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Huang L, Sun Y, Huo DD, Xu M, Xia LY, Yang N, Hong W, Huang L, Nie WM, Liao RH, Zhang MZ, Zhu DY, Li Y, Ma HC, Zhang X, Li YG, Huang XA, Wang JY, Cao WC, Wang FS, Jiang JF. Successful treatment with doxycycline monotherapy for human infection with Babesia venatorum (Babesiidae, Sporozoa) in China: a case report and proposal for a clinical regimen. Infect Dis Poverty 2023; 12:67. [PMID: 37443058 PMCID: PMC10339522 DOI: 10.1186/s40249-023-01111-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Accepted: 05/31/2023] [Indexed: 07/15/2023] Open
Abstract
BACKGROUND Human babesiosis is a worldwide disease caused by intraerythrocytic protozoa of the genus Babesia. It is transmitted by bites from ixodid ticks, and mechanically transmitted by blood transfusion. It is primarily treated with quinine and/or atovaquone, which are not readily available in China. In this study, we developed a novel treatment regimen involving doxycycline monotherapy in a patient with severe Babesia venatorum infection as an alternative therapeutic medication. The aim of our study is to provide a guidance for clinical practice treatment of human babesiosis. CASE PRESENTATION A 73-year-old man who had undergone splenectomy and blood transfusion 8 years prior, presented with an unexplained fever, headache, and thrombocytopenia, and was admitted to the Fifth Medical Center of the PLA General Hospital. He was diagnosed with B. venatorum infection by morphological review of thin peripheral blood smears, which was confirmed by multi-gene polymerase chain reaction (PCR), and sequencing of the entire 18s rRNA and partial β-tubulin encoding genes, as well as isolation by animal inoculation. The doxycycline monotherapy regimen (peros, 0.1 g bisindie) was administered following pharmacological guidance and an effective outcome was observed. The patient recovered rapidly following the doxycycline monotherapy. The protozoan load in peripheral blood samples decreased by 88% in hematocrit counts after 8 days, and negative PCR results were obtained after 90 days of follow-up at the hospital. The treatment lasted for 3 months without any side effects or sequelae. The nine-month follow-up survey of the patient did not reveal any signs of recrudescence or anti-babesial tolerance. CONCLUSIONS We have reported a clinical case of successful doxycycline monotherapy for human babesiosis caused by B. venatorum, which provides an optional medical intervention for human babesiosis.
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Affiliation(s)
- Lei Huang
- Department of Infectious Diseases, The Fifth Medical Center of Chinese PLA General Hospital, Beijing, 100039, People's Republic of China
| | - Yi Sun
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Academy of Military Medical Sciences, Beijing, 100071, People's Republic of China
| | - Dan-Dan Huo
- Department of Infectious Diseases, The Fifth Medical Center of Chinese PLA General Hospital, Beijing, 100039, People's Republic of China
| | - Ming Xu
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Academy of Military Medical Sciences, Beijing, 100071, People's Republic of China
- Inner Mongolia Medical University, Hohhot, 010059, People's Republic of China
| | - Luo-Yuan Xia
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Academy of Military Medical Sciences, Beijing, 100071, People's Republic of China
- School of Public Health, Shandong University, Jinan, 250100, People's Republic of China
| | - Ning Yang
- The Center for Clinical Laboratory, The Fifth Medical Center of Chinese PLA General Hospital, Beijing, 100039, People's Republic of China
| | - Wei Hong
- The Center for Clinical Laboratory, The Fifth Medical Center of Chinese PLA General Hospital, Beijing, 100039, People's Republic of China
| | - Lin Huang
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Academy of Military Medical Sciences, Beijing, 100071, People's Republic of China
| | - Wei-Min Nie
- Department of Infectious Diseases, The Fifth Medical Center of Chinese PLA General Hospital, Beijing, 100039, People's Republic of China
| | - Ru-He Liao
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Academy of Military Medical Sciences, Beijing, 100071, People's Republic of China
- Artemisinin Research Center, Guangzhou University of Chinese Medicine, Guangzhou, 510000, People's Republic of China
| | - Ming-Zhu Zhang
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Academy of Military Medical Sciences, Beijing, 100071, People's Republic of China
| | - Dai-Yun Zhu
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Academy of Military Medical Sciences, Beijing, 100071, People's Republic of China
| | - Yan Li
- The Center for Clinical Laboratory, The Fifth Medical Center of Chinese PLA General Hospital, Beijing, 100039, People's Republic of China
| | - He-Cheng Ma
- Department of Infectious Diseases, The Fifth Medical Center of Chinese PLA General Hospital, Beijing, 100039, People's Republic of China
| | - Xin Zhang
- Department of Infectious Diseases, The Fifth Medical Center of Chinese PLA General Hospital, Beijing, 100039, People's Republic of China
| | - Yong-Gang Li
- Department of Infectious Diseases, The Fifth Medical Center of Chinese PLA General Hospital, Beijing, 100039, People's Republic of China
| | - Xin-An Huang
- Artemisinin Research Center, Guangzhou University of Chinese Medicine, Guangzhou, 510000, People's Republic of China
| | - Jing-Yuan Wang
- School of Public Health, Shandong University, Jinan, 250100, People's Republic of China
| | - Wu-Chun Cao
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Academy of Military Medical Sciences, Beijing, 100071, People's Republic of China.
- School of Public Health, Shandong University, Jinan, 250100, People's Republic of China.
| | - Fu-Sheng Wang
- Department of Infectious Diseases, The Fifth Medical Center of Chinese PLA General Hospital, Beijing, 100039, People's Republic of China.
| | - Jia-Fu Jiang
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Academy of Military Medical Sciences, Beijing, 100071, People's Republic of China.
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Gao P, Liu YQ, Xiao W, Xia F, Chen JY, Gu LW, Yang F, Zheng LH, Zhang JZ, Zhang Q, Li ZJ, Meng YQ, Zhu YP, Tang H, Shi QL, Guo QY, Zhang Y, Xu CC, Dai LY, Wang JG. Identification of antimalarial targets of chloroquine by a combined deconvolution strategy of ABPP and MS-CETSA. Mil Med Res 2022; 9:30. [PMID: 35698214 PMCID: PMC9195458 DOI: 10.1186/s40779-022-00390-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Accepted: 05/31/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Malaria is a devastating infectious disease that disproportionally threatens hundreds of millions of people in developing countries. In the history of anti-malaria campaign, chloroquine (CQ) has played an indispensable role, however, its mechanism of action (MoA) is not fully understood. METHODS We used the principle of photo-affinity labeling and click chemistry-based functionalization in the design of a CQ probe and developed a combined deconvolution strategy of activity-based protein profiling (ABPP) and mass spectrometry-coupled cellular thermal shift assay (MS-CETSA) that identified the protein targets of CQ in an unbiased manner in this study. The interactions between CQ and these identified potential protein hits were confirmed by biophysical and enzymatic assays. RESULTS We developed a novel clickable, photo-affinity chloroquine analog probe (CQP) which retains the antimalarial activity in the nanomole range, and identified a total of 40 proteins that specifically interacted and photo-crosslinked with CQP which was inhibited in the presence of excess CQ. Using MS-CETSA, we identified 83 candidate interacting proteins out of a total of 3375 measured parasite proteins. At the same time, we identified 8 proteins as the most potential hits which were commonly identified by both methods. CONCLUSIONS We found that CQ could disrupt glycolysis and energy metabolism of malarial parasites through direct binding with some of the key enzymes, a new mechanism that is different from its well-known inhibitory effect of hemozoin formation. This is the first report of identifying CQ antimalarial targets by a parallel usage of labeled (ABPP) and label-free (MS-CETSA) methods.
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Affiliation(s)
- Peng Gao
- Artemisinin Research Center, Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, 100700, China
| | - Yan-Qing Liu
- Artemisinin Research Center, Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, 100700, China
| | - Wei Xiao
- Department of Traditional Chinese Medicine, Southern Medical University, Guangzhou, 510515, China
| | - Fei Xia
- Artemisinin Research Center, Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, 100700, China
| | - Jia-Yun Chen
- Artemisinin Research Center, Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, 100700, China
| | - Li-Wei Gu
- Artemisinin Research Center, Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, 100700, China
| | - Fan Yang
- Department of Geriatrics, the Second Clinical Medical College of Jinan University, the First Affiliated Hospital of Southern University of Science and Technology, Shenzhen People's Hospital, Shenzhen, 518020, Guangdong, China
| | - Liu-Hai Zheng
- Department of Geriatrics, the Second Clinical Medical College of Jinan University, the First Affiliated Hospital of Southern University of Science and Technology, Shenzhen People's Hospital, Shenzhen, 518020, Guangdong, China
| | - Jun-Zhe Zhang
- Artemisinin Research Center, Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, 100700, China
| | - Qian Zhang
- Artemisinin Research Center, Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, 100700, China
| | - Zhi-Jie Li
- Department of Geriatrics, the Second Clinical Medical College of Jinan University, the First Affiliated Hospital of Southern University of Science and Technology, Shenzhen People's Hospital, Shenzhen, 518020, Guangdong, China
| | - Yu-Qing Meng
- Artemisinin Research Center, Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, 100700, China
| | - Yong-Ping Zhu
- Artemisinin Research Center, Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, 100700, China
| | - Huan Tang
- Artemisinin Research Center, Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, 100700, China
| | - Qiao-Li Shi
- Artemisinin Research Center, Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, 100700, China
| | - Qiu-Yan Guo
- Artemisinin Research Center, Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, 100700, China
| | - Ying Zhang
- Artemisinin Research Center, Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, 100700, China
| | - Cheng-Chao Xu
- Artemisinin Research Center, Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, 100700, China.
| | - Ling-Yun Dai
- Department of Geriatrics, the Second Clinical Medical College of Jinan University, the First Affiliated Hospital of Southern University of Science and Technology, Shenzhen People's Hospital, Shenzhen, 518020, Guangdong, China. .,Institute of Molecular and Cell Biology, Agency for Science, Technology and Research (A*STAR), Singapore, 138673, Singapore.
| | - Ji-Gang Wang
- Artemisinin Research Center, Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, 100700, China. .,Department of Geriatrics, the Second Clinical Medical College of Jinan University, the First Affiliated Hospital of Southern University of Science and Technology, Shenzhen People's Hospital, Shenzhen, 518020, Guangdong, China. .,Department of Biological Sciences, National University of Singapore, Singapore, 117543, Singapore.
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The Role of the Iron Protoporphyrins Heme and Hematin in the Antimalarial Activity of Endoperoxide Drugs. Pharmaceuticals (Basel) 2022; 15:ph15010060. [PMID: 35056117 PMCID: PMC8779033 DOI: 10.3390/ph15010060] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Revised: 12/01/2021] [Accepted: 12/08/2021] [Indexed: 02/05/2023] Open
Abstract
Plasmodium has evolved to regulate the levels and oxidative states of iron protoporphyrin IX (Fe-PPIX). Antimalarial endoperoxides such as 1,2,4-trioxane artemisinin and 1,2,4-trioxolane arterolane undergo a bioreductive activation step mediated by heme (FeII-PPIX) but not by hematin (FeIII-PPIX), leading to the generation of a radical species. This can alkylate proteins vital for parasite survival and alkylate heme into hematin–drug adducts. Heme alkylation is abundant and accompanied by interconversion from the ferrous to the ferric state, which may induce an imbalance in the iron redox homeostasis. In addition to this, hematin–artemisinin adducts antagonize the spontaneous biomineralization of hematin into hemozoin crystals, differing strikingly from artemisinins, which do not directly suppress hematin biomineralization. These hematin–drug adducts, despite being devoid of the peroxide bond required for radical-induced alkylation, are powerful antiplasmodial agents. This review addresses our current understanding of Fe-PPIX as a bioreductive activator and molecular target. A compelling pharmacological model is that by alkylating heme, endoperoxide drugs can cause an imbalance in the iron homeostasis and that the hematin–drug adducts formed have strong cytocidal effects by possibly reproducing some of the toxifying effects of free Fe-PPIX. The antiplasmodial phenotype and the mode of action of hematin–drug adducts open new possibilities for reconciliating the mechanism of endoperoxide drugs and for malaria intervention.
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Gil JP, Fançony C. Plasmodium falciparum Multidrug Resistance Proteins ( pfMRPs). Front Pharmacol 2021; 12:759422. [PMID: 34790129 PMCID: PMC8591188 DOI: 10.3389/fphar.2021.759422] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Accepted: 10/05/2021] [Indexed: 12/19/2022] Open
Abstract
The capacity of the lethal Plasmodium falciparum parasite to develop resistance against anti-malarial drugs represents a central challenge in the global control and elimination of malaria. Historically, the action of drug transporters is known to play a pivotal role in the capacity of the parasite to evade drug action. MRPs (Multidrug Resistance Protein) are known in many phylogenetically diverse groups to be related to drug resistance by being able to handle a large range of substrates, including important endogenous substances as glutathione and its conjugates. P. falciparum MRPs are associated with in vivo and in vitro altered drug response, and might be important factors for the development of multi-drug resistance phenotypes, a latent possibility in the present, and future, combination therapy environment. Information on P. falciparum MRPs is scattered in the literature, with no specialized review available. We herein address this issue by reviewing the present state of knowledge.
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Affiliation(s)
- José Pedro Gil
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden.,Faculty of Sciences, BioISI-Biosystems and Integrative Sciences Institute, University of Lisbon, Lisbon, Portugal.,Global Health and Tropical Medicine, Institute of Hygiene and Tropical Medicine, Nova University of Lisbon, Lisbon, Portugal
| | - Cláudia Fançony
- Centro de Investigação em Saúde de Angola (CISA)/Instituto Nacional de Investigação em Saúde (INIS), Caxito, Angola
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5
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Erhunse N, Sahal D. Protecting future antimalarials from the trap of resistance: Lessons from artemisinin-based combination therapy (ACT) failures. J Pharm Anal 2021; 11:541-554. [PMID: 34765267 PMCID: PMC8572664 DOI: 10.1016/j.jpha.2020.07.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2020] [Revised: 07/19/2020] [Accepted: 07/19/2020] [Indexed: 11/01/2022] Open
Abstract
Having faced increased clinical treatment failures with dihydroartemisinin-piperaquine (DHA-PPQ), Cambodia swapped the first line artemisinin-based combination therapy (ACT) from DHA-PPQ to artesunate-mefloquine given that parasites resistant to piperaquine are susceptible to mefloquine. However, triple mutants have now emerged, suggesting that drug rotations may not be adequate to keep resistance at bay. There is, therefore, an urgent need for alternative treatment strategies to tackle resistance and prevent its spread. A proper understanding of all contributors to artemisinin resistance may help us identify novel strategies to keep artemisinins effective until new drugs become available for their replacement. This review highlights the role of the key players in artemisinin resistance, the current strategies to deal with it and suggests ways of protecting future antimalarial drugs from bowing to resistance as their predecessors did.
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Affiliation(s)
- Nekpen Erhunse
- Malaria Drug Discovery Research Group, International Centre for Genetic Engineering and Biotechnology, New Delhi, 110067, India
- Department of Biochemistry, Faculty of Life Sciences, University of Benin, Benin City, Edo-State, Nigeria
| | - Dinkar Sahal
- Malaria Drug Discovery Research Group, International Centre for Genetic Engineering and Biotechnology, New Delhi, 110067, India
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6
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Renard I, Ben Mamoun C. Treatment of Human Babesiosis: Then and Now. Pathogens 2021; 10:pathogens10091120. [PMID: 34578153 PMCID: PMC8469882 DOI: 10.3390/pathogens10091120] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 08/23/2021] [Accepted: 08/27/2021] [Indexed: 12/26/2022] Open
Abstract
Babesiosis is an emerging tick-borne disease caused by apicomplexan parasites of the genus Babesia. With its increasing incidence worldwide and the risk of human-to-human transmission through blood transfusion, babesiosis is becoming a rising public health concern. The current arsenal for the treatment of human babesiosis is limited and consists of combinations of atovaquone and azithromycin or clindamycin and quinine. These combination therapies were not designed based on biological criteria unique to Babesia parasites, but were rather repurposed based on their well-established efficacy against other apicomplexan parasites. However, these compounds are associated with mild or severe adverse events and a rapid emergence of drug resistance, thus highlighting the need for new therapeutic strategies that are specifically tailored to Babesia parasites. Herein, we review ongoing babesiosis therapeutic and management strategies and their limitations, and further review current efforts to develop new, effective, and safer therapies for the treatment of this disease.
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Wang K, Shao X, Tian Z, Liu L, Zhang C, Tan C, Zhang J, Ling P, Liu F, Chen Q, Diao J, Mao Z. A Continuous Add-On Probe Reveals the Nonlinear Enlargement of Mitochondria in Light-Activated Oncosis. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2021; 8:e2004566. [PMID: 34197052 PMCID: PMC8425930 DOI: 10.1002/advs.202004566] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Revised: 05/03/2021] [Indexed: 05/25/2023]
Abstract
Oncosis, depending on DNA damage and mitochondrial swelling, is an important approach for treating cancer and other diseases. However, little is known about the behavior of mitochondria during oncosis, due to the lack of probes for in situ visual illumination of the mitochondrial membrane and mtDNA. Herein, a mitochondrial lipid and mtDNA dual-labeled probe, MitoMN, and a continuous add-on assay, are designed to image the dynamic process of mitochondria in conditions that are unobservable with current mitochondrial probes. Meanwhile, the MitoMN can induce oncosis in a light-activated manner, which results in the enlargement of mitochondria and the death of cancer cells. Using structured illumination microscopy (SIM), MitoMN-stained mitochondria with a dual-color response reveals, for the first time, how swelled mitochondria interacts and fuses with each other for a nonlinear enlargement to accelerate oncosis into an irreversible stage. With this sign of irreversible oncosis revealed by MitoMN, oncosis can be segregated into three stages, including before oncosis, initial oncosis, and accelerated oncosis.
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Affiliation(s)
- Kang‐Nan Wang
- MOE Key Laboratory of Bioinorganic and Synthetic ChemistrySchool of ChemistryState Key Laboratory of Oncology in South ChinaSun Yat‐Sen UniversityGuangzhou510275P. R. China
| | - Xintian Shao
- Institute of Materia MedicaShandong First Medical University & Shandong Academy of Medical SciencesJinan250000P. R. China
- Department of Cancer BiologyUniversity of Cincinnati College of MedicineCincinnati45267USA
- Shandong Academy of Pharmaceutical ScienceKey Laboratory of BiopharmaceuticalsEngineering Laboratory of Polysaccharide DrugsNational‐Local Joint Engineering Laboratory of Polysaccharide DrugsJinan250101P. R. China
| | - Zhiqi Tian
- Department of Molecular Genetics, Biochemistry, and MicrobiologyUniversity of Cincinnati College of MedicineCincinnati45267USA
| | - Liu‐Yi Liu
- MOE Key Laboratory of Bioinorganic and Synthetic ChemistrySchool of ChemistryState Key Laboratory of Oncology in South ChinaSun Yat‐Sen UniversityGuangzhou510275P. R. China
| | - Chengying Zhang
- Institute of Materia MedicaShandong First Medical University & Shandong Academy of Medical SciencesJinan250000P. R. China
- Shandong Academy of Pharmaceutical ScienceKey Laboratory of BiopharmaceuticalsEngineering Laboratory of Polysaccharide DrugsNational‐Local Joint Engineering Laboratory of Polysaccharide DrugsJinan250101P. R. China
- School of Pharmaceutical SciencesShandong UniversityJinan250101P. R. China
| | - Cai‐Ping Tan
- MOE Key Laboratory of Bioinorganic and Synthetic ChemistrySchool of ChemistryState Key Laboratory of Oncology in South ChinaSun Yat‐Sen UniversityGuangzhou510275P. R. China
| | - Jie Zhang
- Advanced Medical Research Institute/Translational Medicine Core Facility of Advanced Medical Research InstituteShandong UniversityJinan250101P. R. China
| | - Peixue Ling
- Shandong Academy of Pharmaceutical ScienceKey Laboratory of BiopharmaceuticalsEngineering Laboratory of Polysaccharide DrugsNational‐Local Joint Engineering Laboratory of Polysaccharide DrugsJinan250101P. R. China
- School of Pharmaceutical SciencesShandong UniversityJinan250101P. R. China
| | - Fei Liu
- Shandong Academy of Pharmaceutical ScienceKey Laboratory of BiopharmaceuticalsEngineering Laboratory of Polysaccharide DrugsNational‐Local Joint Engineering Laboratory of Polysaccharide DrugsJinan250101P. R. China
- School of Pharmaceutical SciencesShandong UniversityJinan250101P. R. China
| | - Qixin Chen
- Institute of Materia MedicaShandong First Medical University & Shandong Academy of Medical SciencesJinan250000P. R. China
- Department of Cancer BiologyUniversity of Cincinnati College of MedicineCincinnati45267USA
- Shandong Academy of Pharmaceutical ScienceKey Laboratory of BiopharmaceuticalsEngineering Laboratory of Polysaccharide DrugsNational‐Local Joint Engineering Laboratory of Polysaccharide DrugsJinan250101P. R. China
| | - Jiajie Diao
- Department of Cancer BiologyUniversity of Cincinnati College of MedicineCincinnati45267USA
| | - Zong‐Wan Mao
- MOE Key Laboratory of Bioinorganic and Synthetic ChemistrySchool of ChemistryState Key Laboratory of Oncology in South ChinaSun Yat‐Sen UniversityGuangzhou510275P. R. China
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Broichhagen J, Kilian N. Chemical Biology Tools To Investigate Malaria Parasites. Chembiochem 2021; 22:2219-2236. [PMID: 33570245 PMCID: PMC8360121 DOI: 10.1002/cbic.202000882] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 02/10/2021] [Indexed: 02/06/2023]
Abstract
Parasitic diseases like malaria tropica have been shaping human evolution and history since the beginning of mankind. After infection, the response of the human host ranges from asymptomatic to severe and may culminate in death. Therefore, proper examination of the parasite's biology is pivotal to deciphering unique molecular, biochemical and cell biological processes, which in turn ensure the identification of treatment strategies, such as potent drug targets and vaccine candidates. However, implementing molecular biology methods for genetic manipulation proves to be difficult for many parasite model organisms. The development of fast and straightforward applicable alternatives, for instance small-molecule probes from the field of chemical biology, is essential. In this review, we will recapitulate the highlights of previous molecular and chemical biology approaches that have already created insight and understanding of the malaria parasite Plasmodium falciparum. We discuss current developments from the field of chemical biology and explore how their application could advance research into this parasite in the future. We anticipate that the described approaches will help to close knowledge gaps in the biology of P. falciparum and we hope that researchers will be inspired to use these methods to gain knowledge - with the aim of ending this devastating disease.
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Affiliation(s)
- Johannes Broichhagen
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP)Robert-Roessle-Strasse 1013125BerlinGermany
| | - Nicole Kilian
- Centre for Infectious DiseasesParasitologyHeidelberg University HospitalIm Neuenheimer Feld 32469120HeidelbergGermany
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de Villiers KA, Egan TJ. Heme Detoxification in the Malaria Parasite: A Target for Antimalarial Drug Development. Acc Chem Res 2021; 54:2649-2659. [PMID: 33982570 DOI: 10.1021/acs.accounts.1c00154] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Over the last century, malaria deaths have decreased by more than 85%. Nonetheless, there were 405 000 deaths in 2018, mostly resulting from Plasmodium falciparum infection. In the 21st century, much of the advance has arisen from the deployment of insecticide-treated bed nets and artemisinin combination therapy. However, over the past few decades parasites with a delayed artemisinin clearance phenotype have appeared in Southeast Asia, threatening further gains. The effort to find new drugs is thus urgent. A prominent process in blood stage malaria parasites, which we contend remains a viable drug target, is hemozoin formation. This crystalline material consisting of heme can be readily seen when parasites are viewed microscopically. The process of its formation in the parasite, however, is still not fully understood.In early work, we recognized hemozoin formation as a biomineralization process. We have subsequently investigated the kinetics of synthetic hemozoin (β-hematin) crystallization catalyzed at lipid-aqueous interfaces under biomimetic conditions. This led us to the use of neutral detergent-based high-throughput screening (HTS) for inhibitors of β-hematin formation. A good hit rate against malaria parasites was obtained. Simultaneously, we developed a pyridine-based assay which proved successful in measuring the concentrations of hematin not converted to β-hematin.The pyridine assay was adapted to determine the effects of chloroquine and other clinical antimalarials on hemozoin formation in the cell. This permitted the determination of the dose-dependent amounts of exchangeable heme and hemozoin in P. falciparum for the first time. These studies have shown that hemozoin inhibitors cause a dose-dependent increase in exchangeable heme, correlated with decreased parasite survival. Electron spectroscopic imaging (ESI) showed a relocation of heme iron into the parasite cytoplasm, while electron microscopy provided evidence of the disruption of hemozoin crystals. This cellular assay was subsequently extended to top-ranked hits from a wide range of scaffolds found by HTS. Intriguingly, the amounts of exchangeable heme at the parasite growth IC50 values of these scaffolds showed substantial variation. The amount of exchangeable heme was found to be correlated with the amount of inhibitor accumulated in the parasitized red blood cell. This suggests that heme-inhibitor complexes, rather than free heme, lead to parasite death. This was supported by ESI using a Br-containing compound which showed the colocalization of Fe and Br as well as by confocal Raman microscopy which confirmed the presence of a complex in the parasite. Current evidence indicates that inhibitors block hemozoin formation by surface adsorption. Indeed, we have successfully introduced molecular docking with hemozoin to find new inhibitors. It follows that the resulting increase in free heme leads to the formation of the parasiticidal heme-inhibitor complex. We have reported crystal structures of heme-drug complexes for several aryl methanol antimalarials in nonaqueous media. These form coordination complexes but most other inhibitors interact noncovalently, and the determination of their structures remains a major challenge.It is our view that key future developments will include improved assays to measure cellular heme levels, better in silico approaches for predicting β-hematin inhibition, and a concerted effort to determine the structure and properties of heme-inhibitor complexes.
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Affiliation(s)
- Katherine A. de Villiers
- Department of Chemistry and Polymer Science, Stellenbosch University, Private Bag, Matieland 7600, South Africa
| | - Timothy J. Egan
- Department of Chemistry, University of Cape Town, Private Bag, Rondebosch 7701, South Africa
- Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Observatory, Cape Town 7945, South Africa
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Kapishnikov S, Hempelmann E, Elbaum M, Als-Nielsen J, Leiserowitz L. Malaria Pigment Crystals: The Achilles' Heel of the Malaria Parasite. ChemMedChem 2021; 16:1515-1532. [PMID: 33523575 PMCID: PMC8252759 DOI: 10.1002/cmdc.202000895] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Indexed: 12/14/2022]
Abstract
The biogenic formation of hemozoin crystals, a crucial process in heme detoxification by the malaria parasite, is reviewed as an antimalarial drug target. We first focus on the in‐vivo formation of hemozoin. A model is presented, based on native‐contrast 3D imaging obtained by X‐ray and electron microscopy, that hemozoin nucleates at the inner membrane leaflet of the parasitic digestive vacuole, and grows in the adjacent aqueous medium. Having observed quantities of hemoglobin and hemozoin in the digestive vacuole, we present a model that heme liberation from hemoglobin and hemozoin formation is an assembly‐line process. The crystallization is preceded by reaction between heme monomers yielding hematin dimers involving fewer types of isomers than in synthetic hemozoin; this is indicative of protein‐induced dimerization. Models of antimalarial drugs binding onto hemozoin surfaces are reviewed. This is followed by a description of bromoquine, a chloroquine drug analogue, capping a significant fraction of hemozoin surfaces within the digestive vacuole and accumulation of the drug, presumably a bromoquine–hematin complex, at the vacuole's membrane.
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Affiliation(s)
- Sergey Kapishnikov
- Dept. of Chemical Research Support, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - Ernst Hempelmann
- Center of Cellular and Molecular Biology of Diseases, Instituto de Investigaciones Científicas y Servicios de Alta Tecnología (INDICASAT AIP), City of Knowledge, 0843 (Republic of, Panama
| | - Michael Elbaum
- Dept. of Chemical and Biological Physics, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - Jens Als-Nielsen
- Niels Bohr Institute, University of Copenhagen, 2100, Copenhagen, Denmark
| | - Leslie Leiserowitz
- Dept. of Molecular Chemistry and Materials Science, Weizmann Institute of Science, Rehovot, 7610001, Israel
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11
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Melis DR, Hsiao CY, Combrinck JM, Wiesner L, Smith GS. Subcellular Localisation of a Quinoline-Containing Fluorescent Cyclometallated Ir III Complex in Plasmodium falciparum. Chembiochem 2021; 22:1568-1572. [PMID: 33453069 DOI: 10.1002/cbic.202000847] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 12/31/2020] [Indexed: 11/06/2022]
Abstract
A fluorescent analogue of a previously synthesised N,N-chelated IrIII complex was prepared by coordination of the organic ligand to an extrinsic bis(2-phenylpyridine)iridium(III) fluorophore. This cyclometallated IrIII complex in itself displays good, micromolar activity against the chloroquine-sensitive NF54 strain of Plasmodium falciparum. Live-cell confocal microscopy found negligible localisation of the fluorescent complex within the digestive vacuole of the parasite. This eliminated the haem detoxification pathway as a potential mechanism of action. Similarly, no localisation of the complex within the parasitic nucleus was found, thus suggesting that this complex probably does not interfere with the DNA replication process. A substantial saturation of fluorescence from the complex was found near phospholipid structures such as the plasma and nuclear membranes but not in neutral lipid bodies. This indicates that an association with these membranes, or organelles such as the endoplasmic reticulum or branched mitochondrion, could be essential to the efficacies of these types of antimalarial compounds.
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Affiliation(s)
- Diana R Melis
- Department of Chemistry, University of Cape Town, PD Hahn, Chemistry Mall, Rondebosch, 7701, Cape Town, South Africa
| | - Chiao-Yu Hsiao
- Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Cape Town, Observatory, 7925, Cape Town, South Africa
| | - Jill M Combrinck
- Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Cape Town, Observatory, 7925, Cape Town, South Africa
| | - Lubbe Wiesner
- Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Cape Town, Observatory, 7925, Cape Town, South Africa
| | - Gregory S Smith
- Department of Chemistry, University of Cape Town, PD Hahn, Chemistry Mall, Rondebosch, 7701, Cape Town, South Africa
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12
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de Souza Pereira C, Costa Quadros H, Magalhaes Moreira DR, Castro W, Santos De Deus Da Silva RI, Botelho Pereira Soares M, Fontinha D, Prudêncio M, Schmitz V, Dos Santos HF, Gendrot M, Fonta I, Mosnier J, Pradines B, Navarro M. A Novel Hybrid of Chloroquine and Primaquine Linked by Gold(I): Multitarget and Multiphase Antiplasmodial Agent. ChemMedChem 2020; 16:662-678. [PMID: 33231370 DOI: 10.1002/cmdc.202000653] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Revised: 11/02/2020] [Indexed: 12/23/2022]
Abstract
Plasmodium parasites kill 435 000 people around the world every year due to unavailable vaccines, a limited arsenal of antimalarial drugs, delayed treatment, and the reduced clinical effectiveness of current practices caused by drug resistance. Therefore, there is an urgent need to discover and develop new antiplasmodial candidates. In this work, we present a novel strategy to develop a multitarget metallic hybrid antimalarial agent with possible dual efficacy in both sexual and asexual erythrocytic stages. A hybrid of antimalarial drugs (chloroquine and primaquine) linked by gold(I) was synthesized and characterized by spectroscopic and analytical techniques. The CQPQ-gold(I) hybrid molecule affects essential parasite targets, it inhibits β-hematin formation and interacts moderately with the DNA minor groove. Its interaction with PfTrxR was also examined in computational modeling studies. The CQPQ-gold(I) hybrid displayed an excellent in vitro antimalarial activity against the blood-stage of Plasmodium falciparum and liver-stage of Plasmodium berghei and efficacy in vivo against P. berghei, thereby demonstrating its multiple-stage antiplasmodial activity. This metallic hybrid is a promising chemotherapeutic agent that could act in the treatment, prevention, and transmission of malaria.
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Affiliation(s)
- Caroline de Souza Pereira
- Departamento de Química, Universidade Federal de Juiz de Fora, Rua José Lourenço Kelmer, s/n - Campus Universitário, Bairro Martelos, CEP 36036-900, Juiz de Fora, Minas Gerais, Brasil
| | - Helenita Costa Quadros
- Instituto Gonçalo Moniz, Fundação Oswaldo Cruz, Av. Waldemar Falcão, 121, Candeal, Salvador, Bahia, Brasil
| | | | - William Castro
- Centro de Química, Instituto Venezolano de Investigaciones Científicas (IVIC), Centro de Química, Carretera Panamericana, Km 11, Altos de Pipe, San Antonio de los Altos Miranda, 1020-A, Caracas, Venezuela
| | | | | | - Diana Fontinha
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa <, Lisboa, Portugal
| | - Miguel Prudêncio
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa <, Lisboa, Portugal
| | - Vinicius Schmitz
- Departamento de Química, Universidade Federal de Juiz de Fora, Rua José Lourenço Kelmer, s/n - Campus Universitário, Bairro Martelos, CEP 36036-900, Juiz de Fora, Minas Gerais, Brasil
| | - Hélio F Dos Santos
- Departamento de Química, Universidade Federal de Juiz de Fora, Rua José Lourenço Kelmer, s/n - Campus Universitário, Bairro Martelos, CEP 36036-900, Juiz de Fora, Minas Gerais, Brasil
| | - Mathieu Gendrot
- Unité Parasitologie et entomologie, Institut de recherche biomédicale des armées, 19-21 Bd Jean Moulin, 13005, Marseille, France.,Aix-Marseille Univ, IRD, SSA, AP-HM, VITROME, 19-21 Bd Jean Moulin, 13005, Marseille, France.,IHU Méditerranée Infection, 19-21 Bd Jean Moulin, 13005, Marseille, France
| | - Isabelle Fonta
- Unité Parasitologie et entomologie, Institut de recherche biomédicale des armées, 19-21 Bd Jean Moulin, 13005, Marseille, France.,Aix-Marseille Univ, IRD, SSA, AP-HM, VITROME, 19-21 Bd Jean Moulin, 13005, Marseille, France.,IHU Méditerranée Infection, 19-21 Bd Jean Moulin, 13005, Marseille, France.,Centre National de Référence du Paludisme, 19-21 Bd Jean Moulin, 13005, Marseille, France
| | - Joel Mosnier
- Unité Parasitologie et entomologie, Institut de recherche biomédicale des armées, 19-21 Bd Jean Moulin, 13005, Marseille, France.,Aix-Marseille Univ, IRD, SSA, AP-HM, VITROME, 19-21 Bd Jean Moulin, 13005, Marseille, France.,IHU Méditerranée Infection, 19-21 Bd Jean Moulin, 13005, Marseille, France.,Centre National de Référence du Paludisme, 19-21 Bd Jean Moulin, 13005, Marseille, France
| | - Bruno Pradines
- Unité Parasitologie et entomologie, Institut de recherche biomédicale des armées, 19-21 Bd Jean Moulin, 13005, Marseille, France.,Aix-Marseille Univ, IRD, SSA, AP-HM, VITROME, 19-21 Bd Jean Moulin, 13005, Marseille, France.,IHU Méditerranée Infection, 19-21 Bd Jean Moulin, 13005, Marseille, France.,Centre National de Référence du Paludisme, 19-21 Bd Jean Moulin, 13005, Marseille, France
| | - Maribel Navarro
- Departamento de Química, Universidade Federal de Juiz de Fora, Rua José Lourenço Kelmer, s/n - Campus Universitário, Bairro Martelos, CEP 36036-900, Juiz de Fora, Minas Gerais, Brasil
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13
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Pillat MM, Krüger A, Guimarães LMF, Lameu C, de Souza EE, Wrenger C, Ulrich H. Insights in Chloroquine Action: Perspectives and Implications in Malaria and COVID-19. Cytometry A 2020; 97:872-881. [PMID: 32686260 PMCID: PMC7404934 DOI: 10.1002/cyto.a.24190] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 07/13/2020] [Accepted: 07/16/2020] [Indexed: 12/19/2022]
Abstract
Malaria is a threat to human mankind and kills about half a million people every year. On the other hand, COVID-19 resulted in several hundred thousand deaths since December 2019 and remains without an efficient and safe treatment. The antimalarials chloroquine (CQ) and its analog, hydroxychloroquine (HCQ), have been tested for COVID-19 treatment, and several conflicting evidence has been obtained. Therefore, the aim of this review was to summarize the evidence regarding action mechanisms of these compounds against Plasmodium and SARS-CoV-2 infection, together with cytometry applications. CQ and HCQ act on the renin angiotensin system, with possible implications on the cardiorespiratory system. In this context, flow and image cytometry emerge as powerful technologies to investigate the mechanism of therapeutic candidates, as well as for the identification of the immune response and prognostics of disease severity. Data from the large randomized trials support the conclusion that CQ and HCQ do not provide any clinical improvements in disease severity and progression of SARS-CoV-2 patients, as well as they do not present any solid evidence of increased serious side effects. These drugs are safe and effective antimalarials agents, but in SARS-CoV-2 patients, they need further studies in the context of clinical trials. © 2020 International Society for Advancement of Cytometry.
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Affiliation(s)
- Micheli Mainardi Pillat
- Department of Microbiology and ParasitologyHealth Sciences Center, Federal University of Santa MariaSanta MariaRio Grande do SulBrazil
| | - Arne Krüger
- Department of Parasitology, Institute of Biomedical SciencesUniversity of São PauloSão PauloBrazil
| | | | - Claudiana Lameu
- Department of BiochemistryInstitute of Chemistry, University of São PauloSão PauloBrazil
| | - Edmarcia Elisa de Souza
- Department of Parasitology, Institute of Biomedical SciencesUniversity of São PauloSão PauloBrazil
| | - Carsten Wrenger
- Department of Parasitology, Institute of Biomedical SciencesUniversity of São PauloSão PauloBrazil
| | - Henning Ulrich
- Department of BiochemistryInstitute of Chemistry, University of São PauloSão PauloBrazil
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14
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Coban C. The host targeting effect of chloroquine in malaria. Curr Opin Immunol 2020; 66:98-107. [PMID: 32823144 PMCID: PMC7431399 DOI: 10.1016/j.coi.2020.07.005] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Revised: 07/21/2020] [Accepted: 07/21/2020] [Indexed: 01/07/2023]
Abstract
Due to the rapid onset and spread of the COVID-19 pandemic, the treatment of COVID-19 patients by hydroxychloroquine alone or in combination with other drugs has captured a great deal of attention and triggered considerable debate. Historically, the worldwide use of quinoline based-drugs has led to a spectacular reduction in death from malaria. Unfortunately, scientists have been forced to seek alternative drugs to treat malaria due to the emergence of chloroquine-resistant parasites in the 1960s. The repurposing of hydroxychloroquine against viral infections, various types of cancer and autoimmune diseases has been ongoing for more than 70 years, with no clear understanding of its mechanism of action (MOA). Here, we closely examine the MOA of this old but influential drug in and beyond malaria. Better insights into how chloroquine targets the host's cellular and immune responses may help to develop applications against to new pathogens and diseases, and perhaps even restore the clinical utility of chloroquine against malaria.
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Affiliation(s)
- Cevayir Coban
- Division of Malaria Immunology, Department of Microbiology and Immunology, The Institute of Medical Science (IMSUT), The University of Tokyo, Tokyo, Japan; Laboratory of Malaria Immunology, Immunology Frontier Research Center (IFReC), Osaka University, Osaka, Japan.
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15
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Joshi MC, Egan TJ. Quinoline Containing Side-chain Antimalarial Analogs: Recent Advances and Therapeutic Application. Curr Top Med Chem 2020; 20:617-697. [DOI: 10.2174/1568026620666200127141550] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Revised: 10/25/2019] [Accepted: 10/30/2019] [Indexed: 01/16/2023]
Abstract
The side-chains of quinoline antimalarial agents are the major concern of focus to build
novel and efficaciaous bioactive and clinical antimalarials. Bioative antimalarial analogs may play a
critical role in pH trapping in the food vacuole of RBC’s with the help of fragmented amino acid, thus
lead to β-hematin inhibition. Here, the authors tried to summarize a useful, comprehensive compilation
of side-chain modified ACQs along with their synthesis, biophysical and therapeutic applications etc.
of potent antiplasmodial agents and therefore, opening the door towards the potential clinical status.
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Affiliation(s)
- Mukesh C. Joshi
- Department of Chemistry, Motilal Nehru College, Benito Juarez Marg, South Campus, University of Delhi, New Delhi- 110021, India
| | - Timothy J. Egan
- Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa
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16
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de Sousa ACC, Maepa K, Combrinck JM, Egan TJ. Lapatinib, Nilotinib and Lomitapide Inhibit Haemozoin Formation in Malaria Parasites. Molecules 2020; 25:molecules25071571. [PMID: 32235391 PMCID: PMC7180468 DOI: 10.3390/molecules25071571] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Revised: 03/25/2020] [Accepted: 03/25/2020] [Indexed: 12/20/2022] Open
Abstract
With the continued loss of antimalarials to resistance, drug repositioning may have a role in maximising efficiency and accelerating the discovery of new antimalarial drugs. Bayesian statistics was previously used as a tool to virtually screen USFDA approved drugs for predicted β-haematin (synthetic haemozoin) inhibition and in vitro antimalarial activity. Here, we report the experimental evaluation of nine of the highest ranked drugs, confirming the accuracy of the model by showing an overall 93% hit rate. Lapatinib, nilotinib, and lomitapide showed the best activity for inhibition of β-haematin formation and parasite growth and were found to inhibit haemozoin formation in the parasite, providing mechanistic insights into their mode of antimalarial action. We then screened the USFDA approved drugs for binding to the β-haematin crystal, applying a docking method in order to evaluate its performance. The docking method correctly identified imatinib, lapatinib, nilotinib, and lomitapide. Experimental evaluation of 22 of the highest ranked purchasable drugs showed a 24% hit rate. Lapatinib and nilotinib were chosen as templates for shape and electrostatic similarity screening for lead hopping using the in-stock ChemDiv compound catalogue. The actives were novel structures worthy of future investigation. This study presents a comparison of different in silico methods to identify new haemozoin-inhibiting chemotherapeutic alternatives for malaria that proved to be useful in different ways when taking into consideration their strengths and limitations.
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Affiliation(s)
- Ana Carolina C. de Sousa
- Department of Chemistry, Faculty of Science, University of Cape Town, Rondebosch 7701, South Africa;
| | - Keletso Maepa
- Department of Medicine, Division of Pharmacology, Faculty of Health Sciences, University of Cape Town, Observatory 7925, South Africa; (K.M.); (J.M.C.)
| | - Jill M. Combrinck
- Department of Medicine, Division of Pharmacology, Faculty of Health Sciences, University of Cape Town, Observatory 7925, South Africa; (K.M.); (J.M.C.)
- Institute of Infectious Disease and Molecular Medicine, Wellcome Centre for Infectious Diseases Research in Africa, Faculty of Health Sciences, University of Cape Town, Observatory 7925, South Africa
| | - Timothy J. Egan
- Department of Chemistry, Faculty of Science, University of Cape Town, Rondebosch 7701, South Africa;
- Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Rondebosch 7701, South Africa
- Correspondence:
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17
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Virtual screening as a tool to discover new β-haematin inhibitors with activity against malaria parasites. Sci Rep 2020; 10:3374. [PMID: 32099045 PMCID: PMC7042288 DOI: 10.1038/s41598-020-60221-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Accepted: 02/10/2020] [Indexed: 12/24/2022] Open
Abstract
Malaria remains a major public health problem. With the loss of antimalarials to resistance, the malaria burden will likely continue for decades. New antimalarial scaffolds are crucial to avoid cross-resistance. Here, we present the first structure based virtual screening using the β-haematin crystal as a target for new inhibitor scaffolds by applying a docking method. The ZINC15 database was searched for compounds with high binding affinity with the surface of the β-haematin crystal using the PyRx Virtual Screening Tool. Top-ranked compounds predicted to interact with β-haematin were submitted to a second screen applying in silico toxicity and drug-likeness predictions using Osiris DataWarrior. Fifteen compounds were purchased for experimental testing. An NP-40 mediated β-haematin inhibition assay and parasite growth inhibition activity assay were performed. The benzoxazole moiety was found to be a promising scaffold for further development, showing intraparasitic haemozoin inhibition using a cellular haem fractionation assay causing a decrease in haemozoin in a dose dependent manner with a corresponding increase in exchangeable haem. A β-haematin inhibition hit rate of 73% was found, a large enrichment over random screening, demonstrating that virtual screening can be a useful and cost-effective approach in the search for new haemozoin inhibiting antimalarials.
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18
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Mode of action of quinoline antimalarial drugs in red blood cells infected by Plasmodium falciparum revealed in vivo. Proc Natl Acad Sci U S A 2019; 116:22946-22952. [PMID: 31659055 PMCID: PMC6859308 DOI: 10.1073/pnas.1910123116] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The most widely used antimalarial drugs belong to the quinoline family. The question of their mode of action has been open for centuries. It has been recently narrowed down to whether these drugs interfere with the process of crystallization of heme in the malaria parasite. To date, all studies of the drug action on heme crystals have been done either on model systems or on dried parasites, which yielded limited data and ambiguity. This study was done in actual parasites in their near-native environment, revealing the mode of action of these drugs in vivo. The approach adopted in this study can be extended to other families of antimalarial drugs, such as artemisinins, provided appropriate derivatives can be synthesized. The most widely used antimalarial drugs belong to the quinoline family. Their mode of action has not been characterized at the molecular level in vivo. We report the in vivo mode of action of a bromo analog of the drug chloroquine in rapidly frozen Plasmodium falciparum-infected red blood cells. The Plasmodium parasite digests hemoglobin, liberating the heme as a byproduct, toxic to the parasite. It is detoxified by crystallization into inert hemozoin within the parasitic digestive vacuole. By mapping such infected red blood cells with nondestructive X-ray microscopy, we observe that bromoquine caps hemozoin crystals. The measured crystal surface coverage is sufficient to inhibit further hemozoin crystal growth, thereby sabotaging heme detoxification. Moreover, we find that bromoquine accumulates in the digestive vacuole, reaching submillimolar concentration, 1,000-fold more than that of the drug in the culture medium. Such a dramatic increase in bromoquine concentration enhances the drug’s efficiency in depriving heme from docking onto the hemozoin crystal surface. Based on direct observation of bromoquine distribution in the digestive vacuole and at its membrane surface, we deduce that the excess bromoquine forms a complex with the remaining heme deprived from crystallization. This complex is driven toward the digestive vacuole membrane, increasing the chances of membrane puncture and spillage of heme into the interior of the parasite.
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19
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Schloetel JG, Heine J, Cowman AF, Pasternak M. Guided STED nanoscopy enables super-resolution imaging of blood stage malaria parasites. Sci Rep 2019; 9:4674. [PMID: 30886187 PMCID: PMC6423018 DOI: 10.1038/s41598-019-40718-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Accepted: 02/19/2019] [Indexed: 12/27/2022] Open
Abstract
Malaria remains a major burden world-wide, but the disease-causing parasites from the genus Plasmodium are difficult to study in vitro. Owing to the small size of the parasites, subcellular imaging poses a major challenge and the use of super-resolution techniques has been hindered by the parasites' sensitivity to light. This is particularly apparent during the blood-stage of the Plasmodium life cycle, which presents an important target for drug research. The iron-rich food vacuole of the parasite undergoes disintegration when illuminated with high-power lasers such as those required for high resolution in Stimulated Emission Depletion (STED) microscopy. This causes major damage to the sample precluding the use of this super-resolution technique. Here we present guided STED, a novel adaptive illumination (AI) STED approach, which takes advantage of the highly-reflective nature of the iron deposit in the cell to identify the most light-sensitive parts of the sample. Specifically in these parts, the high-power STED laser is deactivated automatically to prevent local damage. Guided STED nanoscopy finally allows super-resolution imaging of the whole Plasmodium life cycle, enabling multicolour imaging of blood-stage malaria parasites with resolutions down to 35 nm without sample destruction.
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Affiliation(s)
| | - Jörn Heine
- Abberior Instruments GmbH, 37077, Göttingen, Germany
| | - Alan F Cowman
- Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
- Department of Medical Biology, University of Melbourne, Parkville, Victoria, Australia
| | - Michał Pasternak
- Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia.
- Department of Medical Biology, University of Melbourne, Parkville, Victoria, Australia.
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20
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Resistance to Artemisinin Combination Therapies (ACTs): Do Not Forget the Partner Drug! Trop Med Infect Dis 2019; 4:tropicalmed4010026. [PMID: 30717149 PMCID: PMC6473515 DOI: 10.3390/tropicalmed4010026] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2018] [Revised: 01/30/2019] [Accepted: 01/30/2019] [Indexed: 01/30/2023] Open
Abstract
Artemisinin-based combination therapies (ACTs) have become the mainstay for malaria treatment in almost all malaria endemic settings. Artemisinin derivatives are highly potent and fast acting antimalarials; but they have a short half-life and need to be combined with partner drugs with a longer half-life to clear the remaining parasites after a standard 3-day ACT regimen. When introduced, ACTs were highly efficacious and contributed to the steep decrease of malaria over the last decades. However, parasites with decreased susceptibility to artemisinins have emerged in the Greater Mekong Subregion (GMS), followed by ACTs’ failure, due to both decreased susceptibility to artemisinin and partner drug resistance. Therefore, there is an urgent need to strengthen and expand current resistance surveillance systems beyond the GMS to track the emergence or spread of artemisinin resistance. Great attention has been paid to the spread of artemisinin resistance over the last five years, since molecular markers of decreased susceptibility to artemisinin in the GMS have been discovered. However, resistance to partner drugs is critical, as ACTs can still be effective against parasites with decreased susceptibility to artemisinins, when the latter are combined with a highly efficacious partner drug. This review outlines the different mechanisms of resistance and molecular markers associated with resistance to partner drugs for the currently used ACTs. Strategies to improve surveillance and potential solutions to extend the useful therapeutic lifespan of the currently available malaria medicines are proposed.
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21
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L'abbate FP, Müller R, Openshaw R, Combrinck JM, de Villiers KA, Hunter R, Egan TJ. Hemozoin inhibiting 2-phenylbenzimidazoles active against malaria parasites. Eur J Med Chem 2018; 159:243-254. [PMID: 30296683 DOI: 10.1016/j.ejmech.2018.09.060] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Revised: 09/22/2018] [Accepted: 09/24/2018] [Indexed: 12/23/2022]
Abstract
The 2-phenylbenzimidazole scaffold has recently been discovered to inhibit β-hematin (synthetic hemozoin) formation by high throughput screening. Here, a library of 325,728 N-4-(1H-benzo[d]imidazol-2-yl)aryl)benzamides was enumerated, and Bayesian statistics used to predict β-hematin and Plasmodium falciparum growth inhibition. Filtering predicted inactives and compounds with negligible aqueous solubility reduced the library to 35,124. Further narrowing to compounds with terminal aryl ring substituents only, reduced the library to 18, 83% of which were found to inhibit β-hematin formation <100 μM and 50% parasite growth <2 μM. Four compounds showed nanomolar parasite growth inhibition activities, no cross-resistance in a chloroquine resistant strain and low cytotoxicity. QSAR analysis showed a strong association of parasite growth inhibition with inhibition of β-hematin formation and the most active compound inhibited hemozoin formation in P. falciparum, with consequent increasing exchangeable heme. Pioneering use of molecular docking for this system demonstrated predictive ability and could rationalize observed structure activity trends.
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Affiliation(s)
- Fabrizio P L'abbate
- Department of Chemistry, University of Cape Town, Rondebosch, 7701, South Africa
| | - Ronel Müller
- Department of Chemistry and Polymer Science, Stellenbosch University, Private Bag X1, Matieland, 7602, South Africa
| | - Roxanne Openshaw
- Department of Chemistry, University of Cape Town, Rondebosch, 7701, South Africa
| | - Jill M Combrinck
- Department of Medicine, Division of Clinical Pharmacology, University of Cape Town, Observatory, 7925, South Africa
| | - Katherine A de Villiers
- Department of Chemistry and Polymer Science, Stellenbosch University, Private Bag X1, Matieland, 7602, South Africa
| | - Roger Hunter
- Department of Chemistry, University of Cape Town, Rondebosch, 7701, South Africa
| | - Timothy J Egan
- Department of Chemistry, University of Cape Town, Rondebosch, 7701, South Africa; Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Rondebosch, 7701, South Africa.
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