scholarly journals Fe-catalyzed sulfide oxidation in hydrothermal plumes is a source of reactive oxygen species to the ocean

2021 ◽  
Vol 118 (40) ◽  
pp. e2026654118
Author(s):  
Timothy J. Shaw ◽  
George W. Luther ◽  
Richard Rosas ◽  
Véronique E. Oldham ◽  
Nicole R. Coffey ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Hydrogen Peroxide ◽  
Hydroxyl Radical ◽  
Bottom Water ◽  
Sulfide Oxidation ◽  
Reactive Oxygen ◽  
Global Ocean ◽  
Oxygen Species ◽  
Fenton Chemistry ◽  
Hydrothermal Plumes

Historically, the production of reactive oxygen species (ROS) in the ocean has been attributed to photochemical and biochemical reactions. However, hydrothermal vents emit globally significant inventories of reduced Fe and S species that should react rapidly with oxygen in bottom water and serve as a heretofore unmeasured source of ROS. Here, we show that the Fe-catalyzed oxidation of reduced sulfur species in hydrothermal vent plumes in the deep oceans supported the abiotic formation of ROS at concentrations 20 to 100 times higher than the average for photoproduced ROS in surface waters. ROS (measured as hydrogen peroxide) were determined in hydrothermal plumes and seeps during a series of Alvin dives at the North East Pacific Rise. Hydrogen peroxide inventories in emerging plumes were maintained at levels proportional to the oxygen introduced by mixing with bottom water. Fenton chemistry predicts the production of hydroxyl radical under plume conditions through the reaction of hydrogen peroxide with the abundant reduced Fe in hydrothermal plumes. A model of the hydroxyl radical fate under plume conditions supports the role of plume ROS in the alteration of refractory organic molecules in seawater. The ocean’s volume circulates through hydrothermal plumes on timescales similar to the age of refractory dissolved organic carbon. Thus, plume-generated ROS can initiate reactions that may affect global ocean carbon inventories.

Antioxidant Activity of Hizikia fusiformis on Reactive Oxygen Species Scavenging and Lipid Peroxidation Inhibition

2003 ◽  
Vol 9 (5) ◽  
pp. 339-346 ◽  
Author(s):  
Nalin Siriwardhana ◽  
K.-W. Lee ◽  
Y.-J. Jeon ◽  
S.-H. Kim ◽  
J.-W. Haw
Keyword(s):  
Reactive Oxygen Species ◽  
Hydrogen Peroxide ◽  
Lipid Peroxidation ◽  
Hydroxyl Radical ◽  
Radical Scavenging ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Ros Scavenging ◽  
Hizikia Fusiformis ◽  
Lipid Peroxidation Inhibition

Water and organic extracts (diethyl ether, chloroform, ethyl acetate, acetone, ethanol and methanol) obtained from Hizikia fusiformis were screened on reactive oxygen species (ROS) scavenging assays (1,1-diphenyl-2-picrylhydrazyl (DPPH), superoxide anion, hydrogen peroxide and hydroxyl radical) and lipid peroxidation (inhibition of linoleic acid oxidation) inhibitory assays. Water, methanol and ethanol extracts showed significant ROS radical scavenging activities. Water extracts showed high scavenging activities on hydrogen peroxide (around 76%) and DPPH radicals (around 75%) while it presented a moderate scavenging activity on hydroxyl radicals (around 54%). Comparatively higher ROS scavenging activities were recorded in hydroxyl radical and DPPH scavenging assays. DPPH radical scavenging activities were well correlated with the polyphenolic content. ROS scavenging and lipid peroxidation inhibition activities indicated that H. fusiformis might be a valuable natural antioxidative source containing both water and fatsoluble antioxidative components.

Superoxide, hydroxyl radical, and hydrogen peroxide effects on single-diaphragm fiber contractile apparatus

2001 ◽  
Vol 90 (1) ◽  
pp. 45-54 ◽  
Author(s):  
L. A. Callahan ◽  
Z. W. She ◽  
T. M. Nosek
Keyword(s):  
Reactive Oxygen Species ◽  
Hydrogen Peroxide ◽  
Hydroxyl Radical ◽  
Reactive Oxygen ◽  
Calcium Sensitivity ◽  
Oxygen Species ◽  
Contractile Apparatus ◽  
Skeletal Muscle Function ◽  
Bathing Medium ◽  
Specific Species

Reactive oxygen species contribute to diaphragm dysfunction in certain pathophysiological conditions (i.e., sepsis and fatigue). However, the precise alterations induced by reactive oxygen species or the specific species that are responsible for the derangements in skeletal muscle function are incompletely understood. In this study, we evaluated the effect of the superoxide anion radical (O2 −·), hydroxyl radical (·OH), and hydrogen peroxide (H2O2) on maximum calcium-activated force (Fmax) and calcium sensitivity of the contractile apparatus in chemically skinned (Triton X-100) single rat diaphragm fibers. O2 −· was generated using the xanthine/xanthine oxidase system; ·OH was generated using 1 mM FeCl2, 1 mM ascorbate, and 1 mM H2O2; and H2O2 was added directly to the bathing medium. Exposure to O2 −· or ·OH significantly decreased Fmax by 14.5% ( P < 0.05) and 43.9% ( P < 0.005), respectively. ·OH had no effect on Ca2+ sensitivity. Neither 10 nor 1,000 μM H2O2 significantly altered Fmax or Ca2+ sensitivity. We conclude that the diaphragm is susceptible to alterations induced by a direct effect of ·OH and O2 −·, but not H2O2, on the contractile proteins, which could, in part, be responsible for prolonged depression in contractility associated with respiratory muscle dysfunction in certain pathophysiological conditions.

317 RESISTANCE AGAINST DIFFERENT REACTIVE OXYGEN SPECIES IN BOVINE EPIDIDYMAL SPERM UNDER DISTINCT MATURATION STATUS

2010 ◽  
Vol 22 (1) ◽  
pp. 314
Author(s):  
M. Nichi ◽  
E. G. A. Perez ◽  
C. H. C. Viana ◽  
A. C. Teodoro ◽  
P. A. A. Goes ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Hydrogen Peroxide ◽  
Lipid Peroxidation ◽  
Hydroxyl Radical ◽  
Reactive Oxygen ◽  
Lipid Peroxidation Product ◽  
Oxygen Species ◽  
Epididymal Sperm ◽  
Mitochondrial Potential

Oxidative stress is caused by reactive oxygen species (ROS) that may cause structural damage to biomolecules, DNA, lipids, carbohydrates and proteins, as well as other cellular components. Evidence indicates that oxidation products are also deleterious to biological systems. Spermatozoa are particularly susceptible the oxidative stress, mainly due to the reduced cytoplasm and the high content of polyunsaturated fatty acids in its membrane. The mechanisms by which sperm acquire antioxidant capacity are still not completely elucidated. The aim was to study the resistance of sperm derived from different epididymal compartments (caudae and head) to the different ROS and to the lipid peroxidation product malondialdehyde (MDA). Epididymal sperm samples from 4 testicles were collected from the head and caudae epididymides. Sperm samples were then incubated (1 h, 37°C) with 4 ROS inducer mechanisms: xanthine/xanthine oxidase (produces superoxide anion), hydrogen peroxide (4 mM), ascorbate and ferrous sulfate (4 mM; produces hydroxyl radical), and MDA. Samples were analyzed for 3-3′ diaminobenzidine stain, as an index of mitochondrial activity; the eosin nigrosin stain, as an index of membrane integrity; the simple stain (fast green/Bengal rose), as an index of acrosome integrity; and the measurement of thiobarbituric acid reactive substances (TBARS), an index of lipid peroxidation. Statistical analysis was performed using the SAS System for Windows (SAS Institute Inc., Cary, NC, USA; least significant differences test and Pearson correlation). Results showed that immature sperm (head epididymides) were significantly more susceptible to the MDA and to the hydroxyl radical in all studied variables, especially acrosomes, membranes, and mitochondrial potential. Semen derived from the caudae epididymides was more susceptible to the hydrogen peroxide and to the MDA, especially regarding mitochondrial potential. In semen from the epididymal head, a positive correlation was found between TBARS and sperm showing no mitochondrial potential (r = 0.66, P = 0.01). On the other hand, negative correlations were found between TBARS and sperm with damaged acrosome and membrane (r = -0.63, P = 0.01 and r = -0.58, P = 0.02, respectively) in samples collected from the caudae epididymides. The present results suggest that sperm susceptibility to the attack of ROS is different throughout maturation. Although immature sperm are more susceptible to the hydroxyl radical, mature sperm are more susceptible to the hydrogen peroxide. Furthermore, MDA, a product of lipid peroxidation, is also deleterious to the sperm, indicating that once oxidative stress starts, further damage may be caused by their products. The authors thankNutricell for the media used in the experiment andFAPESP for financial support (process #06/05736-1).

320 SUSCEPTIBILITY OF GOAT SPERM TO DIFFERENT REACTIVE OXYGEN SPECIES

2010 ◽  
Vol 22 (1) ◽  
pp. 316
Author(s):  
R. O. C. Silva ◽  
E. G. A. Perez ◽  
R. P. Cabral ◽  
D. G. Silva ◽  
C. H. C. Viana ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Hydrogen Peroxide ◽  
Hydroxyl Radical ◽  
Semen Quality ◽  
Membrane Integrity ◽  
Reactive Oxygen ◽  
Mitochondrial Activity ◽  
Oxygen Species ◽  
Mitochondrial Potential ◽  
Acrosome Integrity

Semen quality is one of the main limiting factors for the success of artificial insemination in goats. It is well known that reactive oxygen species (ROS) lead to structural and functional damages to sperm, impairing or avoiding fecundation. The understanding of sperm oxidative mechanisms in goats may provide information on possible treatments to improve semen quality and fertility rates. The aim of the present study was to verify the resistance of goat spermatozoa to different reactive oxygen species. Sperm samples from 4 goats were collected using an artificial vagina. Sperm samples were then incubated (1 h, 37°C) with 4 ROS inducer mechanisms: xanthine/xanthine oxidase (produces superoxide anion), hydrogen peroxide (4 mM), ascorbate/ferrous sulfate (4 mM; produces hydroxyl radical), and malondialdehyde (MDA, lipid peroxidation product). Samples were analyzed for mitochondrial activity using the 3,3′ diaminobenzidine stain, for membrane integrity using the eosin/nigrosin staining, for acrosome integrity using the simple stain (fast green/Bengal rose), and for lipid peroxidation by dosing thiobarbituric acid reactive substances (TBARS). Results showed that goat sperm is more sensitive to hydrogen peroxide, when compared to superoxide anion, hydroxyl radical, and MDA, when considering acrosome integrity, membrane integrity, and mitochondrial potential (Table 1). On the other hand, TBARS production was increased in samples submitted to hydroxyl radical incubation. Strong negative correlations were found between sperm samples showing impaired mitochondrial potential and both membrane and acrosome integrity (r = -0.97, P < 0.0001 and r = -0.91, P < 0.0001, respectively). The concentration of TBARS correlated negatively with the percentage of sperm showing intact membranes (r = -0.53, P = 0.06), and the later correlated negatively with sperm showing no mitochondrial activity (r = -0.78, P = 0.0006). Results of the present experiment suggest that goat sperm are extremely susceptible to the attack of hydrogen peroxide, being resistant to other ROS. Therefore, an alternative to improve the use of goat semen in reproductive biotechnologies would be the treatment with catalase or glutathione peroxidase, important hydrogen peroxide scavengers. Table 1.Effect of different ROS on goat sperm The authors thank Nutricell for the media used in this experiment.

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...

A Novel pH-responsive Fe-MOF System for Enhanced Cancer Treatment Mediated by Fenton Reaction

2021 ◽  
Author(s):  
Senlin Wang ◽  
Hong-Shuai Wu ◽  
Kai Sun ◽  
Jinzhong Hu ◽  
Fanghui Chen ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Hydroxyl Radical ◽  
Cancer Treatment ◽  
Cell Apoptosis ◽  
Fenton Reaction ◽  
Reactive Oxygen ◽  
Cationic Polymer ◽  
Intracellular Reactive Oxygen Species ◽  
Oxygen Species ◽  
Ph Responsive

Recently, the toxic hydroxyl radical (·OH) has received wide interest in inducing cell apoptosis by increasing the intracellular reactive oxygen species (ROS) levels. Herein, a cationic polymer (MV-PAH) was rationally...

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 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
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