scholarly journals Tetracyclines: light-activated antibiotics?

2019 ◽  
Vol 11 (18) ◽  
pp. 2427-2445 ◽  
Author(s):  
Michael R Hamblin ◽  
Heidi Abrahamse
Keyword(s):  
Reactive Oxygen Species ◽  
Hydrogen Peroxide ◽  
Potassium Iodide ◽  
Side Effect ◽  
Bactericidal Effect ◽  
Photodynamic Inactivation ◽  
Oxygen Species ◽  
Bacterial Cells ◽  
Light Activation ◽  
Bacterial Regrowth

Tetracyclines are well established antibiotics but show phototoxicity as a side effect. Antimicrobial photodynamic inactivation uses nontoxic dyes combined with harmless light to destroy microbial cells by reactive oxygen species. Tetracyclines (demeclocycline and doxycycline) can act as light-activated antibiotics by binding to bacterial cells and killing them only upon illumination. The remaining tetracyclines can prevent bacterial regrowth after illumination has ceased. Antimicrobial photodynamic inactivation can be potentiated by potassium iodide. Azide quenched the formation of iodine, but not hydrogen peroxide. Demeclotetracycline (but not doxycycline) iodinated tyrosine after light activation in the presence of potassium iodide. Bacteria are killed by photoactivation of tetracyclines in the absence of oxygen. Since topical tetracyclines are already used clinically, blue light activation may increase the bactericidal effect.

Hydrogen peroxide-responsive AIE probe for imaging-guided organelle targeting and photodynamic cancer cell ablation

2021 ◽  
Author(s):  
Qian Wu ◽  
Youmei Li ◽  
Ying Li ◽  
Dong Wang ◽  
Ben Zhong Tang
Keyword(s):  
Reactive Oxygen Species ◽  
Hydrogen Peroxide ◽  
Cancer Cell ◽  
Reactive Oxygen ◽  
Living Cells ◽  
Oxygen Species ◽  
Cell Ablation ◽  
Selective Monitoring ◽  
Organelle Targeting

Hydrogen peroxide (H2O2), as one kind of key reactive oxygen species (ROS), is mainly produced endogenously primarily in the mitochondria. The selective monitoring of H2O2 in living cells is of...

scholarly journals Intracellular Sources of ROS/H2O2 in Health and Neurodegeneration: Spotlight on Endoplasmic Reticulum

Cells ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 233
Author(s):  
Tasuku Konno ◽  
Eduardo Pinho Melo ◽  
Joseph E. Chambers ◽  
Edward Avezov
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Hydrogen Peroxide ◽  
Endoplasmic Reticulum ◽  
Neurodegenerative Diseases ◽  
Antioxidative Enzymes ◽  
Redox Reactions ◽  
Ros Production ◽  
Oxygen Species ◽  
Specific Target

Reactive oxygen species (ROS) are produced continuously throughout the cell as products of various redox reactions. Yet these products function as important signal messengers, acting through oxidation of specific target factors. Whilst excess ROS production has the potential to induce oxidative stress, physiological roles of ROS are supported by a spatiotemporal equilibrium between ROS producers and scavengers such as antioxidative enzymes. In the endoplasmic reticulum (ER), hydrogen peroxide (H2O2), a non-radical ROS, is produced through the process of oxidative folding. Utilisation and dysregulation of H2O2, in particular that generated in the ER, affects not only cellular homeostasis but also the longevity of organisms. ROS dysregulation has been implicated in various pathologies including dementia and other neurodegenerative diseases, sanctioning a field of research that strives to better understand cell-intrinsic ROS production. Here we review the organelle-specific ROS-generating and consuming pathways, providing evidence that the ER is a major contributing source of potentially pathologic ROS.

scholarly journals Upconversion-based nanosystems for fluorescence sensing of pH and H2O2

2021 ◽  
Author(s):  
Chunning Sun ◽  
Michael Gradzielski
Keyword(s):  
Reactive Oxygen Species ◽  
Hydrogen Peroxide ◽  
Excitation Energy ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Fluorescence Sensing ◽  
Living Organisms

Hydrogen peroxide (H2O2), a key reactive oxygen species, plays an important role in living organisms, industrial and environmental fields. Here, a non-contact upconversion nanosystem based on the excitation energy attenuation...

scholarly journals Cromoglycate and nedocromil enhanced the reactive oxygen species-dependent suppressions with, but not without, dexamethasone in ischaemic and histamine paw oedema of mice

1997 ◽  
Vol 6 (5-6) ◽  
pp. 369-374
Author(s):  
Y. Oyanagui
Keyword(s):  
Reactive Oxygen Species ◽  
Hydrogen Peroxide ◽  
Superoxide Dismutase ◽  
Glucocorticoid Receptor ◽  
Low Dose ◽  
Natural Antioxidant ◽  
Target Cells ◽  
Oxygen Species ◽  
Paw Oedema ◽  
Β Carotene

Anti-inflammatory actions of two anti-allergic drugs, alone or with dexamethasone (Dex) were examined in two models, because inflammation is claimed to be important for allergic events, especially for asthma. Cromoglycate and nedocromil were tested in ischaemic- and histamineinduced paw oedema models of mice. These antiallergic drugs (1–100 mg/kg, i.p.) failed to suppress these oedemata, but enhanced the suppressions by a low dose of dexamethasone (0.1 mg/kg, s.c.) at 3–8 h after Dex injection. The mode of effects by anti-allergic drugs resembled that of a natural antioxidant (α-tocopherol, β-carotene etc.), and was different from that of an immunosuppressant like FK506. The enhancing potencies of the two anti-allergic drugs were similar at 6 h after Dex in both oedemata, and were diminished by superoxide dismutase (SOD) or catalase (i.p.). Cycloheximide completely abolished suppressions. Nedocromil, but not cromoglycate, inhibits inflammatory events. Therefore, there are common unknown actions by which the two anti-allergics enhance suppression by Dex. A possible mechanism of this action was supposed to enhance the superoxide and/or hydrogen peroxide-dependent glucocorticoid receptor (GR) signalling in the target cells.

scholarly journals Novel Antioxidant Properties of Doxycycline

2018 ◽  
Vol 19 (12) ◽  
pp. 4078 ◽  
Author(s):  
Dahn Clemens ◽  
Michael Duryee ◽  
Cleofes Sarmiento ◽  
Andrew Chiou ◽  
Jacob McGowan ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Hydrogen Peroxide ◽  
Chronic Inflammation ◽  
Antioxidant Properties ◽  
Antibacterial Properties ◽  
Reactive Oxygen ◽  
Protein Adducts ◽  
Oxygen Species ◽  
Free System

Doxycycline (DOX), a derivative of tetracycline, is a broad-spectrum antibiotic that exhibits a number of therapeutic activities in addition to its antibacterial properties. For example, DOX has been used in the management of a number of diseases characterized by chronic inflammation. One potential mechanism by which DOX inhibits the progression of these diseases is by reducing oxidative stress, thereby inhibiting subsequent lipid peroxidation and inflammatory responses. Herein, we tested the hypothesis that DOX directly scavenges reactive oxygen species (ROS) and inhibits the formation of redox-mediated malondialdehyde-acetaldehyde (MAA) protein adducts. Using a cell-free system, we demonstrated that DOX scavenged reactive oxygen species (ROS) produced during the formation of MAA-adducts and inhibits the formation of MAA-protein adducts. To determine whether DOX scavenges specific ROS, we examined the ability of DOX to directly scavenge superoxide and hydrogen peroxide. Using electron paramagnetic resonance (EPR) spectroscopy, we found that DOX directly scavenged superoxide, but not hydrogen peroxide. Additionally, we found that DOX inhibits MAA-induced activation of Nrf2, a redox-sensitive transcription factor. Together, these findings demonstrate the under-recognized direct antioxidant property of DOX that may help to explain its therapeutic potential in the treatment of conditions characterized by chronic inflammation and increased oxidative stress.

A Vinyl-Boronate Ester-Based Persulfide Donor Controllable by Hydrogen Peroxide, a Reactive Oxygen Species (ROS)

2018 ◽  
Vol 20 (24) ◽  
pp. 7916-7920 ◽  
Author(s):  
Prerona Bora ◽  
Preeti Chauhan ◽  
Suman Manna ◽  
Harinath Chakrapani
Keyword(s):  
Reactive Oxygen Species ◽  
Hydrogen Peroxide ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Boronate Ester

A charge transfer assisted fluorescent probe for selective detection of hydrogen peroxide among different reactive oxygen species

2012 ◽  
Vol 48 (39) ◽  
pp. 4719 ◽  
Author(s):  
Manoj Kumar ◽  
Naresh Kumar ◽  
Vandana Bhalla ◽  
Parduman Raj Sharma ◽  
Yasrib Qurishi
Keyword(s):  
Reactive Oxygen Species ◽  
Hydrogen Peroxide ◽  
Charge Transfer ◽  
Fluorescent Probe ◽  
Reactive Oxygen ◽  
Selective Detection ◽  
Oxygen Species ◽  
A Charge

scholarly journals Reduction of Intracellular-Reactive Oxygen Species and Diminished Mitogen-Activated Protein Kinases (MAPKs) Activation are Associated with Oral Squamous Cell Carcinoma Cell Aggressiveness

2017 ◽  
Vol 15 (2) ◽  
pp. 131-141
Author(s):  
Tanyarath UTAIPAN ◽  
Apsorn SATTAYAKHOM ◽  
Issara PRACHONGSAI ◽  
Nurdina CHARONG ◽  
Warangkana CHUNGLOK
Keyword(s):  
Reactive Oxygen Species ◽  
Hydrogen Peroxide ◽  
Squamous Cell Carcinoma ◽  
Oral Squamous Cell Carcinoma ◽  
Cell Carcinoma ◽  
Protein Kinases ◽  
Cell Lines ◽  
Oxygen Species ◽  
Mitogen Activated Protein Kinases ◽  
Mitogen Activated Protein

Oral squamous cell carcinoma (OSCC) is a serious health problem in many countries. Several drugs have been used to treat head and neck and oral cavity cancers. However, the success rate has not been impressive because of the heterogeneity of cancerous cells, resulting in differential responsiveness to chemotherapy. Two distinct phenotypes of OSCC cells, the CLS-354/WT and CLS-354/DXcells, have been used as in vitro cell models for this study. CLS-354/DXcells were more aggressive than CLS-354/WTcells, supported by the observation that CLS-354/DXcells can undergo epithelial-mesenchymal transition (EMT), grow anchorage-independently, and increase invasiveness. We investigated the preliminary redox status of these 2 cell lines, including levels of reactive oxygen species (ROS) and cellular antioxidants, using flow cytometry analysis and ABTS+ free radical scavenging assay, respectively. A 7-fold decrease in ROS level was detected in CLS-354/DXcells, comparing with CLS-354/WTcells, while antioxidant capacity was not different from that of CLS-354/WT cells. Hydrogen peroxide, a ROS modulating agent, could induce ROS levels, and caused cell death in CLS-354/WT greater than that of CLS-354/DX cells. Of note, hydrogen peroxide-induced cytotoxicity could be rescued by N-acetyl cysteine, confirming ROS-mediated cytotoxicity in both cell lines. ROS-sensitive mitogen-activated protein kinases (MAPKs) were observed using immunoblot assay. The expressions of p-JNK1/2 and p-p38 MAPK in CLS-354/DX cells were absent, while these expressions were abundantly detected in CLS-354/WTcells. This suggests that lower ROS levels, with the concomitant reduction of JNK and p38 MAPK activation in CLS-354/DX cells, are associated with cancer cell aggressiveness. These findings provide significant evidence of the resistance to ROS-modulating agents in aggressive OSCC cells.

scholarly journals Caffeic Acid - Potential Antioxidant in Cultured Human Retinal Pigment Epithelial Cells

1970 ◽  
Vol 66 (2) ◽  
Author(s):  
Dumitriţa RUGINǍ ◽  
Adela PINTEA ◽  
Raluca PÂRLOG ◽  
Andreea VARGA
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Hydrogen Peroxide ◽  
Protective Effect ◽  
Caffeic Acid ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Antioxidant Defence ◽  
Rpe Cells ◽  
In Cells

Oxidative stress causes biological changes responsible for carcinogenesis and aging in human cells. The retinal pigmented epithelium is continuously exposed to oxidative stress. Therefore reactive oxygen species (ROS) and products of lipid peroxidation accumulate in RPE. Neutralization of ROS occurs in retina by the action of antioxidant defence systems. In the present study, the protective effect of caffeic acid (3,4-dihydroxy cinnamic acid), a dietary phenolic compound, has been examined in normal and in oxidative stress conditions (500 µM peroxide oxygen) in cultures human epithelial pigment retinal cells (Nowak, M. et al.). The cell viability, the antioxidant enzymes activity (CAT, GPx, SOD) and the level of intracellular reactive oxygen species (ROS) were determined. Exposure to l00 µM caffeic acid for 24 h induced cellular changes indicating the protective effect of caffeic acid in RPE cells. Caffeic acid did not show any cytotoxic effect at concentrations lower than 200 μM in culture medium. Treatment of RPE cells with caffeic acid causes an increase of catalase, glutathione peroxidase and superoxide dismutase activity, especially in cells treated with hydrogen peroxide. Caffeic acid causes a decrease of ROS level in cells treated with hydrogen peroxide. This study proved that caffeic acid or food that contain high levels of this phenolic acid may have beneficial effects in prevention of retinal diseases associated with oxidative stress by improving antioxidant defence systems.

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