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dos Santos M, Oliveira Costa AL, Vaz GHDS, de Souza GCA, Vitor RWDA, Martins-Duarte ÉS. Medicines for Malaria Venture Pandemic Box In Vitro Screening Identifies Compounds Highly Active against the Tachyzoite Stage of Toxoplasma gondii. Trop Med Infect Dis 2023; 8:510. [PMID: 38133442 PMCID: PMC10747034 DOI: 10.3390/tropicalmed8120510] [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: 10/23/2023] [Revised: 11/27/2023] [Accepted: 11/27/2023] [Indexed: 12/23/2023] Open
Abstract
Toxoplasmosis is a disease that causes high mortality in immunocompromised individuals, such as AIDS patients, and sequelae in congenitally infected newborns. Despite its great medical importance, there are few treatments available and these are associated with adverse events and resistance. In this work, after screening the drugs present in the Medicines for Malaria Venture Pandemic Box, we found new hits with anti-Toxoplasma gondii activity. Through our analysis, we selected twenty-three drugs or drug-like compounds that inhibited the proliferation of T. gondii tachyzoites in vitro by more than 50% at a concentration of 1 µM after seven days of treatment. Nineteen of these compounds have never been reported active before against T. gondii. Inhibitory curves showed that most of these drugs were able to inhibit parasite replication with IC50 values on the nanomolar scale. To better understand the unprecedented effect of seven compounds against T. gondii tachyzoites, an ultrastructural analysis was carried out using transmission electron microscopy. Treatment with 0.25 µM verdinexor, 3 nM MMV1580844, and 0.25 µM MMV019724 induced extensive vacuolization, complete ultrastructural disorganization, and lytic effects in the parasite, respectively, and all of them showed alterations in the division process. Treatment with 1 µM Eberconazole, 0.5 µM MMV1593541, 1 µM MMV642550, 1 µM RWJ-67657, and 1 µM URMC-099-C also caused extensive vacuolization in the parasite. The activity of these drugs against intracellular tachyzoites supports the idea that the drugs selected in the Pandemic Box could be potential future drugs for the treatment of acute toxoplasmosis.
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Affiliation(s)
- Mike dos Santos
- Laboratório de Quimioterapia de Protozoários Egler Chiari, Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte 31270-901, Brazil (G.H.d.S.V.)
| | - Andréia Luiza Oliveira Costa
- Laboratório de Quimioterapia de Protozoários Egler Chiari, Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte 31270-901, Brazil (G.H.d.S.V.)
| | - Guilherme Henrique de Souza Vaz
- Laboratório de Quimioterapia de Protozoários Egler Chiari, Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte 31270-901, Brazil (G.H.d.S.V.)
| | - Gabriela Carolina Alves de Souza
- Laboratório de Quimioterapia de Protozoários Egler Chiari, Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte 31270-901, Brazil (G.H.d.S.V.)
| | - Ricardo Wagner de Almeida Vitor
- Laboratório de Toxoplasmose, Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte 31270-901, Brazil;
| | - Érica S. Martins-Duarte
- Laboratório de Quimioterapia de Protozoários Egler Chiari, Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte 31270-901, Brazil (G.H.d.S.V.)
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Vanichtanankul J, Yoomuang A, Taweechai S, Saeyang T, Pengon J, Yuvaniyama J, Tarnchompoo B, Yuthavong Y, Kamchonwongpaisan S. Structural Insight into Effective Inhibitors' Binding to Toxoplasma gondii Dihydrofolate Reductase Thymidylate Synthase. ACS Chem Biol 2022; 17:1691-1702. [PMID: 35715223 DOI: 10.1021/acschembio.1c00627] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Pyrimethamine (Pyr), a known dihydrofolate reductase (DHFR) inhibitor, has long been used to treat toxoplasmosis caused by Toxoplasma gondii (Tg) infection. However, Pyr is effective only at high doses with associated toxicity to patients, calling for safer alternative treatments. In this study, we investigated a series of Pyr analogues, previously developed as DHFR inhibitors of Plasmodium falciparum bifunctional DHFR-thymidylate synthase (PfDHFR-TS), for their activity against T. gondii DHFR-TS (TgDHFR-TS). Of these, a set of compounds with a substitution at the C6 position of the pyrimidine ring exhibited high binding affinities (in a low nanomolar range) against TgDHFR-TS and in vitro T. gondii inhibitory activity. Three-dimensional structures of TgDHFR-TS reported here include the ternary complexes with Pyr, P39, or P40. A comparison of these structures showed the minor steric strain between the p-chlorophenyl group of Pyr and Thr83 of TgDHFR-TS. Such a conflict was relieved in the complexes with the two analogues, P39 and P40, explaining their highest binding affinities described herein. Moreover, these structures suggested that the hydrophobic environment in the active-site pocket could be used for drug design to increase the potency and selectivity of antifolate inhibitors. These findings would accelerate the development of new antifolate drugs to treat toxoplasmosis.
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Affiliation(s)
- Jarunee Vanichtanankul
- National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency (NSTDA), 113 Thailand Science Park, Khlong Nueng, Khlong Luang, Pathum Thani 12120, Thailand
| | - Aphisit Yoomuang
- National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency (NSTDA), 113 Thailand Science Park, Khlong Nueng, Khlong Luang, Pathum Thani 12120, Thailand
| | - Supannee Taweechai
- National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency (NSTDA), 113 Thailand Science Park, Khlong Nueng, Khlong Luang, Pathum Thani 12120, Thailand
| | - Thanaya Saeyang
- National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency (NSTDA), 113 Thailand Science Park, Khlong Nueng, Khlong Luang, Pathum Thani 12120, Thailand
| | - Jutharat Pengon
- National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency (NSTDA), 113 Thailand Science Park, Khlong Nueng, Khlong Luang, Pathum Thani 12120, Thailand
| | - Jirundon Yuvaniyama
- Department of Biochemistry and Center for Excellence in Protein and Enzyme Technology, Faculty of Science, Mahidol University, Ratchathewi, Bangkok 10400, Thailand
| | - Bongkoch Tarnchompoo
- National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency (NSTDA), 113 Thailand Science Park, Khlong Nueng, Khlong Luang, Pathum Thani 12120, Thailand
| | - Yongyuth Yuthavong
- National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency (NSTDA), 113 Thailand Science Park, Khlong Nueng, Khlong Luang, Pathum Thani 12120, Thailand
| | - Sumalee Kamchonwongpaisan
- National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency (NSTDA), 113 Thailand Science Park, Khlong Nueng, Khlong Luang, Pathum Thani 12120, Thailand
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Fu J, Liu S, Hu M, Liao X, Wang X, Xu Z, Li Q, Quan J. Biguanide MC001, a Dual Inhibitor of OXPHOS and Glycolysis, Shows Enhanced Antitumor Activity Without Increasing Lactate Production. ChemMedChem 2022; 17:e202100674. [PMID: 34984842 DOI: 10.1002/cmdc.202100674] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2021] [Revised: 12/29/2021] [Indexed: 11/12/2022]
Abstract
Metformin and other biguanides represent a new class of inhibitors of mitochondrial complex I that show promising antitumor effects. However, stronger inhibition of mitochondrial complex I is generally associated with upregulation of glycolysis and higher risk of lactic acidosis. Herein we report a novel biguanide derivative, N-cystaminylbiguanide (MC001), which was found to inhibit mitochondrial complex I with higher potency while inducing lactate production to a similar degree as metformin.Furthermore, MC001 was found to efficiently inhibit a panel of colorectal cancer (CRC) cells in vitro and to suppress tumor growth in a HCT116 xenograft nude mouse model, while not enhancing lactate production relative to metformin, exhibiting a superior safety profile to other potent biguanides such as phenformin. Mechanistically, MC001 efficiently inhibits mitochondrial complex I, activates AMPK, and represses mTOR, leading to cell-cycle arrest and apoptosis. Notably, MC001 inhibits both oxidative phosphorylation (OXPHOS) and glycolysis. We therefore propose that MC001 warrants further investigation in cancer treatment.
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Affiliation(s)
- Jiamiao Fu
- State Key Laboratory of Chemical Oncogenomics, Key Laboratory of Chemical Genomics, Peking University, Shenzhen Graduate School, Shenzhen, 518055, China
| | - Siyu Liu
- State Key Laboratory of Chemical Oncogenomics, Key Laboratory of Chemical Genomics, Peking University, Shenzhen Graduate School, Shenzhen, 518055, China
| | - Minqiang Hu
- State Key Laboratory of Chemical Oncogenomics, Key Laboratory of Chemical Genomics, Peking University, Shenzhen Graduate School, Shenzhen, 518055, China
| | - Ximing Liao
- State Key Laboratory of Chemical Oncogenomics, Key Laboratory of Chemical Genomics, Peking University, Shenzhen Graduate School, Shenzhen, 518055, China
| | - Xiaoquan Wang
- State Key Laboratory of Chemical Oncogenomics, Key Laboratory of Chemical Genomics, Peking University, Shenzhen Graduate School, Shenzhen, 518055, China
| | - Zhengshuang Xu
- State Key Laboratory of Chemical Oncogenomics, Key Laboratory of Chemical Genomics, Peking University, Shenzhen Graduate School, Shenzhen, 518055, China
| | - Qinkai Li
- State Key Laboratory of Chemical Oncogenomics, Key Laboratory of Chemical Genomics, Peking University, Shenzhen Graduate School, Shenzhen, 518055, China
| | - Junmin Quan
- State Key Laboratory of Chemical Oncogenomics, Key Laboratory of Chemical Genomics, Peking University, Shenzhen Graduate School, Shenzhen, 518055, China
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Kathuria D, Raul AD, Wanjari P, Bharatam PV. Biguanides: Species with versatile therapeutic applications. Eur J Med Chem 2021; 219:113378. [PMID: 33857729 DOI: 10.1016/j.ejmech.2021.113378] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2020] [Revised: 03/04/2021] [Accepted: 03/08/2021] [Indexed: 12/18/2022]
Abstract
Biguanides are compounds in which two guanidine moieties are fused to form a highly conjugated system. Biguanides are highly basic and hence they are available as salts mostly hydrochloride salts, these cationic species have been found to exhibit many therapeutic properties. This review covers the research and development carried out on biguanides and accounts the various therapeutic applications of drugs containing biguanide group-such as antimalarial, antidiabetic, antiviral, anticancer, antibacterial, antifungal, anti-tubercular, antifilarial, anti-HIV, as well as other biological activities. The aim of this review is to compile all the medicinal chemistry applications of this class of compounds so as to pave way for the accelerated efforts in finding the drug action mechanisms associated with this class of compounds. Importance has been given to the organic chemistry of these biguanide derivatives also.
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Affiliation(s)
- Deepika Kathuria
- University Center for Research and Development, Chandigarh University, Gharuan, Punjab, 140413, India
| | - Akshay D Raul
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research (NIPER), Sector 67, S. A. S. Nagar, 160 062, Punjab, India
| | - Pravin Wanjari
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research (NIPER), Sector 67, S. A. S. Nagar, 160 062, Punjab, India
| | - Prasad V Bharatam
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research (NIPER), Sector 67, S. A. S. Nagar, 160 062, Punjab, India.
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Gabel SA, Duff MR, Pedersen LC, DeRose EF, Krahn JM, Howell EE, London RE. A Structural Basis for Biguanide Activity. Biochemistry 2017; 56:4786-4798. [PMID: 28766937 PMCID: PMC5740485 DOI: 10.1021/acs.biochem.7b00619] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Metformin is the most commonly prescribed treatment for type II diabetes and related disorders; however, molecular insights into its mode(s) of action have been limited by an absence of structural data. Structural considerations along with a growing body of literature demonstrating its effects on one-carbon metabolism suggest the possibility of folate mimicry and anti-folate activity. Motivated by the growing recognition that anti-diabetic biguanides may act directly upon the gut microbiome, we have determined structures of the complexes formed between the anti-diabetic biguanides (phenformin, buformin, and metformin) and Escherichia coli dihydrofolate reductase (ecDHFR) based on nuclear magnetic resonance, crystallographic, and molecular modeling studies. Interligand Overhauser effects indicate that metformin can form ternary complexes with p-aminobenzoyl-l-glutamate (pABG) as well as other ligands that occupy the region of the folate-binding site that interacts with pABG; however, DHFR inhibition is not cooperative. The biguanides competitively inhibit the activity of ecDHFR, with the phenformin inhibition constant being 100-fold lower than that of metformin. This inhibition may be significant at concentrations present in the gut of treated individuals, and inhibition of DHFR in intestinal mucosal cells may also occur if accumulation levels are sufficient. Perturbation of folate homeostasis can alter the pyridine nucleotide redox ratios that are important regulators of cellular metabolism.
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Affiliation(s)
- Scott A. Gabel
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, NIH, 111 T. W. Alexander Dr. Research Triangle Park, NC 27709
| | - Michael R. Duff
- Department of Biochemistry, Cellular & Molecular Biology, University of Tennessee, Knoxville, TN 37996
| | - Lars C. Pedersen
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, NIH, 111 T. W. Alexander Dr. Research Triangle Park, NC 27709
| | - Eugene F. DeRose
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, NIH, 111 T. W. Alexander Dr. Research Triangle Park, NC 27709
| | | | - Elizabeth E. Howell
- Department of Biochemistry, Cellular & Molecular Biology, University of Tennessee, Knoxville, TN 37996
| | - Robert E. London
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, NIH, 111 T. W. Alexander Dr. Research Triangle Park, NC 27709
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Review of Experimental Compounds Demonstrating Anti-Toxoplasma Activity. Antimicrob Agents Chemother 2016; 60:7017-7034. [PMID: 27600037 DOI: 10.1128/aac.01176-16] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Toxoplasma gondii is a ubiquitous apicomplexan parasite capable of infecting humans and other animals. Current treatment options for T. gondii infection are limited and most have drawbacks, including high toxicity and low tolerability. Additionally, no FDA-approved treatments are available for pregnant women, a high-risk population due to transplacental infection. Therefore, the development of novel treatment options is needed. To aid this effort, this review highlights experimental compounds that, at a minimum, demonstrate inhibition of in vitro growth of T. gondii When available, host cell toxicity and in vivo data are also discussed. The purpose of this review is to facilitate additional development of anti-Toxoplasma compounds and potentially to extend our knowledge of the parasite.
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Shelke RU, Degani MS, Raju A, Ray MK, Rajan MGR. Fragment Discovery for the Design of Nitrogen Heterocycles asMycobacterium tuberculosisDihydrofolate Reductase Inhibitors. Arch Pharm (Weinheim) 2016; 349:602-13. [DOI: 10.1002/ardp.201600066] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Revised: 05/21/2016] [Accepted: 05/27/2016] [Indexed: 12/22/2022]
Affiliation(s)
- Rupesh U. Shelke
- Institute of Chemical Technology; Nathalal Parekh Marg, Matunga; Mumbai India
| | - Mariam S. Degani
- Institute of Chemical Technology; Nathalal Parekh Marg, Matunga; Mumbai India
| | - Archana Raju
- Institute of Chemical Technology; Nathalal Parekh Marg, Matunga; Mumbai India
| | - Mukti Kanta Ray
- Radiation Medicine Centre; Tata Memorial Hospital, Parel; Mumbai India
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Lele AC, Raju A, Khambete MP, Ray MK, Rajan MGR, Arkile MA, Jadhav NJ, Sarkar D, Degani MS. Design and Synthesis of a Focused Library of Diamino Triazines as Potential Mycobacterium tuberculosis DHFR Inhibitors. ACS Med Chem Lett 2015; 6:1140-4. [PMID: 26617968 DOI: 10.1021/acsmedchemlett.5b00367] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Accepted: 10/17/2015] [Indexed: 11/29/2022] Open
Abstract
We report design of a series of 2,4-diamino triazines as Mycobacterium tuberculosis (Mtb) dihydrofolate reductase inhibitors. The synthesized compounds were evaluated against Mtb (H37Rv and Dormant stage H37Ra), their cytotoxicity was assessed (HepG2 and A549 cell lines), and selectivity toward Mtb was evaluated by testing against other bacterial strains. Some derivatives showed promising activity along with low cytotoxicity. The most potent compound in the whole cell assay (MIC 0.325 μM against H37Rv) showed selectivity in the enzyme assay and exhibited synergy with second line anti-TB agent p-amino salicylic acid. This study therefore provides promising molecules for further development as antituberculosis DHFR inhibitors.
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Affiliation(s)
- Arundhati C. Lele
- Department of Pharmaceutical Sciences and
Technology, Institute of Chemical Technology, Matunga (E), Mumbai 400019, India
| | - Archana Raju
- Department of Pharmaceutical Sciences and
Technology, Institute of Chemical Technology, Matunga (E), Mumbai 400019, India
| | - Mihir P. Khambete
- Department of Pharmaceutical Sciences and
Technology, Institute of Chemical Technology, Matunga (E), Mumbai 400019, India
| | - M. K. Ray
- Radiation Medicine Center, Bhabha Atomic
Research Centre, Tata Memorial Hospital Annex, Parel, Mumbai 400012, India
| | - M. G. R. Rajan
- Radiation Medicine Center, Bhabha Atomic
Research Centre, Tata Memorial Hospital Annex, Parel, Mumbai 400012, India
| | - Manisha A. Arkile
- Combichem-Bioresource
Center, Organic Chemistry Division, CSIR-National Chemical Laboratory, Pune 411008, India
| | - Nandadeep J. Jadhav
- Combichem-Bioresource
Center, Organic Chemistry Division, CSIR-National Chemical Laboratory, Pune 411008, India
| | - Dhiman Sarkar
- Combichem-Bioresource
Center, Organic Chemistry Division, CSIR-National Chemical Laboratory, Pune 411008, India
| | - Mariam S. Degani
- Department of Pharmaceutical Sciences and
Technology, Institute of Chemical Technology, Matunga (E), Mumbai 400019, India
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Rational drug design, synthesis and biological evaluation of dihydrofolate reductase inhibitors as antituberculosis agents. Future Med Chem 2015; 7:979-88. [DOI: 10.4155/fmc.15.48] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Background: A series of 2,4-diamino-s-triazines was designed, with potential for activity against Mycobacterium tuberculosis (Mtb) dihydrofolate reductase enzyme, on the basis of virtual screening results and structure-based drug design. Results: The compounds were evaluated against Mtb (H37Rv) and their cytotoxicity was assessed using VERO cell lines. Of particular note, two compounds were found to have the most promising antituberculosis activity (6b minimum inhibitory concentration: 1.76 μM and 6i minimum inhibitory concentration: 1.57 μM) along with low cytotoxicity (CC50: >300 μM). The enzyme assay results of these two indicated significant inhibition of Mtb dihydrofolate reductase along with selectivity. Selected derivatives were tested against dormant tubercle bacilli in vivo and ex vivo indicating potential inhibition. Conclusion: This study provides promising antituberculosis dihydrofolate reductase inhibitors that can act as potential leads for further development.
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Quantitative assessment of the proliferation of the protozoan parasite Perkinsus marinus using a bioluminescence assay for ATP content. INTERNATIONAL JOURNAL FOR PARASITOLOGY-DRUGS AND DRUG RESISTANCE 2013; 3:85-92. [PMID: 24533297 DOI: 10.1016/j.ijpddr.2013.03.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2012] [Revised: 03/20/2013] [Accepted: 03/21/2013] [Indexed: 11/22/2022]
Abstract
Perkinsus marinus is a protozoan parasite that causes "Dermo" disease in the eastern oyster Crasssostrea virginica in coastal areas of the USA. Until now, intervention strategies against the parasite have found limited success, and Dermo still remains one of the main hurdles for the restoration of oyster populations. We adapted a commercial adenosine tri-phosphate (ATP) content-based assay to assess the in vitro proliferation of P. marinus in a 96-well plate format, and validated the method by measuring the effects of potential anti-proliferative compounds. The sensitivity (1.5-3.1 × 10(4) cells/well), linearity (R (2) = 0.983), and signal stability (60 min) support the reliability of the assay for assessing cell proliferation. Validation of the assay by culturing P. marinus in the presence of increasing concentrations of triclosan showed a dose-response profile. The IC50 value obtained was higher than that reported earlier, possibly due to the use of different viability assay methods and a different P. marinus strain. The antibiotics G418 and tetracycline and the herbicide fluridone were active against P. marinus proliferation; the IC50 of chloramphenicol, ciprofloxacin, and atrazine was relatively high suggesting either off-target effects or inability to reach the targets. The validation of the ATP-based assay, together with significant advantages of the Perkinsus culture methodology (homogeneity, reproducibility, and high cell densities), underscores the value of this assay for developing high-throughput screens for the identification of novel leader compounds against Perkinsus species, and most importantly, for the closely-related apicomplexan parasites.
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Exploration of 2, 4-diaminopyrimidine and 2, 4-diamino-s-triazine derivatives as potential antifilarial agents. Parasitology 2013; 140:959-65. [DOI: 10.1017/s0031182013000309] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
SUMMARYIn view of the mandate from the World Health Organization (WHO) for developing novel drug candidates against human lymphatic filariasis, dihydrofolate reductase (DHFR) inhibitors are explored as potential antifilarial agents. The in vitro biological evaluation of an in-house library of 12 diverse antifolate compounds with 2,4-diaminopyrimidine and 2,4-diamino-s-triazine structural features against Brugia malayi is reported. To confirm the DHFR inhibitory potential of these compounds, reversal studies using folic acid and folinic acid were undertaken. Inhibition of DHFR can induce apoptosis; in this light, preliminary evidence of apoptosis by test compounds was detected using ethidium bromide–acridine orange staining and the poly(adenosine diphosphate-ribose) polymerase (PARP) inhibition assay. Among the evaluated compounds, 3 showed significant activity against both microfilariae and adult worms. The effects of 2 of these compounds were mostly reversed by folic acid, validating DHFR inhibitory activity. Partial reversal of the effect of 2 compounds by folinic acid and non-reversal of the effect of the third compound both by folic and folinic acids are discussed. This study opens new avenues for the discovery of lead molecules by exploiting the folate pathway against one of the major neglected tropical diseases, filariasis.
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Abstract
INTRODUCTION Toxoplasma gondii, the agent that causes toxoplasmosis, is an opportunistic parasite that infects many mammalian species. It is an obligate intracellular parasite that causes severe congenital neurological and ocular disease mostly in immunocompromised humans. The current regimen of therapy includes only a few medications that often lead to hypersensitivity and toxicity. In addition, there are no vaccines available to prevent the transmission of this agent. Therefore, safer and more effective medicines to treat toxoplasmosis are urgently needed. AREAS COVERED The author presents in silico and in vitro strategies that are currently used to screen for novel targets and unique chemotypes against T. gondii. Furthermore, this review highlights the screening technologies and characterization of some novel targets and new chemical entities that could be developed into highly efficacious treatments for toxoplasmosis. EXPERT OPINION A number of diverse methods are being used to design inhibitors against T. gondii. These include ligand-based methods, in which drugs that have been shown to be efficacious against other Apicomplexa parasites can be repurposed to identify lead molecules against T. gondii. In addition, structure-based methods use currently available repertoire of structural information in various databases to rationally design small-molecule inhibitors of T. gondii. Whereas the screening methods have their advantages and limitations, a combination of methods is ideally suited to design small-molecule inhibitors of complex parasites such as T. gondii.
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Affiliation(s)
- Sandhya Kortagere
- Drexel University College of Medicine, Institute for Molecular Medicine, Department of Microbiology and Immunology, 2900, Queen Lane, PA 19129, USA.
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Design, synthesis, and biological evaluation of 4-(5-nitrofuran-2-yl)prop-2-en-1-one derivatives as potent antitubercular agents. Bioorg Med Chem Lett 2010; 20:6175-8. [DOI: 10.1016/j.bmcl.2010.08.127] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2010] [Revised: 07/29/2010] [Accepted: 08/27/2010] [Indexed: 11/23/2022]
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Bag S, Tawari NR, Degani MS, Queener SF. Design, synthesis, biological evaluation and computational investigation of novel inhibitors of dihydrofolate reductase of opportunistic pathogens. Bioorg Med Chem 2010; 18:3187-97. [PMID: 20363634 DOI: 10.1016/j.bmc.2010.03.031] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2010] [Revised: 03/12/2010] [Accepted: 03/13/2010] [Indexed: 10/19/2022]
Abstract
The present work deals with design, synthesis and biological evaluation of novel, diverse compounds as potential inhibitors of dihydrofolate reductase (DHFR) from opportunistic microorganisms; Pneumocystis carinii (pc), Toxoplasma gondii (tg) and Mycobacterium avium (ma). A set of 14 structurally diverse compounds were designed with varying key pharmacophoric features of DHFR inhibitors, bulky distal substitutions and different bridges joining the distal part and 2,4-diaminopyrimidine nucleus. The designed compounds were synthesized and evaluated in enzyme assay against pc, tg and ma DHFR. The rat liver (rl) DHFR was used as mammalian standard. As the next logical step of the project, flexible molecular docking studies were carried out to predict the binding modes of these compounds in pcDHFR active site and the obtained docked poses were post processed using MM-GBSA protocol for prediction of relative binding affinity. The predicted binding modes were able to rationalize the experimental results in most cases. Of particular interest, both the docking scores and MM-GBSA predicted Delta G(bind) were able to distinguish between the active and low active compounds. Furthermore, good correlation coefficient of 0.797 was obtained between the IC(50) values and MM-GBSA predicted Delta G(bind). Taken together, the current work provides not only a novel scaffold for further optimization of DHFR inhibitors but also an understanding of the specific interactions of inhibitors with DHFR and structural modifications that improve selectivity.
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Affiliation(s)
- Seema Bag
- Department of Pharmaceutical Sciences and Technology, Institute of Chemical Technology, Matunga (E), Mumbai 400 019, India
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Bag S, Tawari NR, Sharma R, Goswami K, Reddy M, Degani MS. In vitro biological evaluation of biguanides and dihydrotriazines against Brugia malayi and folate reversal studies. Acta Trop 2010; 113:48-51. [PMID: 19769933 DOI: 10.1016/j.actatropica.2009.09.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2008] [Revised: 08/31/2009] [Accepted: 09/10/2009] [Indexed: 10/20/2022]
Abstract
Dihydrofolate reductase (DHFR) is a well-known target for antibacterial and anticancer therapy. DHFR inhibitors are useful for protozoan parasites, but are yet to be explored against metazoan species; hence the present work was designed to evaluate the efficacy of DHFR inhibitors against filariasis, one of the major neglected tropical diseases. Molecules from our in-house library of synthetic antifolate agents (biguanide and dihydrotriazine derivatives) were evaluated along with the antimalarial drug pyrimethamine and the antibacterial drug trimethoprim in an in vitro model against Brugia malayi microfilariae (Mf). Three biguanides and two dihydrotriazines were more potent than trimethoprim and pyrimethamine against B. malayi Mf. Trimethoprim, pyrimethamine and four of the five compounds active against Mf were also active against adult worms. To probe the mechanism of action of the compounds, reversal of activity of active compounds by folic acid and folinic acid was studied. In conclusion, DHFR inhibitors could be used as leads for new antifilarial drugs.
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