93 EFFECT OF ANTIOXIDANTS SUPPLEMENTATION ON THE QUALITY OF CRYOPRESERVED SPERM OF DOGS

2011 ◽  
Vol 23 (1) ◽  
pp. 152
Author(s):  
C. A. B. Sobrinho ◽  
M. Nichi ◽  
P. A. A. Góes ◽  
A. Dalmazzo ◽  
S. E. Crusco ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Vitamin E ◽  
Reactive Oxygen ◽  
The Other ◽  
Mitochondrial Activity ◽  
Enzymatic Antioxidants ◽  
Oxygen Species ◽  
Intact Membrane

One of the main causes of poor quality of frozen–thawed dog sperm is oxidative stress (i.e. higher production of reactive oxygen species not compensated by improved antioxidant protection). This event is known to impair sperm functionality by attacking plasma membrane, acrosome, mitochondria, and DNA. Spermatozoa are particularly susceptible the oxidative stress, mainly due to the reduced cytoplasm and the high content of polyunsaturated fatty acids (PUFA) in the membrane, which allows the spermatozoa to be motile and confers a higher resistance against the damages caused by cryopreservation, but makes the sperm more susceptible to the attack of the reactive oxygen species (ROS). The present study aimed to evaluate the effects of antioxidant supplementation on semen extender (Tris-egg yolk-citrate-glicerol) with glutathione (GSH) and vitamin E on the quality of cryopreserved dog sperm. Ejaculates of 12 dogs were divided in pools of 3 ejaculates with at least 70% of motility. Each pool was diluted with 7 different extenders for treatment groups as follows: control, vitamin E (1, 5, and 10 mM), and reduced glutathione (GSH; 1, 5, and 10 mM) and submitted to cryopreservation. Samples were thawed (37°C/30′) and evaluated for motility, vigor, percentage of sperm showing intact membrane (eosin/nigrosin), and acrosome (simple stain fast-green and bengal rose), mitochondrial activity (3–3′-diaminobenzidine-DAB), and sperm susceptibility to oxidative stress (TBARS). Statistical analyses were performed using the SAS system for Windows (SAS Institute Inc., Cary, NC, USA; least significant differences test and Spearman correlation; P < 0.05). Samples treated with 1 mM of GSH showed a higher percentage of sperm with intact membrane when compared with the control (11.21 ± 2.84 and 6.21 ± 1.16%, respectively; P < 0.05). On the other hand, treatment with 5 mM of GSH showed better results regarding mitochondrial activity. Vitamin E supplementation also played a protective role on mitochondrial activity; samples treated with 1 mM showed a lower percentage of DAB III sperm (cells with severely compromised mitochondrial activity) when compared with the control group (5.61 ± 0.7 and 8.62 ± 1.05%, respectively; P < 0.05). Both vitamin E and GSH are important non-enzymatic antioxidants responsible for the destruction of the hydroxyl radical. Despite the positive influence of these antioxidants on mitochondrial status, no effect was found on the other variables studied. These results indicate that the action of both antioxidants in dog sperm would be mainly intracellular. Furthermore, other ROS could be responsible for the other damages caused by cryopreservation on the other sperm functionalities (i.e. membrane, acrosome, DNA, oxidative status). Therefore, the use of a combination of enzymatic and non-enzymatic antioxidants could be an alternative to overcome the deleterious influence of oxidative stress in cryopreserved semen of dogs. The authors thank the Brazilian army for the dogs used in this study.

242 PROTECTIVE EFFECT OF VITAMIN E TREATMENT IN HEAT-STRESSED BOS TAURUS BULLS

2013 ◽  
Vol 25 (1) ◽  
pp. 269 ◽  
Author(s):  
V. H. Barnabe ◽  
R. C. Barnabe ◽  
P. Goes ◽  
E. G. A. Perez ◽  
J. D. A. Losano ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Heat Stress ◽  
Vitamin E ◽  
Bos Taurus ◽  
Semen Quality ◽  
Reactive Oxygen ◽  
Mitochondrial Activity ◽  
Oxygen Species ◽  
Tropical Conditions

Bos taurus bulls, when raised under tropical conditions, are highly susceptible to heat stress, which leads to impaired semen quality, leading to significant economical losses because, in these regions, the reproductive mounting season occurs mainly during the summer. Previous studies have indicated that oxidative stress (i.e. attack by reactive oxygen species) may be the main mechanism of sperm damage in such conditions. Therefore, treatment with antioxidants may be an important alternative to improve semen quality in heat-stressed B. taurus bulls. The objective of the present study was to evaluate whether the treatment with vitamin E, an important antioxidant, could improve sperm quality in insulated bulls. Towards this aim, eight adult Holstein bulls were submitted for semen collection, and the sperm was submitted for motility evaluation by computer-assisted sperm analysis (Ivos, Hamilton Thorne Inc., Beverly, MA, USA), examination of membrane and acrosomal integrity (eosin/nigrosin and fast green/bengal rose stain, respectively), mitochondrial activity (diaminobenzidine stain; full mitochondrial activity or no mitochondrial activity), and sperm susceptibility to oxidative stress (thiobarbituric acid-reactive substances). Bulls were then insulated (testicles covered in a thermal bag for 3 days) and randomly assigned to two treatment groups: no vitamin E (placebo) and vitamin E (subcutaneous injection of 3000 IU of α-tocopherol each of 10 days). Subsequent semen analysis was performed 1 and 60 days after the insulation. Statistical analysis was performed with SAS (SAS Institute Inc., Cary, NC, USA) repeated-measures ANOVA, and significance of P < 0.05 was adopted. No differences were found on any of the variables before insulation. One day after insulation, animals treated with vitamin E showed a lower percentage of static sperm and a higher percentage of motile sperm when compared with animals treated with the placebo (28 and 63% v. 56 and 34%, respectively; P < 0.05). Also at this time, sperm susceptibility to oxidative stress was lower in animals treated with vitamin E (vitamin E: 410 ng/106 sperm; no vitamin E: 1760 ng/106 sperm; P < 0.05). Sixty days after insulation, sperm susceptibility to oxidative stress was still lower in animals treated with vitamin E when compared with the placebo group (1176 and 192 ng/106 sperm, respectively; P < 0.05). However, no differences were found on the other variables. Results indicate that vitamin E, an antioxidant whose main function is protection of the plasma membrane, may be an alternative to avoid the acute deleterious effects of the heat stress in B. taurus bulls raised under tropical conditions. In addition, even with no heat stress involved, vitamin E treatment may provide constant protection, increasing the resistance of the sperm against the reactive oxygen species.

scholarly journals Vitamin E Delivery Systems Increase Resistance to Oxidative Stress in Red Deer Sperm Cells: Hydrogel and Nanoemulsion Carriers

Antioxidants ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1780
Author(s):  
Alejandro Jurado-Campos ◽  
Pedro Javier Soria-Meneses ◽  
Francisca Sánchez-Rubio ◽  
Enrique Niza ◽  
Iván Bravo ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Lipid Peroxidation ◽  
Vitamin E ◽  
Reactive Oxygen ◽  
Mitochondrial Activity ◽  
Sperm Cells ◽  
Oxygen Species ◽  
New Formulation ◽  
Species Production

Oxidative stress has become a major concern in the field of spermatology, and one of the possible solutions to this acute problem would be the use of antioxidant protection; however, more studies are required in this field, as highly contradictory results regarding the addition of antioxidants have been obtained. Vitamin E is a powerful biological antioxidant, but its low stability and high hydrophobicity limit its application in spermatology, making the use of organic solvents necessary, which renders spermatozoa practically motionless. Keeping this in mind, we propose the use of hydrogels (HVEs) and nanoemulsions (NVEs), alone or in combination, as carriers for the controlled release of vitamin E, thus, improving its solubility and stability and preventing oxidative stress in sperm cells. Cryopreserved sperm from six stags was thawed and extended to 30 × 106 sperm/mL in Bovine Gamete Medium (BGM). Once aliquoted, the samples were incubated as follows: control, free vitamin E (1 mM), NVEs (9 mM), HVEs (1 mM), and the combination of HVEs and NVEs (H + N), with or without induced oxidative stress (100 µM Fe2+/ascorbate). The different treatments were analyzed after 0, 2, 5, and 24 h of incubation at 37 °C. Motility (CASA®), viability (YO-PRO-1/IP), mitochondrial membrane potential (Mitotracker Deep Red 633), lipid peroxidation (C11 BODIPY 581/591), intracellular reactive oxygen species production (CM-H2DCFDA), and DNA status (SCSA®) were assessed. Our results show that the deleterious effects of exogenous oxidative stress were prevented by the vitamin E-loaded carriers proposed, while the kinematic sperm parameters (p ˂ 0.05) and sperm viability were always preserved. Moreover, the vitamin E formulations maintained and preserved mitochondrial activity, prevented sperm lipid peroxidation, and decreased reactive oxygen species (ROS) production (p ˂ 0.05) under oxidative stress conditions. Vitamin E formulations were significantly different as regards the free vitamin E samples (p < 0.001), whose sperm kinematic parameters drastically decreased. This is the first time that vitamin E has been formulated as hydrogels. This new formulation could be highly relevant for sperm physiology preservation, signifying an excellent approach against sperm oxidative damage.

scholarly journals Redox Regulation and Oxidative Stress: The Particular Case of the Stallion Spermatozoa

Antioxidants ◽  
2019 ◽  
Vol 8 (11) ◽  
pp. 567 ◽  
Author(s):  
Fernando J. Peña ◽  
Cristian O’Flaherty ◽  
José M. Ortiz Rodríguez ◽  
Francisco E. Martín Cano ◽  
Gemma L. Gaitskell-Phillips ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Redox Regulation ◽  
Redox Homeostasis ◽  
Reactive Oxygen ◽  
Mitochondrial Activity ◽  
Oxygen Species ◽  
Redox Biology ◽  
Major Interest ◽  
And Oxidative Stress

Redox regulation and oxidative stress have become areas of major interest in spermatology. Alteration of redox homeostasis is recognized as a significant cause of male factor infertility and is behind the damage that spermatozoa experience after freezing and thawing or conservation in a liquid state. While for a long time, oxidative stress was just considered an overproduction of reactive oxygen species, nowadays it is considered as a consequence of redox deregulation. Many essential aspects of spermatozoa functionality are redox regulated, with reversible oxidation of thiols in cysteine residues of key proteins acting as an “on–off” switch controlling sperm function. However, if deregulation occurs, these residues may experience irreversible oxidation and oxidative stress, leading to malfunction and ultimately death of the spermatozoa. Stallion spermatozoa are “professional producers” of reactive oxygen species due to their intense mitochondrial activity, and thus sophisticated systems to control redox homeostasis are also characteristic of the spermatozoa in the horse. As a result, and combined with the fact that embryos can easily be collected in this species, horses are a good model for the study of redox biology in the spermatozoa and its impact on the embryo.

scholarly journals Zinc Nutritional Status on Physiological and Nutritional Indicators, Metabolism of Oxidative Stress, Yield and Fruit Quality of Pecan Tree

2018 ◽  
Vol 47 (2) ◽  
pp. 531-537
Author(s):  
Damaris OJEDA-BARRIOS ◽  
Jorge CASTILLO-GONZALEZ ◽  
Adriana HERNANDEZ-RODRIGUEZ ◽  
Javier ABADIA ◽  
Estaban SANCHEZ ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Superoxide Dismutase ◽  
Nutritional Status ◽  
Zinc Deficiency ◽  
Fruit Quality ◽  
Reactive Oxygen ◽  
The United States ◽  
Oxygen Species

In the United States of America and in Mexico, zinc deficiency is a common nutritional disorder in pecan trees [Carya illinoinensis (Wangenh.) C. Koch], especially in calcareous soils. This study in Chihuahua, northern Mexico, analyses the effects of zinc nutritional status on various physiological and nutritional indicators, on the metabolism of oxidative stress, and on the yield and fruit quality of pecan. The aim was to identify possible bioindicators of soil zinc deficiency. The experimental design was completely randomized with four nutritional conditions with respect to zinc: a control and three levels of zinc deficiency - slight, moderate and severe. Zinc deficiency is characterised by small leaves with interveinal necrosis and rippled leaf margins. The lowest values of leaf area, SPAD values, total N and NO3 concentration were observed under conditions of severe zinc deficiency. With worsening zinc deficiency, results indicate an increased enzymatic activity of superoxide dismutase, catalase and glutathione peroxidase. Interestingly, under severe zinc deficiency there are decreases in trunk cross-sectional area growth, in yield and in percentage kernel. Increased activity of superoxide dismutase, catalase and peroxidase enzymes is associated with detoxification of reactive oxygen species. The activity of enzymes detoxifying reactive oxygen species lessens the negative effects of zinc deficiency stress, and may be good bioindicators of zinc deficiency and its visual symptoms on pecan trees.

232 INFLUENCE OF SEMINAL PLASMA ON THE SUSCEPTIBILITY OF DOG SPERM AGAINST DIFFERENT REACTIVE OXYGEN SPECIES

2011 ◽  
Vol 23 (1) ◽  
pp. 215
Author(s):  
A. Dalmazzo ◽  
P. A. A. Góes ◽  
M. Nichi ◽  
R. O. C. Silva ◽  
J. R. C. Gurgel ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Lipid Peroxidation ◽  
Hydroxyl Radical ◽  
Seminal Plasma ◽  
Superoxide Anion ◽  
The Other ◽  
Mitochondrial Activity ◽  
Oxygen Species ◽  
Acrosome Integrity

Due to the importance of dogs to humans, there is increasing interest in breeders in the use of reproductive biotechnologies. However, most of the biotechnologies would require the removal or dilution of the seminal plasma, which is known to exert both beneficial and deleterious effects on sperm quality. One of the beneficial effects of seminal plasma would be the antioxidant protection because sperm are particularly susceptible to oxidative stress, mainly due to the reduced cytoplasm and the high content of polyunsaturated fatty acids in their membrane. An alternative to overcome the injuries caused by oxidative stress is the antioxidant treatment, which requires the identification of those reactive oxygen species (ROS) that are the most deleterious. The aim of this study was to identify the most harmful ROS to dog semen. Semen samples from 6 adult dogs were collected and centrifuged. Seminal plasma (SP) was removed and samples were incubated (1 h, 37°C) with 4 ROS-inducing mechanisms: xanthine/xanthine oxidase (produces superoxide anion), hydrogen peroxide (4 mM), ascorbate and ferrous sulfate (4 mM; produces hydroxyl radical) alone or with additional SP. Samples were analysed for motility by computer assisted sperm analysis (CASA). The 3-3′ diaminobenzidine stain was used 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, sperm chromatin structure assay (SCSA) as an index of DNA fragmentation, and measurement of thiobarbituric acid reactive substances (TBARS) as 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 Spearman correlation; P < 0.05). Results showed that dog sperm is differentially modulated depending on the presence of SP. In addition, damage to the different sperm structures depended on the different ROS. Samples incubated with SP showed no differences concerning TBARS (1 233 in SP, 1 260 in Tris; P = 0.99). On the other hand, samples incubated without SP showed higher lipid peroxidation when treated with hydroxyl radical compared with the other ROS. Furthermore, although hydroxyl radical mostly altered mitochondrial activity in samples incubated with SP (DAB IV = 4.3%; P < 0.05 against all other ROS), the most significant ROS in samples incubated without SP was hydrogen peroxide (DAB IV = 4.7%; P < 0.05 against all other ROS). Superoxide anion was less harmful to acrosome integrity in samples incubated with SP and to motility in samples incubated without SP. The present results suggest that seminal plasma may play an important role in the susceptibility of dog sperm to oxidative stress. Moreover, the results indicate that different sperm compartments are susceptible to different ROS. It is concluded that the quality of frozen–thawed dog semen may be improved by treating with a combination of different antioxidants to destroy the chain reaction causing the oxidative stress. FAPESP is acknowledged for financial support.

139 Effect of lycopene supplementation in maturation medium on production of reactive oxygen species and post-vitrification quality of bovine blastocysts

2021 ◽  
Vol 33 (2) ◽  
pp. 177
Author(s):  
S. Sidi ◽  
O. B. Pascottini ◽  
D. Angel-Velez ◽  
N. A. Dolatabad ◽  
G. Residiwati ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Oocyte Maturation ◽  
Embryo Quality ◽  
Reactive Oxygen ◽  
Quality Parameters ◽  
Differential Staining ◽  
Oxygen Species ◽  
Fluorescent Intensity

Excessive production and accumulation of reactive oxygen species (ROS) may cause embryo damage associated with oxidative stress. Lycopene, a natural antioxidant, can scavenge singlet oxygen and is one of the most effective antioxidants among carotenoids. We evaluated the effects of supplementation of lycopene (antioxidant), menadione (prooxidant), and their combination during invitro oocyte maturation on ROS generation in matured oocytes and the quality of vitrified-warmed embryos. Cumulus–oocyte complexes, collected from the slaughterhouse, were matured in groups of 60 in 500μL of TCM-199 medium+50mg mL−1 gentamycin+20ng mL−1 epidermal growth factor, for 22h at 38.5°C in 5% CO2 in air and then supplemented with (1) 0.2μM lycopene, (2) 5μM menadione, (3) 0.2μM lycopene+5μM menadione (L+M), or (4) not supplemented (control). Fertilization and embryo culture were performed similarly for all the groups. In the first experiment, ROS measurement (n=236; via fluorescent microscopy) was performed in denuded, matured oocytes incubated in 5μM CellROX® Green (ThermoFisher Scientific) for 1h. Fluorescent intensity was measured in Image-J. In the second experiment, embryos in the blastocyst stage (n=143) were vitrified as previously described by Ortiz-Escribano et al. (2017 Biol. Reprod. 96, 288-301). Vitrified blastocysts were then warmed and washed in decreasing concentrations of sucrose and incubated for 2 days in culture medium [50µL of synthetic oviductal fluid (SOF)+(5g mL−1 insulin, 5g mL−1 transferrin, 5ng mL−1 selenium)]. The quality of vitrified-warmed blastocysts was assessed using a differential staining as described by Wydooghe et al. (2011 Anal. Biochem. 416, 228–230). The effects of pro- and antioxidant supplementation on oocyte fluorescent intensity and embryo quality parameters were fitted in linear mixed-effects models, and results are expressed as least squares means and standard errors. The fluorescent intensity for ROS was lower (P&lt;0.05) in lycopene (10.06±2.92) than in menadione (16.8±2.92). No differences (P&gt;0.05) in ROS intensity values were found among the other groups [control (13.5±2.92) and L+M (13.7±2.90)]. Total cell number (TCN) was similar (P&gt;0.05) in lycopene (153±2.95), L+M (143±4.59), and control (145±3.67) but lower (P&lt;0.05) in menadione (134±6.08). Lesser numbers of apoptotic cells (AC) and AC/TCN values (P&lt;0.05) were recorded in lycopene (4.12±3.07 and 2.71±2.21) compared with control (6.18±3.82 and 4.31±2.75), L+M (6.00±4.79 and 4.22±3.45), and menadione (7.75±6.33 and 5.82±4.56). For the remaining embryo quality parameters, no differences were found (P&gt;0.05). In conclusion, lycopene supplementation during invitro oocyte maturation effectively scavenged free radicals, lowering oxidative stress and improving embryo quality post-vitrification and warming.

scholarly journals Antioxidants Maintain Cellular Redox Homeostasis by Elimination of Reactive Oxygen Species

2017 ◽  
Vol 44 (2) ◽  
pp. 532-553 ◽  
Author(s):  
Long He ◽  
Ting He ◽  
Shabnam Farrar ◽  
Linbao Ji ◽  
Tianyi Liu ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Critical Role ◽  
Reactive Oxygen ◽  
Signaling Molecules ◽  
Antioxidant Systems ◽  
Enzymatic Antioxidants ◽  
Oxygen Species ◽  
Cytochrome P450 Enzymes ◽  
Cell Death Pathway

Reactive oxygen species (ROS) are produced by living cells as normal cellular metabolic byproduct. Under excessive stress conditions, cells will produce numerous ROS, and the living organisms eventually evolve series of response mechanisms to adapt to the ROS exposure as well as utilize it as the signaling molecules. ROS molecules would trigger oxidative stress in a feedback mechanism involving many biological processes, such as apoptosis, necrosis and autophagy. Growing evidences have suggested that ROS play a critical role as the signaling molecules throughout the entire cell death pathway. Overwhelming production of ROS can destroy organelles structure and bio-molecules, which lead to inflammatory response that is a known underpinning mechanism for the development of diabetes and cancer. Cytochrome P450 enzymes (CYP) are regarded as the markers of oxidative stress, can transform toxic metabolites into ROS, such as superoxide anion, hydrogen peroxide and hydroxyl radical which might cause injury of cells. Accordingly, cells have evolved a balanced system to neutralize the extra ROS, namely antioxidant systems that consist of enzymatic antioxidants such as superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidases (GPxs), thioredoxin (Trx) as well as the non-enzymatic antioxidants which collectively reduce oxidative state. Herein, we review the recent novel findings of cellular processes induced by ROS, and summarize the roles of cellular endogenous antioxidant systems as well as natural anti-oxidative compounds in several human diseases caused by ROS in order to illustrate the vital role of antioxidants in prevention against oxidative stress.

scholarly journals Oxidative stress, reactive oxygen species, antioxidants: a review

2018 ◽  
Vol 29 (1) ◽  
pp. 52-55
Author(s):  
Y. S. Voronkova ◽  
O. S. Voronkova ◽  
V. A. Gorban ◽  
K. K. Holoborodko
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Treatment Options ◽  
Reactive Oxygen ◽  
Natural Aging ◽  
Dietary Factors ◽  
Enzymatic System ◽  
Enzymatic Antioxidants ◽  
Oxygen Species ◽  
Small Molecular Weight

Oxidative stress is a disturbance of the balance between the production of reactive oxygen species (ROS) and antioxidants. Oxidative stress is caused by the presence of any of a number of reactive oxygen species, which the cell is unable to counterbalance. The result is damage to one or more biomolecules including DNA, RNA, proteins and lipids. Oxidative stress has been implicated in the natural aging process as well as a variety of disease states, such as neoplastic, metabolic, neurological etc., accompanied by different complications. Risk factors of generation of oxidative stress are oxidizing species, induced by pathologies include alcohol consumption, cigarette smoking, diet, gender, geographic location specifically at high altitude and occupation. ROS are composed of superoxide, hydroxyl, peroxyl, hydroperoxyl and alkoxyl radicals, hydrogen peroxide and singlet oxygen and ozone. These compounds produced endogenous in reaction of autooxidation in respiratory chaine of bioobjects. Among exogenous sources of ROS can be listed exposure of pollutants, toxins, heavy metals, drugs with different chemical origin and effects, radiation, electromagnetic fields, alcohol, cigarette smoke, stresses, allergies, dietary factors, temperature and microscopic form of life, such as bacteria, yeasts, viruses etc. The oxidative stress in biological systems is often characterized by increase in the formation of radicals; decrease in small-molecular-weight and lipid soluble antioxidants; disturbance in cellular redox balance; oxidative damage to cellular components (biomacromolecules). The presence of oxidative stress may be tested in one of three ways: direct measurement of the ROS; measurement of the resulting damage to biomolecules; and detection of antioxidant levels. Directly measuring ROS might seem the preferred method, but many reactive oxygen species are extremely unstable and difficult to measure directly. Many markers of damage are extremely stable and therefore provide a more reliable method to measure oxidative stress. Another approach is to measure the levels of antioxidant enzymes and other redox molecules which serve to counterbalance ROS generated in the cell. At the same time, it must emphasize that oxidative stress not only has a cytotoxic effect, but also plays an important role in the modulation of messengers that regulate essential cell membrane functions, which are vital for survival. For prevention of oxidative stress cells produce or uptake antioxidants – substance significantly delays or prevents oxidation of that substrate. Antioxidants may be enzymatic and non-enzymatic in nature in which enzymatic system directly or indirectly help in defence against the ROS. Antioxidants are involved in the prevention of oxidants and ROS formation; exhibits scavenger of ROS; and repairs the oxidized molecules through sources like dietary or consecutive antioxidants. Among non-enzymatic antioxidants distinguished glutathione, α-tocopherol, ascorbic acid, beta-carotene, and uric acid; these are mostly considered to be chain-breaking antioxidants in that they interrupt the auto-catalytic spread of radical reactions. Among enzymatic antioxidants most known superoxide dismutase, catalase, glutathione-SH peroxidase. The significant correlation found between ROS, parameters of oxidative stress and pathology indicate that there is a need in finding of measures of prevention of endo- and exogenous factors provoke their generation. There is a need to continue to explore the relationship between free radicals, pathological processes and the complications of them, and to elucidate the mechanisms by which increased oxidative stress accelerates the development of complications, in an effort to expand treatment options. Improvement of complications control seems to be a beneficial factor to decrease oxidative stress. For a better investigation of oxidative stress, it would be wise to supplement the clinical research by determination of special products typical for oxidative stress that let to understand mechanism of some pathological processes more clearly.

Clinical aspects of reactive oxygen and nitrogen species

2004 ◽  
Vol 71 ◽  
pp. 121-133 ◽  
Author(s):  
Ascan Warnholtz ◽  
Maria Wendt ◽  
Michael August ◽  
Thomas Münzel
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Risk Factor ◽  
Endothelial Dysfunction ◽  
Vascular Tissue ◽  
Rapid Development ◽  
Reactive Oxygen ◽  
Clinical Aspects ◽  
No Production ◽  
Oxygen Species

Endothelial dysfunction in the setting of cardiovascular risk factors, such as hypercholesterolaemia, hypertension, diabetes mellitus and chronic smoking, as well as in the setting of heart failure, has been shown to be at least partly dependent on the production of reactive oxygen species in endothelial and/or smooth muscle cells and the adventitia, and the subsequent decrease in vascular bioavailability of NO. Superoxide-producing enzymes involved in increased oxidative stress within vascular tissue include NAD(P)H-oxidase, xanthine oxidase and endothelial nitric oxide synthase in an uncoupled state. Recent studies indicate that endothelial dysfunction of peripheral and coronary resistance and conductance vessels represents a strong and independent risk factor for future cardiovascular events. Ways to reduce endothelial dysfunction include risk-factor modification and treatment with substances that have been shown to reduce oxidative stress and, simultaneously, to stimulate endothelial NO production, such as inhibitors of angiotensin-converting enzyme or the statins. In contrast, in conditions where increased production of reactive oxygen species, such as superoxide, in vascular tissue is established, treatment with NO, e.g. via administration of nitroglycerin, results in a rapid development of endothelial dysfunction, which may worsen the prognosis in patients with established coronary artery disease.

Sign in / Sign up

Export Citation Format

Share Document