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Fredericks J, Hill DE, Zarlenga DS, Fournet VM, Hawkins-Cooper DS, Urban JF, Kramer M. *Inactivation of encysted muscle larvae of Trichinella spiralis in pigs using Mebendazole. Vet Parasitol 2024; 327:110140. [PMID: 38330532 DOI: 10.1016/j.vetpar.2024.110140] [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: 12/30/2022] [Revised: 01/19/2024] [Accepted: 01/23/2024] [Indexed: 02/10/2024]
Abstract
We evaluated the effect of 4 anthelmintic treatments on the viability of Trichinella spiralis encysted muscle larvae (ML) 55 days post infection (PI) in experimentally infected pigs. Muscle larvae were isolated from pig muscle by artificial digestion after oral treatment of pigs with Levamisole (8 mg/kg, daily for 5 days) and Mebendazole (50 mg/kg, daily for 5 days); Doramectin (0.3 mg/kg, single IM injection), and Moxidectin (0.5 mg/kg, single pour on). Isolated larvae from treated pigs were orally inoculated into mice to assess viability of ML from each treatment. Only Mebendazole treatment of pigs significantly reduced ML viability in mice. The effect of timing of the effective Mebendazole treatment on ML from a longer term infection was then examined in a second experiment. Analysis revealed that Mebendazole treatment of pigs with 250 mg/kg over 3 days (83 mg/kg/day) or 5 days (50 mg/kg/day) reduced numbers of ML recovered from pig tissues compared to untreated, infected controls, and rendered ML non-infective to mice; Mebendazole treatment of pigs with 250 mg/kg in a single dose was not effective in reducing ML numbers recovered from pigs or in impacting ML infectivity to mice. An examination of the lowest effective dose of Mebendazole on encysted ML was determined in a third experiment. Mebendazole of pigs with 5, 50, or 100 mg/kg over 3 days demonstrated that 5 or 50 mg/kg over 3 days insufficient to reduce infectivity in recovered ML, while 100 mg/kg (and 83 g from experiment 2) over 3 days significantly reduces infectivity of ML. This procedure provides a means to evaluate the efficacy of various anthelmintic treatments on the viability of Trichinella spiralis ML in pig tissues, and identified Mebendazole, at 83-100 mg/kg administered over a 3-5 day period as an anthelmintic which renders encysted Trichinella spiralis ML from pig tissues non-infective. As risk from Trichinella significantly impacts acceptance of pork from pasture-raised pigs, these data provide a method, especially for producers of these high-risk pigs, to eliminate the potential of Trichinella transmission from infected pork.
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Affiliation(s)
- Jorrell Fredericks
- USDA, ARS, Northeast Area, Animal Parasitic Diseases Laboratory, BARC-East, Beltsville, MD 20705 USA.
| | - Dolores E Hill
- USDA, ARS, Northeast Area, Animal Parasitic Diseases Laboratory, BARC-East, Beltsville, MD 20705 USA
| | - Dante S Zarlenga
- USDA, ARS, Northeast Area, Animal Parasitic Diseases Laboratory, BARC-East, Beltsville, MD 20705 USA
| | - Valsin M Fournet
- USDA, ARS, Northeast Area, Animal Parasitic Diseases Laboratory, BARC-East, Beltsville, MD 20705 USA
| | - Diane S Hawkins-Cooper
- USDA, ARS, Northeast Area, Animal Parasitic Diseases Laboratory, BARC-East, Beltsville, MD 20705 USA
| | - Joseph F Urban
- USDA, ARS, Beltsville Human Nutrition Center, Diet, Genomics, and Immunology Laboratory, BARC-East, Beltsville, MD 20705 USA
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Ichinose P, Miró MV, Larsen K, Lifschitz A, Virkel G. Unravelling drug-drug interactions in pigs: Induction of hepatic cytochrome P450 1A (CYP1A) metabolism after the in-feed medication with the anthelmintic fenbendazole. Res Vet Sci 2024; 167:105113. [PMID: 38141570 DOI: 10.1016/j.rvsc.2023.105113] [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: 10/12/2023] [Revised: 12/12/2023] [Accepted: 12/14/2023] [Indexed: 12/25/2023]
Abstract
The anthelmintic fenbendazole (FBZ) undergoes hepatic S‑oxygenation by monooxygenases belonging to the cytochrome P450 (CYP) and flavin-monooxygenase (FMO) families. The in-feed medication with FBZ induced CYP1A-dependent metabolism in pig liver. This fact may alter the metabolism of the anthelmintic itself, and of CYP1A substrates like aflatoxin B1 (AFB1). This work evaluated the effect of the in-feed administration of FBZ on CYP1A-dependent metabolism, on its own pattern of hepatic S‑oxygenation, and on the metabolism of AFB1. Landrace piglets remained untreated (n = 5) or received a pre-mix of FBZ (n = 6) in feed for 9 days. Pigs were slaughtered for preparation of liver microsomes used for: CYP content determination; monitoring the CYP1A-dependent enzyme activities, 7-ethoxyresorufin O-deethylase (EROD) and 7-methoxyresorufin O-demethylase (MROD); measurement of FBZ (50 μM) S‑oxygenation, and AFB1 (16 nM) disappearance from the incubation medium. In microsomes of FBZ-treated animals, EROD and MROD increased 19-fold (p = 0.002) and 14-fold (p = 0.003), respectively. An enhanced (3-fold, p = 0.004) participation of the CYP pathway in FBZ S‑oxygenation was observed in the liver of piglets treated with the anthelmintic (210 ± 69 pmol/min.nmol CYP) compared to untreated animals (68 ± 34 pmol/min.nmol CYP). AFB1 metabolism was 93% higher (p = 0.009) in the liver of FBZ-treated compared to untreated pigs. Positive and significant (p < 0.05) correlations were observed between CYP1A-dependent enzyme activities and FBZ or AFB1 metabolism. The sustained administration of FBZ caused an auto-induction of the CYP1A-dependent S‑oxygenation of this anthelmintic. The CYP1A induction triggered by the anthelmintic could amplify the production of AFB1 metabolites in pig liver, including the hepatotoxic AFB1-derived epoxide.+.
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Affiliation(s)
- Paula Ichinose
- Universidad Nacional del Centro de la Provincia de Buenos Aires (UNCPBA), Facultad de Ciencias Veterinarias, Tandil, Buenos Aires, Argentina; Centro de Investigación Veterinaria de Tandil (CIVETAN), UNCPBA-CICPBA-CONICET, Tandil, Buenos Aires, Argentina
| | - María Victoria Miró
- Universidad Nacional del Centro de la Provincia de Buenos Aires (UNCPBA), Facultad de Ciencias Veterinarias, Tandil, Buenos Aires, Argentina; Centro de Investigación Veterinaria de Tandil (CIVETAN), UNCPBA-CICPBA-CONICET, Tandil, Buenos Aires, Argentina
| | - Karen Larsen
- Universidad Nacional del Centro de la Provincia de Buenos Aires (UNCPBA), Facultad de Ciencias Veterinarias, Tandil, Buenos Aires, Argentina; Centro de Investigación Veterinaria de Tandil (CIVETAN), UNCPBA-CICPBA-CONICET, Tandil, Buenos Aires, Argentina
| | - Adrián Lifschitz
- Universidad Nacional del Centro de la Provincia de Buenos Aires (UNCPBA), Facultad de Ciencias Veterinarias, Tandil, Buenos Aires, Argentina; Centro de Investigación Veterinaria de Tandil (CIVETAN), UNCPBA-CICPBA-CONICET, Tandil, Buenos Aires, Argentina
| | - Guillermo Virkel
- Universidad Nacional del Centro de la Provincia de Buenos Aires (UNCPBA), Facultad de Ciencias Veterinarias, Tandil, Buenos Aires, Argentina; Centro de Investigación Veterinaria de Tandil (CIVETAN), UNCPBA-CICPBA-CONICET, Tandil, Buenos Aires, Argentina.
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Gałązka M, Klich D, Filip-Hutsch K, Olech W, Anusz K, Pyziel AM. Endoparasite loads and the efficacy of conventional anthelmintics against gastrointestinal nematodes in captive European bison. Int J Parasitol Parasites Wildl 2023; 21:224-231. [PMID: 37415923 PMCID: PMC10319643 DOI: 10.1016/j.ijppaw.2023.06.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Revised: 05/17/2023] [Accepted: 06/17/2023] [Indexed: 07/08/2023]
Abstract
Although little information exists on the efficacy of deworming in wild ruminants, gastrointestinal nematodes have been found to demonstrate increasing drug resistance. The spread of drug-resistant strains may be increased by transmission among livestock and susceptible wildlife species, thus posing a potential threat to endangered species, such as the European bison. The aim of the study was twofold: to identify the parasite loads in captive European bison with the use of coprological techniques, and to test the influence of other nearby ungulates on the richness of bison parasitofauna. Additionally, the efficacy of deworming procedures against gastrointestinal nematodes in bison was evaluated. The survey was based on a coprological investigation of 285 fecal samples from 156 European bison in 15 enclosures. The parasitofauna of the captive European bison was consistent with those of free-ranging populations. The highest prevalence was noted for Eimeria spp. oocysts (60.7%), strongyle eggs (50.9%), Fasciola hepatica eggs (13.1%), Dictyocaulus viviparus larvae (12.3%) and Trichuris sp. Eggs (9.47%). Moreover, the close proximity of other ungulate species resulted in a higher diversity of parasite species. In all cases, deworming with albendazole, fenbendazole and ivermectin proved to be ineffective against strongylids and Trichuris sp. The results of fecal egg count reduction test (FECRT) ranged from 37.2 to 99.6% (95% CI <90%) for albendazole; values >95% (95% CI = 41-100) were noted for fenbendazole, and FECRT ranged from 63.2 to 97.5 (95% CI = 0-99) for ivermectin. As the results of anthelmintic treatment are unsatisfactory, it seems justified to continue study in this area. Our study is the first large-scale attempt to evaluate the efficacy of anthelminthics in captive European bison. The potential sharing of parasite species between bison and other ungulates should also be further investigated from the perspective of minimizing the risk of the spread of drug-resistant parasite strains.
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Affiliation(s)
- Marta Gałązka
- Department of Food Hygiene and Public Health Protection, Institute of Veterinary Medicine, Warsaw University of Life Sciences - WULS, Nowoursynowska 159, 02-776, Warsaw, Poland
- Municipal Zoological Garden in Warsaw, Ratuszowa 1/3, 03-461, Warsaw, Poland
| | - Daniel Klich
- Department of Animal Genetics and Conservation, Institute of Animal Sciences, Warsaw University of Life Sciences - WULS, Ciszewskiego 8, 02-787, Warsaw, Poland
| | - Katarzyna Filip-Hutsch
- Department of Food Hygiene and Public Health Protection, Institute of Veterinary Medicine, Warsaw University of Life Sciences - WULS, Nowoursynowska 159, 02-776, Warsaw, Poland
| | - Wanda Olech
- Department of Animal Genetics and Conservation, Institute of Animal Sciences, Warsaw University of Life Sciences - WULS, Ciszewskiego 8, 02-787, Warsaw, Poland
| | - Krzysztof Anusz
- Department of Food Hygiene and Public Health Protection, Institute of Veterinary Medicine, Warsaw University of Life Sciences - WULS, Nowoursynowska 159, 02-776, Warsaw, Poland
| | - Anna M. Pyziel
- Department of Food Hygiene and Public Health Protection, Institute of Veterinary Medicine, Warsaw University of Life Sciences - WULS, Nowoursynowska 159, 02-776, Warsaw, Poland
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Kaplan RM, Denwood MJ, Nielsen MK, Thamsborg SM, Torgerson PR, Gilleard JS, Dobson RJ, Vercruysse J, Levecke B. World Association for the Advancement of Veterinary Parasitology (W.A.A.V.P.) guideline for diagnosing anthelmintic resistance using the faecal egg count reduction test in ruminants, horses and swine. Vet Parasitol 2023; 318:109936. [PMID: 37121092 DOI: 10.1016/j.vetpar.2023.109936] [Citation(s) in RCA: 38] [Impact Index Per Article: 38.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2023] [Accepted: 04/18/2023] [Indexed: 05/02/2023]
Abstract
The faecal egg count reduction test (FECRT) remains the method of choice for establishing the efficacy of anthelmintic compounds in the field, including the diagnosis of anthelmintic resistance. We present a guideline for improving the standardization and performance of the FECRT that has four sections. In the first section, we address the major issues relevant to experimental design, choice of faecal egg count (FEC) method, statistical analysis, and interpretation of the FECRT results. In the second section, we make a series of general recommendations that are applicable across all animals addressed in this guideline. In the third section, we provide separate guidance details for cattle, small ruminants (sheep and goats), horses and pigs to address the issues that are specific to the different animal types. Finally, we provide overviews of the specific details required to conduct an FECRT for each of the different host species. To address the issues of statistical power vs. practicality, we also provide two separate options for each animal species; (i) a version designed to detect small changes in efficacy that is intended for use in scientific studies, and (ii) a less resource-intensive version intended for routine use by veterinarians and livestock owners to detect larger changes in efficacy. Compared to the previous FECRT recommendations, four important differences are noted. First, it is now generally recommended to perform the FECRT based on pre- and post-treatment FEC of the same animals (paired study design), rather than on post-treatment FEC of both treated and untreated (control) animals (unpaired study design). Second, instead of requiring a minimum mean FEC (expressed in eggs per gram (EPG)) of the group to be tested, the new requirement is for a minimum total number of eggs to be counted under the microscope (cumulative number of eggs counted before the application of a conversion factor). Third, we provide flexibility in the required size of the treatment group by presenting three separate options that depend on the (expected) number of eggs counted. Finally, these guidelines address all major livestock species, and the thresholds for defining reduced efficacy are adapted and aligned to host species, anthelmintic drug and parasite species. In conclusion, these new guidelines provide improved methodology and standardization of the FECRT for all major livestock species.
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Affiliation(s)
- Ray M Kaplan
- Pathobiology Department, School of Veterinary Medicine, St. George's University, W.I., Grenada.
| | - Matthew J Denwood
- Department of Veterinary and Animal Sciences, University of Copenhagen, Denmark
| | - Martin K Nielsen
- Maxwell H. Gluck Equine Research Center, University of Kentucky, KY, USA
| | - Stig M Thamsborg
- Department of Veterinary and Animal Sciences, University of Copenhagen, Denmark
| | - Paul R Torgerson
- Section of Epidemiology, Vetsuisse Faculty, University of Zürich, Switzerland
| | - John S Gilleard
- Department of Comparative Biology and Experimental Medicine, Host-Parasite Interactions Program, Faculty of Veterinary Medicine, University of Calgary, Alberta, Canada
| | - Robert J Dobson
- School of Veterinary and Life Sciences, Murdoch University, Australia
| | - Jozef Vercruysse
- Department of Translational Physiology, Infectiology and Public Health, Ghent University, Merelbeke, Belgium
| | - Bruno Levecke
- Department of Translational Physiology, Infectiology and Public Health, Ghent University, Merelbeke, Belgium
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Wainwright E, Shears RK. Trichuris WAP and CAP proteins: Potential whipworm vaccine candidates? PLoS Negl Trop Dis 2022; 16:e0010933. [PMID: 36548229 PMCID: PMC9778506 DOI: 10.1371/journal.pntd.0010933] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Trichuris trichiura and T. suis are gastrointestinal dwelling roundworms that infect humans and pigs, respectively. Heavy infections cause gastrointestinal symptoms and impaired growth and development. Vaccination has the potential to reduce the disease burden of whipworm infection; however, there are currently no commercially available vaccines against these parasites and very few against other gastrointestinal-dwelling nematodes of medical and agricultural importance. The naturally occurring mouse whipworm, T. muris, has been used for decades to model human trichuriasis, and the immunogenic potential of the excretory/secretory material (E/S, which can be collected following ex vivo culture of worms) has been studied in the context of vaccine candidate identification. Despite this, researchers are yet to progress an effective vaccine candidate to clinical trials. The T. muris, T. trichiura, and T. suis genomes each encode between 10 and 27 whey acidic protein (WAP) domain-containing proteins and 15 to 34 cysteine-rich secretory protein/antigen 5/pathogenesis related-1 (CAP) family members. WAP and CAP proteins have been postulated to play key roles in host-parasite interactions and may possess immunomodulatory functions. In addition, both protein families have been explored in the context of helminth vaccines. Here, we use phylogenetic and functional analysis to investigate the evolutionary relationship between WAP and CAP proteins encoded by T. muris, T. trichiura, and T. suis. We highlight several WAP and CAP proteins that warrant further study to understand their biological function and as possible vaccine candidates against T. trichiura and/or T. suis, based on the close evolutionary relationship with WAP or CAP proteins identified within T. muris E/S products.
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Affiliation(s)
- Eleanor Wainwright
- School of Biological Sciences, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre, University of Manchester, Manchester, United Kingdom
| | - Rebecca K. Shears
- Centre for Bioscience, Manchester Metropolitan University, Manchester, United Kingdom
- Department of Life Sciences, Faculty of Science and Engineering, Manchester Metropolitan University, Manchester, United Kingdom
- * E-mail:
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6
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Medication with fenbendazole in feed: plasma concentrations and effects on hepatic xenobiotic metabolizing enzymes in swine. Vet Res Commun 2022; 47:803-815. [DOI: 10.1007/s11259-022-10041-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Accepted: 11/18/2022] [Indexed: 12/24/2022]
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O'Sullivan JDB, Cruickshank SM, Withers PJ, Else KJ. Morphological variability in the mucosal attachment site of Trichuris muris revealed by X-ray microcomputed tomography. Int J Parasitol 2021; 51:797-807. [PMID: 34216623 DOI: 10.1016/j.ijpara.2021.04.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 04/06/2021] [Accepted: 04/09/2021] [Indexed: 11/27/2022]
Abstract
Parasitic infections can be challenging to study because two dimensional light and electron microscopy are often limited in visualising complex and inaccessible attachment sites. Exemplifying this, Trichuris spp. inhabit a tunnel of epithelial cells within the host caecum and colon. A significant global burden of this infection persists, partly because available anthelminthics lack efficacy, although the mechanisms underlying this remain unknown. Consequently, there is a need to pioneer new approaches to better characterize the parasite niche within the host and investigate how variation in its morphology and integrity may contribute to resistance to therapeutic intervention. To address these aims, we exploited three-dimensional X-ray micro-computed tomography (microCT) to image the mouse whipworm, Trichuris muris, in caeca of wild-type C57BL/6 and SCID mice ex vivo. Using osmium tetroxide staining to effectively enhance the contrast of worms, we found that a subset exhibited preferential positioning towards the bases of the intestinal crypts. Moreover, in one rare event, we demonstrated whipworm traversal of the lamina propria. This morphological variability contradicts widely accepted conclusions from conventional microscopy of the parasite niche, showing Trichuris in close contact with the host proliferative and immune compartments that may facilitate immunomodulation. Furthermore, by using a skeletonization-based approach we demonstrate considerable variation in tunnel length and integrity. The qualitative and quantitative observations provide a new morphological point of reference for future in vitro study of host-Trichuris interactions, and highlight the potential of microCT to characterise enigmatic host-parasite interactions more accurately.
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Affiliation(s)
- James D B O'Sullivan
- Henry Royce Institute, Department of Materials, The University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom; Lydia Becker Institute for Immunology and Inflammation, The University of Manchester, Oxford Road, M13 9PT, United Kingdom
| | - Sheena M Cruickshank
- Lydia Becker Institute for Immunology and Inflammation, The University of Manchester, Oxford Road, M13 9PT, United Kingdom
| | - Philip J Withers
- Henry Royce Institute, Department of Materials, The University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
| | - Kathryn J Else
- Lydia Becker Institute for Immunology and Inflammation, The University of Manchester, Oxford Road, M13 9PT, United Kingdom.
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Bach T, Galbiati S, Kennedy JK, Deye G, Nomicos EYH, Codd EE, Garcia HH, Horton J, Gilman RH, Gonzalez AE, Winokur P, An G. Pharmacokinetics, Safety, and Tolerability of Oxfendazole in Healthy Adults in an Open-Label Phase 1 Multiple Ascending Dose and Food Effect Study. Antimicrob Agents Chemother 2020; 64:e01018-20. [PMID: 32816721 PMCID: PMC7577123 DOI: 10.1128/aac.01018-20] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Accepted: 08/07/2020] [Indexed: 01/05/2023] Open
Abstract
Neurocysticercosis and trichuriasis are difficult-to-treat parasitic infections that affect more than 1.5 billion people worldwide. Oxfendazole, a potent broad-spectrum benzimidazole anthelmintic approved for use in veterinary medicine, has shown substantial antiparasitic activity against neurocysticercosis and intestinal helminths in preclinical studies. As part of a program to transition oxfendazole from veterinary medicine to human use, phase I multiple ascending dose and food effect studies were conducted. Thirty-six healthy adults were enrolled in an open-label study which evaluated (i) the pharmacokinetics and safety of oxfendazole following multiple ascending doses of oxfendazole oral suspension at 3, 7.5, and 15 mg/kg once daily for 5 days and (ii) the effect of food on oxfendazole pharmacokinetics and safety after a single 3-mg/kg dose administered following an overnight fast or the consumption of a fatty breakfast. Following multiple oral dose administration, the intestinal absorption of oxfendazole was rapid, with the time to maximum concentration of drug in serum (Tmax) ranging from 1.92 to 2.56 h. A similar half-life of oxfendazole (9.21 to 11.8 h) was observed across all dose groups evaluated, and oxfendazole exhibited significantly less than a dose-proportional increase in exposure. Oxfendazole plasma exposures were higher in female subjects than in male subjects. Following daily administration, oxfendazole reached a steady state in plasma on study day 3, with minimal accumulation. Food delayed the oxfendazole Tmax by a median of 6.88 h and resulted in a 49.2% increase in the maximum observed drug concentration in plasma (Cmax) and an 86.4% increase in the area under the concentration-time curve (AUC). Oxfendazole was well tolerated in all study groups, and there were no major safety signals identified in this study. (This study has been registered at ClinicalTrials.gov under identifier NCT03035760.).
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Affiliation(s)
- Thanh Bach
- Division of Pharmaceutics and Translational Therapeutics, College of Pharmacy, University of Iowa, Iowa City, Iowa, USA
| | | | | | - Gregory Deye
- Division of Microbiology and Infectious Diseases, National Institute of Allergy and Infectious Diseases, Bethesda, Maryland, USA
| | - Effie Y H Nomicos
- Division of Microbiology and Infectious Diseases, National Institute of Allergy and Infectious Diseases, Bethesda, Maryland, USA
| | - Ellen E Codd
- Codd Consulting, LLC, Blue Bell, Pennsylvania, USA
- Oxfendazole Development Group, Blue Bell, Pennsylvania, USA
| | - Hector H Garcia
- Oxfendazole Development Group, Blue Bell, Pennsylvania, USA
- Center for Global Health, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - John Horton
- Oxfendazole Development Group, Blue Bell, Pennsylvania, USA
- Tropical Projects, Hitchin, United Kingdom
| | - Robert H Gilman
- Oxfendazole Development Group, Blue Bell, Pennsylvania, USA
- Johns Hopkins School of Public Health, Johns Hopkins University, Baltimore, Maryland, USA
| | - Armando E Gonzalez
- Oxfendazole Development Group, Blue Bell, Pennsylvania, USA
- Center for Global Health, Universidad Peruana Cayetano Heredia, Lima, Peru
- School of Veterinary Medicine, Universidad Nacional Mayor de San Marcos, Lima, Peru
| | - Patricia Winokur
- Division of Infectious Diseases, Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA
| | - Guohua An
- Division of Pharmaceutics and Translational Therapeutics, College of Pharmacy, University of Iowa, Iowa City, Iowa, USA
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9
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Lopes-Torres EJ, Girard-Dias W, de Souza W, Miranda K. On the structural organization of the bacillary band of Trichuris muris under cryopreparation protocols and three-dimensional electron microscopy. J Struct Biol 2020; 212:107611. [PMID: 32890779 DOI: 10.1016/j.jsb.2020.107611] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Revised: 08/20/2020] [Accepted: 08/28/2020] [Indexed: 10/23/2022]
Abstract
Whipworms of the genus Trichuris are nematode parasites that infect mammals and can lead to various intestinal diseases of human and veterinary interest. The most intimate interaction between the parasite and the host intestine occurs through the anterior region of the nematode body, inserted into the intestinal mucosa during infection. One of the most prominent structures of the nematode surface found at the infection site is the bacillary band, a surface domain formed by a number of cells, mostly stichocytes and bacillary glands, whose structure and function are still under debate. Here, we used confocal microscopy, field emission scanning electron microscopy, helium ion microscopy, transmission electron microscopy and FIB-SEM tomography to unveil the functional role of the bacillary gland cell. We analyzed the surface organization as well as the intracellular milieu of the bacillary glands of Trichuris muris in high pressure frozen/freeze-substituted samples. Results showed that the secretory content is preserved in all gland openings, presenting a projected pattern. FIB-SEM analysis showed that the lamellar zone within the bacillary gland chamber is formed by a set of lacunar structures that may exhibit secretory or absorptive functions. In addition, incubation of parasites with the fluid phase endocytosis marker sulforhodamine B showed a time-dependent uptake by the parasite mouth, followed by perfusion through different tissues with ultimate secretion through the bacillary gland. Taken together, the results show that the bacillary gland possess structural characteristics of secretory and absorptive cells and unequivocally demonstrate that the bacillary gland cell functions as a secretory structure.
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Affiliation(s)
- E J Lopes-Torres
- Laboratório de Helmintologia Romero Lascasas Porto, Universidade do Estado do Rio de Janeiro, Departamento de Microbiologia, Imunologia e Parasitologia, Brazil.
| | - W Girard-Dias
- Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro, RJ, Brazil
| | - W de Souza
- Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho and Centro Nacional de Biologia Estrutural e Bioimagem, Universidade Federal do Rio de Janeiro, Av. Carlos Chagas Filho, s/n Centro de Ciências da Saúde, Bloco G, CEP: 21941-902, Rio de Janeiro, Brazil; Instituto Nacional de Biologia Estrutural e Bioimagem, Universidade Federal do Rio de Janeiro, Brazil
| | - K Miranda
- Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho and Centro Nacional de Biologia Estrutural e Bioimagem, Universidade Federal do Rio de Janeiro, Av. Carlos Chagas Filho, s/n Centro de Ciências da Saúde, Bloco G, CEP: 21941-902, Rio de Janeiro, Brazil; Instituto Nacional de Biologia Estrutural e Bioimagem, Universidade Federal do Rio de Janeiro, Brazil.
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10
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Ceballos L, Canton C, Cadenazzi G, Virkel G, Dominguez P, Moreno L, Lanusse C, Alvarez L. Oxfendazole kinetics in pigs: In vivo assessment of its pattern of accumulation in Ascaris suum. Exp Parasitol 2019; 199:52-58. [DOI: 10.1016/j.exppara.2019.02.017] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Revised: 01/02/2019] [Accepted: 02/23/2019] [Indexed: 10/27/2022]
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11
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Hansen TVA, Williams AR, Denwood M, Nejsum P, Thamsborg SM, Friis C. Pathway of oxfendazole from the host into the worm: Trichuris suis in pigs. INTERNATIONAL JOURNAL FOR PARASITOLOGY-DRUGS AND DRUG RESISTANCE 2017; 7:416-424. [PMID: 29156431 PMCID: PMC5695533 DOI: 10.1016/j.ijpddr.2017.11.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/17/2017] [Revised: 11/06/2017] [Accepted: 11/07/2017] [Indexed: 12/28/2022]
Abstract
It is well known that the efficacy of a single oral dose of benzimidazoles against Trichuris spp. infections in humans and animals is poor, but is currently still used in control programmes against human trichuriasis. However, the route of the benzimidazoles from the treated host to Trichuris remains unknown. As parts of adult Trichuris are situated intracellularly in the caecum, they might be exposed to anthelmintic drugs in the intestinal content as well as the mucosa. In this study, the pathway of oxfendazole and its metabolites was explored using a T. suis-pig infection model, by simultaneously measuring drug concentrations within the worms and the caecal mucosa, caecal tissue, caecal content and plasma of pigs over time after a single oral dose of 5 mg/kg oxfendazole. Additionally, for comparison to the in vivo study, drug uptake and metabolism of oxfendazole by T. suis was examined after in vitro incubation. Oxfendazole and metabolites were quantified by High Performance Liquid Chromatography. Multivariate linear regression analysis showed a strong and highly significant association between OFZ concentrations within T. suis and in plasma, along with a weaker association between OFZ concentrations in caecal tissue/mucosa and T. suis, suggesting that oxfendazole reaches T. suis after absorption from the gastrointestinal tract and enters the worms by the blood-enterocyte pathway. The fenbendazole sulfone level in T. suis was highly affected by the concentrations in plasma. In addition, correlations between drug concentrations in the host compartments, were generally highest for this metabolite. In comparison to oxfendazole, the correlation between plasma and content was particularly high for this metabolite, suggesting a high level of drug movement between these compartments and the possible involvement of the enterohepatic circulation. Trichuris suis accumulate OFZ, FBZSO2 and FBZ without significant metabolism in vitro. OFZ concentrations in plasma, tissue and mucosa are major determinants of OFZ levels in worms. FBZSO2 concentration in plasma is the main determinant of FBZSO2 levels in T. suis. The blood-enterocyte pathway is proposed as the major route for OFZ to reach T. suis.
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Affiliation(s)
- Tina V A Hansen
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg, Denmark.
| | - Andrew R Williams
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Matthew Denwood
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Peter Nejsum
- Department of Clinical Medicine, Faculty of Health, Aarhus University, Denmark
| | - Stig M Thamsborg
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Christian Friis
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg, Denmark
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12
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Cowan N, Meier C, Neodo A, Keiser J. Exposure of Heligmosomoides polygyrus and Trichuris muris to albendazole, albendazole sulfoxide, mebendazole and oxantel pamoate in vitro and in vivo to elucidate the pathway of drug entry into these gastrointestinal nematodes. Int J Parasitol Drugs Drug Resist 2017; 7:159-173. [PMID: 28371660 PMCID: PMC5377441 DOI: 10.1016/j.ijpddr.2017.03.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Revised: 03/19/2017] [Accepted: 03/22/2017] [Indexed: 10/29/2022]
Abstract
Millions of people are treated with anthelmintics to control soil-transmitted helminth infections; yet, drug distribution in the plasma and gastrointestinal tract compartments and the pathway of drug uptake into gastrointestinal nematodes responsible for the pharmacological effect are unknown. We assessed the distribution and uptake of albendazole, albendazole sulfoxide, albendazole sulfone in the hookworm Heligmosomoides polygyrus in vitro and in vivo as well as the distribution and uptake of albendazole, mebendazole, and oxantel pamoate in the whipworm Trichuris muris in vitro and in vivo. Oral and intraperitoneal treatments (100 mg/kg) were studied. Drug quantities in helminths and host compartments (stomach, the contents and mucosa of the small and large intestine, and the plasma) were determined using HPLC-UV/vis and anthelmintic activities were recorded using phenotypic readout. The influence of 1-aminobenzotriazole (ABT), an irreversible and unspecific cytochrome P450 inhibitor, on albendazole disposition in mice harboring H. polygyrus was evaluated. In vivo, albendazole was found in quantities up to 10 nmol per ten H. polygyrus and up to 31 nmol per ten T. muris. ABT did not change the levels of albendazole or its metabolites in the plasma of mice harboring H. polygyrus or in H. polygyrus, whereas drug levels in the gastrointestinal tract of host mice doubled. Mebendazole and oxantel pamoate quantities per ten T. muris were as high as 21 nmol and 34 nmol, respectively. Albendazole revealed a very dynamic distribution and high rate of metabolism, hence, H. polygyrus and T. muris are exposed to albendazole and both metabolites via multiple pathways. Diffusion through the cuticle seems to be the crucial pathway of oxantel pamoate uptake into T. muris, and likely also for mebendazole. No relationship between concentrations measured in helminths and concentrations in plasma, intestinal content and mucosa of mice, or drug efficacy was noted for any of the drugs studied.
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Affiliation(s)
- Noemi Cowan
- Department of Medical Parasitology and Infection Biology Swiss Tropical and Public Health Institute, P.O. Box, CH-4002 Basel, Switzerland; University of Basel, P.O. Box, CH-4003 Basel, Switzerland
| | - Charles Meier
- Department of Medical Parasitology and Infection Biology Swiss Tropical and Public Health Institute, P.O. Box, CH-4002 Basel, Switzerland; University of Basel, P.O. Box, CH-4003 Basel, Switzerland
| | - Anna Neodo
- Department of Medical Parasitology and Infection Biology Swiss Tropical and Public Health Institute, P.O. Box, CH-4002 Basel, Switzerland; University of Basel, P.O. Box, CH-4003 Basel, Switzerland
| | - Jennifer Keiser
- Department of Medical Parasitology and Infection Biology Swiss Tropical and Public Health Institute, P.O. Box, CH-4002 Basel, Switzerland; University of Basel, P.O. Box, CH-4003 Basel, Switzerland.
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Partridge FA, Murphy EA, Willis NJ, Bataille CJR, Forman R, Heyer-Chauhan N, Marinič B, Sowood DJC, Wynne GM, Else KJ, Russell AJ, Sattelle DB. Dihydrobenz[e][1,4]oxazepin-2(3H)-ones, a new anthelmintic chemotype immobilising whipworm and reducing infectivity in vivo. PLoS Negl Trop Dis 2017; 11:e0005359. [PMID: 28182663 PMCID: PMC5321434 DOI: 10.1371/journal.pntd.0005359] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Revised: 02/22/2017] [Accepted: 01/26/2017] [Indexed: 01/07/2023] Open
Abstract
Trichuris trichiura is a human parasitic whipworm infecting around 500 million people globally, damaging the physical growth and educational performance of those infected. Current drug treatment options are limited and lack efficacy against the worm, preventing an eradication programme. It is therefore important to develop new treatments for trichuriasis. Using Trichuris muris, an established model for T. trichiura, we screened a library of 480 novel drug-like small molecules for compounds causing paralysis of the ex vivo adult parasite. We identified a class of dihydrobenz[e][1,4]oxazepin-2(3H)-one compounds with anthelmintic activity against T. muris. Further screening of structurally related compounds and resynthesis of the most potent molecules led to the identification of 20 active dihydrobenzoxazepinones, a class of molecule not previously implicated in nematode control. The most active immobilise adult T. muris with EC50 values around 25–50μM, comparable to the existing anthelmintic levamisole. The best compounds from this chemotype show low cytotoxicity against murine gut epithelial cells, demonstrating selectivity for the parasite. Developing a novel oral pharmaceutical treatment for a neglected disease and deploying it via mass drug administration is challenging. Interestingly, the dihydrobenzoxazepinone OX02983 reduces the ability of embryonated T. muris eggs to establish infection in the mouse host in vivo. Complementing the potential development of dihydrobenzoxazepinones as an oral anthelmintic, this supports an alternative strategy of developing a therapeutic that acts in the environment, perhaps via a spray, to interrupt the parasite lifecycle. Together these results show that the dihydrobenzoxazepinones are a new class of anthelmintic, active against both egg and adult stages of Trichuris parasites. They demonstrate encouraging selectivity for the parasite, and importantly show considerable scope for further optimisation to improve potency and pharmacokinetic properties with the aim of developing a clinical agent. Trichuris trichiura is a human parasitic whipworm infecting around 500 million people globally and having major consequences on the physical growth and educational performance of those infected. Current drug treatment options are limited and lack efficacy against the worm. Critically, they lack the effectiveness that would allow for a practical program for eradication of this parasite. It is therefore important to develop new treatments for trichuriasis. We screened for molecules that could paralyse the adult of a closely related mouse parasite, and identified a class of compounds, the dihydrobenzoxazepinones, not previously implicated as anthelmintics. Importantly, our compounds are active against the parasite but show only low toxicity against mouse cells, demonstrating selectivity for the parasite. Dihydrobenzoxazepinones could be developed as potential pharmaceutical treatments for trichuriasis. Since developing and deploying new drugs for neglected diseases by mass administration is challenging, we also explored whether the compounds could potentially be used to interrupt the Trichuris lifecycle by acting on eggs. Our dihydrobenzoxazepinone compounds reduced the ability of T. muris eggs to establish infection in their mouse host. This supports an environmental spray strategy for the control of Trichuris targeting their eggs in environmental hotspots such as latrines.
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Affiliation(s)
- Frederick A. Partridge
- Centre for Respiratory Biology, UCL Respiratory, Division of Medicine, University College London, London, United Kingdom
| | - Emma A. Murphy
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Nicky J. Willis
- Department of Chemistry, Chemistry Research Laboratory, University of Oxford, Oxford, United Kingdom
| | - Carole J. R. Bataille
- Department of Chemistry, Chemistry Research Laboratory, University of Oxford, Oxford, United Kingdom
| | - Ruth Forman
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Narinder Heyer-Chauhan
- Centre for Respiratory Biology, UCL Respiratory, Division of Medicine, University College London, London, United Kingdom
| | - Bruno Marinič
- Department of Chemistry, Chemistry Research Laboratory, University of Oxford, Oxford, United Kingdom
| | - Daniel J. C. Sowood
- Department of Chemistry, Chemistry Research Laboratory, University of Oxford, Oxford, United Kingdom
| | - Graham M. Wynne
- Department of Chemistry, Chemistry Research Laboratory, University of Oxford, Oxford, United Kingdom
| | - Kathryn J. Else
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
- * E-mail: (KJE); (AJR); (DBS)
| | - Angela J. Russell
- Department of Chemistry, Chemistry Research Laboratory, University of Oxford, Oxford, United Kingdom
- Department of Pharmacology, University of Oxford, Oxford, United Kingdom
- * E-mail: (KJE); (AJR); (DBS)
| | - David B. Sattelle
- Centre for Respiratory Biology, UCL Respiratory, Division of Medicine, University College London, London, United Kingdom
- * E-mail: (KJE); (AJR); (DBS)
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Hansen TVA, Hansen M, Nejsum P, Mejer H, Denwood M, Thamsborg SM. Glucose Absorption by the Bacillary Band of Trichuris muris. PLoS Negl Trop Dis 2016; 10:e0004971. [PMID: 27588682 PMCID: PMC5010283 DOI: 10.1371/journal.pntd.0004971] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Accepted: 08/10/2016] [Indexed: 12/20/2022] Open
Abstract
Background A common characteristic of Trichuris spp. infections in humans and animals is the variable but low efficacy of single-dose benzimidazoles currently used in mass drug administration programmes against human trichuriasis. The bacillary band, a specialised morphological structure of Trichuris spp., as well as the unique partly intracellular habitat of adult Trichuris spp. may affect drug absorption and perhaps contribute to the low drug accumulation in the worm. However, the exact function of the bacillary band is still unknown. Methodology We studied the dependency of adult Trichuris muris on glucose and/or amino acids for survival in vitro and the absorptive function of the bacillary band. The viability of the worms was evaluated using a motility scale from 0 to 3, and the colorimetric assay Alamar Blue was utilised to measure the metabolic activity. The absorptive function of the bacillary band in living worms was explored using a fluorescent glucose analogue (6-NBDG) and confocal microscopy. To study the absorptive function of the bacillary band in relation to 6-NBDG, the oral uptake was minimised or excluded by sealing the oral cavity with glue and agarose. Principal Findings Glucose had a positive effect on both the motility (p < 0.001) and metabolic activity (p < 0.001) of T. muris in vitro, whereas this was not the case for amino acids. The 6-NBDG was observed in the pores of the bacillary band and within the stichocytes of the living worms, independent of oral sealing. Conclusions/Significance Trichuris muris is dependent on glucose for viability in vitro, and the bacillary band has an absorptive function in relation to 6-NBDG, which accumulates within the stichocytes. The absorptive function of the bacillary band calls for an exploration of its possible role in the uptake of anthelmintics, and as a potential anthelmintic target relevant for future drug development. The human whipworm, Trichuris trichiura is prevalent in many tropical and subtropical countries and is believed to infect more than 460 million people worldwide. Treatment with single-dose albendazole or mebendazole is the current control strategy for human trichuriasis. This strategy, however, has a poor-to-mediocre treatment effect. The reason for the low treatment efficacy has been assessed in various ways, including genetic analysis, and both in vitro and in vivo pharmacological studies. However, these studies have not been conclusive and did not evaluate whether the biology of Trichuris spp. may have an impact on the inadequate treatment efficacy. To assess a possible reason for this, we here explore the absorptive function of a specialised structure, named the bacillary band. We found that glucose was absorbed by the band and accumulated within the worm independent of oral ingestion, and we speculate that anthelmintics may enter the worm by the same route. If this is the case, this new insight may be used to optimise drug formulations of current and/or future anthelmintic drugs in the treatment of human trichuriasis.
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Affiliation(s)
- Tina V. A. Hansen
- Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg, Denmark
- * E-mail:
| | - Michael Hansen
- Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Frederiksberg, Denmark
| | - Peter Nejsum
- Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Helena Mejer
- Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Matthew Denwood
- Department of Large Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Stig M. Thamsborg
- Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg, Denmark
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15
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Cowan N, Raimondo A, Keiser J. Approved oncology drugs lack in vivo activity against Trichuris muris despite in vitro activity. Parasitol Res 2016; 115:4443-4446. [DOI: 10.1007/s00436-016-5225-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Accepted: 07/28/2016] [Indexed: 11/28/2022]
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Belew S, Getachew M, Suleman S, Mohammed T, Deti H, D'Hondt M, Wynendaele E, Mekonnen Z, Vercruysse J, Duchateau L, De Spiegeleer B, Levecke B. Assessment of Efficacy and Quality of Two Albendazole Brands Commonly Used against Soil-Transmitted Helminth Infections in School Children in Jimma Town, Ethiopia. PLoS Negl Trop Dis 2015; 9:e0004057. [PMID: 26406600 PMCID: PMC4583991 DOI: 10.1371/journal.pntd.0004057] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2015] [Accepted: 08/14/2015] [Indexed: 11/30/2022] Open
Abstract
Background There is a worldwide upscale in mass drug administration (MDA) programs to control the morbidity caused by soil-transmitted helminths (STHs): Ascaris lumbricoides, Trichuris trichiura and hookworm. Although anthelminthic drugs which are used for MDA are supplied by two pharmaceutical companies through donation, there is a wide range of brands available on local markets for which the efficacy against STHs and quality remain poorly explored. In the present study, we evaluated the drug efficacy and quality of two albendazole brands (Bendex and Ovis) available on the local market in Ethiopia. Methodology/Principal Findings A randomized clinical trial was conducted according to the World Health Organization (WHO) guidelines to assess drug efficacy, by means of egg reduction rate (ERR), of Bendex and Ovis against STH infections in school children in Jimma, Ethiopia. In addition, the chemical and physicochemical quality of the drugs was assessed according to the United States and European Pharmacopoeia, encompassing mass uniformity of the tablets, amount of active compound and dissolution profile. Both drugs were highly efficacious against A. lumbricoides (>97%), but showed poor efficacy against T. trichiura (~20%). For hookworms, Ovis was significantly (p < 0.05) more efficacious compared to Bendex (98.1% vs. 88.7%). Assessment of the physicochemical quality of the drugs revealed a significant difference in dissolution profile, with Bendex having a slower dissolution than Ovis. Conclusion/Significance The study revealed that differences in efficacy between the two brands of albendazole (ABZ) tablets against hookworm are linked to the differences in the in-vitro drug release profile. Differences in uptake and metabolism of this benzimidazole drug among different helminth species may explain that this efficacy difference was only observed in hookworms and not in the two other species. The results of the present study underscore the importance of assessing the chemical and physicochemical quality of drugs before conducting efficacy assessment in any clinical trials to ensure appropriate therapeutic efficacy and to exclude poor drug quality as a factor of reduced drug efficacy other than anthelminthic resistance. Overall, this paper demonstrates that “all medicines are not created equal”. Soil-transmitted helminths (STHs) infect millions of children worldwide. To fight STH, large-scale de-worming programs are implemented in which anthelmintic drugs (either albendazole (ABZ) or mebendazole (MEB)) are administered. However, there is a wide range of other brands, which are even more accessible, but for which the efficacy and quality remain poorly explored. We evaluated efficacy against STHs and quality of two ABZ brands commonly available on the local markets in Ethiopia (Bendex and Ovis). Both brands showed high efficacy against roundworm infections and poor efficacy against whipworms. However, for hookworm infections, Bendex was significantly less efficacious than Ovis. In terms of drug quality, a significant difference was observed in the dissolution profile, with Bendex having a significantly slower dissolution rate than Ovis. Since dissolution behavior is critical for a drug to be appropriately absorbed into the helminth (through host-blood and/or parasite-cuticle) and produce therapeutic efficacy, the poor dissolution of Bendex compared to Ovis can explain the observed difference in efficacy against hookworms. Our results emphasize the importance of periodically assessing of drug quality to ensure appropriate therapeutic efficacy and to exclude poor drug quality as a potential factor of reduced drug efficacy other than drug resistance.
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Affiliation(s)
- Sileshi Belew
- School of Pharmacy, Jimma University, Jimma, Ethiopia
- Drug Quality and Registration Group, Department of Pharmaceutical Analysis, Faculty of Pharmaceutical Sciences, Ghent University, Gent, Belgium
| | - Mestawet Getachew
- Jimma University Specialized Hospital, Jimma University, Jimma, Ethiopia
| | - Sultan Suleman
- School of Pharmacy, Jimma University, Jimma, Ethiopia
- Drug Quality and Registration Group, Department of Pharmaceutical Analysis, Faculty of Pharmaceutical Sciences, Ghent University, Gent, Belgium
| | | | | | - Matthias D'Hondt
- Drug Quality and Registration Group, Department of Pharmaceutical Analysis, Faculty of Pharmaceutical Sciences, Ghent University, Gent, Belgium
| | - Evelien Wynendaele
- Drug Quality and Registration Group, Department of Pharmaceutical Analysis, Faculty of Pharmaceutical Sciences, Ghent University, Gent, Belgium
| | - Zeleke Mekonnen
- Department of Medical Laboratory Sciences and Pathology, Jimma University, Jimma, Ethiopia
| | - Jozef Vercruysse
- Department of Virology, Parasitology and Immunology, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Luc Duchateau
- Department of Comparative Physiology and Biometrics, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Bart De Spiegeleer
- Drug Quality and Registration Group, Department of Pharmaceutical Analysis, Faculty of Pharmaceutical Sciences, Ghent University, Gent, Belgium
- * E-mail: (BDS); (BL)
| | - Bruno Levecke
- Department of Virology, Parasitology and Immunology, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
- * E-mail: (BDS); (BL)
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Third-stage nematode larvae of Contracaecum osculatum from Baltic cod (Gadus morhua) elicit eosinophilic granulomatous reactions when penetrating the stomach mucosa of pigs. Parasitol Res 2015; 114:1217-20. [DOI: 10.1007/s00436-014-4306-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2014] [Accepted: 12/23/2014] [Indexed: 11/26/2022]
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