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Chung CL, Chen CL. Fluoroquinolones upregulate insulin-like growth factor-binding protein 3, inhibit cell growth and insulin-like growth factor signaling. Eur J Pharmacol 2024; 969:176421. [PMID: 38423242 DOI: 10.1016/j.ejphar.2024.176421] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Revised: 01/27/2024] [Accepted: 02/13/2024] [Indexed: 03/02/2024]
Abstract
Fluoroquinolones (FQs), commonly known for their antibiotic properties, exhibit additional pharmacological potential with anti-proliferative effects on various malignant cell types and immunomodulatory responses. Despite these observed effects, the precise mechanisms of action remain elusive. This study elucidates the biological impact of FQs on insulin-like growth factor-binding protein 3 (IGFBP-3) productions in a p53-dependent manner. Cultured cells and mouse models treated with FQs demonstrated increased IGFBP-3 mRNA expression and protein secretion. The FQ-induced IGFBP-3 was identified to impede cell growth by inhibiting IGF-I signaling and exerting effects through an IGF-independent pathway. Notably, FQ-mediated suppression of cell proliferation was reversed in p53-null and p53 knockdown cells, suggesting the pivotal role of p53 in FQ-induced IGFBP-3 production and IGFBP-3-mediated growth inhibition. Additionally, ciprofloxacin, a clinically used FQ, exhibited the induction of tumor cell apoptosis and attenuation of tumor growth in a syngeneic mouse hepatocellular carcinoma (HCC) model. These findings unveil a novel mechanism through which FQs act as anti-proliferative agents, prompting further exploration of their potential utility or derivative compounds in cancer treatment and prevention.
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Affiliation(s)
- Chih-Ling Chung
- Department of Biological Sciences, National Sun Yat-Sen University, Kaohsiung, 80424, Taiwan
| | - Chun-Lin Chen
- Department of Biological Sciences, National Sun Yat-Sen University, Kaohsiung, 80424, Taiwan; Department of Biotechnology, Kaohsiung Medical University, Kaohsiung, 80708, Taiwan; Graduate Institute of Natural Products, Kaohsiung Medical University, Kaohsiung, 80708, Taiwan.
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2
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Vu OT, Nguyen QH, Nguy Phan T, Luong TT, Eersels K, Wagner P, Truong LTN. Highly Sensitive Molecularly Imprinted Polymer-Based Electrochemical Sensors Enhanced by Gold Nanoparticles for Norfloxacin Detection in Aquaculture Water. ACS OMEGA 2023; 8:2887-2896. [PMID: 36713701 PMCID: PMC9878621 DOI: 10.1021/acsomega.2c04414] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Accepted: 12/26/2022] [Indexed: 06/18/2023]
Abstract
The overuse of antibiotics in aquaculture and pharmaceuticals and their subsequent leaking into the environment have been demonstrated to be a potential route for creating antibiotic resistance in bacteria. In order to assess the impact of this problem and take regulatory measures, it is necessary to develop tools that allow for the detection of antibiotics in environmental samples in a routine, low-cost manner. In this study, we integrated gold nanoparticles (AuNPs) into a molecularly imprinted polymer (MIP) membrane to fabricate a new sensor for the detection of norfloxacin in pharmaceuticals and aquaculture samples. The receptor layers were characterized by scanning electron microscopy, electrochemical impedance spectroscopy, and Raman spectroscopy. The results of these studies demonstrate that the addition of AuNPs to the polymer network enhanced the sensor sensitivity by at least a factor of two. The MIP-AuNPs sensor has a low detection limit (0.15 ng/mL, S/N = 3) with a wide linear range and very high sensitivity. The selectivity of the fabricated sensor was measured in the sample containing other antibiotics (like chloramphenicol, ciprofloxacin, and levofloxacin). Rapid and precise norfloxacin detection in pharmaceutical compounds and fishpond water samples indicates that the fabricated sensor has the potential to be used for routine screening of aquacultures and pharmaceutical processes.
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Affiliation(s)
- Oanh Thi Vu
- Vietnam-Korea
Institute of Science and Technology, Hoa Lac Hi-Tech Park, Research and Development Zone, Hanoi100000, Vietnam
| | - Quoc Hao Nguyen
- Department
of Chemical Engineering (Integrated Engineering), Kyung Hee University, 1732 Deogyeong-daero, Giheung-gu, Yongin-si, Gyeonggi-do17104, Republic of Korea
| | - Tin Nguy Phan
- Vietnam-Korea
Institute of Science and Technology, Hoa Lac Hi-Tech Park, Research and Development Zone, Hanoi100000, Vietnam
| | - Thanh ThuyThi Luong
- National
Institute of Occupational and Environmental Health, 57 Le Quy Don,
Hai Ba Trung District, Hanoi3800 016, Vietnam
| | - Kasper Eersels
- Sensor
Engineering Department, Faculty of Science and Engineering, Maastricht University, Maastricht6200 MD, The Netherlands
| | - Patrick Wagner
- Department
of Physics and Astronomy, Laboratory for Soft Matter and Biophysics, KU Leuven, Celestijnenlaan 200 D, LeuvenB-3001, Belgium
| | - Lien Thi Ngoc Truong
- Vietnam-Korea
Institute of Science and Technology, Hoa Lac Hi-Tech Park, Research and Development Zone, Hanoi100000, Vietnam
- School of
Engineering Physics, Hanoi University of
Science and Technology, No. 1 Dai Co Viet Road, Hai Ba Trung District, Hanoi100000, Vietnam
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3
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Mathpal D, Masand M, Thomas A, Ahmad I, Saeed M, Zaman GS, Kamal M, Jawaid T, Sharma PK, Gupta MM, Kumar S, Srivastava SP, Balaramnavar VM. Pharmacophore modeling, docking and the integrated use of a ligand- and structure-based virtual screening approach for novel DNA gyrase inhibitors: synthetic and biological evaluation studies. RSC Adv 2021; 11:34462-34478. [PMID: 35494744 PMCID: PMC9042709 DOI: 10.1039/d1ra05630a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Accepted: 09/28/2021] [Indexed: 12/03/2022] Open
Abstract
Fluoroquinolones, a class of compound, act via inhibiting DNA gyrase and topoisomerase IV enzymes. This is an important class of drugs with high success rates for the treatment of tuberculosis and other bacterial infections. An indirect drug design approach was used to develop a meaningful pharmacophore model using the HypoGen module of Discovery Studio 2.0 on a set of 27 structurally diverse compounds with a wide range of biological activity (5 log units). The best hypothesis had three hydrogen bond acceptors (HBA) and one hydrophobic (Hy) moiety, showing r = 0.95, and it predicts the test set of 44 compounds well, with r 2 = 0.823. The same features (acceptor and hydrophobic functionality) were validated at the binding site of the DNA gyrase active site using GOLD version 3.0.1 and Molegro Virtual Docker, which showed corresponding hydrogen bond interactions and also π-π stacking interactions that correlated well with the PIC50 values (r 2 = 0.6142). The thoroughly validated model was used to screen an extensive database of 0.25 million compounds to identify potential leads. The validated model was implemented for the identification, design, synthesis, and biological evaluation of leads. Ten new chemical entities were synthesized based on our scaffold hopping techniques from the identified virtual screening and tested against the tuberculosis bacterium to obtain preliminary MIC values. The results showed that 3 out of 10 synthesized compounds exhibited good MICs, from 1.25 to 50 μM. This proves the robustness and applicability of the developed model, which is a promising tool for identifying new topoisomerase II inhibitors for the treatment of tuberculosis.
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Affiliation(s)
- Deepti Mathpal
- Sanskriti University, School of Pharmacy and Research 28 KM. Stone, Mathura - Delhi Highway, Chhata Mathura Uttar Pradesh (UP) 281401 India
| | - Mukesh Masand
- Department of Pharmacy, Faculty of Medicine and Allied Sciences, Galgotias University Gautam Buddha Nagar Uttar Pradesh 226001 India
| | - Anisha Thomas
- Department of Chemistry, School of Advanced Sciences, VIT Vellore India
| | - Irfan Ahmad
- Department of Clinical Laboratory Science, College of Applied Medical Sciences, King Khalid University Abha Saudi Arabia
| | - Mohd Saeed
- Department of Biology College of Sciences, University of Hail Saudi Arabia
| | - Gaffar Sarwar Zaman
- Department of Clinical Laboratory Science, College of Applied Medical Sciences, King Khalid University Abha Saudi Arabia
| | - Mehnaz Kamal
- Department of Pharmaceutical Chemistry, College of Pharmacy, Prince Sattam Bin Abdulaziz University P.O. Box No. 173 Al Kharj 11942 Kingdom of Saudi Arabia
| | - Talha Jawaid
- Department of Pharmacology, College of Medicine, Al Imam Mohammad Ibn Saud Islamic University (IMSIU) Riyadh 13317 Kingdom of Saudi Arabia
| | - Pramod K Sharma
- Department of Pharmacy, Faculty of Medicine and Allied Sciences, Galgotias University Gautam Buddha Nagar Uttar Pradesh 226001 India
| | - Madan M Gupta
- School of Pharmacy, Faculty of the West Indies St Augustine Trinidad and Tobago West Indies
| | - Santosh Kumar
- Government Degree College Hansaur Barabanki Uttar Pradesh (UP) 225415 India
| | - Swayam Prakash Srivastava
- Sanskriti University, School of Pharmacy and Research 28 KM. Stone, Mathura - Delhi Highway, Chhata Mathura Uttar Pradesh (UP) 281401 India
- Department of Pediatrics, Yale University School of Medicine New Haven CT 06520 USA
- Vascular Biology and Therapeutic Program, Yale University School of Medicine New Haven CT 06511 USA
| | - Vishal M Balaramnavar
- Sanskriti University, School of Pharmacy and Research 28 KM. Stone, Mathura - Delhi Highway, Chhata Mathura Uttar Pradesh (UP) 281401 India
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Repurposing of Antimicrobial Agents for Cancer Therapy: What Do We Know? Cancers (Basel) 2021; 13:cancers13133193. [PMID: 34206772 PMCID: PMC8269327 DOI: 10.3390/cancers13133193] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 06/23/2021] [Accepted: 06/24/2021] [Indexed: 02/07/2023] Open
Abstract
The substantial costs of clinical trials, the lengthy timelines of new drug discovery and development, along the high attrition rates underscore the need for alternative strategies for finding quickly suitable therapeutics agents. Given that most approved drugs possess more than one target tightly linked to other diseases, it encourages promptly testing these drugs in patients. Over the past decades, this has led to considerable attention for drug repurposing, which relies on identifying new uses for approved or investigational drugs outside the scope of the original medical indication. The known safety of approved drugs minimizes the possibility of failure for adverse toxicology, making them attractive de-risked compounds for new applications with potentially lower overall development costs and shorter development timelines. This latter case is an exciting opportunity, specifically in oncology, due to increased resistance towards the current therapies. Indeed, a large body of evidence shows that a wealth of non-cancer drugs has beneficial effects against cancer. Interestingly, 335 drugs are currently being evaluated in different clinical trials for their potential activities against various cancers (Redo database). This review aims to provide an extensive discussion about the anti-cancer activities exerted by antimicrobial agents and presents information about their mechanism(s) of action and stage of development/evaluation.
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Ubiquitous Nature of Fluoroquinolones: The Oscillation between Antibacterial and Anticancer Activities. Antibiotics (Basel) 2017; 6:antibiotics6040026. [PMID: 29112154 PMCID: PMC5745469 DOI: 10.3390/antibiotics6040026] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2017] [Revised: 10/26/2017] [Accepted: 11/03/2017] [Indexed: 12/15/2022] Open
Abstract
Fluoroquinolones are synthetic antibacterial agents that stabilize the ternary complex of prokaryotic topoisomerase II enzymes (gyrase and Topo IV), leading to extensive DNA fragmentation and bacteria death. Despite the similar structural folds within the critical regions of prokaryotic and eukaryotic topoisomerases, clinically relevant fluoroquinolones display a remarkable selectivity for prokaryotic topoisomerase II, with excellent safety records in humans. Typical agents that target human topoisomerases (such as etoposide, doxorubicin and mitoxantrone) are associated with significant toxicities and secondary malignancies, whereas clinically relevant fluoroquinolones are not known to exhibit such propensities. Although many fluoroquinolones have been shown to display topoisomerase-independent antiproliferative effects against various human cancer cells, those that are significantly active against eukaryotic topoisomerase show the same DNA damaging properties as other topoisomerase poisons. Empirical models also show that fluoroquinolones mediate some unique immunomodulatory activities of suppressing pro-inflammatory cytokines and super-inducing interleukin-2. This article reviews the extended roles of fluoroquinolones and their prospects as lead for the unmet needs of "small and safe" multimodal-targeting drug scaffolds.
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In Vitro Evaluation of Zn–Norfloxacin Complex as a Potent Cytotoxic and Antibacterial Agent, Proposed Model for DNA Binding. Appl Biochem Biotechnol 2013; 170:988-1009. [DOI: 10.1007/s12010-013-0255-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2012] [Accepted: 04/21/2013] [Indexed: 10/26/2022]
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Abstract
Injudicious use of the fluoroquinolones may result in treatment failure, increased patient morbidity, increased health care cost, and possible patient fatality. Fluoroquinolone-resistant bacteria may also adversely impact the microbiological environment in the hospital, the local community and eventually large geographical regions. Fluoroquinolone resistance develops in a stepwise fashion, and current susceptibility testing methods and recommended MIC susceptible breakpoint values for the United States may fail to identify some bacteria that are resistant due to first step mutations at the fluoroquinolone target site gene sequences. C-8 methoxy- fluoroquinolone compounds are more active against resistant bacteria than the older compounds. Fluoroquinolone resistance relates directly to human and veterinary usage and emerging bacterial resistance poses the single greatest threat to the future survival of the fluoroquinolone drugs as an antibiotic class.
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Affiliation(s)
- Johan S Bakken
- St. Luke's Infectious Disease Associates, Duluth, Minnesota 55805, USA.
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Thibodeaux BA, Dajcs JJ, Caballero AR, Marquart ME, Girgis DO, O'Callaghan RJ. Quantitative comparison of fluoroquinolone therapies of experimental Gram-negative bacterial keratitis. Curr Eye Res 2009; 28:337-42. [PMID: 15287370 DOI: 10.1076/ceyr.28.5.337.28676] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
PURPOSE To determine the effectiveness of topically applied fluoroquinolones for experimental Pseudomonas or Serratia keratitis. METHODS Bacteria were injected intrastromally (10(3) colony forming units [CFU]). From 16 to 22 hours post-infection (PI), a single topical drop of moxifloxacin (Vigamox, 0.545%), levofloxacin (Quixin, 0.5%), ofloxacin (Ocuflox, 0.3%) or ciprofloxacin (Ciloxan, 0.3%) was applied every 30 minutes. At 23 hours PI, corneas were cultured quantitatively. RESULTS For Pseudomonas keratitis, untreated eyes contained 7 log CFU/cornea and antibiotic-treated eyes demonstrated a > or = 5-log reduction in CFU/cornea (p < or = 0.0001). Moxifloxacin, levofloxacin, or ciprofloxacin therapies were not significantly different from each other (p > or = 0.67). For Serratia keratitis, untreated eyes contained 7 logCFU/cornea whereas treated eyes had a > or = 2-log reduction (p < or = 0.0001). Moxifloxacin therapy proved most effective (p < or = 0.001). CONCLUSIONS Overall, moxifloxacin was the most effective of the four fluoroquinolones in reducing CFU/cornea in the rabbit model of gram-negative keratitis.
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Affiliation(s)
- Brett A Thibodeaux
- Department of Microbiology, Immunology, and Parasitology, Louisiana State University Health Sciences Center, New Orleans, LA 70112, USA
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Bourikas LA, Kolios G, Valatas V, Notas G, Drygiannakis I, Pelagiadis I, Manousou P, Klironomos S, Mouzas IA, Kouroumalis E. Ciprofloxacin decreases survival in HT-29 cells via the induction of TGF-beta1 secretion and enhances the anti-proliferative effect of 5-fluorouracil. Br J Pharmacol 2009; 157:362-70. [PMID: 19371339 DOI: 10.1111/j.1476-5381.2009.00161.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND AND PURPOSE Fluoroquinolones are potent anti-microbial agents with multiple effects on host cells and tissues. Previous studies have highlighted their pro-apoptotic effect on human cancer cells and an immunoregulatory role in animal models of inflammatory bowel disease. We examined the effect of ciprofloxacin on proliferation, cell cycle and apoptosis of HT-29 cells, a human colonic epithelial cell line sensitive to transforming growth factor (TGF)-beta1-mediated growth inhibition and its role in TGF-beta1 production. We also examined the effect of ciprofloxacin on proliferation of HT-29 cells in combination with 5-fluorouracil (5-FU), a well-established pro-apoptotic agent. EXPERIMENTAL APPROACH Using subconfluent cultures of HT-29 and Caco-2 cells, we studied the effect of ciprofloxacin, TGF-beta1 and 5-FU on proliferation, apoptosis, necrosis and cell cycle. The effect of ciprofloxacin on TGF-beta1 mRNA expression and production was studied in RNA extracts and cell culture supernatants respectively, using confluent cultures. KEY RESULTS Ciprofloxacin decreased proliferation of HT-29 cells in a concentration- and time-dependent manner. This was mediated by accumulation of HT-29 cells into the S-phase but without any effect on apoptosis or necrosis. Additionally, ciprofloxacin enhanced the antiproliferative effect of 5-FU. Interestingly, ciprofloxacin was found to up-regulate TGF-beta1 production by HT-29 cells and its anti-proliferative effect was abolished when TGF-beta1 was blocked. Confirming this mechanism further, ciprofloxacin had no effect on Caco-2, a human colonic epithelial cell line that lacks functional TGF-beta1 receptors. CONCLUSIONS AND IMPLICATIONS We demonstrate a novel anti-proliferative and immunoregulatory effect of ciprofloxacin on human intestinal epithelial cells mediated via TGF-beta1.
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Abstract
In just 70 short years mankind has progressed from euphoria to despair over the effectiveness of antibiotics to protect and to cure mankind from morbidity and mortality from infectious diseases. Resistance due to evolutionary factors was observed shortly after antibiotics came into use and is now not only widespread but appears to be inevitable. This review is a rather personalized account of the various attempts to deal with this problem over time.
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Affiliation(s)
- Lester A Mitscher
- Department of Medicinal Chemistry, University of Kansas, Lawrence, Kansas 66045, USA.
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11
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Senthilkumar P, Dinakaran M, Yogeeswari P, China A, Nagaraja V, Sriram D. Antimycobacterial activities of novel fluoroquinolones. Biomed Pharmacother 2007; 63:27-35. [PMID: 18031974 DOI: 10.1016/j.biopha.2007.10.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2007] [Accepted: 10/03/2007] [Indexed: 11/28/2022] Open
Abstract
Fifty-one novel 1-(cyclopropyl/2,4-difluorophenyl/t-butyl)-1,4-dihydro-6-fluoro-7-(sub secondary amino)-4-oxoquinoline-3-carboxylic acids were synthesized and evaluated for their antimycobacterial in vitro and in vivo against Mycobacterium tuberculosis H37Rv (MTB), multi-drug resistant Mycobacterium tuberculosis (MDR-TB) and Mycobacterium smegmatis (MC(2)) and also tested for the ability to inhibit the supercoiling activity of DNA gyrase from M. smegmatis. Among the synthesized compounds, 7-(3-(diethylcarbamoyl)piperidin-1-yl)-1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxoquinoline-3-carboxylic acid (7l) was found to be the most active compound in vitro with MIC of 0.09 microM against MTB and MDR-TB respectively. In the in vivo animal model 7l decreased the mycobacterial load in lung and spleen tissues with 2.53- and 4.88-log10 protections respectively at a dose of 50mg/kg body weight.
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Affiliation(s)
- Palaniappan Senthilkumar
- Medicinal Chemistry Research Laboratory, Pharmacy Group, Birla Institute of Technology and Science, Pilani, Rajasthan, India
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Evstigneev MP, Rybakova KA, Davies DB. Formation of complexes of antimicrobial agent norfloxacin with antitumor antibiotics of anthracycline series. RUSSIAN JOURNAL OF PHYSICAL CHEMISTRY A 2007. [DOI: 10.1134/s0036024407050275] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Affiliation(s)
- Stephen Hanessian
- Department of Chemistry, Université de Montréal, C.P. 6128, Succursale Centre-Ville, Montréal, QC, H3C3J7, Canada.
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Evstigneev MP, Baranovsky SF, Rybakova KA, Davies DB. Complexation of the quinolone antibiotic norfloxacin with DNA. Mol Biol 2006. [DOI: 10.1134/s0026893306050165] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Evstigneev MP, Rybakova KA, Davies DB. Heteroassociation of antibiotic norfloxacin with aromatic vitamins in aqueous solution. Biophysics (Nagoya-shi) 2006. [DOI: 10.1134/s0006350906040129] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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Evstigneev MP, Rybakova KA, Davies DB. Complexation of norfloxacin with DNA in the presence of caffeine. Biophys Chem 2006; 121:84-95. [PMID: 16455179 DOI: 10.1016/j.bpc.2005.12.003] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2005] [Revised: 12/05/2005] [Accepted: 12/07/2005] [Indexed: 10/25/2022]
Abstract
(1)H NMR spectroscopy (500 MHz) has been used to quantify the complexation of the antibacterial antibiotic Norfloxacin (NOR) with DNA in the presence of Caffeine (CAF). Separate studies have been made for the self-association of NOR, its hetero-association with CAF and complexation with a model self-complementary DNA tetramer, 5'-d(TpGpCpA), in order to determine the equilibrium parameters (induced chemical shifts, association constants, enthalpy and entropy) of the two-component mixtures to aid the analysis of the three-component systems. Investigations of the self-association of NOR and its hetero-association with CAF show that the aggregation of NOR molecules and association with CAF in solution are driven by the stacking of aromatic chromophores. The complexation of NOR with d(TGCA) has been analysed in terms of intercalation with the double-stranded form and non-intercalative binding with the single-stranded form of DNA. Investigations of the competitive binding of NOR and CAF with DNA show that at physiological concentrations of NOR (muM) and CAF (mM) the dominant mechanism influencing the affinity of NOR with DNA is the displacement of bound NOR molecules from DNA due to CAF-DNA complexation (i.e. the protector action of Caffeine).
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Affiliation(s)
- M P Evstigneev
- Department of Physics, Sevastopol National Technical University, Studgorodok, Sevastopol, 99053, Crimea, Ukraine.
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Langer O, Brunner M, Zeitlinger M, Ziegler S, Müller U, Dobrozemsky G, Lackner E, Joukhadar C, Mitterhauser M, Wadsak W, Minar E, Dudczak R, Kletter K, Müller M. In vitro and in vivo evaluation of [18F]ciprofloxacin for the imaging of bacterial infections with PET. Eur J Nucl Med Mol Imaging 2004; 32:143-50. [PMID: 15690222 DOI: 10.1007/s00259-004-1646-2] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2004] [Accepted: 06/29/2004] [Indexed: 10/26/2022]
Abstract
PURPOSE The suitability of the 18F-labelled fluoroquinolone antibiotic ciprofloxacin ([18F]ciprofloxacin) for imaging of bacterial infections with positron emission tomography (PET) was assessed in vitro and in vivo. METHODS For the in vitro experiments, suspensions of various E. coli strains were incubated with different concentrations of [18F]ciprofloxacin (0.01-5.0 microg/ml) and radioactivity retention was measured in a gamma counter. For the in vivo experiments, 725 +/- 9 MBq [18F]ciprofloxacin was injected intravenously into four patients with microbiologically proven bacterial soft tissue infections of the lower extremities and time-radioactivity curves were recorded in infected and uninfected tissue for 5 h after tracer injection. RESULTS Binding of [18F]ciprofloxacin to bacterial cells was rapid, non-saturable and readily reversible. Moreover, bacterial binding of the agent was similar in ciprofloxacin-resistant and ciprofloxacin-susceptible clinical isolates. These findings suggest that non-specific binding rather than specific binding to bacterial type II topoisomerase enzymes is the predominant mechanism of bacterial retention of the radiotracer. PET studies in the four patients with microbiologically proven bacterial soft tissue infections demonstrated locally increased radioactivity uptake in infected tissue, with peak ratios between infected and uninfected tissue ranging from 1.8 to 5.5. Radioactivity was not retained in infected tissue and appeared to wash out with a similar elimination half-life as in uninfected tissue, suggesting that the kinetics of [18F]ciprofloxacin in infected tissue are governed by increased blood flow and vascular permeability due to local infection rather than by a binding process. CONCLUSION Taken together, our results indicate that [18F]ciprofloxacin is not suited as a bacteria-specific infection imaging agent for PET.
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Affiliation(s)
- Oliver Langer
- Division of Clinical Pharmacokinetics, Department of Clinical Pharmacology, Medical University Vienna, Währinger Gürtel 18-20, 1090, Vienna, Austria.
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Dajcs JJ, Thibodeaux BA, Marquart ME, Girgis DO, Traidej M, O'Callaghan RJ. Effectiveness of ciprofloxacin, levofloxacin, or moxifloxacin for treatment of experimental Staphylococcus aureus keratitis. Antimicrob Agents Chemother 2004; 48:1948-52. [PMID: 15155183 PMCID: PMC415620 DOI: 10.1128/aac.48.6.1948-1952.2004] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The purpose of this study was to quantitatively compare, in a rabbit keratitis model, the levels of effectiveness of moxifloxacin, levofloxacin, and ciprofloxacin for the treatment of Staphylococcus aureus isolates of diverse antibiotic susceptibilities. Rabbit eyes were intrastromally injected with approximately 100 CFU of methicillin-sensitive or methicillin-resistant S. aureus (MSSA or MRSA, respectively) organisms that were either sensitive or resistant to ofloxacin. One drop of moxifloxacin (0.5%), levofloxacin (0.5%), or ciprofloxacin (0.3%) was topically applied hourly from 4 to 9 (early) or 10 to 15 (late) h postinfection. At 1 h after cessation of therapy, the corneas were harvested, and the number of CFU per cornea was determined. For the ofloxacin-sensitive strains, early treatment of MSSA or MRSA with moxifloxacin, levofloxacin, or ciprofloxacin produced approximately a 5-log decrease in CFU per cornea relative to that in untreated eyes (P </= 0.0001). For late therapy of ofloxacin-sensitive strains, moxifloxacin, levofloxacin, and ciprofloxacin produced approximately 5-, 4-, and 2- to 3-log reductions in CFU per cornea, respectively (P </= 0.0001). Early treatment of the ofloxacin-resistant strains with either moxifloxacin or levofloxacin produced a >/=4-log or >/=3-log decrease, respectively, in the MSSA or MRSA strains (P </= 0.0001), whereas ciprofloxacin treatment produced a 1-log decrease in CFU per cornea relative to that in untreated eyes (P = 0.1540). For late treatment of ofloxacin-resistant strains, levofloxacin and ciprofloxacin failed to significantly reduce the number of CFU per cornea (P >/= 0.3627), whereas moxifloxacin produced a significant reduction in CFU per cornea of approximately 1 log (P </= 0.0194). Therefore, for three of the four treatments tested, moxifloxacin demonstrated greater effectiveness than either levofloxacin or ciprofloxacin.
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Affiliation(s)
- Joseph J Dajcs
- Department of Microbiology, Immunology, and Parasitology, LSU Health Sciences Center, 1901 Perdido St., New Orleans, LA 70112, USA
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Sissi C, Perdonà E, Domenici E, Feriani A, Howells AJ, Maxwell A, Palumbo M. Ciprofloxacin affects conformational equilibria of DNA gyrase A in the presence of magnesium ions. J Mol Biol 2001; 311:195-203. [PMID: 11469868 DOI: 10.1006/jmbi.2001.4838] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The conformational equilibria of the A subunit of DNA gyrase (GyrA), of its 59 kDa N-terminal fragment (GyrA59) and of the quinolone-resistant Ser-Trp83 mutant (GyrATrp83), were investigated in the presence of mono- and divalent metal ions and ciprofloxacin, a clinically useful antibacterial quinolone. The stability of the proteins was estimated from temperature denaturation, monitoring unfolding with circular dichroism spectroscopy. Two transitions were observed in GyrA and GyrATrp83, which likely reflect unfolding of the N and C-terminal protein domains. Accordingly, one thermal transition is observed for GyrA59. The melting profile of the GyrA subunit is dramatically affected by monovalent and divalent metal ions, both transitions being shifted to lower temperature upon increasing salt concentration. This effect is much more pronounced with divalent ions (Mg(2+)) and cannot be accounted for by changes in ionic strength only. The presence of ciprofloxacin shifts the melting transitions of the wild-type subunit to higher temperatures when physiological concentrations of Mg(2+) are present. In contrast, both the mutant protein and the 59 kDa fragment do not show evidence for quinolone-driven changes. These data suggest that ciprofloxacin binds to the wild-type subunit in an interaction that involves Ser83 of GyrA and that both C and N-terminal domains may be required for effective drug-protein interactions. The bell-shaped dependence of the binding process upon Mg(2+) concentration, with a maximum centred at 3-4 mM [Mg(2+)], is consistent with a metal-ion mediated GyrA-quinolone-interaction. Affinity chromatography data fully support these findings and additionally confirm the requirement for a free carboxylate to elicit binding of the quinolone to GyrA. We infer that the Mg(2+)-GyrA interaction at physiological metal ion concentration could bear biological relevance, conferring more conformational flexibility to the active enzyme. The results obtained in the presence of ciprofloxacin additionally suggest that the Mg(2+)-mediated quinolone binding to the enzyme might be involved in the mechanism of action of this family of drugs.
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Affiliation(s)
- C Sissi
- Department of Pharmaceutical Sciences, University of Padova, via Marzolo 5, Padova, 35100, Italy
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20
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Abstract
Sequence-specific conformational strains (SSCS) of biopolymers that carry free energy and genetic information have been called conformons, a term coined independently by two groups over two and a half decades ago [Green, D.E., Ji, S., 1972. The electromechanochemical model of mitochondrial structure and function. In: Schultz, J., Cameron, B.F. (Eds.), Molecular Basis of Electron Transport. Academic Press, New York, pp. 1-44; Volkenstein, M.V., 1972. The Conformon. J. Theor. Biol. 34, 193-195]. Conformons provide the molecular mechanisms necessary and sufficient to account for all biological processes in the living cell on the molecular level in principle--including the origin of life, enzymic catalysis, control of gene expression, oxidative phosphorylation, active transport, and muscle contraction. A clear example of SSCS is provided by SIDD (strain-induced duplex destabilization) in DNA recently reported by Benham [Benham, C.J., 1996a. Duplex destabilization in superhelical DNA is predicted to occur at specific transcriptional regulatory regions. J. Mol. Biol. 255, 425-434; Benham, C.J., 1996b. Computation of DNA structural variability--a new predictor of DNA regulatory regions. CABIOS 12(5), 375-381]. Experimental as well as theoretical evidence indicates that conformons in proteins carry 8-16 kcal/mol of free energy and 40-200 bits of information, while those in DNA contain 500-2500 kcal/mol of free energy and 200-600 bits of information. The similarities and differences between conformons and solitons have been analyzed on the basis of the generalized Franck-Condon principle [Ji, S., 1974a. A general theory of ATP synthesis and utilization. Ann. N.Y. Acad. Sci. 227, 211-226; Ji, S., 1974b. Energy and negentropy in enzymic catalysis. Ann. N.Y. Acad. Sci. 227, 419-437]. To illustrate a practical application, the conformon theory was applied to the molecular-clamp model of DNA gyrase proposed by Berger and Wang [Berger, J.M., Wang, J.C., 1996. Recent developments in DNA topoisomerases II structure and mechanism. Curr. Opin. Struct. Biol. 6(1), 84-90], leading to the proposal of an eight-step molecular mechanism for the action of the enzyme. Finally, a set of experimentally testable predictions has been formulated on the basis of the conformon theory.
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Affiliation(s)
- S Ji
- Department of Pharmacology and Toxicology, Rutgers University, Piscataway, NJ 08855, USA.
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21
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Segatore B, Setacci D, Perilli M, Franceschini N, De Santis A, Marchetti F, Amicosante G. Italian survey on comparative levofloxacin susceptibility in 334 clinical isolates of Pseudomonas aeruginosa. Antimicrob Agents Chemother 1999; 43:428-31. [PMID: 9925553 PMCID: PMC89098 DOI: 10.1128/aac.43.2.428] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/1998] [Accepted: 11/30/1998] [Indexed: 11/20/2022] Open
Abstract
A national survey on susceptibility patterns of 334 Pseudomonas aeruginosa isolates from intensive care units and hematology and oncology wards from 13 Italian hospitals compared the in vitro activity of levofloxacin, an injectable oral fluoroquinolone, to those of ciprofloxacin, ofloxacin, ceftazidime, imipenem, amikacin, and gentamicin. Amikacin and imipenem had the best susceptibility profiles. The activity of levofloxacin was superior to those of the other quinolones and was comparable to that of ceftazidime. The effect of levofloxacin in vitro on P. aeruginosa clinical isolates suggests that further clinical investigations are warranted.
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Affiliation(s)
- B Segatore
- Department of Sciences and Biomedical Technologies, School of Medicine, University of L'Aquila, Italy
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22
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Schneider Berlin KR, Ammini CV, Rowe TC. Dequalinium induces a selective depletion of mitochondrial DNA from HeLa human cervical carcinoma cells. Exp Cell Res 1998; 245:137-45. [PMID: 9828109 DOI: 10.1006/excr.1998.4236] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Treatment of cultured human cervical carcinoma cells with the anticancer drug dequalinium (DEQ) was found to cause a delayed inhibition of cell growth. This inhibition was preceded by a loss of mitochondrial DNA (mtDNA), a decrease in cytochrome c oxidase activity, and an increase in the level of lactate, indicating that growth inhibition was due to the loss of mtDNA-encoded functions. There was a progressive two-fold loss of mtDNA following each cell division in the presence of DEQ, suggesting that this drug was acting by inhibiting some aspect of mtDNA synthesis. Furthermore, cells became resistant to the growth inhibitory and cytotoxic affects of DEQ when they were grown under conditions that bypassed the need for mtDNA-encoded functions. Resistance was not associated with significant changes in drug accumulation. These results suggest that the DEQ-induced depletion of mtDNA plays an important role in drug cytotoxicity.
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Affiliation(s)
- K R Schneider Berlin
- Department of Pharmacology and Therapeutics, University of Florida College of Medicine, Gainesville, Florida, 32610-0267, USA
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23
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Li Q, Wang W, Berst KB, Claiborne A, Hasvold L, Raye K, Tufano M, Nilius A, Shen LL, Flamm R, Alder J, Marsh K, Crowell D, Chu DT, Plattner JJ. Synthesis and structure-activity relationships of 2-pyridones: II. 8-(Fluoro-substituted pyrrolidinyl)-2-pyridones as antibacterial agents. Bioorg Med Chem Lett 1998; 8:1953-8. [PMID: 9873465 DOI: 10.1016/s0960-894x(98)00355-2] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The 8-position side chain of 2-pyridones is believed to be involved in the binding with bacterial DNA gyrase to form the ternary complex, making them very important for the activity of 2-pyridones. A series of 2-pyridones having fluoro-substituted amines at the 8-position has been synthesized and their antibacterial activities and parmacokinetic properties are reported.
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Affiliation(s)
- Q Li
- Pharmaceutical Products Division, Abbott Laboratories, Abbott Park, Illinois 60064-3500, USA
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24
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Weissig V, Vetro-Widenhouse TS, Rowe TC. Topoisomerase II inhibitors induce cleavage of nuclear and 35-kb plastid DNAs in the malarial parasite Plasmodium falciparum. DNA Cell Biol 1997; 16:1483-92. [PMID: 9428797 DOI: 10.1089/dna.1997.16.1483] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The topoisomerase II-specific inhibitors VP-16 and ciprofloxacin were used to investigate the presence of topoisomerase II activities associated with nuclear and 35-kb plastid DNAs of the malarial parasite Plasmodium falciparum. The eukaryotic topoisomerase II inhibitor VP-16 induced cleavage of both nuclear and 35-kb parasite DNAs. In contrast, ciprofloxacin, a fluoroquinolone drug known to act on the bacterial type II topoisomerase DNA gyrase, only induced cleavage of the Plasmodial 35-kb DNA. Drug-induced cleavage resulted in the protection of the 5'- but not 3'- ends of the cleaved nuclear and 35-kb DNAs from exonuclease digestion, suggesting that the 5'-ends of the broken DNA were protein-linked, a property reminiscent of DNA cleavage mediated by topoisomerase II enzymes. Furthermore, DNA cleavage induced by both VP-16 and ciprofloxacin was heat-reversible. This is the first evidence that P. falciparum contains two distinct topoisomerase II activities that are molecular targets for chemotherapeutic agents.
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Affiliation(s)
- V Weissig
- Department of Pharmacology and Therapeutics, University of Florida College of Medicine, Gainesville 32610-0267, USA
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25
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Scheirer KE, Higgins NP. The DNA cleavage reaction of DNA gyrase. Comparison of stable ternary complexes formed with enoxacin and CcdB protein. J Biol Chem 1997; 272:27202-9. [PMID: 9341164 DOI: 10.1074/jbc.272.43.27202] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The potent synthetic fluoroquinolones and the natural CcdB protein encoded by the F plasmid both inhibit bacterial growth by attacking DNA gyrase and by stimulating enzyme-induced breaks in bacterial DNA. The cleavage mechanisms of these structurally diverse compounds were analyzed by purifying and characterizing stable ternary complexes of enoxacin and CcdB protein with gyrase bound to a strong gyrase binding site from bacteriophage Mu. Three differences between enoxacin- and CcdB-derived complexes were discovered. 1) Enoxacin binds to the DNA active site and alters the breakage/reunion activity of the enzyme. CcdB binds gyrase-DNA complexes but does not influence enzymatic activity directly. 2) Complexes that produce DNA cleavage with enoxacin are reversible, whereas similar complexes made with CcdB protein are not. 3) Enoxacin stimulates cleavage of both relaxed and supercoiled forms of DNA in the absence of ATP, whereas CcdB induces cleavage only after many cycles of ATP-dependent breakage and reunion. These differences in mechanisms can be explained by a model in which enoxacin induces formation of a novel "cleavable" complex, whereas CcdB protein traps a very rare "cleaved" conformation of the enzyme.
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Affiliation(s)
- K E Scheirer
- Department of Biochemistry and Molecular Genetics, University of Alabama, Birmingham, Alabama 35294, USA
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26
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Bernard FX, Sablé S, Cameron B, Provost J, Desnottes JF, Crouzet J, Blanche F. Glycosylated flavones as selective inhibitors of topoisomerase IV. Antimicrob Agents Chemother 1997; 41:992-8. [PMID: 9145858 PMCID: PMC163839 DOI: 10.1128/aac.41.5.992] [Citation(s) in RCA: 97] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Three flavonoids which promoted Escherichia coli topoisomerase IV-dependent DNA cleavage were isolated from cottonseed flour and identified as quercetin 3-O-beta-D-glucose-[1,6]-O-alpha-L-rhamnose (rutin), quercetin 3-O-beta-D-galactose-[1,6]-O-alpha-L-rhamnose, and quercetin 3-O-beta-D-glucose (isoquercitrin). The most active one (rutin) also inhibited topoisomerase IV-dependent decatenation activity (50% inhibitory concentration, 64 microg/ml) and induced the SOS response of a permeable E. coli strain. Derivatives of quercetin glycosylated at position C-3 were shown to induce two site-specific DNA cleavages of pBR322 DNA, which were mapped by DNA sequence analysis to the gene encoding resistance to tetracycline. Cleavage at these sites was hardly detectable in cleavage reactions with quercetin or fluoroquinolones. None of the three flavonoids isolated from cottonseeds had any stimulatory activity on E. coli DNA gyrase-dependent or calf thymus topoisomerase II-dependent DNA cleavage, and they were therefore specific to topoisomerase IV. These results show that selective inhibitors of topoisomerase IV can be derived from the flavone structure. This is the first report on a DNA topoisomerase inhibitor specific for topoisomerase IV.
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Affiliation(s)
- F X Bernard
- Antibacterial Program, Rhône-Poulenc Rorer S.A., Vitry-sur-Seine, France
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27
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Mizushima T, Matsuo M, Sekimizu K. Induction of DnaK and GroEL heat shock proteins by fluoroquinolones in Escherichia coli. Antimicrob Agents Chemother 1997; 41:193-5. [PMID: 8980780 PMCID: PMC163685 DOI: 10.1128/aac.41.1.193] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Various fluoroquinolones (norfloxacin, enoxacin, ofloxacin, levofloxacin, and sparfloxacin) induce DnaK and GroEL heat shock proteins in Escherichia coli. The induction is transient, consistent with the kinetics of cellular DNA relaxation. The concentrations of fluoroquinolones required for induction are similar to those required for DNA relaxation and much higher than those required for cell death.
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Affiliation(s)
- T Mizushima
- Department of Microbiology, Faculty of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan
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28
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Blanche F, Cameron B, Bernard FX, Maton L, Manse B, Ferrero L, Ratet N, Lecoq C, Goniot A, Bisch D, Crouzet J. Differential behaviors of Staphylococcus aureus and Escherichia coli type II DNA topoisomerases. Antimicrob Agents Chemother 1996; 40:2714-20. [PMID: 9124828 PMCID: PMC163609 DOI: 10.1128/aac.40.12.2714] [Citation(s) in RCA: 119] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Staphylococcus aureus gyrA and gyrB genes encoding DNA gyrase subunits were cloned and coexpressed in Escherichia coli under the control of the T7 promoter-T7 RNA polymerase system, leading to soluble gyrase which was purified to homogeneity. Purified gyrase was catalytically indistinguishable from the gyrase purified from S. aureus and did not contain detectable amounts of topoisomerases from the E. coli host. Topoisomerase IV subunits GrlA and GrlB from S. aureus were also expressed in E. coli and were separately purified to apparent homogeneity. Topoisomerase IV, which was reconstituted by mixing equimolar amounts of GrlA and GrlB, had both ATP-dependent decatenation and DNA relaxation activities in vitro. This enzyme was more sensitive than gyrase to inhibition by typical fluoroquinolone antimicrobial agents such as ciprofloxacin or sparfloxacin, adding strong support to genetic studies which indicate that topoisomerase IV is the primary target of fluoroquinolones in S. aureus. The results obtained with ofloxacin suggest that this fluoroquinolone could also primarily target gyrase. No cleavable complex could be detected with S. aureus gyrase upon incubation with ciprofloxacin or sparfloxacin at concentrations which fully inhibit DNA supercoiling. This suggests that these drugs do not stabilize the open DNA-gyrase complex, at least under standard in vitro incubation conditions, but are more likely to interfere primarily with the DNA breakage step, contrary to what has been reported with E. coli gyrase. Both S. aureus gyrase-catalyzed DNA supercoiling and S. aureus topoisomerase IV-catalyzed decatenation were dramatically stimulated by potassium glutamate or aspartate (500- and 50-fold by 700 and 350 mM glutamate, respectively), whereas topoisomerase IV-dependent DNA relaxation was inhibited 3-fold by 350 mM glutamate. The relevance of the effect of dicarboxylic amino acids on the activities of type II topoisomerases is discussed with regard to the intracellular osmolite composition of S. aureus.
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Affiliation(s)
- F Blanche
- Department of Molecular Microbiology, Rhône-Poulenc Rorer S.A., Vitry-sur-Seine, France.
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29
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Klopman G, Fercu D, Renau TE, Jacobs MR. N-1-tert-butyl-substituted quinolones: in vitro anti-Mycobacterium avium activities and structure-activity relationship studies. Antimicrob Agents Chemother 1996; 40:2637-43. [PMID: 8913479 PMCID: PMC163590 DOI: 10.1128/aac.40.11.2637] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
We determined the MICs of 63 quinolones against 14 selected reference and clinical strains of the Mycobacterium avium-Mycobacterium intracellulare complex. Sixty-one of the compounds were selected from the quinolone library at Parke-Davis, Ann Arbor, Mich., including N-1-tert-butyl-substituted agents. T 3761 and tosufloxacin were also tested. The activities of all 63 compounds were compared with those of ciprofloxacin and sparfloxacin. The results showed 45 of the quinolones to be active against the M. avium-M. intracellulare complex, with MICs at which 50% of the strains were inhibited (MIC50s) of less than 32 micrograms/ml. Twenty-four of these quinolones had activities equivalent to or greater than that of ciprofloxacin, and nine of them had activities equivalent to or greater than that of sparfloxacin. The most active compounds were the N-1-tert-butyl-substituted quinolones, PD 161315 and PD 161314, with MIC50s of 0.25 microgram/ml and MIC90s of 1 microgram/ml; comparable values for ciprofloxacin were 2 and 4 micrograms/ml, respectively, while for sparfloxacin they were 1 and 2 micrograms/ml, respectively. The next most active compounds, with MIC50s of 0.5 microgram/ml and MIC90s of 1 microgram/ml, were the N-1-cyclopropyl-substituted quinolones, PD 138926 and PD 158804. These values show that the tert-butyl substituent is at least as good as cyclopropyl in rendering high levels of antimycobacterial activity. However, none of the quinolones showed activity against ciprofloxacin-resistant laboratory-derived M. avium-M. intracellulare complex strains. A MULTICASE program-based structure-activity relationship analysis of the inhibitory activities of these 63 quinolones and 109 quinolones previously studied against the most resistant clinical strain of M. avium was also performed and led to the identification of two major biophores and two biophobes.
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Affiliation(s)
- G Klopman
- Department of Chemistry, Case Western Reserve University, Cleveland, Ohio 44106, USA
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30
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Hanessian S, Saladino R, Nunez JC. On the binding site of quinolone antibacterials. An attempt to probe the shen model. Bioorg Med Chem Lett 1996. [DOI: 10.1016/0960-894x(96)00430-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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31
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Matsuo M, Ohtsuka Y, Kataoka K, Mizushima T, Sekimizu K. Transient relaxation of plasmid DNA in Escherichia coli by fluoroquinolones. J Pharm Pharmacol 1996; 48:985-7. [PMID: 8910869 DOI: 10.1111/j.2042-7158.1996.tb06018.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
We examined the influence of fluoroquinolones (norfloxacin, enoxacin, ofloxacin, levofloxacin, and sparfloxacin) on DNA supercoiling of plasmids in Escherichia coli cells by analysis with agarose gel electrophoresis in the presence of chloroquine. All the fluoroquinolones tested immediately induced DNA relaxation. The relaxed DNA was re-supercoiled, and the process was sensitive to chloramphenicol, suggesting that newly synthesized proteins participate in the reaction. The concentrations of fluoroquinolones required for DNA relaxation were much higher than those required for cell killing. The bactericidal effect of fluoroquinolones is apparently related to mechanisms other than DNA relaxation.
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Affiliation(s)
- M Matsuo
- Department of Microbiology, Faculty of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan
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32
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Abstract
The increasing incidence of bacterial drug-resistance is stimulating the development of strategies targeting previously unexploited mechanisms of antibiotic action. Combinatorial chemistry, which generates molecularly diverse compounds, target-directed strategies, and high-throughput screens are being used to detect potential antibacterial agents. Bacterial DNA replication and cell division are the targets of new screening methods, as are membrane proteins, particularly those constituting efflux pumps; two-component signalling systems are also being targeted. Secondary-screening methods are being developed to find antibiotics that destroy slowly growing or resting bacteria, and to evaluate whether new antibiotics will be active against intracellular bacteria.
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Affiliation(s)
- J F Desnottes
- Rhône-Poulenc Rorer, Central Research, Vitry sur Seine, France
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