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Hou S, Guo J, Liu L, Qiu F, Liu X. Antibacterial and antibiofilm activity of Lagotis brachystachya extract against extended-spectrum β-lactamases-producing Escherichia coli from broiler chickens. Poult Sci 2022; 101:101555. [PMID: 34847518 PMCID: PMC8637138 DOI: 10.1016/j.psj.2021.101555] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Revised: 10/14/2021] [Accepted: 10/14/2021] [Indexed: 11/01/2022] Open
Abstract
Lagotis brachystachya Maxim (L. brachystachya) is an herb widely used in traditional Tibetan medicine. In the present study, the antibacterial activity of L. brachystachya extract to extended-spectrum-lactamases (ESBLs)-producing E. coli was determined by Kirby-Bauer disc diffusion, minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) methods as well as time-kill curve assay. Meanwhile, the biofilm inhibition and eradication effects of L. brachystachya extract on the ESBLs-producing E. coli were evaluated by crystal violet staining, and further confirmed by confocal laser scanning microscope (CLSM) and scanning electron microscopy (SEM). The results indicated that L. brachystachya extract exhibited moderate antibacterial activity, with diameter of inhibition zones varying from 15.4 to 20.3 mm, and the MIC and MBC values were 6.25 to 25 mg/mL and 12.5 to 100 mg/mL, respectively. Time-kill curve showed that 4 × MIC level of L. brachystachya extract concentration of was able to kill 99.9% of ESBLs-producing E. coli after 16 h treatment. The biofilm inhibition rate and eradication rate for the ESBLs-producing E. coli were 35.66 to 79.91% and 22.18 to 56.21% at MIC level of extract concentration, respectively. CLSM images showed that the biofilm became thinner as the ESBLs-producing E. coli isolate exposed to L. brachystachya extract with a concentration-dependent manner from 1/4 × MIC to MIC compared with the control isolate. SEM images indicated that L. brachystachya extract at 1/2 × MIC and MIC levels could evidently inhibit the biofilm formation or eradicate the mature biofilms. The effect of L. brachystachya highlights its potential of antibacterial and antibiofilm activities against the ESBLs-producing E. coli.
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Affiliation(s)
- Simeng Hou
- College of Veterinary Medicine, Northwest A&F University, Yangling 712100, Shaanxi, China
| | - Jingjing Guo
- College of Veterinary Medicine, Northwest A&F University, Yangling 712100, Shaanxi, China
| | - Lianjie Liu
- College of Veterinary Medicine, Northwest A&F University, Yangling 712100, Shaanxi, China
| | - Fang Qiu
- College of Veterinary Medicine, Northwest A&F University, Yangling 712100, Shaanxi, China
| | - Xiaoqiang Liu
- College of Veterinary Medicine, Northwest A&F University, Yangling 712100, Shaanxi, China.
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Spiga L, Jimenez AG, Santos RL, Winter SE. How microbiological tests reflect bacterial pathogenesis and host adaptation. Braz J Microbiol 2021; 52:1745-1753. [PMID: 34251610 PMCID: PMC8578236 DOI: 10.1007/s42770-021-00571-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Accepted: 06/29/2021] [Indexed: 10/20/2022] Open
Abstract
Historically, clinical microbiological laboratories have often relied on isolation of pure cultures and phenotypic testing to identify microorganisms. These clinical tests are often based on specific biochemical reactions, growth characteristics, colony morphology, and other physiological aspects. The features used for identification in clinical laboratories are highly conserved and specific for a given group of microbes. We speculate that these features might be the result of evolutionary selection and thus may reflect aspects of the life cycle of the organism and pathogenesis. Indeed, several of the metabolic pathways targeted by diagnostic tests in some cases may represent mechanisms for host colonization or pathogenesis. Examples include, but are not restricted to, Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella pneumoniae, Salmonella enterica, Shigella spp., and enteroinvasive Escherichia coli (EIEC). Here, we provide an overview of how some common tests reflect molecular mechanisms of bacterial pathogenesis.
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Affiliation(s)
- Luisella Spiga
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Angel G Jimenez
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Renato L Santos
- Departamento de Clínica E Cirurgia Veterinárias, Escola de Veterinária, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Sebastian E Winter
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, TX, USA.
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Rhodomyrtone Accumulates in Bacterial Cell Wall and Cell Membrane and Inhibits the Synthesis of Multiple Cellular Macromolecules in Epidemic Methicillin-Resistant Staphylococcus aureus. Antibiotics (Basel) 2021; 10:antibiotics10050543. [PMID: 34067029 PMCID: PMC8150934 DOI: 10.3390/antibiotics10050543] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Revised: 04/19/2021] [Accepted: 05/04/2021] [Indexed: 12/23/2022] Open
Abstract
As the burden of antibacterial resistance worsens and treatment options become narrower, rhodomyrtone—a novel natural antibiotic agent with a new antibacterial mechanism—could replace existing antibiotics for the treatment of infections caused by multi-drug resistant Gram-positive bacteria. In this study, rhodomyrtone was detected within the cell by means of an easy an inexpensive method. The antibacterial effects of rhodomyrtone were investigated on epidemic methicillin-resistant Staphylococcus aureus. Thin-layer chromatography demonstrated the entrapment and accumulation of rhodomyrtone within the bacterial cell wall and cell membrane. The incorporation of radiolabelled precursors revealed that rhodomyrtone inhibited the synthesis of macromolecules including DNA, RNA, proteins, the cell wall, and lipids. Following the treatment with rhodomyrtone at MIC (0.5–1 µg/mL), the synthesis of all macromolecules was significantly inhibited (p ≤ 0.05) after 4 h. Inhibition of macromolecule synthesis was demonstrated after 30 min at a higher concentration of rhodomyrtone (4× MIC), comparable to standard inhibitor compounds. In contrast, rhodomyrtone did not affect lipase activity in staphylococci—both epidemic methicillin-resistant S. aureus and S. aureus ATCC 29213. Interfering with the synthesis of multiple macromolecules is thought to be one of the antibacterial mechanisms of rhodomyrtone.
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Porras G, Chassagne F, Lyles JT, Marquez L, Dettweiler M, Salam AM, Samarakoon T, Shabih S, Farrokhi DR, Quave CL. Ethnobotany and the Role of Plant Natural Products in Antibiotic Drug Discovery. Chem Rev 2021; 121:3495-3560. [PMID: 33164487 PMCID: PMC8183567 DOI: 10.1021/acs.chemrev.0c00922] [Citation(s) in RCA: 138] [Impact Index Per Article: 46.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The crisis of antibiotic resistance necessitates creative and innovative approaches, from chemical identification and analysis to the assessment of bioactivity. Plant natural products (NPs) represent a promising source of antibacterial lead compounds that could help fill the drug discovery pipeline in response to the growing antibiotic resistance crisis. The major strength of plant NPs lies in their rich and unique chemodiversity, their worldwide distribution and ease of access, their various antibacterial modes of action, and the proven clinical effectiveness of plant extracts from which they are isolated. While many studies have tried to summarize NPs with antibacterial activities, a comprehensive review with rigorous selection criteria has never been performed. In this work, the literature from 2012 to 2019 was systematically reviewed to highlight plant-derived compounds with antibacterial activity by focusing on their growth inhibitory activity. A total of 459 compounds are included in this Review, of which 50.8% are phenolic derivatives, 26.6% are terpenoids, 5.7% are alkaloids, and 17% are classified as other metabolites. A selection of 183 compounds is further discussed regarding their antibacterial activity, biosynthesis, structure-activity relationship, mechanism of action, and potential as antibiotics. Emerging trends in the field of antibacterial drug discovery from plants are also discussed. This Review brings to the forefront key findings on the antibacterial potential of plant NPs for consideration in future antibiotic discovery and development efforts.
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Affiliation(s)
- Gina Porras
- Center for the Study of Human Health, Emory University, 1557 Dickey Dr., Atlanta, Georgia 30322
| | - François Chassagne
- Center for the Study of Human Health, Emory University, 1557 Dickey Dr., Atlanta, Georgia 30322
| | - James T. Lyles
- Center for the Study of Human Health, Emory University, 1557 Dickey Dr., Atlanta, Georgia 30322
| | - Lewis Marquez
- Molecular and Systems Pharmacology Program, Laney Graduate School, Emory University, 615 Michael St., Whitehead 115, Atlanta, Georgia 30322
| | - Micah Dettweiler
- Department of Dermatology, Emory University, 615 Michael St., Whitehead 105L, Atlanta, Georgia 30322
| | - Akram M. Salam
- Molecular and Systems Pharmacology Program, Laney Graduate School, Emory University, 615 Michael St., Whitehead 115, Atlanta, Georgia 30322
| | - Tharanga Samarakoon
- Emory University Herbarium, Emory University, 1462 Clifton Rd NE, Room 102, Atlanta, Georgia 30322
| | - Sarah Shabih
- Center for the Study of Human Health, Emory University, 1557 Dickey Dr., Atlanta, Georgia 30322
| | - Darya Raschid Farrokhi
- Center for the Study of Human Health, Emory University, 1557 Dickey Dr., Atlanta, Georgia 30322
| | - Cassandra L. Quave
- Center for the Study of Human Health, Emory University, 1557 Dickey Dr., Atlanta, Georgia 30322
- Emory University Herbarium, Emory University, 1462 Clifton Rd NE, Room 102, Atlanta, Georgia 30322
- Department of Dermatology, Emory University, 615 Michael St., Whitehead 105L, Atlanta, Georgia 30322
- Molecular and Systems Pharmacology Program, Laney Graduate School, Emory University, 615 Michael St., Whitehead 115, Atlanta, Georgia 30322
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Abstract
Rhodomyrtone (Rom) is a plant-derived broad-spectrum antibiotic active against many Gram-positive pathogens. A single point mutation in the regulatory farR gene (farR*) confers resistance to Rom in Staphylococcus aureus (RomR). The mutation in farR* alters the activity of the regulator, FarR*, in such a way that not only its own gene, farR*, but also the divergently transcribed farE gene and genes controlled by the global regulator, agr, are highly upregulated. Here, we show that mainly the upregulation of the fatty acid efflux pump FarE causes the RomR phenotype, as farE deletion in either the parent or the RomR strain (RomR ΔfarE) yielded hypersensitivity to Rom. Comparative lipidome analysis of the supernatant (exolipidomics) and the pellet fraction revealed that the RomR strain excreted about 10 times more phospholipids (PGs) than the parent strain or the ΔfarE mutants. Since the PG content in the supernatant (2,244 ng/optical density [OD]) was more than 100-fold higher than that of fatty acids (FA), we assumed that PG interacts with Rom, thereby abrogating its antimicrobial activity. Indeed, by static and dynamic light scattering (SLS and DLS) and isothermal titration calorimetry (ITC) analyses, we could demonstrate that both PG and Rom were vesicular and reacted with each other in milliseconds to form a 1:1.49 [Rom-PG(32:0), where PG(32:0) is PG with C32:0 lipids] complex. The binding is entropically driven and hence hydrophobic and of low specificity in nature. Our results indicate that the cytoplasmic membrane is the actual target of Rom, which is also in agreement with Rom's induced rapid collapse of the membrane potential and decreased membrane integrity. IMPORTANCE Antibiotic resistance is a growing public health problem, and alternative antibiotics are urgently needed. Rhodomyrtone (Rom), an antimicrobial compound originally isolated from Rhodomyrtus tomentosa, is active against multidrug-resistant Gram-positive pathogens. However, Rom-resistant (RomR) mutants occur with low frequency. In this study, we unraveled the underlying resistance mechanism, which is based on a point mutation in the farR regulator gene, causing overexpression of FarE, which most likely acts as a phospholipid (PG) efflux pump, as large amounts of PG were found in the supernatant and the pellet fraction. We show that PG can bind to Rom, thereby abrogating its antimicrobial activity. The direct interaction of Rom with PG suggests that Rom's actual target is the cytoplasmic membrane. Antibiotics that interact with PG are rare. Since Rom can be chemically synthesized, it serves as a lead compound for synthesis of improved variants.
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Rhodomyrtus tomentosa Leaf Extract and Rhodomyrtone Combat Streptococcus pneumoniae Biofilm and Inhibit Invasiveness to Human Lung Epithelial and Enhance Pneumococcal Phagocytosis by Macrophage. Curr Microbiol 2020; 77:3546-3554. [PMID: 32812080 DOI: 10.1007/s00284-020-02164-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2020] [Accepted: 08/10/2020] [Indexed: 12/20/2022]
Abstract
Rhodomyrtus tomentosa leaf has been traditionally used to treat many infections. This plant species has been documented to possess a wide spectrum of pharmacological effects. This study aimed to determine the effects of Rhodomyrtus tomentosa leaf extract and its potent purified compound, rhodomyrtone, on Streptococcus pneumoniae virulence factors including biofilms, capsule formation, and invasiveness which play important roles in infections. Ethanol leaf extract and rhodomyrtone demonstrated excellent antibacterial activity against S. pneumoniae with minimal inhibitory concentration (MIC) ranging from 16-32 µg/ml and 0.125-1 µg/ml, respectively. The ability of the extract and rhodomyrtone to prevent biofilm formation and eradicate mature biofilms was assessed. The extract and rhodomyrtone at 1/8 × MIC significantly inhibited biofilm formation in all clinical isolates (P < 0.05). The viability of 8-day biofilm-grown cells significantly decreased following the treatment with the extract and rhodomyrtone at 16 × MIC. 40-90% reduction in the bacterial adhesion and invasion to A549 human alveolar epithelial cells was observed after challenging with the extract and rhodomyrtone, compared with the control within 60 min. Increase in 90-99% phagocytosis of the bacterial cells by RAW264.7 macrophage cell line was detected following the treatment with the extract and rhodomyrtone at 1/2 × MIC, compared with the control. The results suggested potential medicinal benefits of the extract and rhodomyrtone for the treatment of pneumococcal infections.
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Antimetastatic Potential of Rhodomyrtone on Human Chondrosarcoma SW1353 Cells. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2020; 2020:8180261. [PMID: 32802134 PMCID: PMC7403900 DOI: 10.1155/2020/8180261] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 06/09/2020] [Accepted: 07/08/2020] [Indexed: 11/17/2022]
Abstract
Chondrosarcoma is primary bone cancer, with the forceful capacity to cause local invasion and distant metastasis, and has a poor prognosis. Cancer metastasis is a complication of most cancers; it is one of the leading causes of cancer-related death. Rhodomyrtone is a pure compound that has been shown to induce apoptosis and antimetastasis in skin cancer. However, the inhibitory effect of rhodomyrtone on human chondrosarcoma cell metastasis is largely unknown. Effect of rhodomyrtone on cell viability in SW1353 cell was determined by MTT assay. Antimigration, anti-invasion, and antiadhesion were carried out to investigate the antimetastatic potential of rhodomyrtone on SW1353 cells. Gelatin zymography was performed to determine matrix metalloproteinase-2 (MMP-2) and MMP-9 activities. The effect of rhodomyrtone on the underlying mechanisms was performed by Western blot analysis. The results demonstrated that rhodomyrtone reduced cell viability of SW1353 cells at the low concentration (<3 μg/mL); cell viability was >80%. Rhodomyrtone at the subcytotoxic concentrations (0.5, 1.5, and 3 μg/mL) significantly inhibited cell migration, invasion, and adhesion of SW1353 cells in a dose-dependent fashion. Protein expression of integrin αv, integrin β3, and the downstream migratory proteins including focal adhesion kinase (FAK) and the phosphorylation of serine/threonine AKT, Ras, RhoA, Rac1, and Cdc42 were inhibited after treatment with rhodomyrtone. Moreover, we found that rhodomyrtone decreased the protein level of MMP-2 and MMP-9 as well as the enzyme activity in SW1353 cells. Meanwhile, tissue inhibitor of metalloproteinase-1 (TIMP-1) and TIMP-2 expression was increased in a dose-dependent fashion. Besides, rhodomyrtone dramatically inhibited the expression of growth factor receptor-bound protein-2 (GRB2) and the phosphorylated form of extracellular signal regulation kinase1/2 (ERK1/2) and c-Jun N-terminal kinase1/2 (JNK1/2). These results indicated that rhodomyrtone inhibited SW1353 cell migration, invasion, and metastasis by suppressing integrin αvβ3/FAK/AKT/small Rho GTPases pathway as well as downregulation of MMP-2/9 via ERK and JNK signal inhibition. These findings indicate that rhodomyrtone possessed the antimetastasis activity that may be used for antimetastasis therapy in the future.
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Ontong JC, Paosen S, Shankar S, Voravuthikunchai SP. Eco-friendly synthesis of silver nanoparticles using Senna alata bark extract and its antimicrobial mechanism through enhancement of bacterial membrane degradation. J Microbiol Methods 2019; 165:105692. [PMID: 31437555 DOI: 10.1016/j.mimet.2019.105692] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Revised: 08/14/2019] [Accepted: 08/16/2019] [Indexed: 01/24/2023]
Abstract
Biological synthesis of nanomaterials has been increasingly gaining popularity due to its eco-friendly nature and cost-effectiveness. This study aimed to synthesize silver nanoparticles (AgNPs) using Senna alata bark extract as reducing and capping agents, and to evaluate their antimicrobial activities. AgNPs was characterized using UV-vis spectrophotometry, transmission electron microscopy, and Fourier transform infrared spectroscopy (FTIR). The formation of AgNPs was monitored by recording the surface plasmon resonance peak observed at 425 nm. High-resolution TEM images elucidated the formation of spherical AgNPs with an average diameter of 10-30 nm. Energy dispersive spectroscopy (EDS) revealed the presence of silver. The functional groups of biomolecules present in the extract and their interaction with AgNPs were identified through FTIR analysis. Biosynthesized AgNPs displayed antimicrobial activity against different microorganisms, including Gram-positive and Gram-negative bacteria as well as fungi, as indicated by the diameter of inhibition zones between 11.37 and 14.87 mm. Minimum inhibitory concentration of AgNPs for the tested microorganisms was in the range from 31.25 to 125 μg/mL. Potassium leakage is a primary indicator of membrane damage which is a significant mode of action of AgNPs against the tested microorganisms. The amount of potassium ions leaked from the microbial cells after 4 h contact time ranged between 0.97 and 3.05 ppm. Morphological changes were observed in all AgNPs-treated microorganisms. The green synthesized AgNPs with high antimicrobial activity has potential to be used in food packaging and biomedical research areas.
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Affiliation(s)
- Julalak C Ontong
- Natural Product Research Center of Excellence, Prince of Songkla University, Hat Yai, Songkhla 90112, Thailand
| | - Supakit Paosen
- Natural Product Research Center of Excellence, Prince of Songkla University, Hat Yai, Songkhla 90112, Thailand; Department of Microbiology, Faculty of Science and Excellence Research Laboratory on Natural Products, Prince of Songkla University, Hat Yai, Songkhla 90112, Thailand
| | - Shiv Shankar
- Center for Humanities and Sciences, BioNanocomposite Research Center, Department of Food and Nutrition, Kyung Hee University, 26 Kyungheedae-ro, Dongdaemun-gu, Seoul 02447, Republic of Korea.
| | - Supayang P Voravuthikunchai
- Natural Product Research Center of Excellence, Prince of Songkla University, Hat Yai, Songkhla 90112, Thailand; Department of Microbiology, Faculty of Science and Excellence Research Laboratory on Natural Products, Prince of Songkla University, Hat Yai, Songkhla 90112, Thailand.
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Mordmuang A, Brouillette E, Voravuthikunchai SP, Malouin F. Evaluation of a Rhodomyrtus tomentosa ethanolic extract for its therapeutic potential on Staphylococcus aureus infections using in vitro and in vivo models of mastitis. Vet Res 2019; 50:49. [PMID: 31221210 PMCID: PMC6585048 DOI: 10.1186/s13567-019-0664-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Accepted: 05/25/2019] [Indexed: 01/23/2023] Open
Abstract
An ethanolic extract from Rhodomyrtus tomentosa leaves (RTL) was studied as a natural alternative to control Staphylococcus aureus, which is an important pathogen responsible for bovine mastitis. The minimal inhibitory concentrations (MICs) of the RTL extract and of rhodomyrtone, a pure compound isolated from the plant, were determined by a microdilution method. Rhodomyrtone and the RTL extract exhibited antibacterial activity against S. aureus, including its persistent phenotype (SCV: small-colony variant) and a biofilm hyperproducer strain, with MICs of 0.25–0.5 and 8–16 µg/mL, respectively. Time-kill kinetics showed a strong bactericidal activity for both the RTL extract- and rhodomyrtone-treated bacteria at 2 × MIC as early as 4 h post-exposure. An additive effect of the extract at 0.5 × MIC was observed in a combination with oxytetracycline or pirlimycin against S. aureus by showing a 64- to 128-fold reduction in antibiotic MICs. Moreover, the RTL extract significantly decreased the number of intracellular SCVs inside bovine mammary epithelial cells. However, the extract or its combination with pirlimycin only slightly improved the activity of pirlimycin against the bacterial colonization of mouse mammary glands. In vitro MICs determined in the presence of casein indicated that the limited activity of the RTL extract in the murine model of mastitis could be linked to neutralization of active components by milk proteins. While the RTL extract showed interesting antibacterial properties in vitro, to be considered as an alternative to antibiotics in dairy farms, formulation studies are needed to cope with the observed reduction of activity in vivo.
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Affiliation(s)
- Auemphon Mordmuang
- Department of Microbiology and Excellence Research Laboratory on Natural Products, Faculty of Science and Natural Product Research Center of Excellence, Prince of Songkla University, Hat Yai, Songkhla, 90112, Thailand.,School of Medicine, Walailak University, Tha Sala, Nakhon Si Thammarat, 80160, Thailand
| | - Eric Brouillette
- Centre d'Étude et de Valorisation de la Diversité Microbienne (CEVDM), Département de biologie, Faculté des sciences, Université de Sherbrooke, Sherbrooke, QC, J1K 2R1, Canada
| | - Supayang Piyawan Voravuthikunchai
- Department of Microbiology and Excellence Research Laboratory on Natural Products, Faculty of Science and Natural Product Research Center of Excellence, Prince of Songkla University, Hat Yai, Songkhla, 90112, Thailand.
| | - François Malouin
- Centre d'Étude et de Valorisation de la Diversité Microbienne (CEVDM), Département de biologie, Faculté des sciences, Université de Sherbrooke, Sherbrooke, QC, J1K 2R1, Canada.
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Nguyen MT, Saising J, Tribelli PM, Nega M, Diene SM, François P, Schrenzel J, Spröer C, Bunk B, Ebner P, Hertlein T, Kumari N, Härtner T, Wistuba D, Voravuthikunchai SP, Mäder U, Ohlsen K, Götz F. Inactivation of farR Causes High Rhodomyrtone Resistance and Increased Pathogenicity in Staphylococcus aureus. Front Microbiol 2019; 10:1157. [PMID: 31191485 PMCID: PMC6547885 DOI: 10.3389/fmicb.2019.01157] [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: 01/17/2019] [Accepted: 05/07/2019] [Indexed: 12/22/2022] Open
Abstract
Rhodomyrtone (Rom) is an acylphloroglucinol antibiotic originally isolated from leaves of Rhodomyrtus tomentosa. Rom targets the bacterial membrane and is active against a wide range of Gram-positive bacteria but the exact mode of action remains obscure. Here we isolated and characterized a spontaneous Rom-resistant mutant from the model strain Staphylococcus aureus HG001 (RomR) to learn more about the resistance mechanism. We showed that Rom-resistance is based on a single point mutation in the coding region of farR [regulator of fatty acid (FA) resistance] that causes an amino acid change from Cys to Arg at position 116 in FarR, that affects FarR activity. Comparative transcriptome analysis revealed that mutated farR affects transcription of many genes in distinct pathways. FarR represses for example the expression of its own gene (farR), its flanking gene farE (effector of FA resistance), and other global regulators such as agr and sarA. All these genes were consequently upregulated in the RomR clone. Particularly the upregulation of agr and sarA leads to increased expression of virulence genes rendering the RomR clone more cytotoxic and more pathogenic in a mouse infection model. The Rom-resistance is largely due to the de-repression of farE. FarE is described as an efflux pump for linoleic and arachidonic acids. We observed an increased release of lipids in the RomR clone compared to its parental strain HG001. If farE is deleted in the RomR clone, or, if native farR is expressed in the RomR strain, the corresponding strains become hypersensitive to Rom. Overall, we show here that the high Rom-resistance is mediated by overexpression of farE in the RomR clone, that FarR is an important regulator, and that the point mutation in farR (RomR clone) makes the clone hyper-virulent.
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Affiliation(s)
- Minh-Thu Nguyen
- Microbial Genetics, Interfaculty Institute of Microbiology and Infection Medicine Tübingen (IMIT), University of Tübingen, Tübingen, Germany.,Federal Regulatory Agency for Vaccines and Biomedicines, Paul Ehrlich Institute, Langen, Germany
| | - Jongkon Saising
- Microbial Genetics, Interfaculty Institute of Microbiology and Infection Medicine Tübingen (IMIT), University of Tübingen, Tübingen, Germany.,School of Health Science, Mae Fah Luang University, Chiang Rai, Thailand
| | - Paula Maria Tribelli
- Microbial Genetics, Interfaculty Institute of Microbiology and Infection Medicine Tübingen (IMIT), University of Tübingen, Tübingen, Germany.,Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales - Universidad de Buenos Aires, IQUIBICEN-CONICET, Buenos Aires, Argentina
| | - Mulugeta Nega
- Microbial Genetics, Interfaculty Institute of Microbiology and Infection Medicine Tübingen (IMIT), University of Tübingen, Tübingen, Germany
| | - Seydina M Diene
- Genomic Research Laboratory, Service of Infectious Diseases, Geneva University Hospitals, Geneva, Switzerland
| | - Patrice François
- Genomic Research Laboratory, Service of Infectious Diseases, Geneva University Hospitals, Geneva, Switzerland
| | - Jacques Schrenzel
- Genomic Research Laboratory, Service of Infectious Diseases, Geneva University Hospitals, Geneva, Switzerland
| | - Cathrin Spröer
- Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany
| | - Boyke Bunk
- Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany
| | - Patrick Ebner
- Microbial Genetics, Interfaculty Institute of Microbiology and Infection Medicine Tübingen (IMIT), University of Tübingen, Tübingen, Germany
| | - Tobias Hertlein
- Institute of Molecular Infection Biology, University of Würzburg, Würzburg, Germany
| | - Nimerta Kumari
- Microbial Genetics, Interfaculty Institute of Microbiology and Infection Medicine Tübingen (IMIT), University of Tübingen, Tübingen, Germany
| | - Thomas Härtner
- Microbiology/Biotechnology, Interfaculty Institute of Microbiology and Infection Medicine Tübingen (IMIT), University of Tübingen, Tübingen, Germany
| | - Dorothee Wistuba
- Institute for Organic Chemistry, University of Tübingen, Tübingen, Germany
| | - Supayang P Voravuthikunchai
- Department of Microbiology, Natural Product Centre of Excellence, Prince of Songkla University, Hat Yai, Thailand
| | - Ulrike Mäder
- Interfaculty Institute for Genetics and Functional Genomics, University Medicine Greifswald, Greifswald, Germany
| | - Knut Ohlsen
- Institute of Molecular Infection Biology, University of Würzburg, Würzburg, Germany
| | - Friedrich Götz
- Microbial Genetics, Interfaculty Institute of Microbiology and Infection Medicine Tübingen (IMIT), University of Tübingen, Tübingen, Germany
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Umaternate A. Identification of Chemical Compounds from Karamunting Stem (Rhodomyrtus tomentosa) by Thin Layer Chromatography. BORNEO JOURNAL OF PHARMACY 2019. [DOI: 10.33084/bjop.v2i1.695] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Karamunting or Kalimantan Grapes (Rhodomyrtus tomentosa) is a medicinal plant from Central Kalimantan that is easily found in shrubs. Based on hereditary experiences of the people of Central Kalimantan, karamunting can be used for the treatment of various diseases, one of which is diabetes. This study aims to identify the chemical compounds contained in the karamunting stem. The method used is thin layer chromatography with eluent n-hexane : ethyl acetate and methanol : chloroform. Besides, a color reaction was carried out to determine the group of compounds contained in the methanol extract of the karamunting stem. The TLC results show better stain separation in eluent n-hexane : ethyl acetate with the formation of four stains. Positive results are indicated by the content of phenol, saponin, flavonoid and terpenoid compounds. The existence of this group of compounds can be a clue to further research on the truth of the efficacy of karamunting.
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The Health Beneficial Properties of Rhodomyrtus tomentosa as Potential Functional Food. Biomolecules 2019; 9:biom9020076. [PMID: 30795643 PMCID: PMC6406238 DOI: 10.3390/biom9020076] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Revised: 02/15/2019] [Accepted: 02/18/2019] [Indexed: 12/16/2022] Open
Abstract
Rhodomyrtus tomentosa (Aiton) Hassk. is a flowering plant belonging to the family Myrtaceae, native to southern and southeastern Asia. It has been used in traditional Vietnamese, Chinese, and Malaysian medicine for a long time for the treatment of diarrhea, dysentery, gynecopathy, stomachache, and wound healing. Moreover, R. tomentosa is used to make various food products such as wine, tea, and jam. Notably, R. tomentosa has been known to contain structurally diverse and biologically active metabolites, thus serving as a potential resource for exploring novel functional agents. Up to now, numerous phenolic and terpenoid compounds from the leaves, root, or fruits of R. tomentosa have been identified, and their biological activities such as antioxidant, antibacterial, anti-inflammatory, and anticancer have been evidenced. In this contribution, an overview of R. tomentosa and its health beneficial properties was focused on and emphasized.
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Deredas D, Łągiewka B, Maniukiewicz W. A facile synthesis of novel 9-substituted 2,3,4,9-tetrahydro-1H-xanthen-1-ones. Tetrahedron Lett 2019. [DOI: 10.1016/j.tetlet.2019.01.022] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Bach QN, Hongthong S, Quach LT, Pham LV, Pham TV, Kuhakarn C, Reutrakul V, Nguyen PT. Antimicrobial activity of rhodomyrtone isolated from Rhodomyrtus tomentosa (Aiton) Hassk. Nat Prod Res 2019; 34:2518-2523. [DOI: 10.1080/14786419.2018.1540479] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Affiliation(s)
- Quynh N. Bach
- Haiphong University of Medicine and Pharmacology, Haiphong, Vietnam
| | - Sakchai Hongthong
- Center of Excellence for Innovation in Chemistry (PERCH-CIC) and Department of Chemistry, Faculty of Science, Mahidol University, Bangkok, Thailand
| | - Lien T. Quach
- Institute of Biotechnology, Vietnam Academy of Science and Technology, Hanoi, Vietnam
| | - Lieu V. Pham
- Haiphong University of Medicine and Pharmacology, Haiphong, Vietnam
| | - Thuc V. Pham
- Haiphong University of Medicine and Pharmacology, Haiphong, Vietnam
| | - Chutima Kuhakarn
- Center of Excellence for Innovation in Chemistry (PERCH-CIC) and Department of Chemistry, Faculty of Science, Mahidol University, Bangkok, Thailand
| | - Vichai Reutrakul
- Center of Excellence for Innovation in Chemistry (PERCH-CIC) and Department of Chemistry, Faculty of Science, Mahidol University, Bangkok, Thailand
| | - Phuong T.M. Nguyen
- Institute of Biotechnology, Vietnam Academy of Science and Technology, Hanoi, Vietnam
- Graduate University of Science and Technology, Vietnam Academy of Science and Technology, Hanoi, Vietnam
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15
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Zhang YB, Li W, Jiang L, Yang L, Chen NH, Wu ZN, Li YL, Wang GC. Cytotoxic and anti-inflammatory active phloroglucinol derivatives from Rhodomyrtus tomentosa. PHYTOCHEMISTRY 2018; 153:111-119. [PMID: 29906657 DOI: 10.1016/j.phytochem.2018.05.018] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Revised: 05/24/2018] [Accepted: 05/27/2018] [Indexed: 06/08/2023]
Abstract
Seven undescribed phloroglucinol derivatives, tomentodiones N-T, and eleven known ones were isolated from Rhodomyrtus tomentosa. Tomentodione N is the first example of a β-triketone unit coupled with an isoamyl alcohol through a furan fused-ring, and tomentodiones N, S, T were three racemates. The undescribed structures were elucidated by means of spectroscopic, X-ray diffraction, electronic circular dichroism calculation, and chemical methods. In addition, the isolated compounds were determined for the cytotoxic activities on HeLa cells and anti-inflammatory activities in LPS-stimulated RAW 264.7 cells.
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MESH Headings
- Animals
- Anti-Inflammatory Agents, Non-Steroidal/chemistry
- Anti-Inflammatory Agents, Non-Steroidal/isolation & purification
- Anti-Inflammatory Agents, Non-Steroidal/pharmacology
- Antineoplastic Agents, Phytogenic/chemistry
- Antineoplastic Agents, Phytogenic/isolation & purification
- Antineoplastic Agents, Phytogenic/pharmacology
- Cell Proliferation/drug effects
- Cell Survival/drug effects
- Chlorocebus aethiops
- Crystallography, X-Ray
- Dose-Response Relationship, Drug
- Drug Screening Assays, Antitumor
- HeLa Cells
- Humans
- Lipopolysaccharides/antagonists & inhibitors
- Lipopolysaccharides/pharmacology
- Mice
- Models, Molecular
- Molecular Structure
- Myrtaceae/chemistry
- Nitric Oxide/antagonists & inhibitors
- Nitric Oxide/biosynthesis
- Phloroglucinol/analogs & derivatives
- Phloroglucinol/chemistry
- Phloroglucinol/pharmacology
- RAW 264.7 Cells
- Structure-Activity Relationship
- Vero Cells
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Affiliation(s)
- Yu-Bo Zhang
- Institute of Traditional Chinese Medicine & Natural Products, Guangdong Province Key Laboratory of Pharmacodynamic Constituents of TCM and New Drugs Research, College of Pharmacy, Jinan University, Guangzhou 510632, PR China; Integrated Chinese and Western Medicine Postdoctoral Research Station, Jinan University, Guangzhou 510632, PR China
| | - Wen Li
- Institute of Traditional Chinese Medicine & Natural Products, Guangdong Province Key Laboratory of Pharmacodynamic Constituents of TCM and New Drugs Research, College of Pharmacy, Jinan University, Guangzhou 510632, PR China
| | - Lin Jiang
- Institute of Traditional Chinese Medicine & Natural Products, Guangdong Province Key Laboratory of Pharmacodynamic Constituents of TCM and New Drugs Research, College of Pharmacy, Jinan University, Guangzhou 510632, PR China
| | - Li Yang
- Institute of Traditional Chinese Medicine & Natural Products, Guangdong Province Key Laboratory of Pharmacodynamic Constituents of TCM and New Drugs Research, College of Pharmacy, Jinan University, Guangzhou 510632, PR China
| | - Neng-Hua Chen
- Institute of Traditional Chinese Medicine & Natural Products, Guangdong Province Key Laboratory of Pharmacodynamic Constituents of TCM and New Drugs Research, College of Pharmacy, Jinan University, Guangzhou 510632, PR China
| | - Zhong-Nan Wu
- Institute of Traditional Chinese Medicine & Natural Products, Guangdong Province Key Laboratory of Pharmacodynamic Constituents of TCM and New Drugs Research, College of Pharmacy, Jinan University, Guangzhou 510632, PR China
| | - Yao-Lan Li
- Institute of Traditional Chinese Medicine & Natural Products, Guangdong Province Key Laboratory of Pharmacodynamic Constituents of TCM and New Drugs Research, College of Pharmacy, Jinan University, Guangzhou 510632, PR China.
| | - Guo-Cai Wang
- Institute of Traditional Chinese Medicine & Natural Products, Guangdong Province Key Laboratory of Pharmacodynamic Constituents of TCM and New Drugs Research, College of Pharmacy, Jinan University, Guangzhou 510632, PR China; Integrated Chinese and Western Medicine Postdoctoral Research Station, Jinan University, Guangzhou 510632, PR China.
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16
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Saising J, Nguyen MT, Härtner T, Ebner P, Al Mamun Bhuyan A, Berscheid A, Muehlenkamp M, Schäkermann S, Kumari N, Maier ME, Voravuthikunchai SP, Bandow J, Lang F, Brötz-Oesterhelt H, Götz F. Rhodomyrtone (Rom) is a membrane-active compound. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2018; 1860:1114-1124. [PMID: 29317198 DOI: 10.1016/j.bbamem.2018.01.011] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Revised: 12/15/2017] [Accepted: 01/04/2018] [Indexed: 12/24/2022]
Abstract
Particularly in Asia medicinal plants with antimicrobial activity are used for therapeutic purpose. One such plant-derived antibiotic is rhodomyrtone (Rom) isolated from Rhodomyrtus tomentosa leaves. Rom shows high antibacterial activity against a wide range of Gram-positive bacteria, however, its mode of action is still unclear. Reporter gene assays and proteomic profiling experiments in Bacillus subtilis indicate that Rom does not address classical antibiotic targets like translation, transcription or DNA replication, but acts at the cytoplasmic membrane. In Staphylococcus aureus, Rom decreases the membrane potential within seconds and at low doses, causes release of ATP and even the excretion of cytoplasmic proteins (ECP), but does not induce pore-formation as for example nisin. Lipid staining revealed that Rom induces local membrane damage. Rom's antimicrobial activity can be antagonized in the presence of a very narrow spectrum of saturated fatty acids (C15:0, C16:0, or C18:0) that most likely contribute to counteract the membrane damage. Gram-negative bacteria are resistant to Rom, presumably due to reduced penetration through the outer membrane and its neutralization by LPS. Rom is cytotoxic for many eukaryotic cells and studies with human erythrocytes showed that Rom induces eryptosis accompanied by erythrocyte shrinkage, cell membrane blebbing, and membrane scrambling with phosphatidylserine translocation to the erythrocyte surface. Rom's distinctive interaction with the cytoplasmic membrane reminds on the amphipathic, alpha-helical peptides, the phenol-soluble modulins (PSMs), and renders Rom an important tool for the investigation of membrane physiology.
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Affiliation(s)
- Jongkon Saising
- Microbial Genetics, Interfaculty Institute of Microbiology and Infection Medicine Tübingen (IMIT), University of Tübingen, Tübingen, Germany; School of Health Science, Mae Fah Luang University, Muang, Chiang Rai 57100, Thailand
| | - Minh-Thu Nguyen
- Microbial Genetics, Interfaculty Institute of Microbiology and Infection Medicine Tübingen (IMIT), University of Tübingen, Tübingen, Germany; School of Biological and Food Technology, Hanoi University of Science and Technology, Hanoi, Viet Nam
| | - Thomas Härtner
- Biotechnology, Interfaculty Institute of Microbiology and Infection Medicine Tübingen (IMIT), University of Tübingen, Tübingen, Germany
| | - Patrick Ebner
- Microbial Genetics, Interfaculty Institute of Microbiology and Infection Medicine Tübingen (IMIT), University of Tübingen, Tübingen, Germany
| | | | - Anne Berscheid
- Microbial Bioactive Compounds, Interfaculty Institute of Microbiology and Infection Medicine Tübingen (IMIT), University of Tübingen, Germany
| | - Melanie Muehlenkamp
- Microbial Bioactive Compounds, Interfaculty Institute of Microbiology and Infection Medicine Tübingen (IMIT), University of Tübingen, Germany
| | | | - Nimerta Kumari
- Microbial Genetics, Interfaculty Institute of Microbiology and Infection Medicine Tübingen (IMIT), University of Tübingen, Tübingen, Germany
| | - Martin E Maier
- Institut für Organische Chemie, Universität Tübingen, Auf der Morgenstelle 18, 72076 Tübingen, Germany
| | | | - Julia Bandow
- Applied Microbiology, Ruhr University Bochum, Bochum, Germany
| | - Florian Lang
- Departments of Cardiology, Vascular Medicine & Physiology, University of Tübingen, Germany
| | - Heike Brötz-Oesterhelt
- Microbial Bioactive Compounds, Interfaculty Institute of Microbiology and Infection Medicine Tübingen (IMIT), University of Tübingen, Germany
| | - Friedrich Götz
- Microbial Genetics, Interfaculty Institute of Microbiology and Infection Medicine Tübingen (IMIT), University of Tübingen, Tübingen, Germany.
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17
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Niyomdecha S, Limbut W, Numnuam A, Asawatreratanakul P, Kanatharana P, Thavarungkul P. Capacitive antibacterial susceptibility screening test with a simple renewable sensing surface. Biosens Bioelectron 2017; 96:84-88. [DOI: 10.1016/j.bios.2017.04.042] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Revised: 04/11/2017] [Accepted: 04/25/2017] [Indexed: 10/19/2022]
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18
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Tayeh M, Nilwarangoon S, Mahabusarakum W, Watanapokasin R. Anti-metastatic effect of rhodomyrtone from Rhodomyrtus tomentosa on human skin cancer cells. Int J Oncol 2017; 50:1035-1043. [PMID: 28075447 DOI: 10.3892/ijo.2017.3845] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Accepted: 12/27/2016] [Indexed: 11/05/2022] Open
Abstract
This study focused on the inhibitory effect of rhodomyrtone, a bioactive compound isolated from the leaves of Rhodomyrtus tomentosa (Aiton) Hassk., on cancer metastasis in epidermoid carcinoma A431 cells and on the verification of the underlying related molecular mechanisms of this event. We demonstrated that rhodomyrtone at the subcytotoxic concentration (0.5 and 1.5 µg/ml) exhibited pronounced inhibition of cancer metastasis by reducing cell migration, cell adhesive ability and cell invasion of A431 cells in a dose-dependent manner. Data demonstrated that rhodomyrtone could inhibit the focal adhesion kinase (FAK) and phosphorylation of protein kinase B (AKT), c-Raf, extracellular signal-regulated kinase 1/2 (ERK1/2) and p38 MAPK involved in the downregulation the enzyme activities and protein expression of matrix metalloproteinase-2 (MMP-2) and MMP-9. Moreover, we found that rhodomyrtone increased the expression of TIMP-1 and TIMP-2, which are inhibitors of MMP-9 and MMP-2, respectively. Rhodomyrtone also inhibited the expression of NF-κB and phosphorylation of NF-κB in a dose-dependent manner. These results suggested that rhodomyrtone inhibited A431 cell metastasis by reducing MMP-2/9 activities and expression through inhibiting ERK1/2, p38 and FAK/Akt signaling pathways via NF-κB activities. This finding suggested that rhodomyrtone may be a novel antimetastasis agent for treatment of skin cancer cells.
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Affiliation(s)
- Malatee Tayeh
- Department of Biochemistry, Faculty of Medicine, Srinakharinwirot University, Bangkok 10110, Thailand
| | - Sirinun Nilwarangoon
- Department of Biochemistry, Faculty of Medicine, Srinakharinwirot University, Bangkok 10110, Thailand
| | - Wilawan Mahabusarakum
- Department of Chemistry, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla 90112, Thailand
| | - Ramida Watanapokasin
- Department of Biochemistry, Faculty of Medicine, Srinakharinwirot University, Bangkok 10110, Thailand
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19
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Tan H, Liu H, Zhao L, Yuan Y, Li B, Jiang Y, Gong L, Qiu S. Structure-activity relationships and optimization of acyclic acylphloroglucinol analogues as novel antimicrobial agents. Eur J Med Chem 2016; 125:492-499. [PMID: 27689731 DOI: 10.1016/j.ejmech.2016.09.054] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Revised: 09/17/2016] [Accepted: 09/18/2016] [Indexed: 11/29/2022]
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) poses a serious threat to global public health, because it exhibits resistance to existing antibiotics and therefore high rates of morbidity and mortality. In this study, twenty-one natural product-based acylphloroglucinol congeners were synthesized, which possessed different side chains. Antibacterial screening against MRSA strains revealed that acyl moiety tailoring is a prerequisite for the antibacterial activity. Moreover, the lipophilicity, rather than the magnitude of the hydrophobic acyl tail dominates variability in activity potency. Compound 11j was identified as a promising lead for the generation of new anti-MRSA drug development. It was discovered by optimization of the side chain length in light of the potency, the breadth of the antibacterial spectrum, the rate of bactericidal action, as well as the membrane selectivity. Compound 11j exerted profound in vitro antibacterial activity against the MRSA strain (JCSC 2172), and its MIC was 3-4 orders of magnitude lower than that of vancomycin. A preliminary mode of action study of compound 11j at the biophysical and morphology levels disclosed that the mechanism underlying its anti-MRSA activity included membrane depolarization and, to a lesser extent, membrane disruption and cell lysis.
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Affiliation(s)
- Haibo Tan
- Key Laboratory of Plant Resources Conservation and Sustainable Utilization, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, People's Republic of China
| | - Hongxin Liu
- Key Laboratory of Plant Resources Conservation and Sustainable Utilization, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, People's Republic of China; State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Open Laboratory of Applied Microbiology, Guangdong Institute of Microbiology, Guangzhou 510070, People's Republic of China
| | - Liyun Zhao
- Key Laboratory of Plant Resources Conservation and Sustainable Utilization, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, People's Republic of China; University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
| | - Yao Yuan
- Key Laboratory of Plant Resources Conservation and Sustainable Utilization, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, People's Republic of China; University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
| | - Bailin Li
- Key Laboratory of Plant Resources Conservation and Sustainable Utilization, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, People's Republic of China; University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
| | - Yueming Jiang
- Key Laboratory of Plant Resources Conservation and Sustainable Utilization, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, People's Republic of China
| | - Liang Gong
- Key Laboratory of Plant Resources Conservation and Sustainable Utilization, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, People's Republic of China.
| | - Shengxiang Qiu
- Key Laboratory of Plant Resources Conservation and Sustainable Utilization, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, People's Republic of China.
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20
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Yan X, Shen D, Han J, Chen J, Deng H, Shao M, Zhang H, Cao W. l-Proline catalyzed intermolecular cyclization of methyl perfluoroalk-2-ynoates with salicylaldehyde: Synthesis of perfluoroalkylated 2H-chromenes. J Fluor Chem 2016. [DOI: 10.1016/j.jfluchem.2016.06.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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21
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Gervais A, Lazarski KE, Porco JA. Divergent Total Syntheses of Rhodomyrtosones A and B. J Org Chem 2016; 80:9584-91. [PMID: 26351970 DOI: 10.1021/acs.joc.5b01570] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Herein, we report total syntheses of the tetramethyldihydroxanthene natural product rhodomyrtosone B and the related bis-furan β-triketone natural product rhodomyrtosone A. Nickel-(II)-catalyzed 1,4-conjugate addition of an α-alkylidene-β-dicarbonyl substrate was developed to access the congener rhodomyrtosone B, and oxygenation of the same monoalkylidene derivative followed by cyclization was employed to obtain the bis-furan natural product rhodomyrtosone A.
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Affiliation(s)
- Anais Gervais
- Department of Chemistry, Center for Molecular Discovery (BU-CMD), Boston University , 590 Commonwealth Avenue, Boston, Massachusetts 02215, United States
| | - Kiel E Lazarski
- Department of Chemistry, Center for Molecular Discovery (BU-CMD), Boston University , 590 Commonwealth Avenue, Boston, Massachusetts 02215, United States
| | - John A Porco
- Department of Chemistry, Center for Molecular Discovery (BU-CMD), Boston University , 590 Commonwealth Avenue, Boston, Massachusetts 02215, United States
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Liu HX, Chen K, Yuan Y, Xu ZF, Tan HB, Qiu SX. Rhodomentones A and B, novel meroterpenoids with unique NMR characteristics from Rhodomyrtus tomentosa. Org Biomol Chem 2016; 14:7354-60. [DOI: 10.1039/c6ob01215a] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Two novel meroterpenoids were isolated from Rhodomyrtus tomentosa. Their structures with unique NMR characteristics were determined by extensive spectroscopic analysis, single-crystal X-ray diffraction, quantum molecular calculation, chemical transformation as well as total synthesis.
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Affiliation(s)
- Hong-Xin Liu
- Program for Natural Products Chemical Biology
- Key Laboratory of Plant Resources Conservation and Sustainable Utilization
- South China Botanical Garden
- Chinese Academy of Sciences
- Guangzhou 510650
| | - Kai Chen
- School of Chemistry and Chemical Engineering
- South China University of Technology
- Guangzhou 510640
- China
| | - Yao Yuan
- Program for Natural Products Chemical Biology
- Key Laboratory of Plant Resources Conservation and Sustainable Utilization
- South China Botanical Garden
- Chinese Academy of Sciences
- Guangzhou 510650
| | - Zhi-Fang Xu
- Program for Natural Products Chemical Biology
- Key Laboratory of Plant Resources Conservation and Sustainable Utilization
- South China Botanical Garden
- Chinese Academy of Sciences
- Guangzhou 510650
| | - Hai-Bo Tan
- Program for Natural Products Chemical Biology
- Key Laboratory of Plant Resources Conservation and Sustainable Utilization
- South China Botanical Garden
- Chinese Academy of Sciences
- Guangzhou 510650
| | - Sheng-Xiang Qiu
- Program for Natural Products Chemical Biology
- Key Laboratory of Plant Resources Conservation and Sustainable Utilization
- South China Botanical Garden
- Chinese Academy of Sciences
- Guangzhou 510650
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23
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Liu HX, Zhang WM, Xu ZF, Chen YC, Tan HB, Qiu SX. Isolation, synthesis, and biological activity of tomentosenol A from the leaves of Rhodomyrtus tomentosa. RSC Adv 2016. [DOI: 10.1039/c6ra01594h] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Tomentosenol A (1), along with a pair of epimers, 4S-focifolidione (2) and 4R-focifolidione (3), were isolated from the leaves of Rhodomyrtus tomentosa.
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Affiliation(s)
- Hong-Xin Liu
- Program for Natural Product Chemical Biology
- Key Laboratory of Plant Resources Conservation and Sustainable Utilization
- South China Botanical Garden
- Chinese Academy of Sciences
- Guangzhou 510650
| | - Wei-Min Zhang
- State Key Laboratory of Applied Microbiology Southern China
- Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application
- Guangdong Open Laboratory of Applied Microbiology
- Guangdong Institute of Microbiology
- Guangzhou 510070
| | - Zhi-Fang Xu
- Program for Natural Product Chemical Biology
- Key Laboratory of Plant Resources Conservation and Sustainable Utilization
- South China Botanical Garden
- Chinese Academy of Sciences
- Guangzhou 510650
| | - Yu-Chan Chen
- State Key Laboratory of Applied Microbiology Southern China
- Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application
- Guangdong Open Laboratory of Applied Microbiology
- Guangdong Institute of Microbiology
- Guangzhou 510070
| | - Hai-Bo Tan
- Program for Natural Product Chemical Biology
- Key Laboratory of Plant Resources Conservation and Sustainable Utilization
- South China Botanical Garden
- Chinese Academy of Sciences
- Guangzhou 510650
| | - Sheng-Xiang Qiu
- Program for Natural Product Chemical Biology
- Key Laboratory of Plant Resources Conservation and Sustainable Utilization
- South China Botanical Garden
- Chinese Academy of Sciences
- Guangzhou 510650
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Effects of Rhodomyrtus tomentosa Leaf Extract on Staphylococcal Adhesion and Invasion in Bovine Udder Epidermal Tissue Model. Nutrients 2015; 7:8503-17. [PMID: 26501314 PMCID: PMC4632430 DOI: 10.3390/nu7105410] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2015] [Revised: 09/05/2015] [Accepted: 09/23/2015] [Indexed: 12/15/2022] Open
Abstract
Bovine mastitis is one of the most important infectious diseases in dairy herds, and staphylococci are the most important etiologic agents of this disease. Antibiotics and chemical agents used in livestock for prevention and cure of the disease can accumulate in milk and give rise to food safety concerns. Rhodomyrtus tomentosa leaf extract was studied as an alternative approach to reduce the bacterial infections. The ethanolic extract of this plant demonstrated antibacterial activity with minimum inhibitory concentration (MIC) values as low as 16–64 μg/mL against staphylococcal isolates. In addition, the extract had an effect on the bacterial cell surface properties by increasing its hydrophobicity in a concentration dependent manner. To further extend the antibacterial efficacy, silver nanoparticles synthesized with the extract, a pure rhodomyrtone, and liposomal encapsulated rhodomyrtone were applied and their inhibitory effects on bacterial adhesion and invasion were determined by ex vivo study in a bovine udder epidermal tissue model. These agents exerted remarkable antibacterial activity against staphylococci and decreased the adhesion of the bacterial cells to the tissues. These results supported that R. tomentosa ethanolic extract could be applied as an alternative agent for bovine udder care in dairy farms.
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25
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Mordmuang A, Voravuthikunchai SP. Rhodomyrtus tomentosa (Aiton) Hassk. leaf extract: An alternative approach for the treatment of staphylococcal bovine mastitis. Res Vet Sci 2015; 102:242-6. [DOI: 10.1016/j.rvsc.2015.07.018] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2014] [Revised: 07/06/2015] [Accepted: 07/26/2015] [Indexed: 10/23/2022]
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26
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Wu P, Ma G, Li N, Deng Q, Yin Y, Huang R. Investigation of in vitro and in vivo antioxidant activities of flavonoids rich extract from the berries of Rhodomyrtus tomentosa(Ait.) Hassk. Food Chem 2014; 173:194-202. [PMID: 25466012 DOI: 10.1016/j.foodchem.2014.10.023] [Citation(s) in RCA: 87] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2013] [Revised: 08/10/2014] [Accepted: 10/04/2014] [Indexed: 02/03/2023]
Abstract
This study investigated the in vitro and in vivo antioxidant activities of the flavonoids rich extract from Rhodomyrtus tomentosa Hassk (R. tomentosa) berries. The in vitro antioxidant assay demonstrated that the flavonoids rich extract (62.09% rutin equivalent) extracted by ethanol and purified by AB-8 macroporous resin was strong in reducing power, superoxide radical, hydroxyl radical and DPPH radical scavenging activity, as well as inhibiting lipid peroxidation. In the in vivo assays, the flavonoids rich extract significantly enhanced the activities of antioxidant enzymes in serums of mice after they were administered with the extract. The results suggested that the flavonoids rich extract from R. tomentosa fruits possesses potent antioxidant properties. In addition, the chemical compositions of flavonoids rich extract were identified by UPLC-TOF-MS/MS. Six flavonoids were tentatively identified as myricetin, quercetin, dihydromyricetin, kaempferol, quercetin 7,4'-diglucoside and vitexin. Therefore, R. tomentosa berries could be used as a new source of antioxidant ingredient.
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Affiliation(s)
- Pingping Wu
- College of Life Science, South China Normal University, Guangzhou 510631, PR China
| | - Guangzhi Ma
- College of Life Science, South China Normal University, Guangzhou 510631, PR China
| | - Nianghui Li
- College of Life Science, South China Normal University, Guangzhou 510631, PR China
| | - Qian Deng
- Milne Fruit Products, Inc, 804 Bennett Avenue, Prosser, WA 99350, USA
| | - Yanyan Yin
- College of Life Science, South China Normal University, Guangzhou 510631, PR China
| | - Ruqiang Huang
- College of Life Science, South China Normal University, Guangzhou 510631, PR China.
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Rhodomyrtone modulates innate immune responses of THP-1 monocytes to assist in clearing methicillin-resistant Staphylococcus aureus. PLoS One 2014; 9:e110321. [PMID: 25329066 PMCID: PMC4199624 DOI: 10.1371/journal.pone.0110321] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2014] [Accepted: 09/19/2014] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND The increasing resistance of Staphylococcus aureus to conventional antibiotics poses a major health problem. Moreover, S. aureus can survive within phagocytes, thus evading some antibiotics and the innate immune response. Rhodomyrtone, a bioactive compound from the leaves of Rhodomyrtus tomentosa, possesses potent antibacterial activity against methicillin-resistant S. aureus (MRSA). This study was to investigate the immunomodulatory effects of rhodomyrtone on THP-1 monocytes in response to MRSA. METHODS THP-1 monocytes were stimulated with heat-killed MRSA, followed by treatment with rhodomyrtone. The cell pellets were prepared to detect pro-inflammatory molecules using real-time PCR. The supernatants were collected to assess nitric oxide production using Griess assay. Assays for phagocytosis and bacterial killing by THP-1 monocytes were performed to determine if they were affected by rhodomyrtone. RESULTS Expression of pro-inflammatory molecules including IL-1β, TNF-α, IL-6, and iNOS was enhanced in THP-1 monocytes stimulated with high doses of heat-killed MRSA (108 to 109 cfu/ml). In contrast, monocytes stimulated with MRSA at lower doses (106 to 107 cfu/ml) did not induce the expression of these cytokines. However, rhodomyrtone significantly increased the expression of pro-inflammatory mediators, IL-6 and iNOS in monocytes stimulated with heat-killed MRSA at low doses, and displayed some anti-inflammatory activity by reducing TNF-α expression in monocytes stimulated with heat-killed MRSA at high doses. Treatment with rhodomyrtone also significantly up-regulated the expression of the key pattern recognition receptors, TLR2 and CD14, in THP-1 monocytes stimulated with heat-killed MRSA at 106 to 109 cfu/ml, while heat-killed MRSA alone did not induce the expression of these molecules. The ability of rhodomyrtone to eliminate MRSA from the monocytes was observed within 24 h after treatment. CONCLUSION Rhodomyrtone enhanced the expression of pattern recognition receptors by monocytes in response to MRSA. Increased expression of these receptors might improve MRSA clearance by modulating pro- and anti-inflammatory cytokine responses.
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Inhibition of microbial adhesion to plastic surface and human buccal epithelial cells by Rhodomyrtus tomentosa leaf extract. Arch Oral Biol 2014; 59:1256-65. [PMID: 25146902 DOI: 10.1016/j.archoralbio.2014.07.017] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2013] [Revised: 05/02/2014] [Accepted: 07/22/2014] [Indexed: 11/21/2022]
Abstract
OBJECTIVE The adherence of oral pathogenic microorganisms to host tissues is the initial step for successful process of oral diseases. This study aimed to determine the effect of the Rhodomyrtus tomentosa leaf extract and rhodomyrtone, an antibacterial compound from R. tomentosa leaf, on adhesion of some oral pathogens to polystyrene plastic surface and human buccal epithelial cells. METHODS The minimum inhibitory concentration (MIC) was evaluated using broth microdilution method. The microbial adhesion to the plastic surface and buccal cells was determined using microtiter plate method and microscopy technique. RESULTS The ethanol extract of leaf demonstrated antibacterial activity against oral microorganisms including Staphylococcus aureus ATCC 25923, Streptococcus mutans (clinical isolate), and Candida albicans ATCC 90028 with the MIC values of 31.25, 15.62, and 1000μg/ml, respectively. Rhodomyrtone displayed activity with the MIC values of 0.78 and 0.39μg/ml against S. aureus ATCC 25923 and S. mutans, respectively. The MIC value of the compound against C. albicans ATCC 90028 was more than 100μg/ml which was the highest test concentration. All pathogenic microorganisms treated with the extract and rhodomyrtone at their subinhibitory concentrations resulted in a decrease in their adherence ability to both plastic surface and buccal cells. CONCLUSION It is suggested that R. tomentosa extract and rhodomyrtone may be useful in therapy or as prophylaxis in infections involving oral pathogens.
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Inhibition of staphylococcal biofilm-related gene transcription by rhodomyrtone, a new antibacterial agent. ANN MICROBIOL 2014. [DOI: 10.1007/s13213-014-0904-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
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Shou Q, Smith JE, Mon H, Brkljača Z, Smith AS, Smith DM, Griesser HJ, Wohlmuth H. Rhodomyrtals A–D, four unusual phloroglucinol-sesquiterpene adducts from Rhodomyrtus psidioides. RSC Adv 2014. [DOI: 10.1039/c4ra00154k] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Four unusual phloroglucinol-sesquiterpene adducts, rhodomyrtals A–D (1–4), representing two unprecendented carbon frameworks of phloroglucinol coupled eudesmane with the linkage at C-12′, were isolated from Rhodomyrtus psidioides.
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Affiliation(s)
- Qingyao Shou
- Southern Cross Plant Science
- Southern Cross University
- Lismore NSW 2480, Australia
| | - Joshua E. Smith
- Southern Cross Plant Science
- Southern Cross University
- Lismore NSW 2480, Australia
| | - Htwe Mon
- Ian Wark Research Institute
- University of South Australia
- Mawson Lakes SA 5095, Australia
| | - Zlatko Brkljača
- Institute for Theoretical Physics
- Friedrich Alexander University Erlangen-Nürnberg
- Erlangen, Germany
| | - Ana-Sunčana Smith
- Institute for Theoretical Physics
- Friedrich Alexander University Erlangen-Nürnberg
- Erlangen, Germany
- Ruđer Bošković Institute
- 10000 Zagreb, Croatia
| | - David M. Smith
- Institute for Theoretical Physics
- Friedrich Alexander University Erlangen-Nürnberg
- Erlangen, Germany
- Ruđer Bošković Institute
- 10000 Zagreb, Croatia
| | - Hans J. Griesser
- Ian Wark Research Institute
- University of South Australia
- Mawson Lakes SA 5095, Australia
| | - Hans Wohlmuth
- Southern Cross Plant Science
- Southern Cross University
- Lismore NSW 2480, Australia
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Leejae S, Hasap L, Voravuthikunchai SP. Inhibition of staphyloxanthin biosynthesis in Staphylococcus aureus by rhodomyrtone, a novel antibiotic candidate. J Med Microbiol 2012; 62:421-428. [PMID: 23242641 DOI: 10.1099/jmm.0.047316-0] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Staphyloxanthin is the eponymous feature of the human pathogen Staphylococcus aureus, and the pigment promotes resistance to reactive oxygen species and host neutrophil-based killing. To probe the possible use of rhodomyrtone isolated from Rhodomyrtus tomentosa (Aiton) Hassk. leaves to inhibit pigment production in S. aureus, experiments were carried out to compare pigment production and the susceptibility of rhodomyrtone-treated S. aureus and untreated cells to oxidants in vitro. In addition, we observed the innate immune clearance of S. aureus after incubation with rhodomyrtone using an ex vivo assay system - human whole-blood survival. The results indicated that rhodomyrtone-treated S. aureus exhibited reduced pigmentation, and that rhodomyrtone treatment led to a dose-dependent increase in the susceptibility of the pathogen to H(2)O(2) and singlet oxygen killing. Consequently, the survival ability of the treated organisms decreased in freshly isolated human whole blood due to less carotenoid pigment to act as an antioxidant scavenger. Rhodomyrtone may be acting via effects on DnaK and/or σ(B), resulting in many additional effects on bacterial virulence.
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Affiliation(s)
- Sukanlaya Leejae
- Department of Microbiology and Natural Products Research Center, Faculty of Science, Prince of Songkla University, Songkhla 90112, Thailand
| | - Laila Hasap
- Department of Microbiology and Natural Products Research Center, Faculty of Science, Prince of Songkla University, Songkhla 90112, Thailand
| | - Supayang Piyawan Voravuthikunchai
- Department of Microbiology and Natural Products Research Center, Faculty of Science, Prince of Songkla University, Songkhla 90112, Thailand
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Acetone Extract from Rhodomyrtus tomentosa: A Potent Natural Antioxidant. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2012; 2012:535479. [PMID: 23125869 PMCID: PMC3484404 DOI: 10.1155/2012/535479] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/19/2012] [Accepted: 06/18/2012] [Indexed: 11/17/2022]
Abstract
Rhodomyrtus tomentosa (Myrtaceae) has been employed in traditional Thai medicine to treat colic diarrhoea, dysentery, abscesses, haemorrhage, and gynaecopathy. In addition, it has been used to formulate skin-whitening, anti-aging and skin beautifying agents. Ethnomedical activities of this plant may be due its antioxidant property. Hence, the aim of this study was to evaluate both in vitro and in vivo antioxidant activities of R. tomentosa leaf extract. In vitro antioxidant activity of the extract was assessed by lipid peroxidation inhibition capacity, ferric reducing antioxidant power, and metal chelating activity. R. tomentosa extract demonstrated its free radical scavenging effects in concentration dependent manner. In vivo antioxidant activity of the extract was conducted in Swiss Albino mice. Levels of thio-barbituric acid reactive substances (TBARS), glutathione (GSH), and the activities of antioxidant enzymes including superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) in blood, liver, and kidney were analyzed using microtitre plate photometer. Administration of CCl4 caused significant increase in TBARS and decrease in GSH, SOD, CAT and GPx levels. In contrast, R. tomentosa extract (0.8 g/kg) effectively prevented these alterations and maintained the antioxidant status. The results suggest that R. tomentosa extract can serve as a potent antioxidant.
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Antibacterial Activity of Rhodomyrtus tomentosa (Aiton) Hassk. Leaf Extract against Clinical Isolates of Streptococcus pyogenes. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2012; 2012:697183. [PMID: 22973404 PMCID: PMC3438885 DOI: 10.1155/2012/697183] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/03/2012] [Revised: 07/26/2012] [Accepted: 07/31/2012] [Indexed: 11/18/2022]
Abstract
Ethanol extract of Rhodomyrtus tomentosa (Aiton) Hassk. leaf was evaluated for antibacterial activity against 47 clinical isolates of Streptococcus pyogenes. The extract exhibited good anti-S. pyogenes activity against all the tested isolates with similar minimum inhibitory concentration (MIC, 3.91-62.5 μg mL(-1)) and minimum bactericidal concentration (MBC, 3.91-62.5 μg mL(-1)) ranges. No surviving cells were detected at 16 h after treatment with 8 × MIC of the extract. The extract-treated cells demonstrated no lysis and cytoplasmic leakage through the bacterial membrane. Electron micrographs further revealed that the extract did not cause any dramatic changes on the treated cells. Rhodomyrtone, an isolated compound, exhibited good anti-S. pyogenes activity (14 isolates), expressed very low MIC (0.39-1.56 μg mL(-1)) and MBC (0.39-1.56 μg mL(-1)) values. Rhodomyrtus tomentosa leaf extract and rhodomyrtone displayed promising antibacterial activity against clinical isolates of S. pyogenes.
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Synthesis and structure–activity relationship of rhodomyrtone derivatives as antibacterial agent. CHINESE CHEM LETT 2012. [DOI: 10.1016/j.cclet.2012.06.040] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Saising J, Voravuthikunchai SP. Anti Propionibacterium acnes activity of rhodomyrtone, an effective compound from Rhodomyrtus tomentosa (Aiton) Hassk. leaves. Anaerobe 2012; 18:400-4. [PMID: 22626672 DOI: 10.1016/j.anaerobe.2012.05.003] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2012] [Revised: 05/05/2012] [Accepted: 05/10/2012] [Indexed: 11/28/2022]
Abstract
Propionibacterium acnes have been recognized as one of the main causative agents in pathogenesis of acne. Twenty one isolates of P. acnes isolated from acne lesions were screened for lipase and protease activity which are reported to be associated in acne and inflammation. Interestingly, all P. acnes isolates demonstrated lipase activity. Similarly, 90% of test P. acnes produced protease enzyme. Antibacterial activity of the ethanol extract of Rhodomyrtus tomentosa (Aiton) Hassk. leaves and rhodomyrtone, its principle compound were tested against P. acnes using broth macrodilution method. The MIC(90) values of the ethanol extract and rhodomyrtone were 32 and 0.5 μg/mL, respectively. The numbers of the bacterial cells were reduced at least 99% after treatment with the ethanol extract and rhodomyrtone within 72 and 24 h, respectively. Cytotoxicity test of the extract and rhodomyrtone was performed on human normal fibroblast. The IC(50) values of the ethanol extract and rhodomyrtone were 476 and more than 200 μg/mL, approximately 15 and 400 folds higher than the MIC(90) values indicating that both substances were very low cytotoxic which could be applied as topical therapeutic anti-acne agents.
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Affiliation(s)
- Jongkon Saising
- Department of Microbiology, Faculty of Science, Prince of Songkla University, Hat Yai, Thailand
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Saising J, Ongsakul M, Voravuthikunchai SP. Rhodomyrtus tomentosa (Aiton) Hassk. ethanol extract and rhodomyrtone: a potential strategy for the treatment of biofilm-forming staphylococci. J Med Microbiol 2011; 60:1793-1800. [DOI: 10.1099/jmm.0.033092-0] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- Jongkon Saising
- Natural Products Research Center, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla 90112, Thailand
- Department of Microbiology, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla 90112, Thailand
| | - Metta Ongsakul
- Department of Microbiology, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla 90112, Thailand
| | - Supayang Piyawan Voravuthikunchai
- Natural Products Research Center, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla 90112, Thailand
- Department of Microbiology, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla 90112, Thailand
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Hiranrat A, Mahabusarakam W, Carroll AR, Duffy S, Avery VM. Tomentosones A and B, Hexacyclic Phloroglucinol Derivatives from the Thai Shrub Rhodomyrtus tomentosa. J Org Chem 2011; 77:680-3. [DOI: 10.1021/jo201602y] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
| | | | - Anthony R. Carroll
- Environmental Futures
Centre, Griffith University, Gold Coast,
QLD 4222, Australia,
- Eskitis
Institute, Griffith University, Brisbane,
QLD 4111, Australia
| | - Sandra Duffy
- Eskitis
Institute, Griffith University, Brisbane,
QLD 4111, Australia
| | - Vicky M. Avery
- Eskitis
Institute, Griffith University, Brisbane,
QLD 4111, Australia
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Limsuwan S, Hesseling-Meinders A, Voravuthikunchai SP, van Dijl JM, Kayser O. Potential antibiotic and anti-infective effects of rhodomyrtone from Rhodomyrtus tomentosa (Aiton) Hassk. on Streptococcus pyogenes as revealed by proteomics. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2011; 18:934-940. [PMID: 21439802 DOI: 10.1016/j.phymed.2011.02.007] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2010] [Revised: 12/28/2010] [Accepted: 02/07/2011] [Indexed: 05/30/2023]
Abstract
Rhodomyrtone from Rhodomyrtus tomentosa (Aiton) Hassk. leaf extract has a strong antibacterial activity against the bacterial pathogen Streptococcus pyogenes. Our previous studies indicated that the bactericidal activity of rhodomyrtone might involve intracellular targets. In the present studies we followed a proteomics approach to investigate the mode of action of rhodomyrtone on S. pyogenes. For this purpose, S. pyogenes was cultivated in the presence of 0.39 μg/ml rhodomyrtone, which corresponds to 50% of the minimal inhibitory concentration. The results show that the amounts of various enzymes associated with important metabolic pathways were strongly affected, which is consistent with the growth-inhibiting effect of rhodomyrtone. Additionally, cells of S. pyogenes grown in the presence of rhodomyrtone produced reduced amounts of known virulence factors, such as the glyceraldehyde-3-phosphate dehydrogenase, the CAMP factor, and the streptococcal pyrogenic exotoxin C. Taken together, these findings indicate that rhodomyrtone has both antimicrobial and anti-infective activities, which make it an interesting candidate drug.
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Affiliation(s)
- Surasak Limsuwan
- Faculty of Traditional Thai Medicine and Natural Products Research Center, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla 90112, Thailand
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Sianglum W, Srimanote P, Wonglumsom W, Kittiniyom K, Voravuthikunchai SP. Proteome analyses of cellular proteins in methicillin-resistant Staphylococcus aureus treated with rhodomyrtone, a novel antibiotic candidate. PLoS One 2011; 6:e16628. [PMID: 21326597 PMCID: PMC3033880 DOI: 10.1371/journal.pone.0016628] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2010] [Accepted: 01/05/2011] [Indexed: 11/19/2022] Open
Abstract
The ethanolic extract from Rhodomyrtus tomentosa leaf exhibited good antibacterial activities against both methicillin-resistant Staphylococcus aureus (MRSA) and S. aureus ATCC 29213. Its minimal inhibitory concentration (MIC) values ranged from 31.25–62.5 µg/ml, and the minimal bactericidal concentration (MBC) was 250 µg/ml. Rhodomyrtone, an acylphloroglucinol derivative, was 62.5–125 times more potent at inhibiting the bacteria than the ethanolic extract, the MIC and MBC values were 0.5 µg/ml and 2 µg/ml, respectively. To provide insights into antibacterial mechanisms involved, the effects of rhodomyrtone on cellular protein expression of MRSA have been investigated using proteomic approaches. Proteome analyses revealed that rhodomyrtone at subinhibitory concentration (0.174 µg/ml) affected the expression of several major functional classes of whole cell proteins in MRSA. The identified proteins involve in cell wall biosynthesis and cell division, protein degradation, stress response and oxidative stress, cell surface antigen and virulence factor, and various metabolic pathways such as amino acid, carbohydrate, energy, lipid, and nucleotide metabolism. Transmission electron micrographs confirmed the effects of rhodomyrtone on morphological and ultrastructural alterations in the treated bacterial cells. Biological processes in cell wall biosynthesis and cell division were interrupted. Prominent changes including alterations in cell wall, abnormal septum formation, cellular disintegration, and cell lysis were observed. Unusual size and shape of staphylococcal cells were obviously noted in the treated MRSA. These pioneer findings on proteomic profiling and phenotypic features of rhodomyrtone-treated MRSA may resolve its antimicrobial mechanisms which could lead to the development of a new effective regimen for the treatment of MRSA infections.
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Affiliation(s)
- Wipawadee Sianglum
- Department of Microbiology and Natural Products Research Center, Faculty of Science, Prince of Songkla University, Songkla, Thailand
| | - Potjanee Srimanote
- Graduate Study, Faculty of Allied Health Sciences, Thammasat University, Pathumtanee, Thailand
| | - Wijit Wonglumsom
- Department of Clinical Microbiology, Faculty of Medical Technology, Mahidol University, Nakhon Pathom, Thailand
| | - Kanokwan Kittiniyom
- Department of Clinical Microbiology, Faculty of Medical Technology, Mahidol University, Nakhon Pathom, Thailand
| | - Supayang P. Voravuthikunchai
- Department of Microbiology and Natural Products Research Center, Faculty of Science, Prince of Songkla University, Songkla, Thailand
- * E-mail:
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Duda B, Tverdomed SN, Röschenthaler GV. Synthesis of 2-perfluoroalkyl 4H- and 2H-chromenylphosphonates mediated by amines and phosphines. J Org Chem 2010; 76:71-9. [PMID: 21121658 DOI: 10.1021/jo101913u] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
An efficient synthesis of 2-perfluoroalkyl 4H-chromen-3-ylphosphonates 4a-i (R(F) = CF(3)) and 5a-i (R(F) = C(2)F(5)) has been accomplished via regioselective cycloaddition of 2-hydroxybenzaldehydes to diethyl 3,3,3-trifluoropropyn-1-yl- and diethyl 3,3,4,4,4-pentafluorobutyn-1-ylphosphonate, using trialkyl amines or phosphines as mediators. 2H-Chromen-3-ylphosphonates 6a-i were regioselectively obtained in the presence of triphenylphosphine. A convenient method for the isomerization of 4H-chromen-3-ylphosphonates into 2H-chromen-3-ylphosphonates 6a-i (R(F) = CF(3)) and 7a-i (R(F) = C(2)F(5)) was established.
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Affiliation(s)
- Blazej Duda
- School of Engineering and Science, Jacobs University Bremen, Campus Ring 1, 28759 Bremen, Germany
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Voravuthikunchai SP, Dolah S, Charernjiratrakul W. Control of Bacillus cereus in foods by Rhodomyrtus tomentosa (Ait.) Hassk. Leaf extract and its purified compound. J Food Prot 2010; 73:1907-12. [PMID: 21067680 DOI: 10.4315/0362-028x-73.10.1907] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Edible natural products, either standardized plant extracts or pure compounds, provide unlimited opportunities as safe new antimicrobial agents. This study investigated the antibacterial properties of ethanolic extract from Rhodomyrtus tomentosa (Ait.) Hassk. leaves against Bacillus cereus. Preliminary screening to evaluate the activities of the extract used a paper disc diffusion method against 65 food isolates. The extract produced large inhibition zones in all isolates, ranging from 10 to 18 mm. The results were confirmed by MIC and MBC (16 to 64 and 32 to 256 μg/ml, respectively). Rhodomyrtone, a purified compound, exhibited MIC and MBC at 0.5 and at 2 to 8 μg/ml, respectively. The antimicrobial activity of the extract on vegetative cells and endospores of a representative B. cereus isolate (MIC=32 μg/ml) was assessed by enumerating viable cells at different time intervals up to 24 h. At 2 MICs and 4 MICs, a reduction in the viability of the bacterial cells and endospores was at least 3 log within 6 to 8 h and 2 h after incubation, respectively. Application of the extract in precooked rice and tuna steak demonstrated that after exposure to 16 MICs and 32 MICs, the numbers of viable cells and endospores in both model systems were reduced by at least 2 log within 12 and 6 h, respectively. Since the extract consistently produced remarkable activity against both cells and endospores, it could be used as an alternative food additive for controlling B. cereus without compromising food safety.
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Affiliation(s)
- Supayang Piyawan Voravuthikunchai
- Department of Microbiology, Natural Products Research Center, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla 90112, Thailand.
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