10.1016/j.vetpar.2006.04.023] [Citation(s) in RCA: 118] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Seriously escalating global anthelmintic resistance in gastrointestinal nematodes of small ruminants has spawned a variety of alternatives to anthelmintics for worm management, based on the need for sustainable Integrated Parasite Management (sIPM). Pivotal to the sIPM approach is the concept of refugia, the proportion of a given parasite population that escapes exposure to control measures. By balancing drug applications with the maintenance of refugia, the accumulation of anthelmintic resistance alleles in worm populations can be considerably delayed, while still providing good levels of control. The over-dispersed nature of parasitic infections provides an opportunity to achieve this balance, by targeting treatments to the members of a flock or herd that are least tolerant to nematode infection. However, implementation of this strategy has only recently become feasible, with the development of the FAMACHA((c)) system for clinical evaluation of anaemia due to haemonchosis. Subsequently, the use of milk yields has proven an effective indicator in dairy goats infected predominantly with nematodes other than Haemonchus contortus. In addition, short-term weight changes and perhaps also body condition scoring may provide indices of parasitism, permitting the rapid identification of animals likely to benefit from treatment. However, sIPM and refugia-based approaches are more complex than whole-flock treatments in conventional programs, and adoption by farmers is most likely where the theoretical basis is understood. As close communication with informed advisors is generally limited, there is a danger that sIPM will remain a theoretical concept without alternative modes of communication. The development of computer-based decision support programs, which use epidemiological, seasonal and clinical information to provide recommendations for specific situations, should be accorded high priority in the future development of worm management systems.
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Affiliation(s)
- J A van Wyk
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, South Africa
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22
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Holden-Dye L, Walker RJ. Actions of glutamate and ivermectin on the pharyngeal muscle of Ascaridia galli: a comparative study with Caenorhabditis elegans. Int J Parasitol 2005; 36:395-402. [PMID: 16442540 DOI: 10.1016/j.ijpara.2005.11.006] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2005] [Revised: 11/14/2005] [Accepted: 11/15/2005] [Indexed: 11/16/2022]
Abstract
The actions of glutamate and ivermectin were examined in the pharynx of Ascaridia galli and the results compared with those on the pharynx of Caenorhabditis elegans. In both preparations glutamate elicits a depolarization and inhibition of pharyngeal pumping, but the response of the pharynx of A. galli was much less than for C. elegans. This may be either because the pharyngeal membrane potential of the former is closely linked to the equilibrium potential for chloride ions (E(Cl)) while that of C. elegans is independent of E(Cl), or that there is a lower density of glutamate receptors on the pharyngeal muscle of A. galli compared with C. elegans. The maximum depolarization to glutamate of the pharyngeal muscle was 4.5+/-0.8 mV in A. galli while it was >25 mV in C. elegans. Picrotoxin was a weak antagonist of the glutamate response in both species. Flufenamic acid, pentobarbitone and flurazepam had no significant effect on either preparation at concentrations up to 100 microM. Three glutamate receptor agonists, ibotenate, kainate and quisqualate were all more potent than glutamate on the A. galli pharyngeal muscle. In contrast, only ibotenate was more potent than glutamate in C. elegans pharynx, the other two agonists being approximately 20 times less potent. The potency of ivermectin differed markedly between the two species, being approximately three orders of magnitude less potent on the pharynx of A. galli compared with C. elegans. This study demonstrates clear differences between the properties of the pharyngeal muscle of the two species and shows that care must be taken when extrapolating data from free-living to parasitic species of nematode.
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Affiliation(s)
- L Holden-Dye
- School of Biological Sciences, University of Southampton, Bassett Crescent East, Southampton SO167PX, UK.
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23
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von Samson-Himmelstjerna G, Blackhall W. Will technology provide solutions for drug resistance in veterinary helminths? Vet Parasitol 2005; 132:223-39. [PMID: 16118040 DOI: 10.1016/j.vetpar.2005.07.014] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Drug resistance in veterinary helminths affects a growing number of livestock producers on a global basis. The parasites infecting the major species of livestock are presently showing resistance in varying degrees to the commonly used classes of anthelmintics. The degree and extent of this problem especially with respect to multidrug resistance (MDR) in nematode populations is likely to increase. Finding solutions to the spread of resistance requires knowledge of the drugs' modes of action and mechanisms of resistance. This knowledge can then be applied to detect and monitor the state of resistance. Here we present a brief overview of resistance mechanisms and some of the technologies being used to study them. We also discuss some of the strategies for slowing the spread of resistance. The issue of reversal of drug resistance is analysed under consideration of recent progress in the field of MDR reversal in non-infectious diseases. Finally, we propose an application of currently available technologies that could assist in the detection and monitoring of anthelmintic resistance. Taking into account the significant complexity of the genetic mechanism of anthelmintic resistance in and between the various species, we suggest to undertake a co-ordinated effort to systematically identify anthelmintic-related single nucleotide polymorphisms (SNPs) in the most important helminth parasites. Monitoring the state of resistance in field populations could be achieved with a SNP-based protocol for genotyping the many genes known or suspected to contribute to the modes of action or mechanisms of resistance to the various classes of anthelmintics. If significant associations between genotypes and phenotypes exist within a species, then a single test with sufficient SNPs could potentially have universal applicability. These could then be explored for the development of new molecular diagnostic procedures. New classes of anthelmintics are needed, but until they are developed and available to the producers, technology can assist to achieve the goal of better sustainability in anthelmintic usage.
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Peter RJ, Van den Bossche P, Penzhorn BL, Sharp B. Tick, fly, and mosquito control—Lessons from the past, solutions for the future. Vet Parasitol 2005; 132:205-15. [PMID: 16099104 DOI: 10.1016/j.vetpar.2005.07.004] [Citation(s) in RCA: 116] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
In order to continue to produce livestock in a sustainable fashion, it is suggested that what was used in the past will continue to form the mainstay of future control. For the foreseeable future, we must conserve what we have, and use it in combination with all the principles of integrated pest management, namely strategic and focussed treatments of animals, environmental control of breeding sites, disease management (including the principles of enzootic stability), and resistant breeds. Whilst new technologies, such as the development of vaccines both against the insect pest in some cases or the disease they transmit in others, and genetic engineering hold out some hope for the future; these are not sufficiently well advanced to permit wholesale application.
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Affiliation(s)
- R J Peter
- Argos Veterinary Science (Pty) Ltd., P.O. Box 1726, Mt. Edgecombe 4300, South Africa.
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Mousley A, Marks NJ, Maule AG. Neuropeptide signalling: a repository of targets for novel endectocides? Trends Parasitol 2004; 20:482-7. [PMID: 15363442 DOI: 10.1016/j.pt.2004.07.011] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
The only available parasiticides with a spectrum of action that includes a broad range of helminth and arthropod parasites are the macrocyclic lactones. Designated endectocides, these drugs have action against both endoparasitic nematodes and ectoparasitic arthropods. Unfortunately, the discovery of such drugs is exceedingly rare and there is no evidence that novel endectocidal agents will be identified and developed in the short to medium term. However, the discovery of neuropeptides with motor-modulatory activities in both arthropods and helminths, coupled with recent progress in the characterization of invertebrate neuropeptide receptors, has the potential to propel neuropeptide signalling to the forefront of efforts to develop a novel endectocide.
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Affiliation(s)
- Angela Mousley
- Parasitology Research Group, School of Biology and Biochemistry, Queen's University Belfast, 97 Lisburn Rd, Belfast, Northern Ireland, BT9 7BL, UK
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Vercruysse J, Knox DP, Schetters TPM, Willadsen P. Veterinary parasitic vaccines: pitfalls and future directions. Trends Parasitol 2004; 20:488-92. [PMID: 15363443 DOI: 10.1016/j.pt.2004.07.009] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Most available antiparasitic drugs are safe, cheap and highly effective against a broad spectrum of parasites. However, the alarming increase in the number of parasite species that are resistant to these drugs, the issue of residues in the food chain and the lack of new drugs stimulate development of alternative control methods in which vaccines would have a central role. Parasite vaccines are still rare, but there are encouraging signs that their number will increase in the next decade. The modern paradigm is that an understanding of parasite genes will lead to the identification of useful antigens, which can then be produced in recombinant systems developed as a result of the huge investment in biotechnology. However, we should also continue to devote efforts to basic research on the host-parasite interface.
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Affiliation(s)
- Jozef Vercruysse
- Ghent University, Faculty of Veterinary Medicine, Department of Virology, Parasitology and Immunology, Salisburylaan 133, B9820 Merelbeke, Belgium.
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Geary TG, Conder GA, Bishop B. The changing landscape of antiparasitic drug discovery for veterinary medicine. Trends Parasitol 2004; 20:449-55. [PMID: 15363437 DOI: 10.1016/j.pt.2004.08.003] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Changes in economic imperatives in the pharmaceutical industry have led to a wave of consolidation, which has had the unintended side effect of shrinking the resource devoted to antiparasitic drug discovery in animal health companies. Scientific changes have altered the way in which drugs could be discovered in the future. New science and business models will need to be implemented to address the demand for innovative antiparasitic drugs in veterinary medicine. Novel drugs are needed to combat drug resistance and for currently non-addressed problems. At the center of the future for this field, however, lies the need for more support into the basic research on the biology of parasites.
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Affiliation(s)
- Thomas R Shryock
- Elanco Animal Health, 2001 West Main Street, GL21, Greenfield, Indiana 46140, USA.
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