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Sivarajan K, Ravindhiran R, Sekar JN, Murugesan R, Chidambaram K, Dhandapani K. Deciphering the impact of Acinetobacter baumannii on human health, and exploration of natural compounds as efflux pump inhibitors to treat multidrug resistance. J Med Microbiol 2024; 73. [PMID: 39212030 DOI: 10.1099/jmm.0.001867] [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] [Indexed: 09/04/2024] Open
Abstract
Acinetobacter baumannii is an ESKAPE pathogen and threatens human health by generating infections with high fatality rates. A. baumannii leads to a spectrum of infections such as skin and wound infections, endocarditis, meningitis pneumonia, septicaemia and urinary tract infections. Recently, strains of A. baumannii have emerged as multidrug-resistant (MDR), meaning they are resistant to at least three different classes of antibiotics. MDR development is primarily intensified by widespread antibiotic misuse and inadequate stewardship. The World Health Organization (WHO) declared A. baumannii a precarious MDR species. A. baumannii maintains the MDR phenotype via a diverse array of antimicrobial metabolite-hydrolysing enzymes, efflux of antibiotics, impermeability and antibiotic target modification, thereby complicating treatment. Hence, a deeper understanding of the resistance mechanisms employed by MDR A. baumannii can give possible approaches to treat antimicrobial resistance. Resistance-nodulation-cell division (RND) efflux pumps have been identified as the key contributors to MDR determinants, owing to their capacity to force a broad spectrum of chemical substances out of the bacterial cell. Though synthetic inhibitors have been reported previously, their efficacy and safety are of debate. As resistance-modifying agents, phytochemicals are ideal choices. These natural compounds could eliminate the bacteria or interact with pathogenicity events and reduce the bacteria's ability to evolve resistance. This review aims to highlight the mechanism behind the multidrug resistance in A. baumannii and elucidate the utility of natural compounds as efflux pump inhibitors to deal with the infections caused by A. baumannii.
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Affiliation(s)
- Karthiga Sivarajan
- Department of Biochemistry, Biotechnology and Bioinformatics, Avinashilingam Institute for Home Science and Higher Education for Women, Coimbatore 641043, Tamil Nadu, India
| | - Ramya Ravindhiran
- Department of Biochemistry, Biotechnology and Bioinformatics, Avinashilingam Institute for Home Science and Higher Education for Women, Coimbatore 641043, Tamil Nadu, India
| | - Jothi Nayaki Sekar
- Department of Biochemistry, Biotechnology and Bioinformatics, Avinashilingam Institute for Home Science and Higher Education for Women, Coimbatore 641043, Tamil Nadu, India
| | - Rajeswari Murugesan
- Department of Biochemistry, Biotechnology and Bioinformatics, Avinashilingam Institute for Home Science and Higher Education for Women, Coimbatore 641043, Tamil Nadu, India
| | - Kumarappan Chidambaram
- Department of Pharmacology and Toxicology, School of Pharmacy, King Khalid University, Abha 652529, Saudi Arabia
| | - Kavitha Dhandapani
- Department of Biochemistry, Biotechnology and Bioinformatics, Avinashilingam Institute for Home Science and Higher Education for Women, Coimbatore 641043, Tamil Nadu, India
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Processing Technologies for the Extraction of Value-Added Bioactive Compounds from Tea. FOOD ENGINEERING REVIEWS 2023. [DOI: 10.1007/s12393-023-09338-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/27/2023]
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Multidrug-Resistant Acinetobacter baumannii Infections in the United Kingdom versus Egypt: Trends and Potential Natural Products Solutions. Antibiotics (Basel) 2023; 12:antibiotics12010077. [PMID: 36671278 PMCID: PMC9854726 DOI: 10.3390/antibiotics12010077] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Revised: 12/19/2022] [Accepted: 12/21/2022] [Indexed: 01/03/2023] Open
Abstract
Acinetobacter baumannii is a problematic pathogen of global concern. It causes multiple types of infection, especially among immunocompromised individuals in intensive care units. One of the most serious concerns related to this pathogen is its ability to become resistant to almost all the available antibiotics used in clinical practice. Moreover, it has a great tendency to spread this resistance at a very high rate, crossing borders and affecting healthcare settings across multiple economic levels. In this review, we trace back the reported incidences in the PubMed and the Web of Science databases of A. baumannii infections in both the United Kingdom and Egypt as two representative examples for countries of two different economic levels: high and low-middle income countries. Additionally, we compare the efforts made by researchers from both countries to find solutions to the lack of available treatments by looking into natural products reservoirs. A total of 113 studies reporting infection incidence were included, with most of them being conducted in Egypt, especially the recent ones. On the one hand, this pathogen was detected in the UK many years before it was reported in Egypt; on the other hand, the contribution of Egyptian researchers to identifying a solution using natural products is more notable than that of researchers in the UK. Tracing the prevalence of A. baumannii infections over the years showed that the infections are on the rise, especially in Egypt vs. the UK. Further concerns are linked to the spread of antibiotic resistance among the isolates collected from Egypt reaching very alarming levels. Studies conducted in the UK showed earlier inclusion of high-throughput technologies in the tracking and detection of A. baumannii and its resistance than those conducted in Egypt. Possible explanations for these variations are analyzed and discussed.
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Panda SK, Buroni S, Swain SS, Bonacorsi A, da Fonseca Amorim EA, Kulshrestha M, da Silva LCN, Tiwari V. Recent advances to combat ESKAPE pathogens with special reference to essential oils. Front Microbiol 2022; 13:1029098. [PMID: 36560948 PMCID: PMC9763703 DOI: 10.3389/fmicb.2022.1029098] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Accepted: 11/01/2022] [Indexed: 12/12/2022] Open
Abstract
Biofilm-associated bacteria, especially ESKAPE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp.), are a serious challenge worldwide. Due to the lack of discovery of novel antibiotics, in the past two decades, it has become necessary to search for new antibiotics or to study synergy with the existing antibiotics so as to counter life-threatening infections. Nature-derived compounds/based products are more efficient than the chemically synthesized ones with less resistance and lower side effects. In this descriptive review, we discuss the most promising therapeutics for the treatment of ESKAPE-related biofilms. The first aspect includes different types of natural agents [botanical drugs, essential oils (EOs), antimicrobial peptides, bacteriophages, and endolysins] effective against ESKAPE pathogens. The second part of the review deals with special references to EOs/essential oil components (EOCs) (with some exclusive examples), mode of action (via interfering in the quorum-sensing pathways, disruption of biofilm and their inhibitory concentrations, expression of genes that are involved, other virulence factors), existing in literature so far. Moreover, different essential oils and their major constituents were critically discussed using in vivo models to target ESKAPE pathogens along with the studies involving existing antibiotics.
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Affiliation(s)
- Sujogya Kumar Panda
- Centre of Environment Studies, Climate Change and Public Health, RUSA 2.0, Utkal University, Vani Vihar, Bhubaneswar, Odisha, India
| | - Silvia Buroni
- Department of Biology and Biotechnology, University of Pavia, Pavia, Italy
| | - Shasank Sekhar Swain
- Division of Microbiology and Noncommunicable Diseases (NCDs), Indian Council of Medical Research (ICMR)–Regional Medical Research Centre, Bhubaneswar, Odisha, India
| | - Andrea Bonacorsi
- Department of Biology and Biotechnology, University of Pavia, Pavia, Italy
| | | | - Mukta Kulshrestha
- Department of Biochemistry, Central University of Rajasthan, Ajmer, Rajasthan, India
| | | | - Vishvanath Tiwari
- Department of Biochemistry, Central University of Rajasthan, Ajmer, Rajasthan, India,*Correspondence: Vishvanath Tiwari,
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Dolma KG, Khati R, Paul AK, Rahmatullah M, de Lourdes Pereira M, Wilairatana P, Khandelwal B, Gupta C, Gautam D, Gupta M, Goyal RK, Wiart C, Nissapatorn V. Virulence Characteristics and Emerging Therapies for Biofilm-Forming Acinetobacter baumannii: A Review. BIOLOGY 2022; 11:biology11091343. [PMID: 36138822 PMCID: PMC9495682 DOI: 10.3390/biology11091343] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Revised: 09/04/2022] [Accepted: 09/08/2022] [Indexed: 11/20/2022]
Abstract
Simple Summary Acinetobacter baumannii (A. baumannii) is one of the ESKAPE organisms and has the competency to build biofilms. These biofilms account for the most nosocomial infections all over the world. This review reflects on the various physicochemical and environmental factors such as adhesion, pili expression, growth surfaces, drug-resistant genes, and virulence factors that profoundly affect its resistant forte. Emerging drug-resistant issues and limitations to newer drugs are other factors affecting the hospital environment. Here, we discuss newer and alternative methods that can significantly enhance the susceptibility to Acinetobacter spp. Many new antibiotics are under trials, such as GSK-3342830, The Cefiderocol (S-649266), Fimsbactin, and similar. On the other hand, we can also see the impact of traditional medicine and the secondary metabolites of these natural products’ application in searching for new treatments. The field of nanoparticles has demonstrated effective antimicrobial actions and has exhibited encouraging results in the field of nanomedicine. The use of various phages such as vWUPSU and phage ISTD as an alternative treatment for its specificity and effectiveness is being investigated. Cathelicidins obtained synthetically or from natural sources can effectively produce antimicrobial activity in the micromolar range. Radioimmunotherapy and photodynamic therapy have boundless prospects if explored as a therapeutic antimicrobial strategy. Abstract Acinetobacter species is one of the most prevailing nosocomial pathogens with a potent ability to develop antimicrobial resistance. It commonly causes infections where there is a prolonged utilization of medical devices such as CSF shunts, catheters, endotracheal tubes, and similar. There are several strains of Acinetobacter (A) species (spp), among which the majority are pathogenic to humans, but A. baumannii are entirely resistant to several clinically available antibiotics. The crucial mechanism that renders them a multidrug-resistant strain is their potent ability to synthesize biofilms. Biofilms provide ample opportunity for the microorganisms to withstand the harsh environment and further cause chronic infections. Several studies have enumerated multiple physiological and virulence factors responsible for the production and maintenance of biofilms. To further enhance our understanding of this pathogen, in this review, we discuss its taxonomy, pathogenesis, current treatment options, global resistance rates, mechanisms of its resistance against various groups of antimicrobials, and future therapeutics.
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Affiliation(s)
- Karma G. Dolma
- Department of Microbiology, Sikkim Manipal Institute of Medical Sciences, Sikkim Manipal University, Gangtok 737102, Sikkim, India
| | - Rachana Khati
- Department of Microbiology, Sikkim Manipal Institute of Medical Sciences, Sikkim Manipal University, Gangtok 737102, Sikkim, India
| | - Alok K. Paul
- School of Pharmacy and Pharmacology, University of Tasmania, Hobart, TAS 7001, Australia
| | - Mohammed Rahmatullah
- Department of Biotechnology & Genetic Engineering, University of Development Alternative, Lalmatia, Dhaka 1207, Bangladesh
| | - Maria de Lourdes Pereira
- CICECO-Aveiro Institute of Materials, University of Aveiro, 3810-193 Aveiro, Portugal
- Department of Medical Sciences, University of Aveiro, 3810-193 Aveiro, Portugal
| | - Polrat Wilairatana
- Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol University, Bangkok 10400, Thailand
- Correspondence: (P.W.); (V.N.)
| | - Bidita Khandelwal
- Department of Medicine, Sikkim Manipal Institute of Medical Sciences, Sikkim Manipal University, Gangtok 737102, Sikkim, India
| | - Chamma Gupta
- Department of Biotechnology, Sikkim Manipal Institute of Medical Sciences, Sikkim Manipal University, Gangtok 737102, Sikkim, India
| | - Deepan Gautam
- Department of Microbiology, Sikkim Manipal Institute of Medical Sciences, Sikkim Manipal University, Gangtok 737102, Sikkim, India
| | - Madhu Gupta
- Department of Pharmaceutics, Delhi Pharmaceutical Sciences and Research University, New Delhi 110017, India
| | - Ramesh K. Goyal
- Department of Pharmaceutics, Delhi Pharmaceutical Sciences and Research University, New Delhi 110017, India
| | - Christophe Wiart
- Institute for Tropical Biology and Conservation, Universiti Malaysia Sabah, Kota Kinabalu 88400, Malaysia
| | - Veeranoot Nissapatorn
- School of Allied Health Sciences and World Union for Herbal Drug Discovery (WUHeDD), Walailak University, Nakhon Si Thammarat 80160, Thailand
- Correspondence: (P.W.); (V.N.)
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Dassanayake MK, Khoo TJ, An J. Antibiotic resistance modifying ability of phytoextracts in anthrax biological agent Bacillus anthracis and emerging superbugs: a review of synergistic mechanisms. Ann Clin Microbiol Antimicrob 2021; 20:79. [PMID: 34856999 PMCID: PMC8641154 DOI: 10.1186/s12941-021-00485-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2021] [Accepted: 11/22/2021] [Indexed: 01/17/2023] Open
Abstract
Background and objectives The chemotherapeutic management of infections has become challenging due to the global emergence of antibiotic resistant pathogenic bacteria. The recent expansion of studies on plant-derived natural products has lead to the discovery of a plethora of phytochemicals with the potential to combat bacterial drug resistance via various mechanisms of action. This review paper summarizes the primary antibiotic resistance mechanisms of bacteria and also discusses the antibiotic-potentiating ability of phytoextracts and various classes of isolated phytochemicals in reversing antibiotic resistance in anthrax agent Bacillus anthracis and emerging superbug bacteria. Methods Growth inhibitory indices and fractional inhibitory concentration index were applied to evaluate the in vitro synergistic activity of phytoextract-antibiotic combinations in general. Findings A number of studies have indicated that plant-derived natural compounds are capable of significantly reducing the minimum inhibitory concentration of standard antibiotics by altering drug-resistance mechanisms of B. anthracis and other superbug infection causing bacteria. Phytochemical compounds allicin, oleanolic acid, epigallocatechin gallate and curcumin and Jatropha curcas extracts were exceptional synergistic potentiators of various standard antibiotics. Conclusion Considering these facts, phytochemicals represents a valuable and novel source of bioactive compounds with potent antibiotic synergism to modulate bacterial drug-resistance.
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Affiliation(s)
- Mackingsley Kushan Dassanayake
- School of Pharmacy, Faculty of Science and Engineering, University of Nottingham Malaysia, Jalan Broga, 43500, Semenyih, Malaysia.
| | - Teng-Jin Khoo
- School of Pharmacy, Faculty of Science and Engineering, University of Nottingham Malaysia, Jalan Broga, 43500, Semenyih, Malaysia
| | - Jia An
- Singapore Centre for 3D Printing, School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore, Singapore
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Chen Y, Cheng S, Dai J, Wang L, Xu Y, Peng X, Xie X, Peng C. Molecular mechanisms and applications of tea polyphenols: A narrative review. J Food Biochem 2021; 45:e13910. [PMID: 34426979 DOI: 10.1111/jfbc.13910] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Revised: 07/29/2021] [Accepted: 08/09/2021] [Indexed: 12/12/2022]
Abstract
Tea is a worldwide popular drink with high nutritional and medicinal values as it is rich in nutrients, such as polyphenols, amino acids, vitamins, glycosides, and so on. Among them, tea polyphenols (TPs) are the current research hotspot. TPs are known to have multiple biological activities such as anti-oxidation, anti-tumor, anti-inflammation, anti-bacteria, lowering lipid, and liver protection. By reviewing a large number of literatures, we explained the mechanism of TPs exerting biological activity and a wide range of applications. We also discussed the deficiencies and development potential of TPs, in order to provide theoretical reference and scientific basis for the subsequent development and utilization of TPs. PRACTICAL APPLICATIONS: We summarized the bioactivity mechanisms of TPs in anti-tumor, anti-oxidation, antibacterial, anti-inflammatory, lipid-lowering, and liver protection, focused on its application fields in food and medicine, and discussed the deficiency and development potential of current research on TPs, so as to provide a certain convenient way for scholars studying TPs. It is expected to contribute to the subsequent discovery of biological activity and the broadening of the field of TPs.
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Affiliation(s)
- Yan Chen
- State Key Laboratory of Southwestern Chinese Medicine Resources, Chengdu, China.,School of Public Health, Chengdu University of Traditional Chinese Medicine, Chengdu, China.,College of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Si Cheng
- School of Public Health, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Jiangang Dai
- School of Public Health, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Liang Wang
- School of Public Health, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Yun Xu
- School of Public Health, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Xiaoyu Peng
- School of Public Health, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Xiaofang Xie
- State Key Laboratory of Southwestern Chinese Medicine Resources, Chengdu, China.,College of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Cheng Peng
- State Key Laboratory of Southwestern Chinese Medicine Resources, Chengdu, China.,College of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, China
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Buchmann D, Schultze N, Borchardt J, Böttcher I, Schaufler K, Guenther S. Synergistic antimicrobial activities of epigallocatechin gallate, myricetin, daidzein, gallic acid, epicatechin, 3-hydroxy-6-methoxyflavone and genistein combined with antibiotics against ESKAPE pathogens. J Appl Microbiol 2021; 132:949-963. [PMID: 34365707 DOI: 10.1111/jam.15253] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 07/16/2021] [Accepted: 07/28/2021] [Indexed: 11/29/2022]
Abstract
AIM To verify synergistic effects, we investigated the antimicrobial activity of seven phenolic phytochemicals (gallic acid; epicatechin; epigallocatechin gallate; daidzein; genistein; myricetin; 3-hydroxy-6-methoxyflavone) in combination with six antibiotics against multidrug-resistant isolates from the ESKAPE group. METHODS AND RESULTS To investigate single phytochemicals and combinations, initial microdilution and checkerboard assays were used, followed by time-kill assays to evaluate the obtained results. The research revealed that phenolic compounds on their own resulted in little or no inhibitory effects. During preliminary tests, most of the combinations resulted in indifference (134 [71.3%]). In all, 30 combinations led to antagonism (15.9%); however, 24 showed synergistic effects (12.8%). The main tests resulted in nine synergistic combinations for the treatment of four different bacteria strains, including two substances (3-hydroxy-6-methoxyflavone, genistein) never tested before in such setup. Time-kill curves for combinations with possible synergistic effects confirmed the results against Acinetobacter baumannii as the one with the greatest need for research. CONCLUSIONS The results highlight the potential use of antibiotic-phytocompound combinations for combating infections with multi-resistant pathogens. Synergistic combinations could downregulate the resistance mechanisms of bacteria. SIGNIFICANCE AND IMPACT OF THE STUDY The aim of this study is to demonstrate the potential use of phenolic natural compounds in combination with conventional antibiotics against multidrug-resistant bacteria of the ESKAPE group. Due to synergistic effects of natural phenolic compounds combined with antibiotics, pathogens that are already resistant to antibiotics could be resensitized as we were able to reduce their MICs back to sensitive. In addition, combination therapies could prevent the development of resistance by reducing the dose of antibiotics. This approach opens up the basis for future development of antimicrobial therapy strategies, which are so urgently needed in the age of multidrug-resistant pathogens.
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In vitro and in silico evaluation of some plant extracts and phytocompounds against multidrug-resistant Gram-negative bacteria. ADVANCES IN TRADITIONAL MEDICINE 2021. [DOI: 10.1007/s13596-021-00602-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Hao S, Yang D, Zhao L, Shi F, Ye G, Fu H, Lin J, Guo H, He R, Li J, Chen H, Khan MF, Li Y, Tang H. EGCG-Mediated Potential Inhibition of Biofilm Development and Quorum Sensing in Pseudomonas aeruginosa. Int J Mol Sci 2021; 22:ijms22094946. [PMID: 34066609 PMCID: PMC8125375 DOI: 10.3390/ijms22094946] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Revised: 04/25/2021] [Accepted: 04/27/2021] [Indexed: 12/13/2022] Open
Abstract
Pseudomonas aeruginosa (P. aeruginosa), one of the dangerous multidrug resistance pathogens, orchestrates virulence factors production through quorum sensing (QS). Since the exploration of QS inhibitors, targeting virulence to circumvent bacterial pathogenesis without causing significant growth inhibition is a promising approach to treat P. aeruginosa infections. The present study has evaluated the anti-QS and anti-infective activity of epigallocatechin-3-gallate (EGCG), a bioactive ingredient of the traditional green tea, against P. aeruginosa. EGCG showed significant inhibitory effects on the development of biofilm, protease, elastase activity, swimming, and swarming motility, which was positively related to the production of C4-AHL. The expression of QS-related and QS-regulated virulence factors genes was also evaluated. Quantitative PCR analysis showed that EGCG significantly reduced the expression of las, rhl, and PQS genes and was highly correlated with the alterations of C4-AHL production. In-vivo experiments demonstrated that EGCG treatment reduced P. aeruginosa pathogenicity in Caenorhabditis elegans (C. elegans). EGCG increased the survival of C. elegans by 23.25%, 30.04%, and 36.35% in a dose-dependent manner. The findings of this study strongly suggest that EGCG could be a potential candidate for QS inhibition as an anti-virulence compound against bacterial infection.
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Affiliation(s)
- Suqi Hao
- College of Veterinary Medicine, Sichuan Agricultural University, No. 211 Huimin Road, Wenjiang District, Chengdu 611130, China; (S.H.); (D.Y.); (L.Z.); (F.S.); (G.Y.); (H.F.); (J.L.); (H.G.); (R.H.)
| | - Dan Yang
- College of Veterinary Medicine, Sichuan Agricultural University, No. 211 Huimin Road, Wenjiang District, Chengdu 611130, China; (S.H.); (D.Y.); (L.Z.); (F.S.); (G.Y.); (H.F.); (J.L.); (H.G.); (R.H.)
| | - Ling Zhao
- College of Veterinary Medicine, Sichuan Agricultural University, No. 211 Huimin Road, Wenjiang District, Chengdu 611130, China; (S.H.); (D.Y.); (L.Z.); (F.S.); (G.Y.); (H.F.); (J.L.); (H.G.); (R.H.)
| | - Fei Shi
- College of Veterinary Medicine, Sichuan Agricultural University, No. 211 Huimin Road, Wenjiang District, Chengdu 611130, China; (S.H.); (D.Y.); (L.Z.); (F.S.); (G.Y.); (H.F.); (J.L.); (H.G.); (R.H.)
| | - Gang Ye
- College of Veterinary Medicine, Sichuan Agricultural University, No. 211 Huimin Road, Wenjiang District, Chengdu 611130, China; (S.H.); (D.Y.); (L.Z.); (F.S.); (G.Y.); (H.F.); (J.L.); (H.G.); (R.H.)
| | - Hualin Fu
- College of Veterinary Medicine, Sichuan Agricultural University, No. 211 Huimin Road, Wenjiang District, Chengdu 611130, China; (S.H.); (D.Y.); (L.Z.); (F.S.); (G.Y.); (H.F.); (J.L.); (H.G.); (R.H.)
| | - Juchun Lin
- College of Veterinary Medicine, Sichuan Agricultural University, No. 211 Huimin Road, Wenjiang District, Chengdu 611130, China; (S.H.); (D.Y.); (L.Z.); (F.S.); (G.Y.); (H.F.); (J.L.); (H.G.); (R.H.)
| | - Hongrui Guo
- College of Veterinary Medicine, Sichuan Agricultural University, No. 211 Huimin Road, Wenjiang District, Chengdu 611130, China; (S.H.); (D.Y.); (L.Z.); (F.S.); (G.Y.); (H.F.); (J.L.); (H.G.); (R.H.)
| | - Ran He
- College of Veterinary Medicine, Sichuan Agricultural University, No. 211 Huimin Road, Wenjiang District, Chengdu 611130, China; (S.H.); (D.Y.); (L.Z.); (F.S.); (G.Y.); (H.F.); (J.L.); (H.G.); (R.H.)
| | - Jianlong Li
- College of Food Science, Sichuan Agricultural University, Chengdu 611130, China;
| | - Hongwei Chen
- College of Veterinary Medicine, Southwest University, Chongqing 402460, China;
| | - Muhammad Faraz Khan
- Department of Botany, Faculty of Basic and Applied Sciences, University of Poonch Rawalakot, Rawalakot 12350, Pakistan;
| | - Yinglun Li
- College of Veterinary Medicine, Sichuan Agricultural University, No. 211 Huimin Road, Wenjiang District, Chengdu 611130, China; (S.H.); (D.Y.); (L.Z.); (F.S.); (G.Y.); (H.F.); (J.L.); (H.G.); (R.H.)
- Correspondence: (Y.L.); (H.T.)
| | - Huaqiao Tang
- College of Veterinary Medicine, Sichuan Agricultural University, No. 211 Huimin Road, Wenjiang District, Chengdu 611130, China; (S.H.); (D.Y.); (L.Z.); (F.S.); (G.Y.); (H.F.); (J.L.); (H.G.); (R.H.)
- Correspondence: (Y.L.); (H.T.)
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Chang EH, Brown AC. Epigallocatechin gallate alters leukotoxin secretion and Aggregatibacter actinomycetemcomitans virulence. J Pharm Pharmacol 2021; 73:505-514. [PMID: 33793838 DOI: 10.1093/jpp/rgaa051] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Accepted: 12/08/2020] [Indexed: 12/27/2022]
Abstract
OBJECTIVES We and others have previously shown that epigallocatechin gallate (EGCg) inhibits the activity of an important virulence factor, leukotoxin (LtxA), produced by the oral bacterium Aggregatibacter actinomycetemcomitans, suggesting the potential use of this molecule as an anti-virulence strategy to treat periodontal infections. Here, we sought to better understand the effects of EGCg on toxin secretion and A. actinomycetemcomitans pathogenicity in a co-culture model. METHODS We used a quantitative immunoblot assay to determine the concentrations of LtxA in the bacterial supernatant and on the bacterial cell surface. Using a co-culture model, consisting of A. actinomycetemcomitans and THP-1 cells, we studied the impact of EGCg-mediated changes in LtxA secretion on the toxicity of A. actinomycetemcomitans. KEY FINDINGS EGCg increased production of LtxA and changed the localization of secreted LtxA from the supernatant to the surface of the bacterial cells. In the co-culture model, a single low dose of EGCg did not protect host THP-1 cells from A. actinomycetemcomitans-mediated cytotoxicity, but a multiple dosing strategy had improved effects. CONCLUSIONS Together, these results demonstrate that EGCg has important, but complicated, effects on toxin secretion and activity; new dosing strategies and comprehensive model systems may be required to properly develop these anti-virulence activities.
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Affiliation(s)
- En Hyung Chang
- Department of Chemical and Biomolecular Engineering, Lehigh University, Bethlehem, PA, USA
| | - Angela C Brown
- Department of Chemical and Biomolecular Engineering, Lehigh University, Bethlehem, PA, USA
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Abstract
Catechin exhibits numerous physiological characteristics. In this study, we determined the photosensitivity of catechin to various lights under alkaline conditions, and the mechanisms by which catechin generates free radical species and polymerizes via a photoreaction. In addition to this, the application of catechin photolysis was investigated. A solution of catechin is transparent, but turns yellowish under blue light illumination (BLI) in neutral or weak alkaline solutions. When catechin is subjected to BLI, a dimeric catechin (proanthocyanidin) and a superoxide anion radical (O2•−) are generated in a photolytic reaction. When ascorbic acid or gallic acid is added to catechin and the mixture is subjected to BLI at alkaline pH, fewer catechin dimers and less O2•− are produced, because both acids inhibit the photosensitive oxidation of catechin. When AlCl3 is added to catechin and the mixture is subjected to BLI at pH 8, a photolytic reaction is suppressed by AlCl3, and AlCl3 acts as a catalyst for the disconnection of proanthocyanidin during photolysis. Under alkaline conditions, catechin generates O2•− via photosensitive oxidation, which suppresses the growth of Acinetobacter baumannii (A. baumannii) by at least 4 logs, and deactivates its multi-drug-resistant strain. This study shows that catechin photolysis is a process of oxidation, and that it can be safely applied as a tool for environmental applications.
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Yan Q, Hao S, Shi F, Zou Y, Song X, Li L, Li Y, Guo H, He R, Zhao L, Ye G, Tang H. Epigallocatechin-3-gallate reduces liver and immune system damage in Acinetobacter baumannii-loaded mice with restraint stress. Int Immunopharmacol 2021; 92:107346. [PMID: 33412390 DOI: 10.1016/j.intimp.2020.107346] [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: 09/12/2020] [Revised: 12/08/2020] [Accepted: 12/25/2020] [Indexed: 11/28/2022]
Abstract
AIM Due to the significant increase in the antimicrobial resistance of Acinetobacter baumannii (A. baumannii), new drugs to block the progression of infection are strongly needed. Epigallocatechin-3-gallate (EGCG), a major component of green tea, has exhibited potential activity against A. baumannii in vitro. The aim of this study was to determine if EGCG could be used for pretreating stress-related effects, liver damage, and immune dysfunction caused by A. baumannii infection in vivo. METHODS Levels of stress hormones, oxidative stress, liver damage, and immune components were analyzed in a murine infection model in which the mice were pretreated with EGCG for one week then intranasally inoculated with A. baumannii. The mice were restrained for 12 h to promote infection because A. baumannii is an opportunistic pathogen. The pretreatment efficacy of EGCG against A. baumannii in mice was assessed for 24 h after the bacterial infection. RESULTS Restraint stress strengthened the damage from the A. baumannii infection. Pretreatment with EGCG in the murine pneumonia model markedly reduced stress hormones, oxidative metabolites, and proinflammatory cytokine production. EGCG also increased the immune function by increasing the levels of sIgA, T cells and neutrophils after infection. Moreover, pretreatment with EGCG significantly decreased the liver damage by inhibiting the levels of transaminases, oxidative stress metabolites, and cytokines, while maintaining the normal activity of CYP450 enzymes in the liver. CONCLUSION EGCG was efficacious as a preventative treatment for the damage seen in an experimental model of A. baumannii infection.
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Affiliation(s)
- Qiaohua Yan
- Department of Pharmacy, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China
| | - Suqi Hao
- Department of Pharmacy, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China
| | - Fei Shi
- Department of Pharmacy, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China
| | - Yuanfeng Zou
- Department of Pharmacy, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China
| | - Xu Song
- Department of Pharmacy, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China
| | - Lixia Li
- Department of Pharmacy, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China
| | - Yinglun Li
- Department of Pharmacy, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China
| | - Hongrui Guo
- Department of Pharmacy, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China
| | - Ran He
- Department of Pharmacy, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China
| | - Ling Zhao
- Department of Pharmacy, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China
| | - Gang Ye
- Department of Pharmacy, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China
| | - Huaqiao Tang
- Department of Pharmacy, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China.
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Chang EH, Giaquinto P, Huang J, Balashova NV, Brown AC. Epigallocatechin gallate inhibits leukotoxin release by Aggregatibacter actinomycetemcomitans by promoting association with the bacterial membrane. Mol Oral Microbiol 2020; 35:29-39. [PMID: 31816197 PMCID: PMC7015128 DOI: 10.1111/omi.12275] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Revised: 11/22/2019] [Accepted: 12/06/2019] [Indexed: 12/21/2022]
Abstract
The oral pathogen, Aggregatibacter actinomycetemcomitans, produces a number of virulence factors, including a leukotoxin (LtxA), which specifically kills human white blood cells, to provide a colonization advantage to the bacterium. Strains of A. actinomycetemcomitans that produce more LtxA have been more closely linked to disease, indicating that this toxin plays a key role in pathogenesis of the bacterium. Disruption of the activity of LtxA thus represents a promising approach to reducing the pathogenicity of the bacterium. Catechins are polyphenolic molecules derived from plants, which have shown potent antibacterial and antitoxin activities. We have previously shown that galloylated catechins are able to prevent LtxA delivery to host cells by altering the toxin's secondary structure and preventing binding to cholesterol on the host cell membrane. Here, we have investigated how one particular galloylated catechin, epigallocatechin gallate (EGCg), affects A. actinomycetemcomitans growth and toxin secretion. Our results demonstrate that EGCg, at micromolar concentrations, inhibits A. actinomycetemcomitans growth, as has been reported for other bacterial species. At subinhibitory concentrations, EGCg promotes LtxA production, but the toxicity of the bacterial supernatant against human immune cells is reduced. The results of our biophysical studies indicate that this seemingly contradictory result is caused by an EGCg-mediated enhancement of LtxA affinity for the bacterial cell surface. Together, these results demonstrate the potential of EGCg in the treatment of virulent A. actinomycetemcomitans infections.
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Affiliation(s)
- En Hyung Chang
- Department of Chemical and Biomolecular Engineering, Lehigh University, Bethlehem, PA 18015
| | - Peter Giaquinto
- Department of Chemical and Biomolecular Engineering, Lehigh University, Bethlehem, PA 18015
| | - Joanne Huang
- Department of Chemical and Biomolecular Engineering, Lehigh University, Bethlehem, PA 18015
| | - Nataliya V. Balashova
- Department of Basic and Translational Sciences, University of Pennsylvania School of Dental Medicine, Philadelphia, PA, 19104
| | - Angela C. Brown
- Department of Chemical and Biomolecular Engineering, Lehigh University, Bethlehem, PA 18015
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Lovato A, Pignatti A, Vitulo N, Vandelle E, Polverari A. Inhibition of Virulence-Related Traits in Pseudomonas syringae pv. actinidiae by Gunpowder Green Tea Extracts. Front Microbiol 2019; 10:2362. [PMID: 31681224 PMCID: PMC6797950 DOI: 10.3389/fmicb.2019.02362] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Accepted: 09/27/2019] [Indexed: 12/23/2022] Open
Abstract
Green tea is a widely-consumed healthy drink produced from the leaves of Camellia sinensis. It is renowned for its antioxidant and anticarcinogenic properties, but also displays significant antimicrobial activity against numerous human pathogens. Here we analyzed the antimicrobial activity of Gunpowder green tea against Pseudomonas syringae pv. actinidiae (Psa), the agent that causes kiwifruit bacterial canker. At the phenotypic level, tea extracts strongly inhibited Psa growth and swimming motility, suggesting it could reduce Psa epiphytic survival during plant colonization. The loss of bacterial virulence-related traits following treatment with tea extracts was also investigated by large-scale transcriptome analysis, which confirmed the in vitro phenotypes and revealed the induction of adaptive responses in the treated bacteria allowing them to cope with iron deficiency and oxidative stress. Such molecular changes may account for the ability of Gunpowder green tea to protect kiwifruit against Psa infection.
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Affiliation(s)
| | | | | | - Elodie Vandelle
- Biotechnology Department, University of Verona, Verona, Italy
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16
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Dadresanfar B, Vatanpour M, Farahmand M, Taheri S, Mahaseni Aghdam HR. Ex Vivo Comparative Study of the Effect of Different Concentrations of Green Tea Extract and Two Common Irrigants on Root Canals Infected with Enterococcus faecalis. JOURNAL OF RESEARCH IN DENTAL AND MAXILLOFACIAL SCIENCES 2019. [DOI: 10.29252/jrdms.4.2.32] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
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17
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Zhao Y, Li H, Wei S, Zhou X, Xiao X. Antimicrobial Effects of Chemical Compounds Isolated from Traditional Chinese Herbal Medicine (TCHM) Against Drug-Resistant Bacteria: A Review Paper. Mini Rev Med Chem 2019; 19:125-137. [PMID: 30332952 DOI: 10.2174/1389557518666181017143141] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2018] [Revised: 10/07/2018] [Accepted: 10/09/2018] [Indexed: 01/02/2023]
Abstract
Infectious diseases caused by pathogenic bacteria seriously threaten human lives. Although antibiotic therapy is effective in the treatment of bacterial infections, the overuse of antibiotics has led to an increased risk of antibiotic resistance, putting forward urgent requirements for novel antibacterial drugs. Traditional Chinese herbal medicine (TCHM) and its constituents are considered to be potential sources of new antimicrobial agents. Currently, a series of chemical compounds purified from TCHM have been reported to fight against infections by drug-resistant bacteria. In this review, we summarized the recent findings on TCHM-derived compounds treating drug-resistant bacterial infections. Further studies are still needed for the discovery of potential antibacterial components from TCHM.
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Affiliation(s)
- Yanling Zhao
- Department of Pharmacy, 302 Military Hospital of China, Beijing, 100039, China
| | - Haotian Li
- Department of Pharmacy, 302 Military Hospital of China, Beijing, 100039, China
| | - Shizhang Wei
- Department of Pharmacy, 302 Military Hospital of China, Beijing, 100039, China
| | - Xuelin Zhou
- Department of Pharmacy, 302 Military Hospital of China, Beijing, 100039, China
| | - Xiaohe Xiao
- China Military Institute of Chinese Medicine, 302 Military Hospital of China, Beijing, 100039, China
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18
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Chang EH, Huang J, Lin Z, Brown AC. Catechin-mediated restructuring of a bacterial toxin inhibits activity. Biochim Biophys Acta Gen Subj 2018; 1863:191-198. [PMID: 30342156 DOI: 10.1016/j.bbagen.2018.10.011] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Revised: 10/12/2018] [Accepted: 10/15/2018] [Indexed: 10/28/2022]
Abstract
BACKGROUND Catechins, polyphenols derived from tea leaves, have been shown to have antibacterial properties, through direct killing of bacteria as well as through inhibition of bacterial toxin activity. In particular, certain catechins have been shown to have bactericidal effects on the oral bacterium, Aggregatibacter actinomycetemcomitans, as well as the ability to inhibit a key virulence factor of this organism, leukotoxin (LtxA). The mechanism of catechin-mediated inhibition of LtxA has not been shown. METHODS In this work, we studied the ability of six catechins to inhibit LtxA-mediated cytotoxicity in human white blood cells, using Trypan blue staining, and investigated the mechanism of action using a combination of techniques, including fluorescence and circular dichroism spectroscopy, confocal microscopy, and surface plasmon resonance. RESULTS We found that all the catechins except (-)-catechin inhibited the activity of this protein, with the galloylated catechins having the strongest effect. Pre-incubation of the toxin with the catechins increased the inhibitory action, indicating that the catechins act on the protein, rather than the cell. The secondary structure of LtxA was dramatically altered in the presence of catechin, which resulted in an inhibition of toxin binding to cholesterol, an important initial step in the cytotoxic mechanism of the toxin. CONCLUSIONS These results demonstrate that the catechins inhibit LtxA activity by altering its structure to prevent interaction with specific molecules present on the host cell surface. GENERAL SIGNIFICANCE Galloylated catechins modify protein toxin structure, inhibiting the toxin from binding to the requisite molecules on the host cell surface.
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Affiliation(s)
- En Hyung Chang
- Department of Chemical and Biomolecular Engineering, Lehigh University, Bethlehem, PA 18015, USA
| | - Joanne Huang
- Department of Chemical and Biomolecular Engineering, Lehigh University, Bethlehem, PA 18015, USA
| | - Zixiang Lin
- Department of Chemical and Biomolecular Engineering, Lehigh University, Bethlehem, PA 18015, USA
| | - Angela C Brown
- Department of Chemical and Biomolecular Engineering, Lehigh University, Bethlehem, PA 18015, USA.
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Melok AL, Lee LH, Mohamed Yussof SA, Chu T. Green Tea Polyphenol Epigallocatechin-3-Gallate-Stearate Inhibits the Growth of Streptococcus mutans: A Promising New Approach in Caries Prevention. Dent J (Basel) 2018; 6:dj6030038. [PMID: 30082585 PMCID: PMC6162448 DOI: 10.3390/dj6030038] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2018] [Revised: 07/30/2018] [Accepted: 08/01/2018] [Indexed: 01/08/2023] Open
Abstract
Streptococcus mutans (S. mutans) is the main etiological bacteria present in the oral cavity that leads to dental caries. All of the S. mutans in the oral cavity form biofilms that adhere to the surfaces of teeth. Dental caries are infections facilitated by the development of biofilm. An esterified derivative of epigallocatechin-3-gallate (EGCG), epigallocatechin-3-gallate-stearate (EGCG-S), was used in this study to assess its ability to inhibit the growth and biofilm formation of S. mutans. The effect of EGCG-S on bacterial growth was evaluated with colony forming units (CFU) and log reduction; biofilm formation was qualitatively determined by Congo red assay, and quantitatively determined by crystal violet assay, fluorescence-based LIVE/DEAD assays to study the cell viability, and scanning electron microscopy (SEM) was used to evaluate the morphological changes. The results indicated that EGCG-S was able to completely inhibit growth and biofilm formation at concentrations of 250 µg/mL. Its effectiveness was also compared with a commonly prescribed mouthwash in the United States, chlorhexidine gluconate. EGCG-S was shown to be equally effective in reducing S. mutans growth as chlorhexidine gluconate. In conclusion, EGCG-S is potentially an anticariogenic agent by reducing bacterial presence in the oral cavity.
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Affiliation(s)
- Amy Lynn Melok
- Department of Biology, Montclair State University, Montclair, NJ 07043, USA.
| | - Lee H Lee
- Department of Biology, Montclair State University, Montclair, NJ 07043, USA.
| | - Siti Ayuni Mohamed Yussof
- Department of Biology, Montclair State University, Montclair, NJ 07043, USA.
- Department of Biological Sciences, Seton Hall University, South Orange, NJ 07079, USA.
| | - Tinchun Chu
- Department of Biological Sciences, Seton Hall University, South Orange, NJ 07079, USA.
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Abstract
With the advent of the global antimicrobial resistance (AMR) crisis, our arsenal of effective antibiotics is diminishing. The widespread use and misuse of antibiotics in human and veterinary medicine, compounded by the lack of novel classes of antibiotic in the pharmaceutical pipeline, has left a hole in our antibiotic armamentarium. Thus, alternatives to traditional antibiotics are being investigated, including two major groups of antibacterial agents, which have been extensively studied, phytochemicals and metals. Within these groups, there are several subclasses of compound/elements, including polyphenols and metal nanoparticles, which could be used to complement traditional antibiotics, either to increase their potency or extend their spectrum of activity. Alone or in combination, these antibacterial agents have been shown to be effective against a vast array of human and animal bacterial pathogens, including those resistant to licensed antibacterials. These alternative antibacterial agents could be a key element in our fight against AMR and provide desperately needed options, to veterinary and medical clinicians alike.
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Yang MJ, Hung YA, Wong TW, Lee NY, Yuann JMP, Huang ST, Wu CY, Chen IZ, Liang JY. Effects of Blue-Light-Induced Free Radical Formation from Catechin Hydrate on the Inactivation of Acinetobacter baumannii, Including a Carbapenem-Resistant Strain. Molecules 2018; 23:molecules23071631. [PMID: 29973539 PMCID: PMC6100571 DOI: 10.3390/molecules23071631] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Revised: 06/29/2018] [Accepted: 07/02/2018] [Indexed: 01/22/2023] Open
Abstract
Catechin is a flavan-3-ol, a derivative of flavans, with four phenolic hydroxyl groups, which exhibits a wide range of physiological properties. Chromatographic analyses were employed to examine the effects of blue light irradiation on the changes of catechin hydrate in an alkaline condition. In particular, the detection of a superoxide anion radical (O2•−), a reactive oxygen species (ROS), and the inactivation of Acinetobacter baumannii (A. baumannii)—including a carbapenem-resistant A. baumannii (CRAB)—was investigated during the photoreaction of catechin hydrate. Following basification with blue light irradiation, the transparent solution of catechin hydrate turned yellowish, and a chromogenic catechin dimer was separated and identified as a proanthocyanidin. Adding ascorbic acid during the photolytic treatment of catechin hydrate decreased the dimer formation, suggesting that ascorbic acid can suppress the photosensitive oxidation of catechin. When catechin hydrate was irradiated by blue light in an alkaline solution, O2•− was produced via photosensitized oxidation, enhancing the inactivation of A. baumannii and CRAB. The present findings on the photon-induced oxidation of catechin hydrate provides a safe practice for the inactivation of environmental microorganisms.
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Affiliation(s)
- Meei-Ju Yang
- Tea Research and Extension Station, Taoyuan 32654, Taiwan.
| | - Yi-An Hung
- Department of Biotechnology, Ming-Chuan University, Gui-Shan 33343, Taiwan.
| | - Tak-Wah Wong
- Department of Dermatology, Department of Biochemistry and Molecular Biology, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan 70101, Taiwan.
| | - Nan-Yao Lee
- Division of Infection, Department of Internal Medicine, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan 70101, Taiwan.
| | - Jeu-Ming P Yuann
- Department of Biotechnology, Ming-Chuan University, Gui-Shan 33343, Taiwan.
| | - Shiuh-Tsuen Huang
- Department of Science Education and Application, National Taichung University of Education, Taichung 40306, Taiwan.
| | - Chun-Yi Wu
- Department of Biotechnology, Ming-Chuan University, Gui-Shan 33343, Taiwan.
| | - Iou-Zen Chen
- Department of Horticulture and Landscape Architecture, National Taiwan University, Taipei 10617, Taiwan.
| | - Ji-Yuan Liang
- Department of Biotechnology, Ming-Chuan University, Gui-Shan 33343, Taiwan.
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Hacioglu M, Dosler S, Birteksoz Tan AS, Otuk G. Antimicrobial activities of widely consumed herbal teas, alone or in combination with antibiotics: an in vitro study. PeerJ 2017; 5:e3467. [PMID: 28761777 PMCID: PMC5533155 DOI: 10.7717/peerj.3467] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2016] [Accepted: 05/25/2017] [Indexed: 02/02/2023] Open
Abstract
Background Because of increasing antibiotic resistance, herbal teas are the most popular natural alternatives for the treatment of infectious diseases, and are currently gaining more importance. We examined the antimicrobial activities of 31 herbal teas both alone and in combination with antibiotics or antifungals against some standard and clinical isolates of Pseudomonas aeruginosa, Acinetobacter baumannii, Escherichia coli, Klebsiella pneumoniae, Enterococcus faecalis, methicillin susceptible/resistant Staphylococcus aureus and Candida albicans. Methods The antimicrobial activities of the teas were determined by using the disk diffusion and microbroth dilution methods, and the combination studies were examined by using the microbroth checkerboard and the time killing curve methods. Results Rosehip, rosehip bag, pomegranate blossom, thyme, wormwood, mint, echinacea bag, cinnamon, black, and green teas were active against most of the studied microorganisms. In the combination studies, we characterized all the expected effects (synergistic, additive, and antagonistic) between the teas and the antimicrobials. While synergy was observed more frequently between ampicillin, ampicillin-sulbactam, or nystatine, and the various tea combinations, most of the effects between the ciprofloxacin, erythromycin, cefuroxime, or amikacin and various tea combinations, particularly rosehip, rosehip bag, and pomegranate blossom teas, were antagonistic. The results of the time kill curve analyses showed that none of the herbal teas were bactericidal in their usage concentrations; however, in combination with antibiotics they showed some bactericidal effect. Discussion Some herbal teas, particularly rosehip and pomegranate blossom should be avoided because of their antagonistic interactions with some antibiotics during the course of antibiotic treatment or they should be consumed alone for their antimicrobial activities.
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Affiliation(s)
- Mayram Hacioglu
- Department of Pharmaceutical Microbiology, Istanbul University, Faculty of Pharmacy, Istanbul, Turkey
| | - Sibel Dosler
- Department of Pharmaceutical Microbiology, Istanbul University, Faculty of Pharmacy, Istanbul, Turkey
| | - Ayse Seher Birteksoz Tan
- Department of Pharmaceutical Microbiology, Istanbul University, Faculty of Pharmacy, Istanbul, Turkey
| | - Gulten Otuk
- Department of Pharmaceutical Microbiology, Istanbul University, Faculty of Pharmacy, Istanbul, Turkey
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Villanueva-Bermejo D, Reglero G, Fornari T. Recent advances in the processing of green tea biomolecules using ethyl lactate. A review. Trends Food Sci Technol 2017. [DOI: 10.1016/j.tifs.2016.12.009] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Lee S, Razqan GSA, Kwon DH. Antibacterial activity of epigallocatechin-3-gallate (EGCG) and its synergism with β-lactam antibiotics sensitizing carbapenem-associated multidrug resistant clinical isolates of Acinetobacter baumannii. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2017; 24:49-55. [PMID: 28160861 DOI: 10.1016/j.phymed.2016.11.007] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Revised: 11/02/2016] [Accepted: 11/10/2016] [Indexed: 06/06/2023]
Abstract
BACKGROUND Infections caused by Acinetobacter baumannii were responsive to conventional antibiotic therapy. However, recently, carbapenem-associated multidrug resistant isolates have been reported worldwide and present a major therapeutic challenge. Epigallocatechin-3-Gallate (EGCG) extracted from green tea exhibits antibacterial activity. PURPOSE We evaluated the antibacterial activity of EGCG and possible synergism with antibiotics in carbapenem-associated multidrug resistant A. baumannii. A potential mechanism for synergism was also explored. MATERIALS AND METHODS Seventy clinical isolates of A. baumannii collected from geographically different areas were analyzed by minimal inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of EGCG. Checkerboard and time-killing assays were performed to exam the synergism between EGCG and antibiotics. The effects of EGCG on a multidrug efflux pump inhibitor (1-[1-naphthylmethyl] piperazine; NMP) and β-lactamase production were also examined in A. baumannii. RESULTS Sixty-three of 70 clinical isolates of A. baumannii carried carbapenemase-encoding genes with carbapenem-associated multidrug resistance. Levels of MIC and MBC of EGCG ranged from 64 to 512µg/ml and from 128 to ≥1024µg/ml, respectively among the clinical isolates. MIC90 and MBC86 levels were 256µg/ml and 512µg/ml of EGCG, respectively. Subinhibitory concentration of EGCG in combination with all antibiotics tested, including carbapenem, sensitized (MICs fall≤1.0µg/ml) all carbapenem-associated multidrug resistant isolates. Checkerboard and time-killing assays showed synergism between EGCG and meropenem (or carbenicillin) counted as fractional inhibitory concentration of < 0.5 and cell numbers' decrease per ml of >2log10 within 12h, respectively. EGCG significantly increased the effect of NMP but was unrelated to β-lactamase production in A. baumannii, suggesting EGCG may be associated with inhibition of efflux pumps. CONCLUSION Overall we suggest that EGCG-antibiotic combinations might provide an alternative approach to treat infections with A. baumannii regardless of antibiotic resistance.
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Affiliation(s)
- Spencer Lee
- Jericho Senior High School, Jericho, New York 11753, United States
| | | | - Dong H Kwon
- Department of Biology, Long Island University, Brooklyn, New York, 11201, United States ; Department of Medicine, Michael E. DeBakey VA Medical Center, Baylor College of Medicine, Houston, Texas, 77030, United States.
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Fazly Bazzaz BS, Sarabandi S, Khameneh B, Hosseinzadeh H. Effect of Catechins, Green tea Extract and Methylxanthines in Combination with Gentamicin Against Staphylococcus aureus and Pseudomonas aeruginosa: - Combination therapy against resistant bacteria. J Pharmacopuncture 2016; 19:312-318. [PMID: 28097041 PMCID: PMC5234351 DOI: 10.3831/kpi.2016.19.032] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Objectives: Bacterial resistant infections have become a global health challenge and threaten the society’s health. Thus, an urgent need exists to find ways to combat resistant pathogens. One promising approach to overcoming bacterial resistance is the use of herbal products. Green tea catechins, the major green tea polyphenols, show antimicrobial activity against resistant pathogens. The present study aimed to investigate the effect of catechins, green tea extract, and methylxanthines in combination with gentamicin against standard and clinical isolates of Staphylococcus aureus (S. aureus) and the standard strain of Pseudomonas aeruginosa (P. aeruginosa). Methods: The minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) values of different agents against bacterial strains were determined. The interactions of green tea extract, epigallate catechin, epigallocatechin gallate, two types of methylxanthine, caffeine, and theophylline with gentamicin were studied in vitro by using a checkerboard method and calculating the fraction inhibitory concentration index (FICI). Results: The MICs of gentamicin against bacterial strains were in the range of 0.312 - 320 μg/mL. The MIC values of both types of catechins were 62.5 - 250 μg/ mL. Green tea extract showed insufficient antibacterial activity when used alone. Methylxanthines had no intrinsic inhibitory activity against any of the bacterial strains tested. When green tea extract and catechins were combined with gentamicin, the MIC values of gentamicin against the standard strains and a clinical isolate were reduced, and synergistic activities were observed (FICI < 1). A combination of caffeine with gentamicin did not alter the MIC values of gentamicin. Conclusion: The results of the present study revealed that green tea extract and catechins potentiated the antimicrobial action of gentamicin against some clinical isolates of S. aureus and standard P. aeruginosa strains. Therefore, combinations of gentamicin with these natural compounds might be a promising approach to combat microbial resistance.
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Affiliation(s)
- Bibi Sedigheh Fazly Bazzaz
- Biotechnology Research Center, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Sahar Sarabandi
- Students' Research Committee, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Bahman Khameneh
- Department of Pharmaceutical Control, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Hossein Hosseinzadeh
- Pharmaceutical Research Center, Department of Pharmacodynamy and Toxicology, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran
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26
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Protective effect of epigallocatechin-3-gallate (EGCG) via Nrf2 pathway against oxalate-induced epithelial mesenchymal transition (EMT) of renal tubular cells. Sci Rep 2016; 6:30233. [PMID: 27452398 PMCID: PMC4958994 DOI: 10.1038/srep30233] [Citation(s) in RCA: 76] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Accepted: 07/01/2016] [Indexed: 12/24/2022] Open
Abstract
This study evaluated effect of oxalate on epithelial mesenchymal transition (EMT) and potential anti-fibrotic property of epigallocatechin-3-gallate (EGCG). MDCK renal tubular cells were incubated with 0.5 mM sodium oxalate for 24-h with/without 1-h pretreatment with 25 μM EGCG. Microscopic examination, immunoblotting and immunofluorescence staining revealed that oxalate-treated cells gained mesenchymal phenotypes by fibroblast-like morphological change and increasing expression of vimentin and fibronectin, while levels of epithelial markers (E-cadherin, occludin, cytokeratin and ZO-1) were decreased. EGCG pretreatment could prevent all these changes and molecular mechanisms underlying the prevention by EGCG were most likely due to reduced production of intracellular ROS through activation of Nrf2 signaling and increased catalase anti-oxidant enzyme. Knockdown of Nrf2 by small interfering RNA (siRNA) abrogated all the effects of EGCG, confirming that the EGCG protection against oxalate-induced EMT was mediated via Nrf2. Taken together, our data indicate that oxalate turned on EMT of renal tubular cells that could be prevented by EGCG via Nrf2 pathway. These findings also shed light onto development of novel therapeutics or preventive strategies of renal fibrosis in the future.
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Hui X, Liu H, Tian FL, Li FF, Li H, Gao WY. Inhibition of green tea and the catechins against 1-deoxy-d-xylulose 5-phosphate reductoisomerase, the key enzyme of the MEP terpenoid biosynthetic pathway. Fitoterapia 2016; 113:80-4. [PMID: 27439219 DOI: 10.1016/j.fitote.2016.07.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Revised: 07/15/2016] [Accepted: 07/16/2016] [Indexed: 11/17/2022]
Abstract
1-Deoxy-d-xylulose 5-phosphate reductoisomerase (DXR) is the first committed enzyme in the MEP terpenoid biosynthetic pathway and also a validated antimicrobial target. Green tea which is rich in polyphenolic components such as the catechins, possesses a plenty of pharmacological activities, in particular an antibacterial effect. To uncover the antibacterial mechanism of green tea and to seek new DXR inhibitors from natural sources, the DXR inhibitory activity of green tea and its main antimicrobial catechins were investigated in this study. The results show that the raw extract of green tea and its ethyl acetate fraction are able to suppress DXR activity explicitly. Further determination of the DXR inhibitory capacity of eight catechin compounds demonstrates that the most active compound is gallocatechin gallate that is able to inhibit around 50% activity of DXR at 25μM. Based on these data, the primary structure-activity relationship of the catechins against DXR is discussed. This study would be very helpful to elucidate the antimicrobial mechanism of green tea and the catechins and also would be very useful to direct the rational utilization of them as food additives.
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Affiliation(s)
- Xian Hui
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, College of Life Sciences, Northwest University, 229 North Taibai Road, Xi'an, Shaanxi 710069, China
| | - Hui Liu
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, College of Life Sciences, Northwest University, 229 North Taibai Road, Xi'an, Shaanxi 710069, China
| | - Fang-Lin Tian
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, College of Life Sciences, Northwest University, 229 North Taibai Road, Xi'an, Shaanxi 710069, China
| | - Fei-Fei Li
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, College of Life Sciences, Northwest University, 229 North Taibai Road, Xi'an, Shaanxi 710069, China
| | - Heng Li
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, College of Life Sciences, Northwest University, 229 North Taibai Road, Xi'an, Shaanxi 710069, China
| | - Wen-Yun Gao
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, College of Life Sciences, Northwest University, 229 North Taibai Road, Xi'an, Shaanxi 710069, China.
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Liang W, Fernandes AP, Holmgren A, Li X, Zhong L. Bacterial thioredoxin and thioredoxin reductase as mediators for epigallocatechin 3-gallate-induced antimicrobial action. FEBS J 2015; 283:446-58. [PMID: 26546231 DOI: 10.1111/febs.13587] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Revised: 10/03/2015] [Accepted: 11/02/2015] [Indexed: 01/04/2023]
Abstract
Epigallocatechin 3-gallate (EGCG) is the most abundant catechin in green tea and may combat bacteria with few side-effects. Its selectivity for different bacterial infections remains unclear, and hence the identification of the underlying mechanism is of practical importance. Both the thioredoxin (Trx) system and the glutathione/glutaredoxin (Grx) system support bacterial growth. Some pathogenic bacteria are naturally deficient in the Grx system. We analyzed the effect of green tea extract (GTE) and EGCG on wild-type and null mutants of Escherichia coli with either Trx or Grx system deficiency and found that GTE and EGCG selected the Trx system as a target and killed the mutant that is exclusively dependent on Trx/Trx reductase (TrxR). EGCG inhibited the activity of both Trx1 and TrxR of E. coli in a dose-dependent and time-dependent manner. The IC50 values of EGCG for the reduced forms of E. coli Trx1/TrxR were ~ 3-4-fold lower than those for their non-reduced forms. The IC50 value of EGCG for the E. coli Trx1 system was 56-fold lower than that for the mammalian Trx1 system. The inhibition by EGCG of both Trx1 and TrxR of E. coli was irreversible. EGCG-induced inactivation of E. coli Trx1 was a second-order process, and that of E. coli TrxR was an affinity-labeling process. The covalent binding sites for EGCG in E. coli Trx1 were Trp(28) , Trp(31) and Cys(32) , and in E. coli TrxR were Cys(135) and Cys(138) . Moreover, the sensitivity of Staphylococcus aureus to EGCG was similar to that of an E. coli mutant with Grx system deficiency. EGCG-induced inactivation of Trx/TrxR in S. aureus coincided with suppressed growth of this virulent pathogen. Our findings suggest a role for EGCG-dependent Trx/TrxR inactivation in potentiating antibacterial activity of EGCG.
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Affiliation(s)
- Wei Liang
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Aristi P Fernandes
- Division of Biochemistry, Department of Medical Biochemistry and Biophysics, Karolinska Institute, Stockholm, Sweden
| | - Arne Holmgren
- Division of Biochemistry, Department of Medical Biochemistry and Biophysics, Karolinska Institute, Stockholm, Sweden
| | - Xiaoming Li
- The State Key Laboratory of Biomembrane and Membrane Biotechnology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Liangwei Zhong
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
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Bermejo DV, Mendiola JA, Ibáñez E, Reglero G, Fornari T. Pressurized liquid extraction of caffeine and catechins from green tea leaves using ethyl lactate, water and ethyl lactate + water mixtures. FOOD AND BIOPRODUCTS PROCESSING 2015. [DOI: 10.1016/j.fbp.2015.07.008] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Tiwari V, Roy R, Tiwari M. Antimicrobial active herbal compounds against Acinetobacter baumannii and other pathogens. Front Microbiol 2015; 6:618. [PMID: 26150810 PMCID: PMC4471432 DOI: 10.3389/fmicb.2015.00618] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2015] [Accepted: 06/03/2015] [Indexed: 11/27/2022] Open
Abstract
Bacterial pathogens cause a number of lethal diseases. Opportunistic bacterial pathogens grouped into ESKAPE pathogens that are linked to the high degree of morbidity, mortality and increased costs as described by Infectious Disease Society of America. Acinetobacter baumannii is one of the ESKAPE pathogens which cause respiratory infection, pneumonia and urinary tract infections. The prevalence of this pathogen increases gradually in the clinical setup where it can grow on artificial surfaces, utilize ethanol as a carbon source and resists desiccation. Carbapenems, a β-lactam, are the most commonly prescribed drugs against A. baumannii. The high level of acquired and intrinsic carbapenem resistance mechanisms acquired by these bacteria makes their eradication difficult. The pharmaceutical industry has no solution to this problem. Hence, it is an urgent requirement to find a suitable alternative to carbapenem, a commonly prescribed drug for Acinetobacter infection. In order to do this, here we have made an effort to review the active compounds of plants that have potent antibacterial activity against many bacteria including carbapenem resistant strain of A. baumannii. We have also briefly highlighted the separation and identification methods used for these active compounds. This review will help researchers involved in the screening of herbal active compounds that might act as a replacement for carbapenem.
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Affiliation(s)
- Vishvanath Tiwari
- Department of Biochemistry, Central University of Rajasthan Ajmer, India
| | - Ranita Roy
- Department of Biochemistry, Central University of Rajasthan Ajmer, India
| | - Monalisa Tiwari
- Department of Biochemistry, Central University of Rajasthan Ajmer, India
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Abstract
Green tea is a popular drink, especially in Asian countries, although its popularity continues to spread across the globe. The health benefits of green tea, derived from the leaves of the Camellia sinensis plant, have been studied for many years. Fairly recently, researchers have begun to look at the possibility of using green tea in antimicrobial therapy, and the potential prevention of infections. The particular properties of catechins found in the tea have shown promise for having antimicrobial effects. There are four main catechins (polyphenols) found in green tea: (-)-epicatechin (EC), (-)-epicatechin-3-gallate (ECG), (-)-epigallocatechin (EGC), and (-)-epigallocatechin-3-gallate (EGCG). Three of these, ECG, EGC, and EGCG have been shown to have antimicrobial effects against a variety of organisms. These catechins have exhibited a variety of antimicrobial mechanisms. The results of studies on the antimicrobial effects of green tea have shown that the potential for preventive and therapeutic purposes is present. Further data collection on studies performed with human consumption during the course of infections, and studies on the occurrence of infections in populations that consume regular amounts of green tea will be necessary to complete the picture of its antimicrobial possibilities.
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Affiliation(s)
- Wanda C Reygaert
- Department of Biomedical Sciences, Oakland University William Beaumont School of Medicine Rochester, MI, USA
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Betts JW, Wareham DW. In vitro activity of curcumin in combination with epigallocatechin gallate (EGCG) versus multidrug-resistant Acinetobacter baumannii. BMC Microbiol 2014; 14:172. [PMID: 24969489 PMCID: PMC4083870 DOI: 10.1186/1471-2180-14-172] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2014] [Accepted: 06/19/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Acinetobacter baumannii is an opportunistic human pathogen often associated with life-threatening infections in the immunocompromised and the critically ill. Strains are often multidrug-resistant (MDR) and due to the lack of new synthetic antimicrobials in development for treatment, attention is increasingly focused on natural compounds either as stand-alone or adjunctive agents. Curcumin (CCM) is a natural polyphenol found in turmeric and isolated from the plant, Curcuma longa. Curcumin has been found to possess many biological properties, including antibacterial activity. In this study the antimicrobial activity of CCM and synergistic effects with epigallocatechin gallate (EGCG) against multidrug-resistant strains of A. baumannii were investigated and assessed via checkerboard and time-kill assays. RESULTS The MIC of CCM was >256 μg/mL against all strains of A. baumannii whilst those for EGCG ranged from 128-1024 μg/mL. In checkerboard studies synergy was observed against 5/9 isolates, with an additive effect noted in the remaining 4. The addition of EGCG reduced the MIC of CCM by 3- to 7-fold, with the greatest interaction resulting in a CCM MIC of 4 μg/mL. Time-kill curves indicated that a CCM-EGCG (1:8 and 1:4) combination was bactericidal with a 4 to 5-log reduction in viable counts after 24 h compared to the most effective polyphenol alone. CONCLUSIONS This study demonstrates that despite little antibacterial activity alone, CCM activity is greatly enhanced in the presence of EGCG resulting in antibacterial activity against MDR A. baumannii. The combination may have a potential use in medicine as a topical agent to prevent or treat A. baumannii infections.
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Affiliation(s)
- Jonathan W Betts
- Antimicrobial Research Group, Centre for Immunology and Infectious Disease, Blizard Institute, Queen Mary University London, 4, Newark Street, Whitechapel, London E1 2AT, UK
| | - David W Wareham
- Antimicrobial Research Group, Centre for Immunology and Infectious Disease, Blizard Institute, Queen Mary University London, 4, Newark Street, Whitechapel, London E1 2AT, UK
- Division of Infection, Barts Health NHS Trust, London E1 2ES, UK
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Vidigal PG, Müsken M, Becker KA, Häussler S, Wingender J, Steinmann E, Kehrmann J, Gulbins E, Buer J, Rath PM, Steinmann J. Effects of green tea compound epigallocatechin-3-gallate against Stenotrophomonas maltophilia infection and biofilm. PLoS One 2014; 9:e92876. [PMID: 24690894 PMCID: PMC3972220 DOI: 10.1371/journal.pone.0092876] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2013] [Accepted: 02/27/2014] [Indexed: 12/21/2022] Open
Abstract
We investigated the in vitro and in vivo activities of epigallocatechin-3-gallate (EGCg), a green tea component, against Stenotrophomonas maltophilia (Sm) isolates from cystic fibrosis (CF) patients. In vitro effects of EGCg and the antibiotic colistin (COL) on growth inhibition, survival, and also against young and mature biofilms of S. maltophilia were determined. Qualitative and quantitative changes on the biofilms were assessed by confocal laser scanning microscopy (CLSM). Further, in vivo effects of nebulized EGCg in C57BL/6 and Cftr mutant mice during acute Sm lung infection were evaluated. Subinhibitory concentrations of EGCg significantly reduced not only biofilm formation, but also the quantity of viable cells in young and mature biofilms. CLSM showed that EGCg-exposed biofilms exhibited either a change in total biofilm biovolume or an increase of the fraction of dead cells contained within the biofilm in a dose depended manner. Sm infected wild-type and Cftr mutant mice treated with 1,024 mg/L EGCg by inhalation exhibited significantly lower bacterial counts than those undergoing no treatment or treated with COL. EGCg displayed promising inhibitory and anti-biofilm properties against CF Sm isolates in vitro and significantly reduced Sm bacterial counts in an acute infection model with wild type and CF mice. This natural compound may represent a novel therapeutic agent against Sm infection in CF.
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Affiliation(s)
- Pedrina G. Vidigal
- Institute of Medical Microbiology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Mathias Müsken
- Institute for Molecular Bacteriology, TWINCORE, Center for Experimental and Clinical Infection Research, Hannover, Germany
- Department of Molecular Bacteriology, Helmholtz Center for Infection Research, Braunschweig, Germany
| | - Katrin A. Becker
- Institute of Molecular Biology, University of Duisburg-Essen, Essen, Germany
| | - Susanne Häussler
- Institute for Molecular Bacteriology, TWINCORE, Center for Experimental and Clinical Infection Research, Hannover, Germany
- Department of Molecular Bacteriology, Helmholtz Center for Infection Research, Braunschweig, Germany
| | - Jost Wingender
- Biofilm Center, Department of Aquatic Microbiology, Faculty of Chemistry, University of Duisburg-Essen, Essen, Germany
| | - Eike Steinmann
- Division of Experimental Virology, TWINCORE, Center for Experimental and Clinical Infection Research, Hannover, Germany
| | - Jan Kehrmann
- Institute of Medical Microbiology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Erich Gulbins
- Institute of Molecular Biology, University of Duisburg-Essen, Essen, Germany
| | - Jan Buer
- Institute of Medical Microbiology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Peter Michael Rath
- Institute of Medical Microbiology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Jörg Steinmann
- Institute of Medical Microbiology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
- * E-mail:
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Peek J, Shi T, Christendat D. Identification of Novel Polyphenolic Inhibitors of Shikimate Dehydrogenase (AroE). ACTA ACUST UNITED AC 2014; 19:1090-8. [DOI: 10.1177/1087057114527127] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2013] [Accepted: 02/17/2014] [Indexed: 11/15/2022]
Abstract
Shikimate dehydrogenase (AroE) is an attractive target for herbicides and antimicrobial agents due to its conserved and essential nature in plants, fungi, and bacteria. Here, we have performed an in vitro screen using a collection of more than 5500 compounds and identified 24 novel inhibitors of AroE from Pseudomonas putida. The IC50 values for the two most potent inhibitors we identified, epigallocatechin gallate (EGCG) and epicatechin gallate (ECG), were 3.0 ± 0.2 µM and 3.7 ± 0.5 µM, respectively. Based on the high level of structural conservation between AroE orthologs, we predicted that the identified compounds would also inhibit AroE enzymes from other organisms. Consistent with this hypothesis, we found that EGCG and ECG inhibit the AroE domain of the bifunctional dehydroquinate dehydratase-shikimate dehydrogenase (DHQ-SDH) from Arabidopsis thaliana with IC50 values of 2.1 ± 0.3 µM and 2.0 ± 0.2 µM, respectively.
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Affiliation(s)
- James Peek
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada
| | - Thomas Shi
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada
| | - Dinesh Christendat
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada
- Centre for the Analysis of Genome Evolution and Function, University of Toronto, Toronto, ON, Canada
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Bansal S, Choudhary S, Sharma M, Kumar SS, Lohan S, Bhardwaj V, Syan N, Jyoti S. Tea: A native source of antimicrobial agents. Food Res Int 2013. [PMCID: PMC7126541 DOI: 10.1016/j.foodres.2013.01.032] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Tea (Camellia sinensis) is one of the most popular nonalcoholic beverages, consumed by over two-thirds of the world's population because of its refreshing, mild stimulant and medicinal properties. It is processed in different ways in different parts of the world to give green, black, oolong, and pu-erh tea. Among all tea polyphenols, epigallocatechin-3-gallate has been responsible for much of the health promoting abilities of tea including anti-inflammatory, antimicrobial, antitumour, anti-oxidative, protection from cardiovascular disease, anti-obesity, and anti-aging properties. In the present review, the antibacterial, antiviral, and antifungal activities of different types of tea and their polyphenols are reported, highlighting their mechanisms of action and structure–activity relationship. Moreover, considering that the changing patterns of infectious diseases and the emergence of microbial strains resistant to current antibiotics, there is an urgent need to find out new potent antimicrobial agents as adjuvants to antibiotic therapy. The synergistic effect of tea polyphenols in combination with conventional antimicrobial agents against clinical multidrug-resistant microorganisms has also been discussed in this review.
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Affiliation(s)
- Sumit Bansal
- Department of Pharmacy, Jaypee University of Information Technology, Waknaghat, Himachal Pradesh, India
- Corresponding author. Tel.: + 91 1792 239219; fax: + 91 1792 245362.
| | - Shivani Choudhary
- Department of Pharmaceutical Chemistry, Manipal College of Pharmaceutical Sciences, Manipal, Karnataka, India
| | - Manu Sharma
- Department of Pharmacy, Jaypee University of Information Technology, Waknaghat, Himachal Pradesh, India
| | - Suthar Sharad Kumar
- Department of Pharmacy, Jaypee University of Information Technology, Waknaghat, Himachal Pradesh, India
| | - Sandeep Lohan
- Department of Pharmacy, Jaypee University of Information Technology, Waknaghat, Himachal Pradesh, India
| | - Varun Bhardwaj
- Department of Pharmacy, Jaypee University of Information Technology, Waknaghat, Himachal Pradesh, India
| | - Navneet Syan
- Department of Pharmaceutical Chemistry, Ganpati Institute of Pharmacy, Bilaspur, Haryana, India
| | - Saras Jyoti
- Department of Biotechnology & Bioinformatics, Jaypee University of Information Technology, Waknaghat, Himachal Pradesh, India
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Steinmann J, Buer J, Pietschmann T, Steinmann E. Anti-infective properties of epigallocatechin-3-gallate (EGCG), a component of green tea. Br J Pharmacol 2013; 168:1059-73. [PMID: 23072320 DOI: 10.1111/bph.12009] [Citation(s) in RCA: 338] [Impact Index Per Article: 30.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2012] [Revised: 09/12/2012] [Accepted: 10/02/2012] [Indexed: 12/14/2022] Open
Abstract
The consumption of green tea (Camellia sinensis) has been shown to have many physiological and pharmacological health benefits. In the past two decades several studies have reported that epigallocatechin-3-gallate (EGCG), the main constituent of green tea, has anti-infective properties. Antiviral activities of EGCG with different modes of action have been demonstrated on diverse families of viruses, such as Retroviridae, Orthomyxoviridae and Flaviviridae and include important human pathogens like human immunodeficiency virus, influenza A virus and the hepatitis C virus. Furthermore, the molecule interferes with the replication cycle of DNA viruses like hepatitis B virus, herpes simplex virus and adenovirus. Most of these studies demonstrated antiviral properties within physiological concentrations of EGCG in vitro. In contrast, the minimum inhibitory concentrations against bacteria were 10-100-fold higher. Nevertheless, the antibacterial effects of EGCG alone and in combination with different antibiotics have been intensively analysed against a number of bacteria including multidrug-resistant strains such as methicillin-resistant Staphylococcus aureus or Stenotrophomonas maltophilia. Furthermore, the catechin EGCG has antifungal activity against human-pathogenic yeasts like Candida albicans. Although the mechanistic effects of EGCG are not fully understood, there are results indicating that EGCG binds to lipid membranes and affects the folic acid metabolism of bacteria and fungi by inhibiting the cytoplasmic enzyme dihydrofolate reductase. This review summarizes the current knowledge and future perspectives on the antibacterial, antifungal and antiviral effects of the green tea constituent EGCG.
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Affiliation(s)
- J Steinmann
- Institute of Medical Microbiology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany.
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Miyasaki Y, Rabenstein JD, Rhea J, Crouch ML, Mocek UM, Kittell PE, Morgan MA, Nichols WS, Van Benschoten MM, Hardy WD, Liu GY. Isolation and characterization of antimicrobial compounds in plant extracts against multidrug-resistant Acinetobacter baumannii. PLoS One 2013; 8:e61594. [PMID: 23630600 PMCID: PMC3632535 DOI: 10.1371/journal.pone.0061594] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2012] [Accepted: 03/11/2013] [Indexed: 11/18/2022] Open
Abstract
The number of fully active antibiotic options that treat nosocomial infections due to multidrug-resistant Acinetobacter baumannii (A. baumannii) is extremely limited. Magnolia officinalis, Mahonia bealei, Rabdosia rubescens, Rosa rugosa, Rubus chingii, Scutellaria baicalensis, and Terminalia chebula plant extracts were previously shown to have growth inhibitory activity against a multidrug-resistant clinical strain of A. baumannii. In this study, the compounds responsible for their antimicrobial activity were identified by fractionating each plant extract using high performance liquid chromatography, and determining the antimicrobial activity of each fraction against A. baumannii. The chemical structures of the fractions inhibiting >40% of the bacterial growth were elucidated by liquid chromatography/mass spectrometry analysis and nuclear magnetic resonance spectroscopy. The six most active compounds were identified as: ellagic acid in Rosa rugosa; norwogonin in Scutellaria baicalensis; and chebulagic acid, chebulinic acid, corilagin, and terchebulin in Terminalia chebula. The most potent compound was identified as norwogonin with a minimum inhibitory concentration of 128 µg/mL, and minimum bactericidal concentration of 256 µg/mL against clinically relevant strains of A. baumannii. Combination studies of norwogonin with ten anti-Gram negative bacterial agents demonstrated that norwogonin did not enhance the antimicrobial activity of the synthetic antibiotics chosen for this study. In conclusion, of all identified antimicrobial compounds, norwogonin was the most potent against multidrug-resistant A. baumannii strains. Further studies are warranted to ascertain the prophylactic and therapeutic potential of norwogonin for infections due to multidrug-resistant A. baumannii.
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Affiliation(s)
- Yoko Miyasaki
- Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California, United States of America.
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Cui Y, Kim SH, Kim H, Yeom J, Ko K, Park W, Park S. AFM probing the mechanism of synergistic effects of the green tea polyphenol (-)-epigallocatechin-3-gallate (EGCG) with cefotaxime against extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli. PLoS One 2012; 7:e48880. [PMID: 23152812 PMCID: PMC3496731 DOI: 10.1371/journal.pone.0048880] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2012] [Accepted: 10/01/2012] [Indexed: 11/26/2022] Open
Abstract
Background Extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae poses serious challenges to clinicians because of its resistance to many classes of antibiotics. Methods and Findings The mechanism of synergistic activity of a combination of (−)-epigallocatechin-3-gallate (EGCG) and β-lactam antibiotics cefotaxime was studied on Extended-spectrum β-lactamase producing Escherichia coli (ESBL-EC), by visualizing the morphological alteration on the cell wall induced by the combination using atomic force microscopy (AFM). Cells at sub-MICs (sub-minimum inhibitory concentrations) of cefotaxime were initially filamentated but recovered to the normal shape later, whereas cells at sub-MICs of EGCG experienced temporal disturbance on the cell wall such as leakage and release of cellular debris and groove formation, but later recovered to the normal shape. In contrast, the combination of cefotaxime and EGCG at their respective sub-MICs induced permanent cellular damages as well as continuous elongation in cells and eventually killed them. Flow cytometry showed that intracellular oxidative stress levels in the cell treated with a combination of EGCG and cefotaxime at sub-MICs were higher than those in the cells treated with either cefotaxime or EGCG at sub-MICs. Conclusions These results suggest that the synergistic effect of EGCG between EGCG and cefotaxime against ESBL-EC is related to cooperative activity of exogenous and endogenous reactive oxygen species (ROS) generated by EGCG and cefotaxime, respectively.
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Affiliation(s)
- Yidan Cui
- Department of Chemistry and Nano Sciences, Ewha Womans University, Seoul, Korea
- Mechanobiology Institute, National University of Singapore, Singapore, Singapore
| | - So Hyun Kim
- Department of Chemistry and Nano Sciences, Ewha Womans University, Seoul, Korea
| | - Hyunseok Kim
- Department of Chemistry and Nano Sciences, Ewha Womans University, Seoul, Korea
| | - Jinki Yeom
- Division of Environmental Science and Ecological Engineering, Korea University, Seoul, Korea
| | - Kisung Ko
- Department of Medicine, College of Medicine, Chung-Ang University, Seoul, Korea
| | - Woojun Park
- Division of Environmental Science and Ecological Engineering, Korea University, Seoul, Korea
| | - Sungsu Park
- Department of Chemistry and Nano Sciences, Ewha Womans University, Seoul, Korea
- Mechanobiology Institute, National University of Singapore, Singapore, Singapore
- * E-mail:
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Akhtar N, Haqqi TM. Current nutraceuticals in the management of osteoarthritis: a review. Ther Adv Musculoskelet Dis 2012; 4:181-207. [PMID: 22850529 DOI: 10.1177/1759720x11436238] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Osteoarthritis (OA) is a progressive degenerative joint disease that has a major impact on joint function and quality of life. Nutraceuticals and dietary supplements derived from herbs have long been used in traditional medicine and there is considerable evidence that nutraceuticals may play an important role in inflammation and joint destruction in OA. We review the biological effects of some medicinal fruits and herbs - pomegranate, green tea, cat's claw, devil's claw, ginger, Indian olibaum, turmeric and ananas - in an attempt to understand the pivotal molecular targets involved in inflammation and the joint destruction process and to summarize their toxicities and efficacy for OA management. So far there is insufficient reliable evidence on the effectiveness of ginger, turmeric and ananas. Pomegranate and green tea only have preclinical evidence of efficacy due to the lack of clinical data. In vivo and clinical studies are required to understand their targets and efficacy in OA. Limited in vitro and in vivo evidence is available for cat's claw and Indian olibaum. More extensive studies are required before long-term controlled trials of whole cat's claw and Indian olibaum extracts, or isolated active compounds, are carried out in patients with OA to determine their long-term efficacy and safety. Devil's claw has not been rigorously tested to determine its antiarthritic potential in in vitro and in vivo models. There is strong clinical evidence of the effectiveness of devil's claw in pain reduction. However, high-quality clinical trials are needed to determine its effectiveness. No serious side effects have been reported for any fruits and herbs. Overall, these studies identify and support the use of nutraceuticals to provide symptomatic relief to patients with OA and to be used as adjunct therapy for OA management. More high-quality trials are needed to provide definitive answers to questions related to their efficacy and safety for OA prevention and/or treatment.
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Affiliation(s)
- Nahid Akhtar
- Department of Medicine/Rheumatology, MetroHealth Medical Center, Case Western Reserve University, Cleveland, OH, USA
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Im M, Kim SY, Sohn KC, Choi DK, Lee Y, Seo YJ, Kim CD, Hwang YL, Zouboulis CC, Lee JH. Epigallocatechin-3-gallate suppresses IGF-I-induced lipogenesis and cytokine expression in SZ95 sebocytes. J Invest Dermatol 2012; 132:2700-8. [PMID: 22763784 DOI: 10.1038/jid.2012.202] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Acne vulgaris is the most common disease of the pilosebaceous unit. The pathogenesis of this inflammatory disease is complex, involving increased sebum production and perifollicular inflammation. To identify effective agents for factors that induce acne vulgaris, we explored the pharmacological potential of epigallocatechin-3-gallate (EGCG), which has been widely investigated as an anti-proliferative and anti-inflammatory agent. In this study, we demonstrated that topical application of EGCG to rabbit auricles reduced the size of the sebaceous glands. When applied to cultured human SZ95 sebocytes, EGCG strongly suppressed cell proliferation and lipogenesis. These actions of EGCG were reproduced in IGF-I-differentiated SZ95 sebocytes. To investigate the anti-inflammatory potential of EGCG, we evaluated pro-inflammatory cytokine synthesis in IGF-I-differentiated SZ95 sebocytes and found that expression of IL-1, IL-6, and IL-8 was decreased. These results provide early evidence that EGCG is an effective candidate for acne therapy whose mechanisms of action in IGF-I-differentiated SZ95 sebocytes include the inhibition of lipogenesis and inflammation.
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Affiliation(s)
- Myung Im
- Department of Dermatology, College of Medicine, Chungnam National University, Daejeon, Korea
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Park HS, Im NG, Kim KH. Extraction behaviors of caffeine and chlorophylls in supercritical decaffeination of green tea leaves. Lebensm Wiss Technol 2012. [DOI: 10.1016/j.lwt.2011.07.023] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Sadeghian A, Pordel M, Safdari H, Fahmidekar MA, Sadeghian H. 11-Chloro-3-methyl-3H-imidazo[4,5-a]acridine (CMIA) as a potent and selective antimicrobial agent against clinical isolates of highly antibiotic-resistant Acinetobacter baumannii. Med Chem Res 2011. [DOI: 10.1007/s00044-011-9933-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Betts JW, Kelly SM, Haswell SJ. Antibacterial effects of theaflavin and synergy with epicatechin against clinical isolates of Acinetobacter baumannii and Stenotrophomonas maltophilia. Int J Antimicrob Agents 2011; 38:421-5. [PMID: 21885260 DOI: 10.1016/j.ijantimicag.2011.07.006] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2011] [Revised: 07/07/2011] [Accepted: 07/14/2011] [Indexed: 10/17/2022]
Abstract
Stenotrophomonas maltophilia and Acinetobacter baumannii are recognised as important nosocomial pathogens; however, due to their intrinsic resistance to multiple antibiotics, treatment options are limited. Polyphenols from black tea have been shown to possess antibacterial action. In this study, the antibacterial effects of various concentrations of theaflavin as well as combinations of theaflavin and epicatechin were determined using the disk diffusion assay. The results showed strong antibacterial activity of theaflavin against eight clinical isolates of S. maltophilia and A. baumannii. Significant synergy (P≤0.05) was also observed between theaflavin and epicatechin against all isolates. Although the mechanisms for this activity and synergy are not well understood, the clinical potential is clear and further research is recommended to determine the modes of action.
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Affiliation(s)
- J W Betts
- Department of Chemistry, University of Hull, Hull HU6 7RX, UK
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Cho YS, Oh JJ, Oh KH. Synergistic anti-bacterial and proteomic effects of epigallocatechin gallate on clinical isolates of imipenem-resistant Klebsiella pneumoniae. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2011; 18:941-946. [PMID: 21596543 DOI: 10.1016/j.phymed.2011.03.012] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2010] [Revised: 02/09/2011] [Accepted: 03/26/2011] [Indexed: 05/30/2023]
Abstract
Imipenem-resistant Klebsiella pneumoniae (IRKP) were used to explore the synergistic anti-bacterial and proteomic effects of imipenem alone or in combination with epigallocatechin gallate (EGCg). The minimal inhibitory concentrations (MICs) of EGCG for 12 clinically isolated IRKP strains ranged from 300 to 650 μg/ml. Each of the 12 IRKP strains experienced a 4- to 64-fold reduction in the MIC of imipenem upon co-incubation with 0.25 × MIC level of EGCg. The time-kill method was used on the 12 IRKP clinical isolates to evaluate the bactericidal activities of imipenem alone or with EGCg. Compared to imipenem alone, EGCg with imipenem demonstrated enhanced bactericidal activity. Two-dimensional polyacrylamide gel electrophoresis identified eight down-regulated and four up-regulated proteins in the IRKP strain upon exposure to 1 × MIC of EGCg. Analysis of the outer membrane protein profiles of IRKP cultures treated with EGCg revealed unique changes in outer membrane proteins. In addition, scanning electron microscopic analysis demonstrated the presence of cells with wrinkled surfaces containing perforations and irregular rod-shaped forms after treatment with EGCg or imipenem. These studies demonstrate that EGCg can synergize the bacterial activity of imipenem and differentially stimulate the expression of various proteins in IRKP.
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Affiliation(s)
- Yun-Seok Cho
- Department of Biotechnology, Soonchunhyang University, P.O. Box 97, Asan, Chung-Nam 336-600, Republic of Korea
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Singh R, Akhtar N, Haqqi TM. Green tea polyphenol epigallocatechin-3-gallate: inflammation and arthritis. [corrected]. Life Sci 2010; 86:907-18. [PMID: 20462508 PMCID: PMC3146294 DOI: 10.1016/j.lfs.2010.04.013] [Citation(s) in RCA: 134] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2010] [Revised: 04/15/2010] [Accepted: 04/29/2010] [Indexed: 12/18/2022]
Abstract
A number of factors including inflammation and oxidative stress are believed to play a role in the development of chronic joint diseases. Green tea has become a popular drink and is consumed throughout the world. Extracts of green tea and polyphenols present therein have been shown to inhibit the inflammatory responses in vitro in different cell types and the development of arthritis in animal model studies. There is considerable evidence that (-)-epigallocatechin-3-gallate (EGCG), the predominant green tea polyphenol which mimic its effects, inhibits enzyme activities and signal transduction pathways that play important roles in inflammation and joint destruction in arthritis. After oral consumption EGCG become bioavailable and proteomic studies suggest that EGCG may directly interact with a large set of protein targets and alter the physiological response of the cells. Taken together these and other studies identify and support the use of EGCG as a possible chemopreventive agent with a potential to inhibit the development of arthritis. Here we review the biological effects of EGCG in an attempt to understand its pivotal molecular targets that directly affect the inflammation and joint destruction process for prevention and/or for the development of new therapeutics for arthritis in humans.
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Affiliation(s)
- Rashmi Singh
- Department of Zoology, Mahila Mahavidyalaya, Banaras Hindu University, Varanasi, India
| | - Nahid Akhtar
- Department of Medicine/Rheumatology, Metrohealth Medical Center, Case Western Reserve University, 2500 Metrohealth Drive, Cleveland, OH 44109
| | - Tariq M. Haqqi
- Department of Medicine/Rheumatology, Metrohealth Medical Center, Case Western Reserve University, 2500 Metrohealth Drive, Cleveland, OH 44109
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Gordon NC, Wareham DW. Antimicrobial activity of the green tea polyphenol (-)-epigallocatechin-3-gallate (EGCG) against clinical isolates of Stenotrophomonas maltophilia. Int J Antimicrob Agents 2010; 36:129-31. [PMID: 20472404 DOI: 10.1016/j.ijantimicag.2010.03.025] [Citation(s) in RCA: 94] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2010] [Accepted: 03/17/2010] [Indexed: 12/25/2022]
Abstract
Stenotrophomonas maltophilia is increasingly recognised as an important nosocomial pathogen. Treatment options are limited due to intrinsic resistance to many antibiotics as well as concerns over toxicity of the mainstay of treatment, co-trimoxazole. Epigallocatechin-3-gallate (EGCG), the major catechin found in green tea, has been shown to have antimicrobial effects against a number of bacterial pathogens. We evaluated the in vitro activity of this compound against 40 clinical isolates of S. maltophilia. MIC(50/90) values (minimal inhibitory concentrations for 50% and 90% of the organisms, respectively) were 256 mg/L when determined by agar dilution and 512 mg/L by broth microdilution. MBC(50/90) values (minimal bactericidal concentrations for 50% and 90% of the organisms, respectively) were 512 mg/L. In time-kill assays, the bactericidal activity of EGCG was analysed by viable colony counts as well as a colorimetric assay for bacterial reduction of XTT. EGCG was slowly bactericidal at 4x MIC, with a 2.5 log reduction in viable bacteria at 24h. EGCG has promising in vitro antimicrobial activity against S. maltophilia. Although the mechanism of action is not yet clear, further studies to evaluate its clinical potential and role in combination with other antimicrobial agents are warranted.
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Affiliation(s)
- Nicola C Gordon
- Division of Infection, Barts & The London NHS Trust, London, UK
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