1
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Askarani HK, Tahghighi A, Ahmadpoor M, Zamani Z. In vitro and in vivo antiplasmodial activity of a synthetic dihydroartemisinin-eosin B hybrid. NAUNYN-SCHMIEDEBERG'S ARCHIVES OF PHARMACOLOGY 2024; 397:4013-4024. [PMID: 37999757 DOI: 10.1007/s00210-023-02815-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2022] [Accepted: 10/22/2023] [Indexed: 11/25/2023]
Abstract
With the inexorable prevalence and spread of drug-resistant malaria strains, many efforts have been made to find alternative chemotherapeutic agents. In this regard, scientists have developed the concept of hybridization of two or more active pharmacophores into a single chemical compound, resulting in "antimalarial hybrids." The aim of this study was planned based on the highly synergistic effect of the physical hybrid of dihydroartemisinin (DHA) with eosin B (EB). Therefore, a chemical hybrid of the two compounds (DHA-EB) was synthesized, and its antimalarial activity was investigated in vitro and in vivo. The drug hybrid was fabricated through a propionyl ester linker between DHA and EB. The antiplasmodial activity of the new hybrid was tested in vitro on the blood stages of Plasmodium falciparum (chloroquine-sensitive, 3D7 strain) and also evaluated in vivo by Peters' standard test in mice infected with Plasmodium berghei. The hybrid compound was also assessed for in vivo toxicity. Among all the compounds studied, a DHA-EB hybrid showed an appropriate inhibition percentage (53%) was at a very low dose (0.65 nM). The highest in vivo antimalarial activity until the 9th day was related to DHA-EB in a low dose (0.5 mg/kg). Also, the most survival rate was observed in the test group of hybrid compound at a dose of 1.5 mg/kg for 22 days. No external changes were identified in the toxicity assay. The weight of internal organs of treated animals and that of controls indicated nontoxicity of DHA-EB even after 60 days of consumption. In vitro and in vivo studies substantiated that DHA-EB hybrid has the potential for developing as a safe antimalarial drug.
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Affiliation(s)
- Hajar Karimi Askarani
- Medicinal Chemistry Laboratory, Department of Clinical Research, Pasteur Institute of Iran, Tehran, Iran
| | - Azar Tahghighi
- Medicinal Chemistry Laboratory, Department of Clinical Research, Pasteur Institute of Iran, Tehran, Iran.
| | | | - Zahra Zamani
- Department of Biochemistry, Pasteur Institute of Iran, Tehran, Iran.
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2
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Abdugheni R, Li L, Yang ZN, Huang Y, Fang BZ, Shurigin V, Mohamad OAA, Liu YH, Li WJ. Microbial Risks Caused by Livestock Excrement: Current Research Status and Prospects. Microorganisms 2023; 11:1897. [PMID: 37630456 PMCID: PMC10456746 DOI: 10.3390/microorganisms11081897] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Revised: 07/21/2023] [Accepted: 07/25/2023] [Indexed: 08/27/2023] Open
Abstract
Livestock excrement is a major pollutant yielded from husbandry and it has been constantly imported into various related environments. Livestock excrement comprises a variety of microorganisms including certain units with health risks and these microorganisms are transferred synchronically during the management and utilization processes of livestock excrement. The livestock excrement microbiome is extensively affecting the microbiome of humans and the relevant environments and it could be altered by related environmental factors as well. The zoonotic microorganisms, extremely zoonotic pathogens, and antibiotic-resistant microorganisms are posing threats to human health and environmental safety. In this review, we highlight the main feature of the microbiome of livestock excrement and elucidate the composition and structure of the repertoire of microbes, how these microbes transfer from different spots, and they then affect the microbiomes of related habitants as a whole. Overall, the environmental problems caused by the microbiome of livestock excrement and the potential risks it may cause are summarized from the microbial perspective and the strategies for prediction, prevention, and management are discussed so as to provide a reference for further studies regarding potential microbial risks of livestock excrement microbes.
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Affiliation(s)
- Rashidin Abdugheni
- State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Ürümqi 830011, China
| | - Li Li
- State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Ürümqi 830011, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhen-Ni Yang
- Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Yin Huang
- State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Ürümqi 830011, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Bao-Zhu Fang
- State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Ürümqi 830011, China
| | - Vyacheslav Shurigin
- State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Ürümqi 830011, China
| | - Osama Abdalla Abdelshafy Mohamad
- State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Ürümqi 830011, China
| | - Yong-Hong Liu
- State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Ürümqi 830011, China
| | - Wen-Jun Li
- State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Ürümqi 830011, China
- State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, China
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3
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Kaur M, Yardley V, Wang K, Masania J, Arroo RRJ, Turner DB, Li M. Artemisinin Cocrystals for Bioavailability Enhancement. Part 2: In Vivo Bioavailability and Physiologically Based Pharmacokinetic Modeling. Mol Pharm 2021; 18:4272-4289. [PMID: 34748332 DOI: 10.1021/acs.molpharmaceut.1c00385] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We report the evaluation and prediction of the pharmacokinetic (PK) performance of artemisinin (ART) cocrystal formulations, that is, 1:1 artemisinin/orcinol (ART-ORC) and 2:1 artemisinin/resorcinol (ART2-RES), using in vivo murine animal and physiologically based pharmacokinetic (PBPK) models. The efficacy of the ART cocrystal formulations along with the parent drug ART was tested in mice infected with Plasmodium berghei. When given at the same dose, the ART cocrystal formulation showed a significant reduction in parasitaemia at day 4 after infection compared to ART alone. PK parameters including Cmax (maximum plasma concentration), Tmax (time to Cmax), and AUC (area under the curve) were obtained by determining drug concentrations in the plasma using liquid chromatography-high-resolution mass spectrometry (LC-HRMS), showing enhanced ART levels after dosage with the cocrystal formulations. The dose-response tests revealed that a significantly lower dose of the ART cocrystals in the formulation was required to achieve a similar therapeutic effect as ART alone. A PBPK model was developed using a PBPK mouse simulator to accurately predict the in vivo behavior of the cocrystal formulations by combining in vitro dissolution profiles with the properties of the parent drug ART. The study illustrated that information from classical in vitro and in vivo experimental investigations of the parent drug of ART formulations can be coupled with PBPK modeling to predict the PK parameters of an ART cocrystal formulation in an efficient manner. Therefore, the proposed modeling strategy could be used to establish in vitro and in vivo correlations for different cocrystals intended to improve dissolution properties and to support clinical candidate selection, contributing to the assessment of cocrystal developability and formulation development.
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Affiliation(s)
- Manreet Kaur
- Leicester School of Pharmacy, De Montfort University, Leicester LE1 9BH, U.K
| | - Vanessa Yardley
- Department of Infection & Immunity, Faculty of Infectious & Tropical Diseases, London School of Hygiene and Tropical Medicine, London WC1E 7HT, U.K
| | - Ke Wang
- Leicester School of Pharmacy, De Montfort University, Leicester LE1 9BH, U.K
| | - Jinit Masania
- Leicester School of Pharmacy, De Montfort University, Leicester LE1 9BH, U.K
| | - Randolph R J Arroo
- Leicester School of Pharmacy, De Montfort University, Leicester LE1 9BH, U.K
| | - David B Turner
- Certara UK Limited, Simcyp Division, Sheffield S1 2BJ, U.K
| | - Mingzhong Li
- Leicester School of Pharmacy, De Montfort University, Leicester LE1 9BH, U.K
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4
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Hughes E, Wallender E, Mohamed Ali A, Jagannathan P, Savic RM. Malaria PK/PD and the Role Pharmacometrics Can Play in the Global Health Arena: Malaria Treatment Regimens for Vulnerable Populations. Clin Pharmacol Ther 2021; 110:926-940. [PMID: 33763871 PMCID: PMC8518425 DOI: 10.1002/cpt.2238] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Accepted: 03/05/2021] [Indexed: 12/23/2022]
Abstract
Malaria is an infectious disease which disproportionately effects children and pregnant women. These vulnerable populations are often excluded from clinical trials resulting in one‐size‐fits‐all treatment regimens based on those established for a nonpregnant adult population. Pharmacokinetic/pharmacodynamic (PK/PD) models can be used to optimize dose selection as they define the drug exposure‐response relationship. Additionally, these models are able to identify patient characteristics that cause alterations in the expected PK/PD profiles and through simulations can recommend changes to dosing which compensate for the differences. In this review, we examine how PK/PD models have been applied to optimize antimalarial dosing recommendations for young children, including those who are malnourished, pregnant women, and individuals receiving concomitant therapies such as those for HIV treatment. The malaria field has had great success in utilizing PK/PD models as a foundation to update treatment guidelines and propose the next generation of dosing regimens to investigate in clinical trials. We propose how the malaria field can continue to use modeling to improve therapies by further integrating PK data into clinical studies and including data on drug resistance and host immunity in PK/PD models. Finally, we suggest that other disease areas can achieve similar success in applying pharmacometrics to improve outcomes by implementing three key principals.
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Affiliation(s)
- Emma Hughes
- Department of Bioengineering and Therapeutic Sciences, University of California San Francisco, San Francisco, California, USA
| | - Erika Wallender
- Department of Clinical Pharmacy, University of California San Francisco, San Francisco, California, USA
| | - Ali Mohamed Ali
- Department of Bioengineering and Therapeutic Sciences, University of California San Francisco, San Francisco, California, USA
| | | | - Radojka M Savic
- Department of Bioengineering and Therapeutic Sciences, University of California San Francisco, San Francisco, California, USA
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5
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Liu L, Zhao J, Li A, Yang X, Sprangers B, Li S. Prolongation of allograft survival by artemisinin treatment is associated with blockade of OX40-OX40L. Immunopharmacol Immunotoxicol 2021; 43:291-298. [PMID: 33757384 DOI: 10.1080/08923973.2021.1902347] [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] [Indexed: 01/19/2023]
Abstract
OBJECTIVES It has been demonstrated that artemisinin (ART) possesses multiple immune modulatory effects. However, its role as immunosuppressant in allogeneic transplantation is undetermined. Here, we investigated the effect of ART on co-stimulatory signaling in OX40+ T cells and evaluated ART as a potential immunosuppressant in transplantation. MATERIALS AND METHODS Allogeneic skin transplantation was performed in C57BL/6 to BALB/c mice. Recipient mice were administrated with vehicle, ART or cyclosporine A daily from day 0 to day 19 post transplantation. Proportions of splenic CD4+OX40+ and CD4+CD44hiCD62Lhi cells, and serum IgG was measured by using flow cytometry. An in vitro lymphocyte stimulation with Con A or LPS under various concentrations of ART was performed, expression of CD4+OX40+ and CD4+CD44hiCD62Lhi cells was evaluated, and interleukin(IL)-6 production was measured by ELISA. RESULTS In in vivo allogeneic skin transplant model, ART significantly prolongs allogeneic skin survival. Furthermore, our in vitro studies demonstrate that the immune suppression of ART on T cells is associated with a reduction in OX40+ T cells and inhibition of IL-6 secretion. CONCLUSION Our data indicate that the OX40-OX40L pathway and IL-6 are possibly involved in ART-induced immunosuppression, and ART is a potential novel immunosuppressant.
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Affiliation(s)
- Lihua Liu
- Department of Medical Ultrasonic, The Fifth Affiliated Hospital, Sun Yat-Sen University, Zhuhai, P.R. China
| | - Juanzhi Zhao
- Department of Pharmacy, The Fifth Affiliated Hospital, Sun Yat-Sen University, Zhuhai, P.R. China
| | - An Li
- Department of Traditional Chinese Medicine, The Fifth Affiliated Hospital, Sun Yat-Sen University, Zhuhai, P.R. China
| | - Xuan Yang
- Department of Traditional Chinese Medicine, The Fifth Affiliated Hospital, Sun Yat-Sen University, Zhuhai, P.R. China
| | - Ben Sprangers
- Laboratory of Molecular Immunology, Department of Microbiology and Immunology, Rega Institute, Leuven, Belgium
| | - Shengqiao Li
- Department of Traditional Chinese Medicine, The Fifth Affiliated Hospital, Sun Yat-Sen University, Zhuhai, P.R. China.,Guangdong Provincial Key Laboratory of Biomedical Imaging, The Fifth Affiliated Hospital, University of Sun Yat-Sen, Zhuhai, P.R. China
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6
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Semimechanistic Pharmacokinetic and Pharmacodynamic Modeling of Piperaquine in a Volunteer Infection Study with Plasmodium falciparum Blood-Stage Malaria. Antimicrob Agents Chemother 2021; 65:AAC.01583-20. [PMID: 33468477 PMCID: PMC8097471 DOI: 10.1128/aac.01583-20] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Accepted: 01/10/2021] [Indexed: 11/20/2022] Open
Abstract
Dihydroartemisinin-piperaquine is a recommended first-line artemisinin combination therapy for Plasmodium falciparum malaria. Piperaquine is also under consideration for other antimalarial combination therapies. The aim of this study was to develop a pharmacokinetic-pharmacodynamic model that might be useful when optimizing the use of piperaquine in new antimalarial combination therapies. The pharmacokinetic-pharmacodynamic model was developed using data from a previously reported dose-ranging study where 24 healthy volunteers were inoculated with 1,800 blood-stage Plasmodium falciparum parasites. All volunteers received a single oral dose of piperaquine (960 mg, 640 mg, or 480 mg) on day 7 or day 8 after parasite inoculation in separate cohorts. Parasite densities were measured by quantitative PCR (qPCR), and piperaquine levels were measured in plasma samples. We used nonlinear mixed-effect modeling to characterize the pharmacokinetic properties of piperaquine and the parasite dynamics associated with piperaquine exposure. The pharmacokinetics of piperaquine was described by a three-compartment disposition model. A semimechanistic parasite dynamics model was developed to explain the maturation of parasites, sequestration of mature parasites, synchronicity of infections, and multiplication of parasites, as seen in natural clinical infections with P. falciparum malaria. Piperaquine-associated parasite killing was estimated using a maximum effect (E max) function. Treatment simulations (i.e., 3-day oral dosing of dihydroartemisinin-piperaquine) indicated that to be able to combat multidrug-resistant infections, an ideal additional drug in a new antimalarial triple-combination therapy should have a parasite reduction ratio of ≥102 per life cycle (38.8 h) with a duration of action of ≥2 weeks. The semimechanistic pharmacokinetic-pharmacodynamic model described here offers the potential to be a valuable tool for assessing and optimizing current and new antimalarial drug combination therapies containing piperaquine and the impact of these therapies on killing multidrug-resistant infections. (This study has been registered in the Australian and New Zealand Clinical Trials Registry under no. ANZCTRN12613000565741.).
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7
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Burgert L, Rottmann M, Wittlin S, Gobeau N, Krause A, Dingemanse J, Möhrle JJ, Penny MA. Ensemble modeling highlights importance of understanding parasite-host behavior in preclinical antimalarial drug development. Sci Rep 2020; 10:4410. [PMID: 32157151 PMCID: PMC7064600 DOI: 10.1038/s41598-020-61304-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Accepted: 02/20/2020] [Indexed: 11/23/2022] Open
Abstract
Emerging drug resistance and high-attrition rates in early and late stage drug development necessitate accelerated development of antimalarial compounds. However, systematic and meaningful translation of drug efficacy and host-parasite dynamics between preclinical testing stages is missing. We developed an ensemble of mathematical within-host parasite growth and antimalarial action models, fitted to extensive data from four antimalarials with different modes of action, to assess host-parasite interactions in two preclinical drug testing systems of murine parasite P. berghei in mice, and human parasite P. falciparum in immune-deficient mice. We find properties of the host-parasite system, namely resource availability, parasite maturation and virulence, drive P. berghei dynamics and drug efficacy, whereas experimental constraints primarily influence P. falciparum infection and drug efficacy. Furthermore, uninvestigated parasite behavior such as dormancy influences parasite recrudescence following non-curative treatment and requires further investigation. Taken together, host-parasite interactions should be considered for meaningful translation of pharmacodynamic properties between murine systems and for predicting human efficacious treatment.
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Affiliation(s)
- Lydia Burgert
- Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | - Matthias Rottmann
- Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | - Sergio Wittlin
- Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | | | - Andreas Krause
- Idorsia Pharmaceuticals Ltd, Clinical Pharmacology, Allschwil, Switzerland
| | - Jasper Dingemanse
- Idorsia Pharmaceuticals Ltd, Clinical Pharmacology, Allschwil, Switzerland
| | - Jörg J Möhrle
- Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel, Switzerland.,Medicines for Malaria Venture, Geneva, Switzerland
| | - Melissa A Penny
- Swiss Tropical and Public Health Institute, Basel, Switzerland. .,University of Basel, Basel, Switzerland.
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8
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Mason DJ, Eastman RT, Lewis RPI, Stott IP, Guha R, Bender A. Using Machine Learning to Predict Synergistic Antimalarial Compound Combinations With Novel Structures. Front Pharmacol 2018; 9:1096. [PMID: 30333748 PMCID: PMC6176478 DOI: 10.3389/fphar.2018.01096] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Accepted: 09/07/2018] [Indexed: 01/28/2023] Open
Abstract
The parasite Plasmodium falciparum is the most lethal species of Plasmodium to cause serious malaria infection in humans, and with resistance developing rapidly novel treatment modalities are currently being sought, one of which being combinations of existing compounds. The discovery of combinations of antimalarial drugs that act synergistically with one another is hence of great importance; however an exhaustive experimental screen of large drug space in a pairwise manner is not an option. In this study we apply our machine learning approach, Combination Synergy Estimation (CoSynE), which can predict novel synergistic drug interactions using only prior experimental combination screening data and knowledge of compound molecular structures, to a dataset of 1,540 antimalarial drug combinations in which 22.2% were synergistic. Cross validation of our model showed that synergistic CoSynE predictions are enriched 2.74 × compared to random selection when both compounds in a predicted combination are known from other combinations among the training data, 2.36 × when only one compound is known from the training data, and 1.5 × for entirely novel combinations. We prospectively validated our model by making predictions for 185 combinations of 23 entirely novel compounds. CoSynE predicted 20 combinations to be synergistic, which was experimentally validated for nine of them (45%), corresponding to an enrichment of 1.70 × compared to random selection from this prospective data set. Such enrichment corresponds to a 41% reduction in experimental effort. Interestingly, we found that pairwise screening of the compounds CoSynE individually predicted to be synergistic would result in an enrichment of 1.36 × compared to random selection, indicating that synergy among compound combinations is not a random event. The nine novel and correctly predicted synergistic compound combinations mainly (where sufficient bioactivity information is available) consist of efflux or transporter inhibitors (such as hydroxyzine), combined with compounds exhibiting antimalarial activity alone (such as sorafenib, apicidin, or dihydroergotamine). However, not all compound synergies could be rationalized easily in this way. Overall, this study highlights the potential for predictive modeling to expedite the discovery of novel drug combinations in fight against antimalarial resistance, while the underlying approach is also generally applicable.
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Affiliation(s)
- Daniel J Mason
- Department of Chemistry, Centre for Molecular Informatics, University of Cambridge, Cambridge, United Kingdom.,Healx Ltd., Cambridge, United Kingdom
| | - Richard T Eastman
- Division of Preclinical Innovation, National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, MD, United States
| | - Richard P I Lewis
- Department of Chemistry, Centre for Molecular Informatics, University of Cambridge, Cambridge, United Kingdom
| | - Ian P Stott
- Unilever Research and Development, Wirral, United Kingdom
| | - Rajarshi Guha
- Division of Preclinical Innovation, National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, MD, United States
| | - Andreas Bender
- Department of Chemistry, Centre for Molecular Informatics, University of Cambridge, Cambridge, United Kingdom
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9
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Superior Pyronaridine Single-Dose Pharmacodynamics Compared to Artesunate, Chloroquine, and Amodiaquine in a Murine Malaria Luciferase Model. Antimicrob Agents Chemother 2018; 62:AAC.00394-18. [PMID: 29967019 DOI: 10.1128/aac.00394-18] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Accepted: 06/15/2018] [Indexed: 11/20/2022] Open
Abstract
Many previous in vitro and in vivo preclinical malaria drug studies have relied on low-parasite-number drug inhibition numerically compared to the untreated controls. In contrast, human malaria drug studies measure the high-parasite-density killing near 100 million/ml. Here we compared the in vivo single-dose pharmacodynamic properties of artesunate and the 4-aminoquinolines pyronaridine, chloroquine, and amodiaquine in a Plasmodium berghei ANKA-green fluorescent protein GFP-luciferase-based murine malaria blood-stage model. Pyronaridine exhibited dose-dependent killing, achieving parasite reductions near 5 to 6 logs at 48 h, with complete cure at 10 mg/kg of body weight compared to artesunate, which exhibited a 48-h dose-dependent killing with a 2-log drop at the noncurative 250-mg/kg dose. Chloroquine, which was noncurative, and amodiaquine, which was partially curative, had nearly the same initial dose-independent killing, with a lag phase of minimal parasite reduction at all doses between 6 and 24 h, followed by a 2.5-log reduction at 48 h. In experiments with drug-treated, washed infected blood transfer to naive mice, chloroquine and amodiaquine showed fewer viable parasites at the 24-h transfer than at the 8-h transfer, measured by a prolonged return to parasitemia, despite a similar parasite log reduction at these time points, in contrast to the correlation of the parasite log reduction to viable parasites with artesunate and pyronaridine. Artesunate in combination with pyronaridine exhibited an initial parasite reduction similar to that achieved with pyronaridine, while with chloroquine or amodiaquine, the reduction was similar to that achieved with artesunate. Single-oral-dose pyronaridine was much more potent in vivo than artesunate, chloroquine, and amodiaquine during the initial decline in parasites and cure.
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10
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Hecht M, Veigure R, Couchman L, S Barker CI, Standing JF, Takkis K, Evard H, Johnston A, Herodes K, Leito I, Kipper K. Utilization of data below the analytical limit of quantitation in pharmacokinetic analysis and modeling: promoting interdisciplinary debate. Bioanalysis 2018; 10:1229-1248. [PMID: 30033744 DOI: 10.4155/bio-2018-0078] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Traditionally, bioanalytical laboratories do not report actual concentrations for samples with results below the LOQ (BLQ) in pharmacokinetic studies. BLQ values are outside the method calibration range established during validation and no data are available to support the reliability of these values. However, ignoring BLQ data can contribute to bias and imprecision in model-based pharmacokinetic analyses. From this perspective, routine use of BLQ data would be advantageous. We would like to initiate an interdisciplinary debate on this important topic by summarizing the current concepts and use of BLQ data by regulators, pharmacometricians and bioanalysts. Through introducing the limit of detection and evaluating its variability, BLQ data could be released and utilized appropriately for pharmacokinetic research.
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Affiliation(s)
- Max Hecht
- Chair of Analytical Chemistry, Institute of Chemistry, University of Tartu, 14a Ravila Street, 50411 Tartu, Estonia
- Analytical Services International, St George's University of London, Cranmer Terrace, London, SW17 0RE, UK
| | - Rūta Veigure
- Chair of Analytical Chemistry, Institute of Chemistry, University of Tartu, 14a Ravila Street, 50411 Tartu, Estonia
| | - Lewis Couchman
- Analytical Services International, St George's University of London, Cranmer Terrace, London, SW17 0RE, UK
| | - Charlotte I S Barker
- Paediatric Infectious Diseases Research Group, Institute for Infection & Immunity, St George's University of London, London, SW17 0RE, UK
- Inflammation, Infection & Rheumatology Section, UCL Great Ormond Street Institute of Child Health, London, WC1N 1EH, UK
- Paediatric Infectious Diseases Unit, St George's University Hospitals NHS Foundation Trust, London, SW17 0RE, UK
| | - Joseph F Standing
- Paediatric Infectious Diseases Research Group, Institute for Infection & Immunity, St George's University of London, London, SW17 0RE, UK
- Inflammation, Infection & Rheumatology Section, UCL Great Ormond Street Institute of Child Health, London, WC1N 1EH, UK
| | - Kalev Takkis
- Analytical Services International, St George's University of London, Cranmer Terrace, London, SW17 0RE, UK
| | - Hanno Evard
- Chair of Analytical Chemistry, Institute of Chemistry, University of Tartu, 14a Ravila Street, 50411 Tartu, Estonia
| | - Atholl Johnston
- Analytical Services International, St George's University of London, Cranmer Terrace, London, SW17 0RE, UK
- Clinical Pharmacology, Barts & The London School of Medicine & Dentistry, Queen Mary University of London, London, EC1M 6BQ, UK
| | - Koit Herodes
- Chair of Analytical Chemistry, Institute of Chemistry, University of Tartu, 14a Ravila Street, 50411 Tartu, Estonia
| | - Ivo Leito
- Chair of Analytical Chemistry, Institute of Chemistry, University of Tartu, 14a Ravila Street, 50411 Tartu, Estonia
| | - Karin Kipper
- Chair of Analytical Chemistry, Institute of Chemistry, University of Tartu, 14a Ravila Street, 50411 Tartu, Estonia
- Analytical Services International, St George's University of London, Cranmer Terrace, London, SW17 0RE, UK
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11
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Andrews KA, Wesche D, McCarthy J, Möhrle JJ, Tarning J, Phillips L, Kern S, Grasela T. Model-Informed Drug Development for Malaria Therapeutics. Annu Rev Pharmacol Toxicol 2017; 58:567-582. [PMID: 28992431 PMCID: PMC7198115 DOI: 10.1146/annurev-pharmtox-010715-103429] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Malaria is a critical public health problem resulting in substantial morbidity and
mortality, particularly in developing countries. Owing to the development of resistance
toward current therapies, novel approaches to accelerate the development efforts of new
malaria therapeutics are urgently needed. There have been significant advancements in the
development of in vitro and in vivo experiments that generate data used to inform
decisions about the potential merit of new compounds. A comprehensive disease-drug model
capable of integrating discrete data from different preclinical and clinical components
would be a valuable tool across all stages of drug development. This could have an
enormous impact on the otherwise slow and resource-intensive process of traditional
clinical drug development.
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Affiliation(s)
- Kayla Ann Andrews
- Cognigen Corporation, a subsidiary of Simulations Plus, Buffalo, New York 14221, USA; , , .,Department of Pharmaceutical Sciences, State University of New York, Buffalo, New York 14214, USA
| | - David Wesche
- Bill and Melinda Gates Foundation, Seattle, Washington 98109, USA; ,
| | - James McCarthy
- QIMR Berghofer Medical Research Institute, Brisbane, Australia.,School of Medicine, University of Queensland, Brisbane, Australia;
| | - Jörg J Möhrle
- Medicines for Malaria Venture, Geneva 1215, Switzerland;
| | - Joel Tarning
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; .,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford OX3 7FZ, United Kingdom
| | - Luann Phillips
- Cognigen Corporation, a subsidiary of Simulations Plus, Buffalo, New York 14221, USA; , ,
| | - Steven Kern
- Bill and Melinda Gates Foundation, Seattle, Washington 98109, USA; ,
| | - Thaddeus Grasela
- Cognigen Corporation, a subsidiary of Simulations Plus, Buffalo, New York 14221, USA; , ,
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12
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Impact of Extended Duration of Artesunate Treatment on Parasitological Outcome in a Cytocidal Murine Malaria Model. Antimicrob Agents Chemother 2017; 61:AAC.02499-16. [PMID: 28096162 DOI: 10.1128/aac.02499-16] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Accepted: 01/11/2017] [Indexed: 11/20/2022] Open
Abstract
Artemisinin-based combination therapies are a key pillar in global malaria control and are recommended as a first-line Plasmodium falciparum treatment. They rely upon a rapid 4-log-unit reduction in parasitemia by artemisinin compounds with a short half-life and the killing of remaining parasites by a partner compound with a longer half-life. Current treatment guidelines stipulate giving three 24-h-interval doses or six 12-h-interval doses over a 3-day period. Due to the short half-life of artesunate and artemether, almost all of the resulting cytocidal activity is confined within a single 48-h asexual P. falciparum cycle. Here, we utilized a luciferase reporter, Plasmodium berghei ANKA, in a cytocidal model in which treatment was initiated at high parasitemia, allowing us to monitor a greater than 3-log-unit reduction in parasite density, as well as 30-day survival. In this study, we demonstrated that increasing the artesunate duration from spanning one asexual cycle to spanning three asexual cycles while keeping the total dose constant results in enhanced cytocidal activity. Single daily artesunate doses at 50 mg/kg of body weight over 7 days were the minimum necessary for curative monotherapy. In combination with a single sub-human-equivalent dose of the partner drug amodiaquine or piperaquine, the three-asexual-cycle artesunate duration was able to cure 75% and 100% of mice, respectively, whereas 0% and 33% cures were achieved with the single-asexual-cycle artesunate duration. In summary, cytocidal activity of the artemisinin compounds, such as artesunate, can be improved solely by altering the dosing duration.
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13
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Slater HC, Okell LC, Ghani AC. Mathematical Modelling to Guide Drug Development for Malaria Elimination. Trends Parasitol 2017; 33:175-184. [PMID: 27727128 PMCID: PMC5347022 DOI: 10.1016/j.pt.2016.09.004] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Revised: 09/05/2016] [Accepted: 09/12/2016] [Indexed: 11/16/2022]
Abstract
Mathematical models of the dynamics of a drug within the host are now frequently used to guide drug development. These generally focus on assessing the efficacy and duration of response to guide patient therapy. Increasingly, antimalarial drugs are used at the population level, to clear infections, provide chemoprevention, and to reduce onward transmission of infection. However, there is less clarity on the extent to which different drug properties are important for these different uses. In addition, the emergence of drug resistance poses new threats to longer-term use and highlights the need for rational drug development. Here, we argue that integrating within-host pharmacokinetic and pharmacodynamic (PK/PD) models with mathematical models for the population-level transmission of malaria is key to guiding optimal drug design to aid malaria elimination.
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Affiliation(s)
- Hannah C Slater
- MRC Centre for Outbreak Analysis & Modelling, Department of Infectious Disease Epidemiology, Imperial College London, UK
| | - Lucy C Okell
- MRC Centre for Outbreak Analysis & Modelling, Department of Infectious Disease Epidemiology, Imperial College London, UK
| | - Azra C Ghani
- MRC Centre for Outbreak Analysis & Modelling, Department of Infectious Disease Epidemiology, Imperial College London, UK.
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14
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Linking Murine and Human Plasmodium falciparum Challenge Models in a Translational Path for Antimalarial Drug Development. Antimicrob Agents Chemother 2016; 60:3669-75. [PMID: 27044554 PMCID: PMC4879391 DOI: 10.1128/aac.02883-15] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Accepted: 03/30/2016] [Indexed: 11/20/2022] Open
Abstract
Effective progression of candidate antimalarials is dependent on optimal dosing in clinical studies, which is determined by a sound understanding of pharmacokinetics and pharmacodynamics (PK/PD). Recently, two important translational models for antimalarials have been developed: the NOD/SCID/IL2Rγ−/− (NSG) model, whereby mice are engrafted with noninfected and Plasmodium falciparum-infected human erythrocytes, and the induced blood-stage malaria (IBSM) model in human volunteers. The antimalarial mefloquine was used to directly measure the PK/PD in both models, which were compared to previously published trial data for malaria patients. The clinical part was a single-center, controlled study using a blood-stage Plasmodium falciparum challenge inoculum in volunteers to characterize the effectiveness of mefloquine against early malaria. The study was conducted in three cohorts (n = 8 each) using different doses of mefloquine. The characteristic delay in onset of action of about 24 h was seen in both NSG and IBSM systems. In vivo 50% inhibitory concentrations (IC50s) were estimated at 2.0 μg/ml and 1.8 μg/ml in the NSG and IBSM models, respectively, aligning with 1.8 μg/ml reported previously for patients. In the IBSM model, the parasite reduction ratios were 157 and 195 for the 10- and 15-mg/kg doses, within the range of previously reported clinical data for patients but significantly lower than observed in the mouse model. Linking mouse and human challenge models to clinical trial data can accelerate the accrual of critical data on antimalarial drug activity. Such data can guide large clinical trials required for development of urgently needed novel antimalarial combinations. (This trial was registered at the Australian New Zealand Clinical Trials Registry [http://anzctr.org.au] under registration number ACTRN12612000323820.)
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15
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Probucol-Induced α-Tocopherol Deficiency Protects Mice against Malaria Infection. PLoS One 2015; 10:e0136014. [PMID: 26296197 PMCID: PMC4546625 DOI: 10.1371/journal.pone.0136014] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2015] [Accepted: 07/29/2015] [Indexed: 12/20/2022] Open
Abstract
The emergence of malaria pathogens having resistance against antimalarials implies the necessity for the development of new drugs. Recently, we have demonstrated a resistance against malaria infection of α-tocopherol transfer protein knockout mice showing undetectable plasma levels of α-tocopherol, a lipid-soluble antioxidant. However, dietary restriction induced α-tocopherol deficiency is difficult to be applied as a clinical antimalarial therapy. Here, we report on a new strategy to potentially treat malaria by using probucol, a drug that can reduce the plasma α-tocopherol concentration. Probucol pre-treatment for 2 weeks and treatment throughout the infection rescued from death of mice infected with Plasmodium yoelii XL-17 or P. berghei ANKA. In addition, survival was extended when the treatment started immediately after parasite inoculation. The ratio of lipid peroxidation products to parent lipids increased in plasma after 2 weeks treatment of probucol. This indicates that the protective effect of probucol might be mediated by the oxidative stressful environment induced by α-tocopherol deficiency. Probucol in combination with dihydroartemisin suppressed the proliferation of P. yoelii XL-17. These results indicated that probucol might be a candidate for a drug against malaria infection by inducing α-tocopherol deficiency without dietary α-tocopherol restriction.
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