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Ma CI, Tirtorahardjo JA, Schweizer SS, Zhang J, Fang Z, Xing L, Xu M, Herman DA, Kleinman MT, McCullough BS, Barrios AM, Andrade RM. Gold(I) ion and the phosphine ligand are necessary for the anti- Toxoplasma gondii activity of auranofin. Microbiol Spectr 2024; 12:e0296823. [PMID: 38206030 PMCID: PMC10845965 DOI: 10.1128/spectrum.02968-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Accepted: 12/08/2023] [Indexed: 01/12/2024] Open
Abstract
Auranofin, an FDA-approved drug for rheumatoid arthritis, has emerged as a promising antiparasitic medication in recent years. The gold(I) ion in auranofin is postulated to be responsible for its antiparasitic activity. Notably, aurothiomalate and aurothioglucose also contain gold(I), and, like auranofin, they were previously used to treat rheumatoid arthritis. Whether they have antiparasitic activity remains to be elucidated. Herein, we demonstrated that auranofin and similar derivatives, but not aurothiomalate and aurothioglucose, inhibited the growth of Toxoplasma gondii in vitro. We found that auranofin affected the T. gondii biological cycle (lytic cycle) by inhibiting T. gondii's invasion and triggering its egress from the host cell. However, auranofin could not prevent parasite replication once T. gondii resided within the host. Auranofin treatment induced apoptosis in T. gondii parasites, as demonstrated by its reduced size and elevated phosphatidylserine externalization (PS). Notably, the gold from auranofin enters the cytoplasm of T. gondii, as demonstrated by scanning transmission electron microscopy-energy dispersive X-ray spectroscopy (STEM-EDS) and Inductively Coupled Plasma-Mass Spectrometry (ICP-MS).IMPORTANCEToxoplasmosis, caused by Toxoplasma gondii, is a devastating disease affecting the brain and the eyes, frequently affecting immunocompromised individuals. Approximately 60 million people in the United States are already infected with T. gondii, representing a population at-risk of developing toxoplasmosis. Recent advances in treating cancer, autoimmune diseases, and organ transplants have contributed to this at-risk population's exponential growth. Paradoxically, treatments for toxoplasmosis have remained the same for more than 60 years, relying on medications well-known for their bone marrow toxicity and allergic reactions. Discovering new therapies is a priority, and repurposing FDA-approved drugs is an alternative approach to speed up drug discovery. Herein, we report the effect of auranofin, an FDA-approved drug, on the biological cycle of T. gondii and how both the phosphine ligand and the gold molecule determine the anti-parasitic activity of auranofin and other gold compounds. Our studies would contribute to the pipeline of candidate anti-T. gondii agents.
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Affiliation(s)
- C. I. Ma
- Department of Medicine, Division of Infectious Diseases, University of California at Irvine, Irvine, California, USA
| | - J. A. Tirtorahardjo
- Department of Microbiology and Molecular Genetics, University of California at Irvine, Irvine, California, USA
| | - S. S. Schweizer
- School of Biological Sciences; University of California at Irvine, Irvine, California, USA
| | - J. Zhang
- School of Biological Sciences; University of California at Irvine, Irvine, California, USA
| | - Z. Fang
- School of Biological Sciences; University of California at Irvine, Irvine, California, USA
| | - L. Xing
- Irvine Materials Research Institute; University of California at Irvine, Irvine, California, USA
| | - M. Xu
- Irvine Materials Research Institute; University of California at Irvine, Irvine, California, USA
| | - D. A. Herman
- Department of Medicine, Occupational and Environmental Medicine, University of California at Irvine, Irvine, California, USA
| | - M. T. Kleinman
- Department of Medicine, Occupational and Environmental Medicine, University of California at Irvine, Irvine, California, USA
| | - B. S. McCullough
- Department of Medicinal Chemistry, University of Utah College of Pharmacy, Salt Lake City, Utah, USA
| | - A. M. Barrios
- Department of Medicinal Chemistry, University of Utah College of Pharmacy, Salt Lake City, Utah, USA
| | - R. M. Andrade
- Department of Medicine, Division of Infectious Diseases, University of California at Irvine, Irvine, California, USA
- Department of Microbiology and Molecular Genetics, University of California at Irvine, Irvine, California, USA
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Abugri DA, Wijerathne SVT, Sharma HN, Ayariga JA, Napier A, Robertson BK. Quercetin inhibits Toxoplasma gondii tachyzoite proliferation and acts synergically with azithromycin. Parasit Vectors 2023; 16:261. [PMID: 37537675 PMCID: PMC10401810 DOI: 10.1186/s13071-023-05849-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Accepted: 06/26/2023] [Indexed: 08/05/2023] Open
Abstract
Quercetin (QUE) is a natural polyphenol known to have numerous pharmacological properties against infectious and non-infectious diseases. Azithromycin (AZ) is an antibiotic that belongs to the azalide class of antimicrobials and an antiparasitic that is known to be effective in combination with clindamycin against pyrimethamine/sulfadiazine-resistant Toxoplasma gondii tachyzoites in clinical settings. Both compounds are known to target protein synthesis and have anti-inflammatory properties. However, little is known about QUE and AZ synergistic interaction against T. gondii growth. Here, we report for the first time the effects of the combination of QUE and AZ on T. gondii growth. The 50% inhibitory concentration (IC50) for QUE at 72 h of interaction was determined to be 0.50 µM, whereas AZ gave an IC50 value of 0.66 µM at 72 h of interaction with parasites. Combination testing of QUE and AZ in a ratio of 2:1 (QUE:AZ) showed an IC50 value of 0.081 µM. Interestingly, a fractional inhibitory index value of 0.28 was observed, indicating a strong synergy. QUE was also found to upregulate the generation of reactive oxygen species and cause dysfunction of the mitochondria membrane of both intracellular and extracellular T. gondii tachyzoites. Overall, the results indicate that QUE is a novel lead capable of synergizing with AZ for inhibiting T. gondii growth and may merit future investigation in vivo for possible combination drug development.
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Affiliation(s)
- Daniel A Abugri
- Department of Biological Sciences, College of Science, Technology, Engineering and Mathematics, Alabama State University, Montgomery, AL, 36104, USA.
- Microbiology PhD Program, Department of Biological Sciences, College of Science, Technology, Engineering and Mathematics, Alabama State University, Montgomery, AL, 36104, USA.
- Laboratory of Ethnomedicine, Parasitology and Drug Discovery, College of Science, Technology, Engineering and Mathematics, Alabama State University, Montgomery, AL, 36104, USA.
| | - Sandani V T Wijerathne
- Department of Biological Sciences, College of Science, Technology, Engineering and Mathematics, Alabama State University, Montgomery, AL, 36104, USA
- Microbiology PhD Program, Department of Biological Sciences, College of Science, Technology, Engineering and Mathematics, Alabama State University, Montgomery, AL, 36104, USA
| | - Homa Nath Sharma
- Department of Biological Sciences, College of Science, Technology, Engineering and Mathematics, Alabama State University, Montgomery, AL, 36104, USA
- Microbiology PhD Program, Department of Biological Sciences, College of Science, Technology, Engineering and Mathematics, Alabama State University, Montgomery, AL, 36104, USA
- Laboratory of Ethnomedicine, Parasitology and Drug Discovery, College of Science, Technology, Engineering and Mathematics, Alabama State University, Montgomery, AL, 36104, USA
| | - Joseph A Ayariga
- Department of Biological Sciences, College of Science, Technology, Engineering and Mathematics, Alabama State University, Montgomery, AL, 36104, USA
| | - Audrey Napier
- Department of Biological Sciences, College of Science, Technology, Engineering and Mathematics, Alabama State University, Montgomery, AL, 36104, USA
| | - Boakai K Robertson
- Department of Biological Sciences, College of Science, Technology, Engineering and Mathematics, Alabama State University, Montgomery, AL, 36104, USA
- Microbiology PhD Program, Department of Biological Sciences, College of Science, Technology, Engineering and Mathematics, Alabama State University, Montgomery, AL, 36104, USA
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Hayward JA, Makota FV, Cihalova D, Leonard RA, Rajendran E, Zwahlen SM, Shuttleworth L, Wiedemann U, Spry C, Saliba KJ, Maier AG, van Dooren GG. A screen of drug-like molecules identifies chemically diverse electron transport chain inhibitors in apicomplexan parasites. PLoS Pathog 2023; 19:e1011517. [PMID: 37471441 PMCID: PMC10403144 DOI: 10.1371/journal.ppat.1011517] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Revised: 08/04/2023] [Accepted: 06/28/2023] [Indexed: 07/22/2023] Open
Abstract
Apicomplexans are widespread parasites of humans and other animals, and include the causative agents of malaria (Plasmodium species) and toxoplasmosis (Toxoplasma gondii). Existing anti-apicomplexan therapies are beset with issues around drug resistance and toxicity, and new treatment options are needed. The mitochondrial electron transport chain (ETC) is one of the few processes that has been validated as a drug target in apicomplexans. To identify new inhibitors of the apicomplexan ETC, we developed a Seahorse XFe96 flux analyzer approach to screen the 400 compounds contained within the Medicines for Malaria Venture 'Pathogen Box' for ETC inhibition. We identified six chemically diverse, on-target inhibitors of the ETC in T. gondii, at least four of which also target the ETC of Plasmodium falciparum. Two of the identified compounds (MMV024937 and MMV688853) represent novel ETC inhibitor chemotypes. MMV688853 belongs to a compound class, the aminopyrazole carboxamides, that were shown previously to target a kinase with a key role in parasite invasion of host cells. Our data therefore reveal that MMV688853 has dual targets in apicomplexans. We further developed our approach to pinpoint the molecular targets of these inhibitors, demonstrating that all target Complex III of the ETC, with MMV688853 targeting the ubiquinone reduction (Qi) site of the complex. Most of the compounds we identified remain effective inhibitors of parasites that are resistant to Complex III inhibitors that are in clinical use or development, indicating that they could be used in treating drug resistant parasites. In sum, we have developed a versatile, scalable approach to screen for compounds that target the ETC in apicomplexan parasites, and used this to identify and characterize novel inhibitors.
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Affiliation(s)
- Jenni A. Hayward
- Research School of Biology, Australian National University, Canberra, Australia
| | - F. Victor Makota
- Research School of Biology, Australian National University, Canberra, Australia
| | - Daniela Cihalova
- Research School of Biology, Australian National University, Canberra, Australia
| | - Rachel A. Leonard
- Research School of Biology, Australian National University, Canberra, Australia
| | - Esther Rajendran
- Research School of Biology, Australian National University, Canberra, Australia
| | - Soraya M. Zwahlen
- Research School of Biology, Australian National University, Canberra, Australia
| | - Laura Shuttleworth
- Research School of Biology, Australian National University, Canberra, Australia
| | - Ursula Wiedemann
- Research School of Biology, Australian National University, Canberra, Australia
| | - Christina Spry
- Research School of Biology, Australian National University, Canberra, Australia
| | - Kevin J. Saliba
- Research School of Biology, Australian National University, Canberra, Australia
| | - Alexander G. Maier
- Research School of Biology, Australian National University, Canberra, Australia
| | - Giel G. van Dooren
- Research School of Biology, Australian National University, Canberra, Australia
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Berneburg I, Stumpf M, Velten AS, Rahlfs S, Przyborski J, Becker K, Fritz-Wolf K. Structure of Leishmania donovani 6-Phosphogluconate Dehydrogenase and Inhibition by Phosphine Gold(I) Complexes: A Potential Approach to Leishmaniasis Treatment. Int J Mol Sci 2023; 24:ijms24108615. [PMID: 37239962 DOI: 10.3390/ijms24108615] [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: 03/28/2023] [Revised: 05/08/2023] [Accepted: 05/09/2023] [Indexed: 05/28/2023] Open
Abstract
As unicellular parasites are highly dependent on NADPH as a source for reducing equivalents, the main NADPH-producing enzymes glucose 6-phosphate dehydrogenase (G6PD) and 6-phosphogluconate dehydrogenase (6PGD) of the pentose phosphate pathway are considered promising antitrypanosomatid drug targets. Here we present the biochemical characterization and crystal structure of Leishmania donovani 6PGD (Ld6PGD) in complex with NADP(H). Most interestingly, a previously unknown conformation of NADPH is visible in this structure. In addition, we identified auranofin and other gold(I)-containing compounds as efficient Ld6PGD inhibitors, although it has so far been assumed that trypanothione reductase is the sole target of auranofin in Kinetoplastida. Interestingly, 6PGD from Plasmodium falciparum is also inhibited at lower micromolar concentrations, whereas human 6PGD is not. Mode-of-inhibition studies indicate that auranofin competes with 6PG for its binding site followed by a rapid irreversible inhibition. By analogy with other enzymes, this suggests that the gold moiety is responsible for the observed inhibition. Taken together, we identified gold(I)-containing compounds as an interesting class of inhibitors against 6PGDs from Leishmania and possibly from other protozoan parasites. Together with the three-dimensional crystal structure, this provides a valid basis for further drug discovery approaches.
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Affiliation(s)
- Isabell Berneburg
- Biochemistry and Molecular Biology, Interdisciplinary Research Center, Justus Liebig University, 35392 Giessen, Germany
| | - Michaela Stumpf
- Biochemistry and Molecular Biology, Interdisciplinary Research Center, Justus Liebig University, 35392 Giessen, Germany
| | - Ann-Sophie Velten
- Biochemistry and Molecular Biology, Interdisciplinary Research Center, Justus Liebig University, 35392 Giessen, Germany
| | - Stefan Rahlfs
- Biochemistry and Molecular Biology, Interdisciplinary Research Center, Justus Liebig University, 35392 Giessen, Germany
| | - Jude Przyborski
- Biochemistry and Molecular Biology, Interdisciplinary Research Center, Justus Liebig University, 35392 Giessen, Germany
| | - Katja Becker
- Biochemistry and Molecular Biology, Interdisciplinary Research Center, Justus Liebig University, 35392 Giessen, Germany
| | - Karin Fritz-Wolf
- Biochemistry and Molecular Biology, Interdisciplinary Research Center, Justus Liebig University, 35392 Giessen, Germany
- Max Planck Institute for Medical Research, 69120 Heidelberg, Germany
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Vallières C, Golinelli-Cohen MP, Guittet O, Lepoivre M, Huang ME, Vernis L. Redox-Based Strategies against Infections by Eukaryotic Pathogens. Genes (Basel) 2023; 14:genes14040778. [PMID: 37107536 PMCID: PMC10138290 DOI: 10.3390/genes14040778] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 03/13/2023] [Accepted: 03/21/2023] [Indexed: 04/29/2023] Open
Abstract
Redox homeostasis is an equilibrium between reducing and oxidizing reactions within cells. It is an essential, dynamic process, which allows proper cellular reactions and regulates biological responses. Unbalanced redox homeostasis is the hallmark of many diseases, including cancer or inflammatory responses, and can eventually lead to cell death. Specifically, disrupting redox balance, essentially by increasing pro-oxidative molecules and favouring hyperoxidation, is a smart strategy to eliminate cells and has been used for cancer treatment, for example. Selectivity between cancer and normal cells thus appears crucial to avoid toxicity as much as possible. Redox-based approaches are also employed in the case of infectious diseases to tackle the pathogens specifically, with limited impacts on host cells. In this review, we focus on recent advances in redox-based strategies to fight eukaryotic pathogens, especially fungi and eukaryotic parasites. We report molecules recently described for causing or being associated with compromising redox homeostasis in pathogens and discuss therapeutic possibilities.
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Affiliation(s)
- Cindy Vallières
- Institut de Chimie des Substances Naturelles, CNRS UPR 2301, Université Paris-Saclay, 91198 Gif-sur-Yvette, France
| | - Marie-Pierre Golinelli-Cohen
- Institut de Chimie des Substances Naturelles, CNRS UPR 2301, Université Paris-Saclay, 91198 Gif-sur-Yvette, France
| | - Olivier Guittet
- Institut de Chimie des Substances Naturelles, CNRS UPR 2301, Université Paris-Saclay, 91198 Gif-sur-Yvette, France
| | - Michel Lepoivre
- Institut de Chimie des Substances Naturelles, CNRS UPR 2301, Université Paris-Saclay, 91198 Gif-sur-Yvette, France
| | - Meng-Er Huang
- Institut de Chimie des Substances Naturelles, CNRS UPR 2301, Université Paris-Saclay, 91198 Gif-sur-Yvette, France
| | - Laurence Vernis
- Institut de Chimie des Substances Naturelles, CNRS UPR 2301, Université Paris-Saclay, 91198 Gif-sur-Yvette, France
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6
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Huffman AM, Ayariga JA, Napier A, Robertson BK, Abugri DA. Inhibition of Toxoplasma gondii Growth by Dihydroquinine and Its Mechanisms of Action. Front Cell Infect Microbiol 2022; 12:852889. [PMID: 35646733 PMCID: PMC9131874 DOI: 10.3389/fcimb.2022.852889] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Accepted: 02/14/2022] [Indexed: 12/17/2022] Open
Abstract
Toxoplasma gondii is a zoonotic parasite that infects the brain of humans and causes cerebral toxoplasmosis. The recommended drugs for the treatment or prophylaxis of toxoplasmosis are pyrimethamine (PY) and sulfadiazine (SZ), which have serious side effects. Other drugs available for toxoplasmosis are poorly tolerated. Dihydroquinine (DHQ) is a compound closely related to quinine-based drugs that have been shown to inhibit Plasmodium falciparum and Plasmodium berghei in addition to its anti-arrhythmia properties. However, little is known about the effect of DHQ in T. gondii growth and its mechanism of action in vitro. In this study, we report the anti-Toxoplasma and anti-invasion properties of DHQ. DHQ significantly inhibited T. gondii tachyzoite growth with IC50s values of 0.63, 0.67, and 0.00137 µM at 24, 48, and 72 h, respectively. Under similar conditions, SZ and PY, considered as the gold standard drugs for the treatment of toxoplasmosis, had IC50s values of 1.29, 1.55, and 0.95 and 3.19, 3.52, and 2.42 µM, respectively. The rapid dose-dependent inhibition of T. gondii tachyzoites by DHQ compared to the standard drugs (SZ and PY) indicates that DHQ has high selective parasiticidal effects against tachyzoite proliferation. Remarkably, DHQ had an excellent selectivity index (SI) of 149- and 357-fold compared to 24- and 143-fold for PY and SZ, respectively, using fibroblast cells. In addition, DHQ disrupted T. gondii tachyzoite mitochondrial membrane potential and adenosine triphosphate (ATP) production and elicited high reactive oxygen species (ROS) generation. Taking all these findings together, DHQ promises to be an effective and safe lead for the treatment of toxoplasmosis.
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Affiliation(s)
- Aarin M. Huffman
- Department of Biology, College of Arts and Sciences, Tuskegee University, Tuskegee, AL, United States
| | - Joseph A. Ayariga
- Department of Biological Sciences, Alabama State University, Montgomery, AL, United States
- Biomedical Engineering Program, Alabama State University, Montgomery, AL, United States
| | - Audrey Napier
- Department of Biological Sciences, Alabama State University, Montgomery, AL, United States
| | - Boakai K. Robertson
- Department of Biological Sciences, Alabama State University, Montgomery, AL, United States
- Microbiology PhD Program, College of Science, Technology, Engineering and Mathematics, Montgomery, AL, United States
| | - Daniel A. Abugri
- Department of Biological Sciences, Alabama State University, Montgomery, AL, United States
- Microbiology PhD Program, College of Science, Technology, Engineering and Mathematics, Montgomery, AL, United States
- Laboratory of Ethnomedicine, Parasitology, and Drug Discovery, College of Science, Technology, Engineering and Mathematics, Montgomery, AL, United States
- *Correspondence: Daniel A. Abugri,
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Shaulov Y, Sarid L, Trebicz-Geffen M, Ankri S. Entamoeba histolytica Adaption to Auranofin: A Phenotypic and Multi-Omics Characterization. Antioxidants (Basel) 2021; 10:antiox10081240. [PMID: 34439488 PMCID: PMC8389260 DOI: 10.3390/antiox10081240] [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: 06/21/2021] [Revised: 07/25/2021] [Accepted: 07/30/2021] [Indexed: 12/01/2022] Open
Abstract
Auranofin (AF), an antirheumatic agent, targets mammalian thioredoxin reductase (TrxR), an important enzyme controlling redox homeostasis. AF is also highly effective against a diversity of pathogenic bacteria and protozoan parasites. Here, we report on the resistance of the parasite Entamoeba histolytica to 2 µM of AF that was acquired by gradual exposure of the parasite to an increasing amount of the drug. AF-adapted E. histolytica trophozoites (AFAT) have impaired growth and cytopathic activity, and are more sensitive to oxidative stress (OS), nitrosative stress (NS), and metronidazole (MNZ) than wild type (WT) trophozoites. Integrated transcriptomics and redoxomics analyses showed that many upregulated genes in AFAT, including genes encoding for dehydrogenase and cytoskeletal proteins, have their product oxidized in wild type trophozoites exposed to AF (acute AF trophozoites) but not in AFAT. We also showed that the level of reactive oxygen species (ROS) and oxidized proteins (OXs) in AFAT is lower than that in acute AF trophozoites. Overexpression of E. histolytica TrxR (EhTrxR) did not protect the parasite against AF, which suggests that EhTrxR is not central to the mechanism of adaptation to AF.
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