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Okutani A, Morikawa S, Maeda K. Green Tea Catechin Epigallocatechin Gallate Inhibits Vegetative Cell Outgrowth and Expression of Beta-Lactamase Genes in Penicillin-Resistant Bacillus anthracis Strain PCr. Pathogens 2024; 13:699. [PMID: 39204299 PMCID: PMC11356866 DOI: 10.3390/pathogens13080699] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2024] [Revised: 08/14/2024] [Accepted: 08/19/2024] [Indexed: 09/04/2024] Open
Abstract
The green tea catechin epigallocatechin gallate (EGCg) has antimicrobial effects on many bacteria. In this study, we investigated the inhibitory effects of EGCg on Bacillus anthracis spores and vegetative cells. The B. anthracis spores were insensitive to EGCg, but the growth of vegetative cells derived from germinated spores was inhibited by EGCg. Moreover, EGCg decreased the minimum inhibitory concentration of penicillin and meropenem for penicillin-resistant B. anthracis. In the penicillin-resistant B. anthracis strain, the transcription levels of the beta-lactamase genes (bla1 and bla2) decreased significantly following the treatment with 50 µg/mL EGCg. These results suggest that the appropriate application of EGCg may effectively control the penicillin-resistant B. anthracis growth and beta-lactamase production.
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Affiliation(s)
- Akiko Okutani
- Department of Veterinary Science, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku-ku, Tokyo 162-8640, Japan; (S.M.); (K.M.)
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Elfawy LA, Ng CY, Amirrah IN, Mazlan Z, Wen APY, Fadilah NIM, Maarof M, Lokanathan Y, Fauzi MB. Sustainable Approach of Functional Biomaterials-Tissue Engineering for Skin Burn Treatment: A Comprehensive Review. Pharmaceuticals (Basel) 2023; 16:ph16050701. [PMID: 37242483 DOI: 10.3390/ph16050701] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Revised: 04/21/2023] [Accepted: 04/25/2023] [Indexed: 05/28/2023] Open
Abstract
Burns are a widespread global public health traumatic injury affecting many people worldwide. Non-fatal burn injuries are a leading cause of morbidity, resulting in prolonged hospitalization, disfigurement, and disability, often with resulting stigma and rejection. The treatment of burns is aimed at controlling pain, removing dead tissue, preventing infection, reducing scarring risk, and tissue regeneration. Traditional burn wound treatment methods include the use of synthetic materials such as petroleum-based ointments and plastic films. However, these materials can be associated with negative environmental impacts and may not be biocompatible with the human body. Tissue engineering has emerged as a promising approach to treating burns, and sustainable biomaterials have been developed as an alternative treatment option. Green biomaterials such as collagen, cellulose, chitosan, and others are biocompatible, biodegradable, environment-friendly, and cost-effective, which reduces the environmental impact of their production and disposal. They are effective in promoting wound healing and reducing the risk of infection and have other benefits such as reducing inflammation and promoting angiogenesis. This comprehensive review focuses on the use of multifunctional green biomaterials that have the potential to revolutionize the way we treat skin burns, promoting faster and more efficient healing while minimizing scarring and tissue damage.
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Affiliation(s)
- Loai A Elfawy
- Centre for Tissue Engineering and Regenerative Medicine, Faculty of Medicine, University Kebangsaan Malaysia, Kuala Lumpur 56000, Malaysia
| | - Chiew Yong Ng
- Centre for Tissue Engineering and Regenerative Medicine, Faculty of Medicine, University Kebangsaan Malaysia, Kuala Lumpur 56000, Malaysia
| | - Ibrahim N Amirrah
- Centre for Tissue Engineering and Regenerative Medicine, Faculty of Medicine, University Kebangsaan Malaysia, Kuala Lumpur 56000, Malaysia
| | - Zawani Mazlan
- Centre for Tissue Engineering and Regenerative Medicine, Faculty of Medicine, University Kebangsaan Malaysia, Kuala Lumpur 56000, Malaysia
| | - Adzim Poh Yuen Wen
- Centre for Tissue Engineering and Regenerative Medicine, Faculty of Medicine, University Kebangsaan Malaysia, Kuala Lumpur 56000, Malaysia
- Department of Surgery, Hospital Canselor Tuanku Muhriz, Universiti Kebangsaan Malaysia, Kuala Lumpur 56000, Malaysia
| | - Nur Izzah Md Fadilah
- Centre for Tissue Engineering and Regenerative Medicine, Faculty of Medicine, University Kebangsaan Malaysia, Kuala Lumpur 56000, Malaysia
| | - Manira Maarof
- Centre for Tissue Engineering and Regenerative Medicine, Faculty of Medicine, University Kebangsaan Malaysia, Kuala Lumpur 56000, Malaysia
| | - Yogeswaran Lokanathan
- Centre for Tissue Engineering and Regenerative Medicine, Faculty of Medicine, University Kebangsaan Malaysia, Kuala Lumpur 56000, Malaysia
| | - Mh Busra Fauzi
- Centre for Tissue Engineering and Regenerative Medicine, Faculty of Medicine, University Kebangsaan Malaysia, Kuala Lumpur 56000, Malaysia
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Díaz-Núñez JL, Pérez-López M, Espinosa N, Campos-Hernández N, García-Contreras R, Díaz-Guerrero M, Cortes-López H, Vázquez-Sánchez M, Quezada H, Martínez-Vázquez M, Soto-Hernández RM, Burgos-Hernández M, González-Pedrajo B, Castillo-Juárez I. Anti-Virulence Properties of Plant Species: Correlation between In Vitro Activity and Efficacy in a Murine Model of Bacterial Infection. Microorganisms 2021; 9:2424. [PMID: 34946027 PMCID: PMC8706108 DOI: 10.3390/microorganisms9122424] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2021] [Revised: 11/13/2021] [Accepted: 11/15/2021] [Indexed: 11/17/2022] Open
Abstract
Several plant extracts exhibit anti-virulence properties due to the interruption of bacterial quorum sensing (QS). However, studies on their effects at the preclinical level are scarce. Here, we used a murine model of abscess/necrosis induced by Pseudomonas aeruginosa to evaluate the anti-pathogenic efficacy of 24 plant extracts at a sub-inhibitory concentration. We analyzed their ability to inhibit QS-regulated virulence factors such as swarming, pyocyanin production, and secretion of the ExoU toxin via the type III secretion system (T3SS). Five of the seven extracts with the best anti-pathogenic activity reduced ExoU secretion, and the extracts of Diphysa americana and Hibiscus sabdariffa were identified as the most active. Therefore, the abscess/necrosis model allows identification of plant extracts that have the capacity to reduce pathogenicity of P. aeruginosa. Furthermore, we evaluated the activity of the plant extracts on Chromobacterium violaceum. T3SS (ΔescU) and QS (ΔcviI) mutant strains were assessed in both the abscess/necrosis and sepsis models. Only the ΔescU strain had lower pathogenicity in the animal models, although no activity of plant extracts was observed. These results demonstrate differences between the anti-virulence activity recorded in vitro and pathogenicity in vivo and between the roles of QS and T3S systems as virulence determinants.
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Affiliation(s)
- José Luis Díaz-Núñez
- Laboratorio de Fitoquímica, Posgrado de Botánica, Colegio de Postgraduados, Texcoco 56230, Mexico; (J.L.D.-N.); (M.P.-L.); (N.C.-H.); (H.C.-L.); (M.V.-S.); (R.M.S.-H.); (M.B.-H.)
| | - Macrina Pérez-López
- Laboratorio de Fitoquímica, Posgrado de Botánica, Colegio de Postgraduados, Texcoco 56230, Mexico; (J.L.D.-N.); (M.P.-L.); (N.C.-H.); (H.C.-L.); (M.V.-S.); (R.M.S.-H.); (M.B.-H.)
| | - Norma Espinosa
- Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Ciudad de México 04510, Mexico; (N.E.); (M.D.-G.)
| | - Nayelli Campos-Hernández
- Laboratorio de Fitoquímica, Posgrado de Botánica, Colegio de Postgraduados, Texcoco 56230, Mexico; (J.L.D.-N.); (M.P.-L.); (N.C.-H.); (H.C.-L.); (M.V.-S.); (R.M.S.-H.); (M.B.-H.)
| | - Rodolfo García-Contreras
- Departamento de Microbiología y Parasitología, Facultad de Medicina, Universidad Nacional Autónoma de México, Ciudad de México 04510, Mexico;
| | - Miguel Díaz-Guerrero
- Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Ciudad de México 04510, Mexico; (N.E.); (M.D.-G.)
| | - Humberto Cortes-López
- Laboratorio de Fitoquímica, Posgrado de Botánica, Colegio de Postgraduados, Texcoco 56230, Mexico; (J.L.D.-N.); (M.P.-L.); (N.C.-H.); (H.C.-L.); (M.V.-S.); (R.M.S.-H.); (M.B.-H.)
| | - Monserrat Vázquez-Sánchez
- Laboratorio de Fitoquímica, Posgrado de Botánica, Colegio de Postgraduados, Texcoco 56230, Mexico; (J.L.D.-N.); (M.P.-L.); (N.C.-H.); (H.C.-L.); (M.V.-S.); (R.M.S.-H.); (M.B.-H.)
| | - Héctor Quezada
- Laboratorio de Investigación en Inmunología y Proteómica, Hospital Infantil de México Federico Gómez, Ciudad de México 06720, Mexico;
| | - Mariano Martínez-Vázquez
- Departamento de Productos Naturales, Instituto de Química, Universidad Nacional Autόnoma de México, Ciudad de México 04510, Mexico;
| | - Ramón Marcos Soto-Hernández
- Laboratorio de Fitoquímica, Posgrado de Botánica, Colegio de Postgraduados, Texcoco 56230, Mexico; (J.L.D.-N.); (M.P.-L.); (N.C.-H.); (H.C.-L.); (M.V.-S.); (R.M.S.-H.); (M.B.-H.)
| | - Mireya Burgos-Hernández
- Laboratorio de Fitoquímica, Posgrado de Botánica, Colegio de Postgraduados, Texcoco 56230, Mexico; (J.L.D.-N.); (M.P.-L.); (N.C.-H.); (H.C.-L.); (M.V.-S.); (R.M.S.-H.); (M.B.-H.)
| | - Bertha González-Pedrajo
- Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Ciudad de México 04510, Mexico; (N.E.); (M.D.-G.)
| | - Israel Castillo-Juárez
- Laboratorio de Fitoquímica, Posgrado de Botánica, Colegio de Postgraduados, Texcoco 56230, Mexico; (J.L.D.-N.); (M.P.-L.); (N.C.-H.); (H.C.-L.); (M.V.-S.); (R.M.S.-H.); (M.B.-H.)
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Applications of Catechins in the Treatment of Bacterial Infections. Pathogens 2021; 10:pathogens10050546. [PMID: 34062722 PMCID: PMC8147231 DOI: 10.3390/pathogens10050546] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 04/26/2021] [Accepted: 04/27/2021] [Indexed: 01/08/2023] Open
Abstract
Tea is the second most commonly consumed beverage worldwide. Along with its aromatic and delicate flavors that make it an enjoyable beverage, studies report numerous health advantages in tea consumption, including applications in antimicrobial therapy. The antimicrobial properties of tea are related to catechin and its derivatives, which are natural flavonoids that are abundant in tea. Increasing evidence from in vitro studies demonstrated antimicrobial effects of catechins on both gram-positive and gram-negative bacteria, and proposed direct and indirect therapeutic mechanisms. Additionally, catechins were reported to be effective anti-virulence agents. Furthermore, a number of studies presented evidence that catechins display synergistic effects with certain antibiotics, thus potentiating the activity of antibiotics in resistant bacteria. Despite their numerous beneficial properties, catechins face many challenges in their development as therapeutic agents, including poor absorption, low bioavailability, and rapid degradation. The introduction of nanobiotechnology provides target-based and stable delivery, which enhances catechin bioavailability and optimizes drug efficacy. As further research continues to focus on overcoming the unresolved challenges, catechins are likely to see additional promising applications in our continual fight against bacterial infections.
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Noor N, Gani A, Gani A, Shah A, Ashraf ZU. Exploitation of polyphenols and proteins using nanoencapsulation for anti-viral and brain boosting properties - Evoking a synergistic strategy to combat COVID-19 pandemic. Int J Biol Macromol 2021; 180:375-384. [PMID: 33716131 PMCID: PMC7946821 DOI: 10.1016/j.ijbiomac.2021.03.028] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 01/31/2021] [Accepted: 03/04/2021] [Indexed: 12/16/2022]
Abstract
The world is currently under the threat of COVID pandemic and has focused every dimension of research in finding a cure to this novel disease. In this current situation, people are facing mental stress, agony, fear, depression and other associated symptoms which are taking a toll on their overall mental health. Nanoencapsulation of certain brain boosting polyphenols including quercetin, caffeine, cocoa flavanols and proteins like lectins can become new area of interest in the present scenario. Besides the brain boosting benefits, we have also highlighted the anti- viral activities of these compounds which we assume can play a possible role in combating COVID-19 given to their previous history of action against certain viruses. This review outlines the nanoencapsulation approaches of such synergistic compounds as a novel strategy to take the ongoing research a step ahead and also provides a new insight in bringing the role of nanotechnology in addressing the issues related to COVID pandemic.
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Affiliation(s)
- Nairah Noor
- Laboratory of Functional Food and Nutraceuticals, Department of Food Science and Technology, University of Kashmir, Srinagar 190006, India
| | - Adil Gani
- Laboratory of Functional Food and Nutraceuticals, Department of Food Science and Technology, University of Kashmir, Srinagar 190006, India; Department of Food Science, Rutgers University, 65 Dudley Road, New Brunswick, NJ 08901, United States.
| | - Asir Gani
- Laboratory of Functional Food and Nutraceuticals, Department of Food Science and Technology, University of Kashmir, Srinagar 190006, India
| | - Asima Shah
- Laboratory of Functional Food and Nutraceuticals, Department of Food Science and Technology, University of Kashmir, Srinagar 190006, India
| | - Zanoor Ul Ashraf
- Laboratory of Functional Food and Nutraceuticals, Department of Food Science and Technology, University of Kashmir, Srinagar 190006, India
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Antileishmanial Activity of Lignans, Neolignans, and Other Plant Phenols. PROGRESS IN THE CHEMISTRY OF ORGANIC NATURAL PRODUCTS 2021; 115:115-176. [PMID: 33797642 DOI: 10.1007/978-3-030-64853-4_3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Secondary metabolites (SM) from organisms have served medicinal chemists over the past two centuries as an almost inexhaustible pool of new drugs, drug-like skeletons, and chemical probes that have been used in the "hunt" for new biologically active molecules with a "beneficial effect on human mind and body." Several secondary metabolites, or their derivatives, have been found to be the answer in the quest to search for new approaches to treat or even eradicate many types of diseases that oppress humanity. A special place among SM is occupied by lignans and neolignans. These phenolic compounds are generated biosynthetically via radical coupling of two phenylpropanoid monomers, and are known for their multitarget activity and low toxicity. The disadvantage of the relatively low specificity of phenylpropanoid-based SM turns into an advantage when structural modifications of these skeletons are made. Indeed, phenylpropanoid-based SM previously have proven to offer great potential as a starting point in drug development. Compounds such as Warfarin® (a coumarin-based anticoagulant) as well as etoposide and teniposide (podophyllotoxin-based anticancer drugs) are just a few examples. At the beginning of the third decade of the twenty-first century, the call for the treatment of more than a dozen rare or previously "neglected" diseases remains for various reasons unanswered. Leishmaniasis, a neglected disease that desperately needs new ways of treatment, is just one of these. This disease is caused by more than 20 leishmanial parasites that are pathogenic to humans and are spread by as many as 800 sandfly species across subtropical areas of the world. With continuing climate changes, the presence of Leishmania parasites and therefore leishmaniasis, the disease caused by these parasites, is spreading from previous locations to new areas. Thus, leishmaniasis is affecting each year a larger proportion of the world's population. The choice of appropriate leishmaniasis treatment depends on the severity of the disease and its form of manifestation. The success of current drug therapy is often limited, due in most cases to requiring long hospitalization periods (weeks to months) and the toxicity (side effects) of administered drugs, in addition to the increasing resistance of the parasites to treatment. It is thus important to develop new drugs and treatments that are less toxic, can overcome drug resistance, and require shorter periods of treatment. These aspects are especially important for the populations of developing countries. It was reported that several phenylpropanoid-based secondary metabolites manifest interesting antileishmanial activities and are used by various indigenous people to treat leishmaniasis. In this chapter, the authors shed some light on the various biological activities of phenylpropanoid natural products, with the main focus being on their possible applications in the context of antileishmanial treatment.
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Lee SC, Yoon MY. Development of a receptor-based inhibitory penta-unit-conjugated peptide to enhance anthrax toxin neutralization. Int J Biol Macromol 2020; 163:327-335. [PMID: 32619663 DOI: 10.1016/j.ijbiomac.2020.06.264] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2020] [Revised: 06/26/2020] [Accepted: 06/28/2020] [Indexed: 12/21/2022]
Abstract
Anthrax toxin is a key virulence factor for Bacillus anthracis. The cell-binding component of anthrax toxin, protective antigen (PA), mediates the entry of the toxin into cells by first binding to the extracellular von Willebrand factor A (VWA) domain of the cellular anthrax toxin receptor (ATR). Herein, we targeted the VWA domain of the cellular receptor to develop a more effective antitoxin agent for neutralization of anthrax toxin. We selected ATR-binding peptides by using a phage display: among these, we identified two novel peptides binding to the ATR with high affinity and specificity, and that neutralized anthrax toxicity in cells. Furthermore, to enhance the functional efficiency of the probes, the peptides were modified and conjugated to three polyvalent probe backbones: a 17 amino-acid-based cyclic form penta-unit, poly-d-lysine (PDL), or the M13 bacteriophage. One of the functionally modified polyvalent peptide probes, the penta-unit-conjugated probe (PUCP) produced the most potent neutralization of anthrax toxin, with half-maximal inhibitory concentration (IC50) of 20 nM. The PUCP disrupted anthrax toxin binding to its receptor and reduced endocytosis of anthrax toxin. This peptide-based approach may, therefore, represent a promising strategy to combat anthrax toxicosis and other bacterial diseases and may be efficient for disease treatment.
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Affiliation(s)
- Sang-Choon Lee
- Department of Chemistry, Georgia State University, Atlanta, GA 30303, USA.
| | - Moon-Young Yoon
- Department of Chemistry and Research Institute for Natural Sciences, Hanyang University, Seoul 04763, Republic of Korea.
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Omersa N, Podobnik M, Anderluh G. Inhibition of Pore-Forming Proteins. Toxins (Basel) 2019; 11:E545. [PMID: 31546810 PMCID: PMC6784129 DOI: 10.3390/toxins11090545] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Revised: 08/27/2019] [Accepted: 09/10/2019] [Indexed: 12/16/2022] Open
Abstract
Perforation of cellular membranes by pore-forming proteins can affect cell physiology, tissue integrity, or immune response. Since many pore-forming proteins are toxins or highly potent virulence factors, they represent an attractive target for the development of molecules that neutralize their actions with high efficacy. There has been an assortment of inhibitors developed to specifically obstruct the activity of pore-forming proteins, in addition to vaccination and antibiotics that serve as a plausible treatment for the majority of diseases caused by bacterial infections. Here we review a wide range of potential inhibitors that can specifically and effectively block the activity of pore-forming proteins, from small molecules to more specific macromolecular systems, such as synthetic nanoparticles, antibodies, antibody mimetics, polyvalent inhibitors, and dominant negative mutants. We discuss their mechanism of inhibition, as well as advantages and disadvantages.
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Affiliation(s)
- Neža Omersa
- Department of Molecular Biology and Nanobiotechnology, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana, Slovenia.
| | - Marjetka Podobnik
- Department of Molecular Biology and Nanobiotechnology, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana, Slovenia.
| | - Gregor Anderluh
- Department of Molecular Biology and Nanobiotechnology, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana, Slovenia.
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Chen AY, Adamek RN, Dick BL, Credille CV, Morrison CN, Cohen SM. Targeting Metalloenzymes for Therapeutic Intervention. Chem Rev 2019; 119:1323-1455. [PMID: 30192523 PMCID: PMC6405328 DOI: 10.1021/acs.chemrev.8b00201] [Citation(s) in RCA: 161] [Impact Index Per Article: 32.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Metalloenzymes are central to a wide range of essential biological activities, including nucleic acid modification, protein degradation, and many others. The role of metalloenzymes in these processes also makes them central for the progression of many diseases and, as such, makes metalloenzymes attractive targets for therapeutic intervention. Increasing awareness of the role metalloenzymes play in disease and their importance as a class of targets has amplified interest in the development of new strategies to develop inhibitors and ultimately useful drugs. In this Review, we provide a broad overview of several drug discovery efforts focused on metalloenzymes and attempt to map out the current landscape of high-value metalloenzyme targets.
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Affiliation(s)
- Allie Y Chen
- Department of Chemistry and Biochemistry , University of California, San Diego , La Jolla , California 92093 , United States
| | - Rebecca N Adamek
- Department of Chemistry and Biochemistry , University of California, San Diego , La Jolla , California 92093 , United States
| | - Benjamin L Dick
- Department of Chemistry and Biochemistry , University of California, San Diego , La Jolla , California 92093 , United States
| | - Cy V Credille
- Department of Chemistry and Biochemistry , University of California, San Diego , La Jolla , California 92093 , United States
| | - Christine N Morrison
- Department of Chemistry and Biochemistry , University of California, San Diego , La Jolla , California 92093 , United States
| | - Seth M Cohen
- Department of Chemistry and Biochemistry , University of California, San Diego , La Jolla , California 92093 , United States
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Falcinelli SD, Shi MC, Friedlander AM, Chua J. Green tea and epigallocatechin-3-gallate are bactericidal against Bacillus anthracis. FEMS Microbiol Lett 2018; 364:3866595. [PMID: 28605495 DOI: 10.1093/femsle/fnx127] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Accepted: 06/09/2017] [Indexed: 01/19/2023] Open
Abstract
Bacillus anthracis, the etiological agent of anthrax, is listed as a category A biothreat agent by the United States Centers for Disease Control and Prevention. The virulence of the organism is due to expression of two exotoxins and capsule, which interfere with host cellular signaling, alter host water homeostasis and inhibit phagocytosis of the pathogen, respectively. Concerns regarding the past and possible future use of B. anthracis as a bioterrorism agent have resulted in an impetus to develop more effective protective measures and therapeutics. In this study, green tea was found to inhibit the in vitro growth of B. anthracis. Epigallocatechin-3-gallate (EGCG), a compound found abundantly in green tea, was shown to be responsible for this activity. EGCG was bactericidal against both the attenuated B. anthracis ANR and the virulent encapsulated B. anthracis Ames strain. This study highlights the antimicrobial activity of green tea and EGCG against anthrax and suggests the need for further investigation of EGCG as a therapeutic candidate against B. anthracis.
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Affiliation(s)
- Shane D Falcinelli
- Bacteriology Division, United States Army Medical Research Institute of Infectious Diseases, Frederick, MD 21702, USA
| | - Maggie C Shi
- Bacteriology Division, United States Army Medical Research Institute of Infectious Diseases, Frederick, MD 21702, USA
| | - Arthur M Friedlander
- Bacteriology Division, United States Army Medical Research Institute of Infectious Diseases, Frederick, MD 21702, USA.,Department of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA
| | - Jennifer Chua
- Bacteriology Division, United States Army Medical Research Institute of Infectious Diseases, Frederick, MD 21702, USA
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11
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Affiliation(s)
- Megan Garland
- Cancer
Biology Program, ‡Department of Pathology, §Department of Microbiology and Immunology, and ∥Department of
Chemical and Systems Biology, Stanford University School of Medicine, 300 Pasteur Drive, Stanford, California 94305, United States
| | - Sebastian Loscher
- Cancer
Biology Program, ‡Department of Pathology, §Department of Microbiology and Immunology, and ∥Department of
Chemical and Systems Biology, Stanford University School of Medicine, 300 Pasteur Drive, Stanford, California 94305, United States
| | - Matthew Bogyo
- Cancer
Biology Program, ‡Department of Pathology, §Department of Microbiology and Immunology, and ∥Department of
Chemical and Systems Biology, Stanford University School of Medicine, 300 Pasteur Drive, Stanford, California 94305, United States
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12
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Dyer PD, Kotha AK, Gollings AS, Shorter SA, Shepherd TR, Pettit MW, Alexander BD, Getti GT, El-Daher S, Baillie L, Richardson SC. An in vitro evaluation of epigallocatechin gallate (eGCG) as a biocompatible inhibitor of ricin toxin. Biochim Biophys Acta Gen Subj 2016; 1860:1541-50. [DOI: 10.1016/j.bbagen.2016.03.024] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2015] [Revised: 03/10/2016] [Accepted: 03/20/2016] [Indexed: 10/22/2022]
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13
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Ambrose EA. Botulinum Neurotoxin, Tetanus Toxin, and Anthrax Lethal Factor Countermeasures. TOPICS IN MEDICINAL CHEMISTRY 2016. [DOI: 10.1007/7355_2016_8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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14
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Zhang X, Amin EA. Highly predictive support vector machine (SVM) models for anthrax toxin lethal factor (LF) inhibitors. J Mol Graph Model 2016; 63:22-8. [PMID: 26615468 PMCID: PMC4713341 DOI: 10.1016/j.jmgm.2015.11.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Revised: 10/07/2015] [Accepted: 11/06/2015] [Indexed: 01/08/2023]
Abstract
Anthrax is a highly lethal, acute infectious disease caused by the rod-shaped, Gram-positive bacterium Bacillus anthracis. The anthrax toxin lethal factor (LF), a zinc metalloprotease secreted by the bacilli, plays a key role in anthrax pathogenesis and is chiefly responsible for anthrax-related toxemia and host death, partly via inactivation of mitogen-activated protein kinase kinase (MAPKK) enzymes and consequent disruption of key cellular signaling pathways. Antibiotics such as fluoroquinolones are capable of clearing the bacilli but have no effect on LF-mediated toxemia; LF itself therefore remains the preferred target for toxin inactivation. However, currently no LF inhibitor is available on the market as a therapeutic, partly due to the insufficiency of existing LF inhibitor scaffolds in terms of efficacy, selectivity, and toxicity. In the current work, we present novel support vector machine (SVM) models with high prediction accuracy that are designed to rapidly identify potential novel, structurally diverse LF inhibitor chemical matter from compound libraries. These SVM models were trained and validated using 508 compounds with published LF biological activity data and 847 inactive compounds deposited in the Pub Chem BioAssay database. One model, M1, demonstrated particularly favorable selectivity toward highly active compounds by correctly predicting 39 (95.12%) out of 41 nanomolar-level LF inhibitors, 46 (93.88%) out of 49 inactives, and 844 (99.65%) out of 847 Pub Chem inactives in external, unbiased test sets. These models are expected to facilitate the prediction of LF inhibitory activity for existing molecules, as well as identification of novel potential LF inhibitors from large datasets.
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Affiliation(s)
- Xia Zhang
- Department of Medicinal Chemistry, College of Pharmacy, University of Minnesota, 717 Delaware St. SE, Minneapolis, MN 55414-2959, United States
| | - Elizabeth Ambrose Amin
- Department of Medicinal Chemistry, College of Pharmacy, University of Minnesota, 717 Delaware St. SE, Minneapolis, MN 55414-2959, United States; Minnesota Supercomputing Institute for Advanced Computational Research, 117 Pleasant St SE, Minneapolis, MN, United States.
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15
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Ahmad A, Kaleem M, Ahmed Z, Shafiq H. Therapeutic potential of flavonoids and their mechanism of action against microbial and viral infections—A review. Food Res Int 2015. [DOI: 10.1016/j.foodres.2015.06.021] [Citation(s) in RCA: 109] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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16
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Kurbanov EK, Chiu TL, Solberg J, Francis S, Maize KM, Fernandez J, Johnson RL, Hawkinson JE, Walters MA, Finzel BC, Amin EA. Probing the S2′ Subsite of the Anthrax Toxin Lethal Factor Using Novel N-Alkylated Hydroxamates. J Med Chem 2015; 58:8723-33. [DOI: 10.1021/acs.jmedchem.5b01446] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Elbek K. Kurbanov
- Department
of Medicinal Chemistry, University of Minnesota, Minneapolis, Minnesota 55414, United States
| | - Ting-Lan Chiu
- Department
of Medicinal Chemistry, University of Minnesota, Minneapolis, Minnesota 55414, United States
| | - Jonathan Solberg
- Institute
for Therapeutics Discovery and Development, University of Minnesota, Minneapolis, Minnesota 55414, United States
| | - Subhashree Francis
- Institute
for Therapeutics Discovery and Development, University of Minnesota, Minneapolis, Minnesota 55414, United States
| | - Kimberly M. Maize
- Department
of Medicinal Chemistry, University of Minnesota, Minneapolis, Minnesota 55414, United States
| | - Jenna Fernandez
- Department
of Medicinal Chemistry, University of Minnesota, Minneapolis, Minnesota 55414, United States
| | - Rodney L. Johnson
- Department
of Medicinal Chemistry, University of Minnesota, Minneapolis, Minnesota 55414, United States
| | - Jon E. Hawkinson
- Institute
for Therapeutics Discovery and Development, University of Minnesota, Minneapolis, Minnesota 55414, United States
| | - Michael A. Walters
- Institute
for Therapeutics Discovery and Development, University of Minnesota, Minneapolis, Minnesota 55414, United States
| | - Barry C. Finzel
- Department
of Medicinal Chemistry, University of Minnesota, Minneapolis, Minnesota 55414, United States
| | - Elizabeth Ambrose Amin
- Department
of Medicinal Chemistry, University of Minnesota, Minneapolis, Minnesota 55414, United States
- Minnesota
Supercomputing Institute for Advanced Computational Research, University of Minnesota, Minneapolis, Minnesota 55455, United States
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17
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Interactions between Autophagy and Bacterial Toxins: Targets for Therapy? Toxins (Basel) 2015; 7:2918-58. [PMID: 26248079 PMCID: PMC4549733 DOI: 10.3390/toxins7082918] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Revised: 07/27/2015] [Accepted: 07/28/2015] [Indexed: 01/07/2023] Open
Abstract
Autophagy is a physiological process involved in defense mechanisms for clearing intracellular bacteria. The autophagic pathway is finely regulated and bacterial toxins interact with this process in a complex manner. Bacterial toxins also interact significantly with many biochemical processes. Evaluations of the effects of bacterial toxins, such as endotoxins, pore-forming toxins and adenylate cyclases, on autophagy could support the development of new strategies for counteracting bacterial pathogenicity. Treatment strategies could focus on drugs that enhance autophagic processes to improve the clearance of intracellular bacteria. However, further in vivo studies are required to decipher the upregulation of autophagy and potential side effects limiting such approaches. The capacity of autophagy activation strategies to improve the outcome of antibiotic treatment should be investigated in the future.
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Ohanjanian L, Remy KE, Li Y, Cui X, Eichacker PQ. An overview of investigational toxin-directed therapies for the adjunctive management of Bacillus anthracis infection and sepsis. Expert Opin Investig Drugs 2015; 24:851-65. [PMID: 25920540 DOI: 10.1517/13543784.2015.1041587] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
INTRODUCTION Sepsis with Bacillus anthracis infection has a very high mortality rate despite appropriate antibiotic and supportive therapies. Over the past 15 years, recent outbreaks in the US and in Europe, coupled with anthrax's bioterrorism weapon potential, have stimulated efforts to develop adjunctive therapies to improve clinical outcomes. Since lethal toxin and edema toxin (LT and ET) make central contributions to the pathogenesis of B. anthracis, these have been major targets in this effort. AREAS COVERED Here, the authors review different investigative biopharmaceuticals that have been recently identified for their therapeutic potential as inhibitors of LT or ET. Among these inhibitors are two antibody preparations that have been included in the Strategic National Stockpile (SNS) and several more that have reached Phase I testing. Presently, however, many of these candidate agents have only been studied in vitro and very few tested in bacteria-challenged models. EXPERT OPINION Although a large number of drugs have been identified as potential therapeutic inhibitors of LT and ET, in most cases their testing has been limited. The use of the two SNS antibody therapies during a large-scale exposure to B. anthracis will be difficult. Further testing and development of agents with oral bioavailability and relatively long shelf lives should be a focus for future research.
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Affiliation(s)
- Lernik Ohanjanian
- National Institutes of Health, Clinical Center, Critical Care Medicine Department , Building 10, Room 2C145, Bethesda, MD 20892 , USA +1 301 402 2914 ; +1 301 402 1213 ;
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Abstract
Resistance of important bacterial pathogens to common antimicrobial therapies and the emergence of multidrug-resistant bacteria are increasing at an alarming rate and constitute one of our greatest challenges in the combat of bacterial infection and accompanied diseases. The current shortage of effective drugs, lack of successful prevention measures and only a few new antibiotics in the clinical pipeline demand the development of novel treatment options and alternative antimicrobial therapies. Our increasing understanding of bacterial virulence strategies and the induced molecular pathways of the infectious disease provides novel opportunities to target and interfere with crucial pathogenicity factors or virulence-associated traits of the bacteria while bypassing the evolutionary pressure on the bacterium to develop resistance. In the past decade, numerous new bacterial targets for anti-virulence therapies have been identified, and structure-based tailoring of intervention strategies and screening assays for small-molecule inhibitors of such pathways were successfully established. In this chapter, we will take a closer look at the bacterial virulence-related factors and processes that present promising targets for anti-virulence therapies, recently discovered inhibitory substances and their promises and discuss the challenges, and problems that have to be faced.
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Identification of exosite-targeting inhibitors of anthrax lethal factor by high-throughput screening. ACTA ACUST UNITED AC 2014; 19:875-82. [PMID: 22840775 DOI: 10.1016/j.chembiol.2012.05.013] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2012] [Revised: 05/10/2012] [Accepted: 05/17/2012] [Indexed: 12/24/2022]
Abstract
Protease inhibitor discovery has focused almost exclusively on compounds that bind to the active site. Inhibitors targeting protease exosites, regions outside of the active site that influence catalysis, offer potential advantages of increased specificity but are difficult to systematically discover. Here, we describe an assay suitable for detecting exosite-targeting inhibitors of the metalloproteinase anthrax lethal factor (LF) based on cleavage of a full-length mitogen-activated protein kinase kinase (MKK) substrate. We used this assay to screen a small-molecule library and then subjected hits to a secondary screen to exclude compounds that efficiently blocked cleavage of a peptide substrate. We identified a compound that preferentially inhibited cleavage of MKKs compared with peptide substrates and could suppress LF-induced macrophage cytolysis. This approach should be generally applicable to the discovery of exosite-targeting inhibitors of many additional proteases.
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21
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Bouzianas DG. Potential biological targets ofBacillus anthracisin anti-infective approaches against the threat of bioterrorism. Expert Rev Anti Infect Ther 2014; 5:665-84. [PMID: 17678429 DOI: 10.1586/14787210.5.4.665] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The terrorist attacks of 2001 involving anthrax underscore the imperative that safe and effective medical countermeasures should be readily available. Vaccination appears to be the most effective form of mass protection against a biological attack, but the current vaccines have drawbacks that justify the enormous amount of effort currently being put into developing more effective vaccines and other treatment modalities. After providing a comprehensive overview of the organism Bacillus anthracis as a biological weapon and its pathogenicity, this review briefly summarizes the current knowledge vital to the management of anthrax disease. This knowledge has been acquired since 2001 as a result of the progress on anthrax research and focuses on the possible development of improved human anti-infective strategies targeting B. anthracis spore components, as well as strategies based on host-pathogen interactions.
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Affiliation(s)
- Dimitrios G Bouzianas
- Department of Medical Laboratories, Faculty of Health and Care Professions, University-level Technological Educational Institute of Thessaloniki, Greece.
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22
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Williams JD, Khan AR, Cardinale SC, Butler MM, Bowlin TL, Peet NP. Small molecule inhibitors of anthrax lethal factor toxin. Bioorg Med Chem 2013; 22:419-34. [PMID: 24290062 DOI: 10.1016/j.bmc.2013.11.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2013] [Revised: 10/29/2013] [Accepted: 11/05/2013] [Indexed: 10/26/2022]
Abstract
This manuscript describes the preparation of new small molecule inhibitors of Bacillus anthracis lethal factor. Our starting point was the symmetrical, bis-quinolinyl compound 1 (NSC 12155). Optimization of one half of this molecule led to new LF inhibitors that were desymmetrized to afford more drug-like compounds.
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Affiliation(s)
- John D Williams
- Microbiotix, Inc., Department of Medicinal Chemistry, One Innovation Drive, Worcester, MA 01605, United States; Microbiotix, Inc., Department of Molecular Biology, One Innovation Drive, Worcester, MA 01605, United States
| | - Atiyya R Khan
- Microbiotix, Inc., Department of Medicinal Chemistry, One Innovation Drive, Worcester, MA 01605, United States; Microbiotix, Inc., Department of Molecular Biology, One Innovation Drive, Worcester, MA 01605, United States
| | - Steven C Cardinale
- Microbiotix, Inc., Department of Medicinal Chemistry, One Innovation Drive, Worcester, MA 01605, United States; Microbiotix, Inc., Department of Molecular Biology, One Innovation Drive, Worcester, MA 01605, United States
| | - Michelle M Butler
- Microbiotix, Inc., Department of Medicinal Chemistry, One Innovation Drive, Worcester, MA 01605, United States; Microbiotix, Inc., Department of Molecular Biology, One Innovation Drive, Worcester, MA 01605, United States
| | - Terry L Bowlin
- Microbiotix, Inc., Department of Medicinal Chemistry, One Innovation Drive, Worcester, MA 01605, United States; Microbiotix, Inc., Department of Molecular Biology, One Innovation Drive, Worcester, MA 01605, United States
| | - Norton P Peet
- Microbiotix, Inc., Department of Medicinal Chemistry, One Innovation Drive, Worcester, MA 01605, United States; Microbiotix, Inc., Department of Molecular Biology, One Innovation Drive, Worcester, MA 01605, United States.
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23
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Antonelli AC, Zhang Y, Golub LM, Johnson F, Simon SR. Inhibition of anthrax lethal factor by curcumin and chemically modified curcumin derivatives. J Enzyme Inhib Med Chem 2013; 29:663-9. [PMID: 24102525 PMCID: PMC4196590 DOI: 10.3109/14756366.2013.837901] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Curcuma longa Curcumin (diferuloylmethane), the active ingredient in the eastern spice turmeric (Curcuma longa), has been shown to inhibit the activities of numerous enzymes and signaling molecules involved in cancer, bacterial and viral infections and inflammatory diseases. We have investigated the inhibitory activities of curcumin and chemically modified curcumin (CMC) derivatives toward lethal factor (LF), the proteolytic component of anthrax toxin produced by the bacterium Bacillus anthracis. Curcumin (Compound 1) appears to inhibit the catalytic activity of LF through a mixture of inhibitory mechanisms, without significant compromise to the binding of oligopeptide substrates, and one CMC derivative in particular, Compound 3 (4-phenylaminocarbonylbis-demethoxycurcumin), is capable of inhibiting LF with potency comparable with the parent compound, while also showing improved solubility and stability. The quantitative reduction in catalytic activity achieved by the different CMC derivatives appears to be a function of the proportion of the multiple mechanisms through which they inhibit the enzyme.
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24
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Reddy S, Taylor M, Zhao M, Cherubin P, Geden S, Ray S, Francis D, Teter K. Grape extracts inhibit multiple events in the cell biology of cholera intoxication. PLoS One 2013; 8:e73390. [PMID: 24039929 PMCID: PMC3764128 DOI: 10.1371/journal.pone.0073390] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2012] [Accepted: 07/01/2013] [Indexed: 01/07/2023] Open
Abstract
Vibrio cholerae produces cholera toxin (CT), an AB5 protein toxin that is primarily responsible for the profuse watery diarrhea of cholera. CT is secreted into the extracellular milieu, but the toxin attacks its Gsα target within the cytosol of a host cell. Thus, CT must cross a cellular membrane barrier in order to function. This event only occurs after the toxin travels by retrograde vesicular transport from the cell surface to the endoplasmic reticulum (ER). The catalytic A1 polypeptide then dissociates from the rest of the toxin and assumes an unfolded conformation that facilitates its transfer to the cytosol by a process involving the quality control system of ER-associated degradation. Productive intoxication is blocked by alterations to the vesicular transport of CT and/or the ER-to-cytosol translocation of CTA1. Various plant compounds have been reported to inhibit the cytopathic activity of CT, so in this work we evaluated the potential anti-CT properties of grape extract. Two grape extracts currently sold as nutritional supplements inhibited CT and Escherichia coli heat-labile toxin activity against cultured cells and intestinal loops. CT intoxication was blocked even when the extracts were added an hour after the initial toxin exposure. A specific subset of host-toxin interactions involving both the catalytic CTA1 subunit and the cell-binding CTB pentamer were affected. The extracts blocked toxin binding to the cell surface, prevented unfolding of the isolated CTA1 subunit, inhibited CTA1 translocation to the cytosol, and disrupted the catalytic activity of CTA1. Grape extract could thus potentially serve as a novel therapeutic to prevent or possibly treat cholera.
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Affiliation(s)
- Srikar Reddy
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, Florida, United States of America
- Lake Highland Preparatory School, Orlando, Florida, United States of America
| | - Michael Taylor
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, Florida, United States of America
| | - Mojun Zhao
- The Center for Infectious Disease Research and Vaccinology, Department of Veterinary and Biomedical Sciences, South Dakota State University, Brookings, South Dakota, United States of America
| | - Patrick Cherubin
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, Florida, United States of America
| | - Sandra Geden
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, Florida, United States of America
| | - Supriyo Ray
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, Florida, United States of America
| | - David Francis
- The Center for Infectious Disease Research and Vaccinology, Department of Veterinary and Biomedical Sciences, South Dakota State University, Brookings, South Dakota, United States of America
| | - Ken Teter
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, Florida, United States of America
- * E-mail:
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25
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Small-molecule inhibitors of lethal factor protease activity protect against anthrax infection. Antimicrob Agents Chemother 2013; 57:4139-45. [PMID: 23774434 DOI: 10.1128/aac.00941-13] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Bacillus anthracis, the causative agent of anthrax, manifests its pathogenesis through the action of two secreted toxins. The bipartite lethal and edema toxins, a combination of lethal factor or edema factor with the protein protective antigen, are important virulence factors for this bacterium. We previously developed small-molecule inhibitors of lethal factor proteolytic activity (LFIs) and demonstrated their in vivo efficacy in a rat lethal toxin challenge model. In this work, we show that these LFIs protect against lethality caused by anthrax infection in mice when combined with subprotective doses of either antibiotics or neutralizing monoclonal antibodies that target edema factor. Significantly, these inhibitors provided protection against lethal infection when administered as a monotherapy. As little as two doses (10 mg/kg) administered at 2 h and 8 h after spore infection was sufficient to provide a significant survival benefit in infected mice. Administration of LFIs early in the infection was found to inhibit dissemination of vegetative bacteria to the organs in the first 32 h following infection. In addition, neutralizing antibodies against edema factor also inhibited bacterial dissemination with similar efficacy. Together, our findings confirm the important roles that both anthrax toxins play in establishing anthrax infection and demonstrate the potential for small-molecule therapeutics targeting these proteins.
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26
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Chiu TL, Amin EA. Development of a comprehensive, validated pharmacophore hypothesis for anthrax toxin lethal factor (LF) inhibitors using genetic algorithms, Pareto scoring, and structural biology. J Chem Inf Model 2012; 52:1886-97. [PMID: 22697455 PMCID: PMC3477282 DOI: 10.1021/ci300121p] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Anthrax is an acute infectious disease caused by the spore-forming bacterium Bacillus anthracis. The anthrax toxin lethal factor (LF), an 89-kDa zinc hydrolase secreted by the bacilli, is the toxin component chiefly responsible for pathogenesis and has been a popular target for rational and structure-based drug design. Although hundreds of small-molecule compounds have been designed to target the LF active site, relatively few reported inhibitors have exhibited activity in cell-based assays, and no LF inhibitor is currently available to treat or prevent anthrax. This study presents a new pharmacophore map assembly, validated by experiment, designed to rapidly identify and prioritize promising LF inhibitor scaffolds from virtual compound libraries. The new hypothesis incorporates structural information from all five available LF enzyme-inhibitor complexes deposited in the Protein Data Bank (PDB) and is the first LF pharmacophore map reported to date that includes features representing interactions involving all three key subsites of the LF catalytic binding region. In a wide-ranging validation study on all 546 compounds for which published LF biological activity data exist, this model displayed strong selectivity toward nanomolar-level LF inhibitors, successfully identifying 72.1% of existing nanomolar-level compounds in an unbiased test set, while rejecting 100% of weakly active (>100 μM) compounds. In addition to its capabilities as a database searching tool, this comprehensive model points to a number of key design principles and previously unidentified ligand-receptor interactions that are likely to influence compound potency.
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Affiliation(s)
- Ting-Lan Chiu
- Department of Medicinal Chemistry and Minnesota Supercomputing Institute for Advanced Computational Research, University of Minnesota, 717 Delaware St. SE, Minneapolis, Minnesota 55414-2959
| | - Elizabeth A. Amin
- Department of Medicinal Chemistry and Minnesota Supercomputing Institute for Advanced Computational Research, University of Minnesota, 717 Delaware St. SE, Minneapolis, Minnesota 55414-2959
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27
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Artenstein AW, Opal SM. Novel approaches to the treatment of systemic anthrax. Clin Infect Dis 2012; 54:1148-61. [PMID: 22438345 DOI: 10.1093/cid/cis017] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Anthrax continues to generate concern as an agent of bioterrorism and as a natural cause of sporadic disease outbreaks. Despite the use of appropriate antimicrobial agents and advanced supportive care, the mortality associated with the systemic disease remains high. This is primarily due to the pathogenic exotoxins produced by Bacillus anthracis as well as other virulence factors of the organism. For this reason, new therapeutic strategies that target events in the pathogenesis of anthrax and may potentially augment antimicrobials are being investigated. These include anti-toxin approaches, such as passive immune-based therapies; non-antimicrobial drugs with activity against anthrax toxin components; and agents that inhibit binding, processing, or assembly of toxins. Adjunct therapies that target spore germination or downstream events in anthrax intoxication are also under investigation. In combination, these modalities may enhance the management of systemic anthrax.
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Affiliation(s)
- Andrew W Artenstein
- Center for Biodefense and Emerging Pathogens, Department of Medicine, Memorial Hospital of Rhode Island, Pawtucket, and The Warren Alpert Medical School of Brown University, Providence, RI 02860, USA
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28
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Beierlein JM, Anderson AC. New developments in vaccines, inhibitors of anthrax toxins, and antibiotic therapeutics for Bacillus anthracis. Curr Med Chem 2012; 18:5083-94. [PMID: 22050756 DOI: 10.2174/092986711797636036] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2011] [Revised: 09/07/2011] [Accepted: 09/09/2011] [Indexed: 01/28/2023]
Abstract
Bacillus anthracis, the causative agent responsible for anthrax infections, poses a significant biodefense threat. There is a high mortality rate associated with untreated anthrax infections; specifically, inhalation anthrax is a particularly virulent form of infection with mortality rates close to 100%, even with aggressive treatment. Currently, a vaccine is not available to the general public and few antibiotics have been approved by the FDA for the treatment of inhalation anthrax. With the threat of natural or engineered bacterial resistance to antibiotics and the limited population for whom the current drugs are approved, there is a clear need for more effective treatments against this deadly infection. A comprehensive review of current research in drug discovery is presented in this article, including efforts to improve the purity and stability of vaccines, design inhibitors targeting the anthrax toxins, and identify inhibitors of novel enzyme targets. High resolution structural information for the anthrax toxins and several essential metabolic enzymes has played a significant role in aiding the structure-based design of potent and selective antibiotics.
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Affiliation(s)
- J M Beierlein
- Dept. Pharmaceutical Sciences, University of Connecticut, 69 N. Eagleville Rd., Storrs, CT 06269, USA
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29
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Nie SP, Xie MY. A review on the isolation and structure of tea polysaccharides and their bioactivities. Food Hydrocoll 2011. [DOI: 10.1016/j.foodhyd.2010.04.010] [Citation(s) in RCA: 139] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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30
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Bouzianas DG. Current and future medical approaches to combat the anthrax threat. J Med Chem 2010; 53:4305-31. [PMID: 20102155 DOI: 10.1021/jm901024b] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Dimitrios G Bouzianas
- Laboratory of Molecular Endocrinology, Division of Endocrinology and Metabolism, AHEPA University Hospital, 1 S. Kyriakidi Street, P.C. 54636, Thessaloniki, Macedonia, Greece.
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31
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Chiu TL, Solberg J, Patil S, Geders TW, Zhang X, Rangarajan S, Francis R, Finzel BC, Walters MA, Hook DJ, Amin EA. Identification of novel non-hydroxamate anthrax toxin lethal factor inhibitors by topomeric searching, docking and scoring, and in vitro screening. J Chem Inf Model 2009; 49:2726-34. [PMID: 19928768 PMCID: PMC2805240 DOI: 10.1021/ci900186w] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Anthrax is an infectious disease caused by Bacillus anthracis, a Gram-positive, rod-shaped, anaerobic bacterium. The lethal factor (LF) enzyme is secreted by B. anthracis as part of a tripartite exotoxin and is chiefly responsible for anthrax-related cytotoxicity. As LF can remain in the system long after antibiotics have eradicated B. anthracis from the body, the preferred therapeutic modality would be the administration of antibiotics together with an effective LF inhibitor. Although LF has garnered a great deal of attention as an attractive target for rational drug design, relatively few published inhibitors have demonstrated activity in cell-based assays and, to date, no LF inhibitor is available as a therapeutic or preventive agent. Here we present a novel in silico high-throughput virtual screening protocol that successfully identified 5 non-hydroxamic acid small molecules as new, preliminary LF inhibitor scaffolds with low micromolar inhibition against that target, resulting in a 12.8% experimental hit rate. This protocol screened approximately 35 million nonredundant compounds for potential activity against LF and comprised topomeric searching, docking and scoring, and drug-like filtering. Among these 5 hit compounds, none of which has previously been identified as a LF inhibitor, three exhibited experimental IC(50) values less than 100 microM. These three preliminary hits may potentially serve as scaffolds for lead optimization as well as templates for probe compounds to be used in mechanistic studies. Notably, our docking simulations predicted that these novel hits are likely to engage in critical ligand-receptor interactions with nearby residues in at least two of the three (S1', S1-S2, and S2') subsites in the LF substrate binding area. Further experimental characterization of these compounds is in process. We found that micromolar-level LF inhibition can be attained by compounds with non-hydroxamate zinc-binding groups that exhibit monodentate zinc chelation as long as key hydrophobic interactions with at least two LF subsites are retained.
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Affiliation(s)
- Ting-Lan Chiu
- Department of Medicinal Chemistry, College of Pharmacy, University of Minnesota, 717 Delaware St. SE, Minneapolis, Minnesota 55414-2959
| | - Jonathan Solberg
- Institute for Therapeutics Discovery and Development, University of Minnesota, 717 Delaware St. SE, Minneapolis, Minnesota 55414-2959
| | - Satish Patil
- Department of Chemistry, University of Minnesota, 207 Pleasant St. SE, Minneapolis, MN 55455-0431
| | - Todd W. Geders
- Department of Medicinal Chemistry, College of Pharmacy, University of Minnesota, 717 Delaware St. SE, Minneapolis, Minnesota 55414-2959
| | - Xia Zhang
- Department of Medicinal Chemistry, College of Pharmacy, University of Minnesota, 717 Delaware St. SE, Minneapolis, Minnesota 55414-2959
| | - Subhashree Rangarajan
- Institute for Therapeutics Discovery and Development, University of Minnesota, 717 Delaware St. SE, Minneapolis, Minnesota 55414-2959
| | - Rawle Francis
- Institute for Therapeutics Discovery and Development, University of Minnesota, 717 Delaware St. SE, Minneapolis, Minnesota 55414-2959
| | - Barry C. Finzel
- Department of Medicinal Chemistry, College of Pharmacy, University of Minnesota, 717 Delaware St. SE, Minneapolis, Minnesota 55414-2959
| | - Michael A. Walters
- Department of Medicinal Chemistry, College of Pharmacy, University of Minnesota, 717 Delaware St. SE, Minneapolis, Minnesota 55414-2959
- Institute for Therapeutics Discovery and Development, University of Minnesota, 717 Delaware St. SE, Minneapolis, Minnesota 55414-2959
| | - Derek J. Hook
- Department of Medicinal Chemistry, College of Pharmacy, University of Minnesota, 717 Delaware St. SE, Minneapolis, Minnesota 55414-2959
- Institute for Therapeutics Discovery and Development, University of Minnesota, 717 Delaware St. SE, Minneapolis, Minnesota 55414-2959
| | - Elizabeth A. Amin
- Department of Medicinal Chemistry, College of Pharmacy, University of Minnesota, 717 Delaware St. SE, Minneapolis, Minnesota 55414-2959
- Minnesota Supercomputing Institute for Advanced Computational Research, 117 Pleasant St. SE, Minneapolis, MN 55455
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Fasanella A, Galante D, Garofolo G, Jones MH. Anthrax undervalued zoonosis. Vet Microbiol 2009; 140:318-31. [PMID: 19747785 DOI: 10.1016/j.vetmic.2009.08.016] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2009] [Revised: 08/03/2009] [Accepted: 08/11/2009] [Indexed: 11/19/2022]
Abstract
Anthrax is a non-contagious disease, known since ancient times. However, it became a matter of global public interest after the bioterrorist attacks in the U.S.A. during the autumn of 2001. The concern of politicians and civil authorities everywhere towards this emergency necessitated a significant research effort and the prevention of new bioterrorist acts. Anthrax is primarily a disease that affects livestock and wildlife; its distribution is worldwide; and it can represent a danger to humans but especially more so when it occurs in areas considered to be free and in atypical seasons and climatic conditions. The atypicality of the phenomenon may lead health workers to misdiagnose and, consequently, an inappropriately manage of affected carcasses with a consequent and inevitable increase in the risk of human infection. This article emphasises the importance of paying increasing attention to this zoonosis. The biggest risk is its underestimation.
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Affiliation(s)
- Antonio Fasanella
- Istituto Zooprofilattico Sperimentale della Puglia e della Basilicata, Anthrax Reference Institute of Italy, Foggia, Italy.
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Tonello F, Montecucco C. The anthrax lethal factor and its MAPK kinase-specific metalloprotease activity. Mol Aspects Med 2009; 30:431-8. [PMID: 19665472 DOI: 10.1016/j.mam.2009.07.006] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2009] [Accepted: 07/30/2009] [Indexed: 02/06/2023]
Abstract
The anthrax lethal factor is a multi-domain protein toxin released by Bacillus anthracis which enters cells in a process mediated by the protective antigen and specific cell receptors. In the cytosol, the lethal factor cleaves the N-terminal tail of many MAPK kinases, thus deranging a major cell signaling pathway. The structural features at the basis of these activities of LF are reviewed here with particular attention to the proteolytic activity and to the identification of specific inhibitors. A significant similarity between the metalloprotease domain of the lethal factor and of that of the clostridial neurotoxins has been noted and is discussed.
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Affiliation(s)
- Fiorella Tonello
- Dipartimento di Scienze Biomediche Sperimentali, Istituto CNR di Neuroscienze, Università di Padova, Viale G. Colombo 3, 35131 Padova, Italy
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Kim J, Yoon MY. ANTHRAX LETHAL FACTOR: CRITICAL VIRULENCE FACTOR OF PATHOGENESIS OF ANTHRAX TOXINS. TOXIN REV 2008. [DOI: 10.1080/15569540500320987] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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35
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Hudson MJ, Beyer W, Böhm R, Fasanella A, Garofolo G, Golinski R, Goossens PL, Hahn U, Hallis B, King A, Mock M, Montecucco C, Ozin A, Tonello F, Kaufmann SH. Bacillus anthracis: balancing innocent research with dual-use potential. Int J Med Microbiol 2008; 298:345-64. [PMID: 18375178 PMCID: PMC7106442 DOI: 10.1016/j.ijmm.2007.09.007] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2007] [Revised: 09/21/2007] [Accepted: 09/28/2007] [Indexed: 12/30/2022] Open
Abstract
Anthrax Euronet, a Coordination Action of the EU 6th Framework Programme, was designed to strengthen networking activities between anthrax research groups in Europe and to harmonise protocols for testing anthrax vaccines and therapeutics. Inevitably, the project also addressed aspects of the current political issues of biosecurity and dual-use research, i.e. research into agents of important diseases of man, livestock or agriculture that could be used as agents of bioterrorism. This review provides a comprehensive overview of the biology of Bacillus anthracis, of the pathogenesis, epidemiology and diagnosis of anthrax, as well as vaccine and therapeutic intervention strategies. The proposed requirement for a code of conduct for working with dual-use agents such as the anthrax bacillus is also discussed.
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Affiliation(s)
| | | | | | - Antonio Fasanella
- Istituto Zooprofilattico Sperimentale of Puglia and Basilicata, Foggia, Italy
| | - Giuliano Garofolo
- Istituto Zooprofilattico Sperimentale of Puglia and Basilicata, Foggia, Italy
| | - Robert Golinski
- Department of Immunology, Max Planck Institute for Infection Biology, Charitéplatz 1, D-10117 Berlin, Germany
| | | | | | - Bassam Hallis
- Health Protection Agency, Porton Down, Salisbury, UK
| | | | | | | | - Amanda Ozin
- Department of Immunology, Max Planck Institute for Infection Biology, Charitéplatz 1, D-10117 Berlin, Germany
| | | | - Stefan H.E. Kaufmann
- Department of Immunology, Max Planck Institute for Infection Biology, Charitéplatz 1, D-10117 Berlin, Germany
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36
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Gaddis BD, Rubert Pérez CM, Chmielewski J. Inhibitors of anthrax lethal factor based upon N-oleoyldopamine. Bioorg Med Chem Lett 2008; 18:2467-70. [DOI: 10.1016/j.bmcl.2008.02.044] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2007] [Revised: 02/12/2008] [Accepted: 02/14/2008] [Indexed: 11/30/2022]
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37
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Hines HB, Kim AD, Stafford RG, Badie SS, Brueggeman EE, Newman DJ, Schmidt JJ. Use of a recombinant fluorescent substrate with cleavage sites for all botulinum neurotoxins in high-throughput screening of natural product extracts for inhibitors of serotypes A, B, and E. Appl Environ Microbiol 2008; 74:653-9. [PMID: 18083881 PMCID: PMC2227718 DOI: 10.1128/aem.01690-07] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2007] [Accepted: 11/26/2007] [Indexed: 11/20/2022] Open
Abstract
The seven serotypes of botulinum neurotoxin (BoNTs) are zinc metalloproteases that cleave and inactivate proteins critical for neurotransmission. The synaptosomal protein of 25 kDa (SNAP-25) is cleaved by BoNTs A, C, and E, while vesicle-associated membrane protein (VAMP) is the substrate for BoNTs B, D, F, and G. BoNTs not only are medically useful drugs but also are potential bioterrorist and biowarfare threat agents. Because BoNT protease activity is required for toxicity, inhibitors of that activity might be effective for antibotulinum therapy. To expedite inhibitor discovery, we constructed a hybrid gene encoding (from the N terminus to the C terminus, with respect to the expressed product) green fluorescent protein, then a SNAP-25 fragment encompassing residues Met-127 to Gly-206, and then VAMP residues Met-1 to Lys-94. Cysteine was added as the C terminus. The expressed product, which contained the protease cleavage sites for all seven botulinum serotypes, was purified and coupled covalently through the C-terminal sulfhydryl group to maleimide-activated 96-well plates. The substrate was readily cleaved by BoNTs A, B, D, E, and F. Using this assay and an automated 96-well pipettor, we screened 528 natural product extracts for inhibitors of BoNT A, B, and E protease activities. Serotype-specific inhibition was found in 30 extracts, while 5 others inhibited two serotypes.
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Affiliation(s)
- Harry B Hines
- Department of Cell Biology and Biochemistry, Integrated Toxicology Division, USAMRIID, Frederick, MD 21702-5011, USA
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38
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Mogridge J. Defensive strategies of Bacillus anthracis that promote a fatal disease. ACTA ACUST UNITED AC 2007; 4:253-258. [PMID: 19081825 DOI: 10.1016/j.ddmec.2007.12.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Bacillus anthracis is a Gram-positive bacterium that causes anthrax. Bacterial spores that enter the host germinate into metabolically active bacilli that disseminate throughout the body and replicate to high numbers. Two virulence factors are essential for this unrestrained growth. The first is a weakly immunogenic poly gamma-D-glutamic acid capsule that surrounds the bacilli and confers resistance to phagocytosis. The second virulence factor, anthrax toxin, disrupts multiple host functions to diminish the immune response.
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Affiliation(s)
- Jeremy Mogridge
- Department of Laboratory Medicine and Pathobiology, University of Toronto, 1 King's College Circle, Toronto, ON M5S 1A8, Canada
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39
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Gaddis BD, Avramova LV, Chmielewski J. Inhibitors of anthrax lethal factor. Bioorg Med Chem Lett 2007; 17:4575-8. [PMID: 17574849 DOI: 10.1016/j.bmcl.2007.05.089] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2007] [Revised: 05/24/2007] [Accepted: 05/30/2007] [Indexed: 10/23/2022]
Abstract
An inhibitor of anthrax lethal toxin mediated cell death (1) was identified by a medium throughput cell-based screen. This compound was determined to specifically inhibit anthrax lethal factor (LF), and subsequent SAR studies produced an even more potent inhibitor (4). Mechanistic studies identified these agents as uncompetitive inhibitors of LF with Ki values of 3.0 and 1.7 microM, respectively, with good cell potency and low cytotoxicity.
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Affiliation(s)
- Brandon D Gaddis
- Department of Chemistry, Purdue University, West Lafayette, IN 47907, USA
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40
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Li Y, Sherer K, Cui X, Eichacker PQ. New insights into the pathogenesis and treatment of anthrax toxin-induced shock. Expert Opin Biol Ther 2007; 7:843-54. [PMID: 17555370 DOI: 10.1517/14712598.7.6.843] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Inhalational Bacillus anthracis infection is a leading bioterrorist health threat in the US today. Lethal (LeTx) and edema toxin production are key to the virulent effects of this lethal bacteria. Recent insights into the structure and function of these toxins have increased the understanding of both the pathogenesis and treatment of anthrax. These are binary type toxins comprised of protective antigen necessary for their cellular uptake and either lethal or edema factors, the toxigenic moieties. Primary cellular receptors for protective antigen have been identified and the processing of the completed toxins clarified. Consistent with the ability of lethal factor to cleave mitogen activated protein kinase kinases, the evidence indicates that an excessive inflammatory response does not contribute to shock with LeTx. Rather, the immunosuppressive effects of LeTx could promote infection; however, direct endothelial dysfunction may have an important role in shock due to LeTx. Recent studies show that edema factor, a potent adenyl cyclase, may have a major role in shock during anthrax and that it may also be immunosuppresive. Therapies under development which target several steps in the cellular uptake and function of these two toxins have been effective in both in vitro and in vivo systems. Understanding how best to apply these agents in combination with conventional treatments should be a goal of future research.
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MESH Headings
- Adenylyl Cyclases/immunology
- Adenylyl Cyclases/metabolism
- Animals
- Anthrax/complications
- Anthrax/drug therapy
- Anthrax/metabolism
- Anthrax Vaccines/therapeutic use
- Antibodies, Monoclonal/therapeutic use
- Antigens, Bacterial/immunology
- Antigens, Bacterial/metabolism
- Bacillus anthracis/immunology
- Bacillus anthracis/metabolism
- Bacillus anthracis/pathogenicity
- Bacterial Toxins/immunology
- Bacterial Toxins/metabolism
- Endothelium, Vascular/microbiology
- Endothelium, Vascular/physiopathology
- Humans
- Receptors, Peptide/metabolism
- Shock, Septic/drug therapy
- Shock, Septic/metabolism
- Shock, Septic/microbiology
- Shock, Septic/physiopathology
- Virulence
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Affiliation(s)
- Yan Li
- National Institutes of Health, Critical Care Medicine Department, Clinical Center, Bethesda, MD 20892, USA
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41
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Friedman M. Overview of antibacterial, antitoxin, antiviral, and antifungal activities of tea flavonoids and teas. Mol Nutr Food Res 2007; 51:116-34. [PMID: 17195249 PMCID: PMC7168386 DOI: 10.1002/mnfr.200600173] [Citation(s) in RCA: 382] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2006] [Revised: 10/20/2006] [Indexed: 12/17/2022]
Abstract
Tea leaves produce organic compounds that may be involved in the defense of the plants against invading pathogens including insects, bacteria, fungi, and viruses. These metabolites include polyphenolic compounds, the six so-called catechins, and the methyl-xanthine alkaloids caffeine, theobromine, and theophylline. Postharvest inactivation of phenol oxidases in green tea leaves prevents oxidation of the catechins, whereas postharvest enzyme-catalyzed oxidation (fermentation) of catechins in tea leaves results in the formation of four theaflavins as well as polymeric thearubigins. These substances impart the black color to black teas. Black and partly fermented oolong teas contain both classes of phenolic compounds. A need exists to develop a better understanding of the roles of polyphenolic tea compounds in food and medical microbiology. This overview surveys and interprets our present knowledge of activities of tea flavonoids and teas against foodborne and other pathogenic bacteria, virulent protein toxins produced by some of the bacteria, virulent bacteriophages, pathogenic viruses and fungi. Also covered are synergistic, mechanistic, and bioavailability aspects of the antimicrobial effects. Further research is suggested for each of these categories. The herein described findings are not only of fundamental interest, but also have practical implications for nutrition, food safety, and animal and human health.
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Affiliation(s)
- Mendel Friedman
- Western Regional Research Center, Agricultural Research Service, United States Department of Agriculture, Albany, CA, USA.
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42
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Sherer K, Li Y, Cui X, Eichacker PQ. Lethal and edema toxins in the pathogenesis of Bacillus anthracis septic shock: implications for therapy. Am J Respir Crit Care Med 2006; 175:211-21. [PMID: 17095744 PMCID: PMC2176088 DOI: 10.1164/rccm.200608-1239cp] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Recent research regarding the structure and function of Bacillus anthracis lethal (LeTx) and edema (ETx) toxins provides growing insights into the pathophysiology and treatment of shock with this lethal bacteria. These are both binary-type toxins composed of protective antigen necessary for their cellular uptake and either lethal or edema factors, the toxigenic moieties. The primary cellular receptors for protective antigen have been identified and constructed and key steps in the extracellular processing and internalization of the toxins clarified. Consistent with the lethal factor's primary action as an intracellular endopeptidase targeting mitogen-activated protein kinase kinases, growing evidence indicates that shock with this toxin does not result from an excessive inflammatory response. In fact, the potent immunosuppressive effects of LeTx may actually contribute to the establishment and persistence of infection. Instead, shock with LeTx may be related to the direct injurious effects of lethal factor on endothelial cell function. Despite the importance of LeTx, very recent studies show that edema factor, a potent adenyl cyclase, has the ability to make a substantial contribution to shock caused by B. anthracis and works additively with LeTx. Furthermore, ETx may contribute to the immunosuppressive effects of LeTx. Therapies under development that target several different steps in the cellular uptake and function of these two toxins have been effective in in vitro and in vivo systems. Understanding how best to apply these agents clinically and how they interact with conventional treatments should be goals for future research.
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Affiliation(s)
- Kevin Sherer
- Critical Care Medicine Department, National Institutes of Health, Bethesda, MD 20892, USA
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43
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Rossi Paccani S, Tonello F, Patrussi L, Capitani N, Simonato M, Montecucco C, Baldari CT. Anthrax toxins inhibit immune cell chemotaxis by perturbing chemokine receptor signalling. Cell Microbiol 2006; 9:924-9. [PMID: 17087730 DOI: 10.1111/j.1462-5822.2006.00840.x] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Pathogenic strains of Bacillus anthracis produce two potent toxins, lethal toxin (LT), a metalloprotease that cleaves mitogen-activated protein kinase kinases, and oedema toxin (ET), a calcium/calmodulin-dependent adenylate cyclase. Emerging evidence indicates a role for both toxins in suppressing the initiation of both innate and adaptive immune responses, which are essential to keep the infection under control. Here we show that LT and ET inhibit chemotaxis of T-cells and macrophages by subverting signalling by both CXC and CC chemokine receptors. The data highlight a novel strategy of immunosuppression by B. anthracis based on inhibition of immune cell homing.
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Affiliation(s)
- Silvia Rossi Paccani
- Department of Evolutionary Biology, University of Siena, Via Aldo Moro 2, 53100 Siena, Italy
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44
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Schepetkin IA, Khlebnikov AI, Kirpotina LN, Quinn MT. Novel small-molecule inhibitors of anthrax lethal factor identified by high-throughput screening. J Med Chem 2006; 49:5232-44. [PMID: 16913712 DOI: 10.1021/jm0605132] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Anthrax lethal factor (LF) is a key virulence factor of anthrax lethal toxin. We screened a chemolibrary of 10,000 drug-like molecules for their ability to inhibit LF and identified 18 novel small molecules with potent LF inhibitory activity. Three additional LF inhibitors were identified through further structure-activity relationship (SAR) analysis. All 21 compounds inhibited LF with an IC50 range of 0.8 to 11 muM, utilizing mixed-mode competitive inhibition. An evaluation of inhibitory activity against a range of unrelated proteases showed relatively high specificity for LF. Furthermore, pharmacophore modeling of these compounds showed a high degree of similarity to the model published by Panchal et al. (Nat. Struct. Mol. Biol. 2004, 11, 67-72), indicating that the conformational features of these inhibitors are structurally compatible with the steric constraints of the substrate-binding pocket. These novel LF inhibitors and the structural scaffolds identified as important for inhibitory activity represent promising leads to pursue for further LF inhibitor development.
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Affiliation(s)
- Igor A Schepetkin
- Department of Veterinary Molecular Biology, Montana State University, Bozeman, Montana 59717, USA
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45
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Jiao GS, Simo O, Nagata M, O'Malley S, Hemscheidt T, Cregar L, Millis SZ, Goldman ME, Tang C. Selectively guanidinylated derivatives of neamine. Syntheses and inhibition of anthrax lethal factor protease. Bioorg Med Chem Lett 2006; 16:5183-9. [PMID: 16870442 DOI: 10.1016/j.bmcl.2006.07.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2006] [Revised: 06/26/2006] [Accepted: 07/05/2006] [Indexed: 11/25/2022]
Abstract
A series of mono-, di-, and tri-guanidinylated derivatives of neamine were prepared via selective guanidinylation of neamine. These molecules represent a novel scaffold as inhibitors of anthrax lethal factor zinc metalloprotease. Methods for the synthesis of these compounds are described, and structure-activity relationships among the series are analyzed. In addition, initial findings regarding the mechanism of LF inhibition for these molecules are presented.
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Affiliation(s)
- Guan-Sheng Jiao
- Department of Chemistry, Hawaii Biotech, Inc., 99-193 Aiea Heights Dr., Suite 200, Aiea, 96701, USA.
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46
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Lewis JA, Mongan J, McCammon JA, Cohen SM. Evaluation and Binding-Mode Prediction of Thiopyrone-Based Inhibitors of Anthrax Lethal Factor. ChemMedChem 2006; 1:694-7. [PMID: 16902919 DOI: 10.1002/cmdc.200600102] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Jana A Lewis
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0358, USA
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47
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Fridman M, Belakhov V, Lee LV, Liang FS, Wong CH, Baasov T. Dual effect of synthetic aminoglycosides: antibacterial activity against Bacillus anthracis and inhibition of anthrax lethal factor. Angew Chem Int Ed Engl 2006; 44:447-52. [PMID: 15624157 DOI: 10.1002/anie.200462003] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Micha Fridman
- Department of Chemistry and Institute of Catalysis Science and Technology, Technion-Israel Institute of Technology, Haifa 32000, Israel
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48
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Friedman M, Henika PR, Levin CE, Mandrell RE, Kozukue N. Antimicrobial activities of tea catechins and theaflavins and tea extracts against Bacillus cereus. J Food Prot 2006; 69:354-61. [PMID: 16496576 DOI: 10.4315/0362-028x-69.2.354] [Citation(s) in RCA: 119] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
We evaluated the antimicrobial activities of seven green tea catechins and four black tea theaflavins, generally referred to as flavonoids, as well as the aqueous extracts (infusions) of 36 commercial black, green, oolong, white, and herbal teas against Bacillus cereus (strain RM3190) incubated at 21 degrees C for 3, 15, 30, and 60 min. The results obtained demonstrate that (i) (-)-gallocatechin-3-gallate, (-)-epigallocatechin-3-gallate, (-)-catechin-3-gallate, (-)-epicatechin-3-gallate, theaflavin-3, 3'-digallate, theaflavin-3'-gallate, and theaflavin-3-gallate showed antimicrobial activities at nanomolar levels; (ii) most compounds were more active than were medicinal antibiotics, such as tetracycline or vancomycin, at comparable concentrations; (iii) the bactericidal activities of the teas could be accounted for by the levels of catechins and theaflavins as determined by high-pressure liquid chromatography; (iv) freshly prepared tea infusions were more active than day-old teas; and (v) tea catechins without gallate side chains, gallic acid and the alkaloids caffeine and theobromine also present in teas, and herbal (chamomile and peppermint) teas that contain no flavonoids are all inactive. These studies extend our knowledge about the antimicrobial effects of food ingredients.
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Affiliation(s)
- Mendel Friedman
- Western Regional Research Center, Agricultural Research Service, US Department of Agriculture, Albany, California 94710, USA.
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49
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Jiao GS, Cregar L, Goldman ME, Millis SZ, Tang C. Guanidinylated 2,5-dideoxystreptamine derivatives as anthrax lethal factor inhibitors. Bioorg Med Chem Lett 2006; 16:1527-31. [PMID: 16386899 DOI: 10.1016/j.bmcl.2005.12.038] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2005] [Revised: 12/09/2005] [Accepted: 12/09/2005] [Indexed: 11/23/2022]
Abstract
Anthrax lethal factor is a Zn(2+)-dependent metalloprotease and the key virulence factor of tripartite anthrax toxin secreted by Bacillus anthracis, the causative agent of anthrax. A series of guanidinylated 2,5-dideoxystreptamine derivatives were designed and synthesized as inhibitors of lethal factor, some of which show strong inhibitory activity against lethal factor in an in vitro FRET assay. Preparation and structure-activity relationships of these compounds are presented.
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Affiliation(s)
- Guan-Sheng Jiao
- Department of Chemistry, Hawaii Biotech Inc., 99-193 Aiea Heights Drive, Suite 200, Aiea, HI 96701, USA.
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50
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Brik A, Wu CY, Wong CH. Microtiter plate based chemistry and in situ screening: a useful approach for rapid inhibitor discovery. Org Biomol Chem 2006; 4:1446-57. [PMID: 16604207 DOI: 10.1039/b600055j] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The use of libraries extracted from nature or constructed by combinatorial chemistry, have been widely appreciated in the drug discovery area. In this perspective, we present our contribution to the field of enzyme inhibitor discovery using a useful approach that allows diversification of a common core in a microtiter plate followed by in situ screening. Our method relies on an organic reaction that is highly selective, high yielding, amenable to the microscale and preferably can be performed in water. The core can be a designed molecule based on the structural and mechanistic information of the target, a compound with a weak binding affinity, or a natural product. Several reactions were found useful for this approach and were applied to the rapid discovery of potent inhibitors of representative enzymes.
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Affiliation(s)
- Ashraf Brik
- Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA, USA
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