OXYGEN AND OXIDATION
Oxygen – essential, versatile, and basic yet complex – the atom and molecules of oxygen are part of all we are, yet so few of us know just how it works to our benefit, or the unavoidable consequences that accompany it.
It can be responsible for life and death, generation and degeneration, composition and decomposition, oxygenation and oxidation. Life revolves around the never-ending rotation and balance of too much, or not enough oxygen.
THE IMPORTANCE OF OXYGEN
There is clear understanding that oxygen management requires a delicate balance for benefits to be maintained and to avoid toxicity and its consequences. This balance can take many forms and is part of many combinations for differing molecular compositions, inevitably inducing different results of biological function, all of which are continuously at play and paramount with regard to the order of the world, as we know it.
Making up just under 21% of the earths atmosphere, and being a relatively heavy gas, it sits low in the atmosphere and when attached to a couple of hydrogen atoms, it sits even lower as water – the ultimate liquid that is responsible for all life on earth. This essential form of both hydrogen and oxygen (H2O) is balanced, stable and abundant, however life also needs both elements separately to facilitate the different roles and chemical reactions that enable and manage both life and death.
This ultimately leads us to what is referred to as the REDOX Theory – Reduction & Oxidation.
Dioxygen, or molecular oxygen, is the form of oxygen that most of us are familiar with. It provides the energy released in both combustion and aerobic cellular respiration, as well as in the many major classes of organic molecules in living organisms that contain oxygen atoms, such as proteins, nucleic acids carbohydrates and fats. Cellular respiration using O2 enables aerobic organisms to produce much more ATP (cellular energy) than anaerobic organisms. The cellular respiration of O2 occurs in all eukaryotes, including all complex multicellular organisms such as plants and animals.
Throughout the environment oxygen is always being consumed, but it is too chemically reactive to remain a free element in the air without being continuously replenished by the photosynthetic action of organisms, which use the energy of sunlight to produce oxygen from water and carbon dioxide. In nature, free oxygen is produced by the light-driven splitting of water during photosynthesis. Putting the carbon back into the ground or plant and releasing the oxygen back into the air to be used again, should be a major objective for all of us considering the current state of our atmosphere.
In the aerobic organism, the chemical energy of oxygen is released in mitochondria to generate ATP during oxidative phosphorylation, with the reaction for aerobic respiration essentially being the reverse of photosynthesis. Reactive oxygen species (ROS), such as superoxide ion (O−2) and hydrogen peroxide (H2O2), are reactive by-products of oxygen use in organisms. Parts of the immune system of higher organisms create peroxide, superoxide, and singlet oxygen to destroy invading microbes. Reactive oxygen species also play an important role in the response of plants against pathogen attacks.
Oxygen is damaging to anaerobic organisms, which were the dominant form of early life on Earth until O2 began to accumulate in the atmosphere about 2.5 billion years ago during the Great Oxygenation Event. When we are well and oxygen-rich we represent a less favourable environment to an anerobic organism, in the same way as the anaerobic environment is unfavourable or toxic to us. This unfavourable environment bias makes it hard for that organism to survive and hinders the ability for it to thrive and replicate to a dangerous level.
Generally speaking, aerobic organisms cannot live in an anerobic environment just as anerobic organisms cannot live in an aerobic environment. There are of course varying severities of this concept that are relevant depending on degree however, aspects of immunity strength correlates strongly with this very principal.
Oxygen is required for life, but it’s a fine balance – too much can cause death, not enough can also result in death, and low levels will promote susceptibility to bacterial, viral, anerobic and oxidative attacks or consequences. Oxygen is imperative in the energy creation processes for an enormous number of organisms, however its use results in the creation of by-products (or species) that in turn need to be managed. It is highly reactive and is an oxidizing agent that readily forms oxides with most elements as well as with other compounds. Having enough oxygen to enable cellular respiration and energy creation is vital, but so is the management of the resulting oxidative species.
Oxidative stress is an inescapable component of all
aerobic life – it affects virtually all living things!
Oxidative stress reflects an imbalance between the
systemic manifestation of reactive oxygen species
and a biological system's ability to readily detoxify
the reactive intermediates or to repair the resulting
damage.
THE WORLD NEED SOLUTIONS TO MANAGE OXIDATIVE STRESS
Oxidative stress is simply a state of unmanaged oxidation, with oxidative stress being referred to as the root cause of well over 170 different dis-eases or ailments across many species.
Nature’s problems need nature’s solutions. Synthetic intervention will only address the symptoms, but will not rectify the root cause at the cellular redox level. It’s like trying to use a watering can to put out a wildfire – sure you might make a splash, but it won’t get the job done. The key is for the organism in question to be able to keep up and maintain the necessary balance in the first place. A natural, clean environment will mean that the organism should be able to keep up by natural internal means, however, we no longer have a natural clean environment.
Depending on the circumstances or the environmental challenges an organism needs to endure, it still needs to provide or ingest its own supply of anti- oxidants for survival in order to achieve cellular respiration in animal and aquatic type species, as well as photosynthesis and microbial soil health for plants. The overall health of any organism will be directly associated with this essential function.
Ensuring that an organism is able to produce its own supply of anti-oxidants, or assisting it with supplementation, oxidative stresses can be managed and the resulting dis-ease potential reduced. The inability to do this manifests into a multitude of examples that cost industry and governments trillions of dollars annually and causes significant distress the world over.
As we now know, disturbances in the normal redox state of cells can cause toxic effects through the production of oxidative species and free radicals that damage all components of the cell, including proteins, lipids, and DNA. Oxidative stress from oxidative metabolism causes base damage, as well as strand breaks in DNA. The base damage is mostly indirect and is caused by the reactive oxygen species (ROS) generated, e.g. O2− (superoxide radical), OH (hydroxyl radical) and H2O2 (hydrogen Peroxide). Furthermore, as some reactive oxidative species act as cellular messengers in redox signalling, oxidative stress can also cause disruptions in the normal mechanisms of cellular signalling.
“Oxidative stress is an inescapable component of all aerobic life”
In a healthy aerobic organism, there exists a balance between the ‘Reactive Oxygen Species’ (ROS) production and the system’s ability to protect cells from ROS. An increase of ROS production results in defects that may cause damage or death to the cell or organism. This imbalance is referred to as oxidative stress.
Reactive Oxygen Species 1
Reactive Oxygen Species 2
Reactive Oxygen Species 3
Reactive Oxygen Species 4
SOME OXIDATIVE INSIGHTS...
Oxidation is any chemical reaction that involves the moving or transport of electrons. Specifically, it means a substance that gives away or loses electrons is oxidized. A familiar example of this is the reaction between the substance iron and oxygen. When iron reacts with oxygen it forms a chemical called rust, which happens because the iron has been oxidized and the oxygen has been reduced (that is, the iron has lost some electrons and the oxygen has gained some electrons).
Oxidation is the opposite of reduction and a reduction-reaction always comes together with an oxidation-reaction. Oxidation and reduction together are called redox reactions (reduction and oxidation). Oxygen specifically does not always have to be present in a reaction for it to be a redox-reaction but they are ever present in biological functions and processes. Generally speaking – Oxidation is the loss of electrons and reduction is the gain of electrons. Both reduction and oxidation go on at the same time, which is a redox-reaction.
Redox is a type of chemical reaction in which the oxidation states of atoms are changed. Redox reactions are characterized by the formal transfer of electrons between chemical species, most often with one species (the reducing agent) undergoing oxidation (it loses electrons), whilst another species (the oxidizing agent) undergoes reduction (gains electrons). The chemical species from which the electron is removed is said to have been oxidized, while the chemical species to which the electron is added is said to have been reduced.
• Oxidation is the loss of electrons or an increase in the oxidation state of an atom, an ion, or of certain atoms in a molecule.
• Reduction is the gain of electrons or a decrease in the oxidation state of an atom, an ion, or of certain atoms in a molecule.
Although oxidative reactions are commonly associated with the formation of oxides from oxygen molecules, oxygen is not necessarily included in all such reactions, as other chemical species often serve the same function. This is expressed throughout nature in many different ways and across a broad range of elements.
Some redox reactions can occur slowly, as in the formation of rust, or much more rapidly, as in the case of burning fuel. There are simple redox processes such as the oxidation of carbon to yield carbon dioxide (CO2) or the reduction of carbon by hydrogen to yield methane (CH4), and there are of course more complex processes such as the oxidation of glucose (C6H12O6) in the human body.
Ozone is a highly oxidative oxygen molecule with the symbol O3. This means one molecule of ozone is made of three oxygen atoms. Ozone is formed from oxygen gas (O2) by the action of ultraviolet light and also atmospheric electrical discharges. It is a completely natural molecule and is present in low concentrations throughout the Earth’s atmosphere. In total, ozone makes up only 0.6 ppm (parts per million) of the atmosphere by volume. Ozone is important to life on planet Earth.
There is a portion of the stratosphere with a high concentration of ozone, called the ozone layer. The ozone layer filters out damaging ultraviolet radiation from the Sun, like a kind of sunscreen. Without this ozone layer things would not be able to live on the surface of our planet. The ozone layer also absorbs a lot of heat from the sun’s rays. However, due to its highly oxidative nature in certain concentrations ozone is toxic to animals, aquatic species and plants. Ozone sanitation is rapidly becoming a popular cleaning agent as it kills a broad range of bacteria, pathogens, and viruses. It is a natural element and will neutralise quickly leaving no chemical residues or odour.
When it comes to biology, these oxidative processes are happening all the time and the biological system is always oxidising other than for its ability to produce and supply itself with antioxidants. If that biological system was to die it would oxidise quickly, and the word we use for that is decomposing.
Aging is a word we use that could ultimately be defined as oxidising slowly, and another biological term commonly used being oxidative stress, simply describes an unmanaged state of oxidation. Homeostasis is the balanced functioning of an organism that is said to be at ease, and the more imbalanced or oxidised something is, will ultimately result in dis-ease and will generally manifest at a weak point in that body.
The mechanics of life exist at a molecular and cellular level utilising an electron transport chain that ultimately results in an oxidative process, which then needs to be reduced by antioxidants. Everything depends on it.
As the oxygen is used there are reactive results that produce reactive oxygen species and free radicals – some good and some bad – and ultimately they all need to be reduced and bought back into balance at some stage. This is where the redox theory comes into play as a reductant needs to be able to donate the electron required to act as the anti-oxidant in order to bring back balance following the oxidation created from the consumption of the oxygen.
Increased performance of a particular organism for example, is directly linked to the increased use of oxygen and while increasing the ability to create energy is fine in most cases, it is only as long as the organism has the ability to manage the resulting by-products produced as a result. This is a fundamental requirement of life and one that cannot be avoided.
It can be likened to a car in that the fuel in the engine is burned to create energy but there is an exhaust that is emitted as a result (the by-product). Animals cannot just vent such a by-product out to the atmosphere. Oxygen and glucose is the fuel, and the reactive oxygen species are the exhaust. If a body cannot clean up that exhaust (oxidation) then it will result in an overload or stress, as in oxidative stress. Oxidative stress then can create all sorts of issues and weaknesses that eventually manifest as some sort of dis-ease at a weak point in the body.
SCIENCE AND
APPLICATIONS
AN OVER VIEW OF OXIDATIVE
STRESS - 2012
The oxidative process that is regularly goes on in a cell is essential for the life and death of a cell. The following are the important key points taken into consideration for this process:
- Molecular oxygen has the ability to un-pair and leave free radicals which are unstable.
- This unstable radical is highly reactive and causes formation of reactive oxygen species.
- Beneficial biological functions such as apoptosis, necrosis, phagocytosis are mediated by reactive oxygen species.
- These reactive metabolites are selectively neutralized by a body's defensive mechanism.
- Principal defensive agents are antioxidant enzymes and endogenous antioxidants.
- Balance is created between pro-oxidants and antioxidants within a cell, and any impairment in equilibrium causes deleterious effects on the cell's life.
It is known that the unpaired electron of molecular oxygen reacts to form highly reactive species, which are known as reactive oxygen species. Reactive oxygen species are generated from enzymatic and non-enzymatic sources.
Oxidative Stress: Molecular Perception and Transduction of Signals Triggering Antioxidant Gene Defences - 2005
The survival of organisms on earth depends upon the interactions of their genomes with the environments in which they exist. In the course of evolution, organisms evolved a complex array of mechanisms for adapting to both minor and major fluctuations in the environment. The emergence of oxygenic photosynthesis presented early life forms with the greatest environmental challenge as well as opportunity. The challenge was to develop antioxidant defences in order to survive; the opportunity was to exploit the reactivity of oxygen for energy yielding and biosynthetic reactions. The opportunity led to highly diversified life forms that evolved sufficient defences and managed to exploit the aerobic lifestyle.
Oxygen toxicity likely led to massive extinctions of those organisms unable to cope with it, unless they took refuge in isolated anaerobic niches. Thus, oxygen is a “double-edged sword” in that it makes life on earth possible, but in its reduced forms (ROS), it is highly toxic and lethal. Oxidative stress arises from an imbalance between generation and elimination of ROS, leading to excess ROS levels inflicting indiscriminate damage to virtually all biomolecules, which leads in turn to various diseases and cell death. Redox regulation of gene expression by oxidants and antioxidants is emerging as a vital mechanism in the health and disease of all organisms.
The Roles of Environmental Factors in Regulation of
Oxidative Stress in Plants - 2019
Exposure to a variety of environmental factors such as salinity, drought, metal toxicity, extreme temperature, air pollutants, ultraviolet-B (UV-B) radiation, pesticides, and pathogen infection leads to subject oxidative stress in plants, which in turn affects multiple biological processes via reactive oxygen species (ROS) generation. ROS include hydroxyl radicals, singlet oxygen, and hydrogen peroxide in the plant cells and activates signalling pathways leading to some changes of physiological, biochemical, and molecular mechanisms in cellular metabolism.
Excessive ROS, however, causes oxidative stress as a state of imbalance between the production of ROS and the neutralization of free radicals by antioxidants, resulting in damage of cellular components including lipids, nucleic acids, metabolites, and proteins, which finally leads to the death of cells in plants. Thus, maintaining a physiological level of ROS is crucial for aerobic organisms, which relies on the combined operation of enzymatic and nonenzymatic antioxidants.
In order to improve plants’ tolerance towards the harsh environment, it is vital to reinforce the comprehension of oxidative stress and antioxidant systems. In this review, recent findings on the metabolism of ROS as well as the antioxidative defence machinery are briefly updated. The latest findings on differential regulation of antioxidants at multiple levels under adverse environment are also discussed here.
The Growing Threat that Salinity Poses to Global Food Production
Irrigation plays an important role in food production, as it helps the world to keep pace with increased food demand associated with increasing populations. Irrigation is used on 20 per cent of the world’s cropland but helps to produce 40 per cent of the world’s food. Irrigated agriculture is likely to play an even larger role in global food security, as about half to two-thirds of future gains in crop production are expected to come from irrigated land.
With the growing use of irrigation as a method to achieve global food security, the risk of salinisation increases. Salt contamination, which leads to stunted and uneven plant growth, is already estimated to affect 20 per cent of cultivated land worldwide. Soil salinisation has long been a looming issue for global agriculture with about one billion hectares of agricultural land being affected globally; 60 million hectares damaged by salinisation and a staggering 76 million hectares of arable land permanently lost. While salt-affected land can still produce crops, albeit at a lower yield, cultivated land that is damaged will not be able to produce any agricultural product because it is affected to such an extent that nothing will grow. If rising global salinity is not addressed, it poses a real threat to the world achieving a 70 per cent increase in food production that the United Nations has projected will be needed by 2050.
Tuning of Redox Regulatory Mechanisms, Reactive Oxygen Species & Redox Homeostasis Under Salinity Stress - 2016
Soil salinity is a crucial environmental constraint that limits biomass production at many sites on a global scale. Saline growth conditions cause osmotic and ionic imbalances, oxidative stress and perturb metabolism, for example the photosynthetic electron flow. A plants ability to tolerate salinity is determined by multiple biochemical and physiological mechanisms protecting cell functions, in particular by regulating proper water relations and maintaining ion homeostasis.
Redox homeostasis is a fundamental cell property. Its regulation includes control of reactive oxygen species (ROS) generation, sensing deviation from and readjustment of the cellular redox state. All these redox related functions have been recognized as decisive factors in salinity acclimation and adaptation. This review focuses on the core response of plants to overcome the challenges of salinity stress through regulation of ROS generation and detoxification systems and to maintain redox homeostasis. Emphasis is given to the role of NADH oxidase (RBOH), alternative oxidase (AOX), the plastid terminal oxidase (PTOX) and the malate valve with the malate dehydrogenase isoforms under salt stress. Overwhelming evidence assigns an essential auxiliary function of ROS and redox homeostasis to salinity acclimation of plants.
Fish Health: An Oxidative Stress Perspective
An emerging concept to define and monitor the metabolic status of animals and to determine to what extent their phenotype, as well as their environment, is providing conditions sufficient to fulfil their metabolic requirements is oxidative stress. Oxidative stress results from the imbalance between the production of Reactive Oxygen Species (ROS) principally from mitochondria and the ROS buffering activity of some enzymes or other antioxidant molecules. Especially, mitochondria seem to be good sensors of the general stress status of the cell or the animal, and transduce this status in terms of ROS production level. The impairment of the balance, and therefore the occurrence of oxidative stress, has been related to an increased susceptibility to different environmental or biotic stress and to the development of different types of pathology in different animal species.
We therefore suggest that the monitoring of oxidative stress or of the different markers of oxidative stress could be powerful tools to evaluate the metabolic and general health status of fish. This new approach could grant development of healthier strains or populations that could better resist stress, pathogens and disease and therefore limit chemical and biochemical intervention for curing fish. We could for example include in the selection programs metabolic criteria that guarantee the development of strains with good oxidative stress management ability and higher resistance to biotic and abiotic stress. Monitoring these oxidative stress markers could also be of major interest for the management and conservation of wild populations.
Effects of Oxidative Stress During Exercise in the Horse - 2016
Oxidative stress is an imbalance of the oxidant-to-antioxidant ratio in the body. Increases in oxidative stress and changes in antioxidant status have been shown during endurance, intense exercise and eventing competition in horses. Antioxidants include vitamins, minerals, enzymes and proteins that must be synthesized in the body or obtained from the diet. Therefore, exercise level and diet are both factors that play a role in influencing the oxidative stress and antioxidant status of the equine athlete.
Along with exercise intensity and duration, the diet, age and training program can also affect oxidative stress in the horse. The “free radical theory of aging” states that long-term effects of the degenerative changes associated with aging may induce oxidative stress. Exercise training reduced oxidative stress markers and improved antioxidant status in mares, whereas few effects were seen in yearlings. This indicates that youth provided more defence against oxidative stress due to exercise than the exercise training program itself.
AN OVER VIEW OF OXIDATIVE
STRESS - 2012
The oxidative process that is regularly goes on in a cell is essential for the life and death of a cell. The following are the important key points taken into consideration for this process:
- Molecular oxygen has the ability to un-pair and leave free radicals which are unstable.
- This unstable radical is highly reactive and causes formation of reactive oxygen species.
- Beneficial biological functions such as apoptosis, necrosis, phagocytosis are mediated by reactive oxygen species.
- These reactive metabolites are selectively neutralized by a body's defensive mechanism.
- Principal defensive agents are antioxidant enzymes and endogenous antioxidants.
- Balance is created between pro-oxidants and antioxidants within a cell, and any impairment in equilibrium causes deleterious effects on the cell's life.
It is known that the unpaired electron of molecular oxygen reacts to form highly reactive species, which are known as reactive oxygen species. Reactive oxygen species are generated from enzymatic and non-enzymatic sources.
Oxidative Stress: Molecular Perception and Transduction of Signals Triggering Antioxidant Gene Defences - 2005
The survival of organisms on earth depends upon the interactions of their genomes with the environments in which they exist. In the course of evolution, organisms evolved a complex array of mechanisms for adapting to both minor and major fluctuations in the environment. The emergence of oxygenic photosynthesis presented early life forms with the greatest environmental challenge as well as opportunity. The challenge was to develop antioxidant defences in order to survive; the opportunity was to exploit the reactivity of oxygen for energy yielding and biosynthetic reactions. The opportunity led to highly diversified life forms that evolved sufficient defences and managed to exploit the aerobic lifestyle.
Oxygen toxicity likely led to massive extinctions of those organisms unable to cope with it, unless they took refuge in isolated anaerobic niches. Thus, oxygen is a “double-edged sword” in that it makes life on earth possible, but in its reduced forms (ROS), it is highly toxic and lethal. Oxidative stress arises from an imbalance between generation and elimination of ROS, leading to excess ROS levels inflicting indiscriminate damage to virtually all biomolecules, which leads in turn to various diseases and cell death. Redox regulation of gene expression by oxidants and antioxidants is emerging as a vital mechanism in the health and disease of all organisms.
The Roles of Environmental Factors in Regulation of
Oxidative Stress in Plants - 2019
Exposure to a variety of environmental factors such as salinity, drought, metal toxicity, extreme temperature, air pollutants, ultraviolet-B (UV-B) radiation, pesticides, and pathogen infection leads to subject oxidative stress in plants, which in turn affects multiple biological processes via reactive oxygen species (ROS) generation. ROS include hydroxyl radicals, singlet oxygen, and hydrogen peroxide in the plant cells and activates signalling pathways leading to some changes of physiological, biochemical, and molecular mechanisms in cellular metabolism.
Excessive ROS, however, causes oxidative stress as a state of imbalance between the production of ROS and the neutralization of free radicals by antioxidants, resulting in damage of cellular components including lipids, nucleic acids, metabolites, and proteins, which finally leads to the death of cells in plants. Thus, maintaining a physiological level of ROS is crucial for aerobic organisms, which relies on the combined operation of enzymatic and nonenzymatic antioxidants.
In order to improve plants’ tolerance towards the harsh environment, it is vital to reinforce the comprehension of oxidative stress and antioxidant systems. In this review, recent findings on the metabolism of ROS as well as the antioxidative defence machinery are briefly updated. The latest findings on differential regulation of antioxidants at multiple levels under adverse environment are also discussed here.
The Growing Threat that Salinity Poses to Global Food Production
Irrigation plays an important role in food production, as it helps the world to keep pace with increased food demand associated with increasing populations. Irrigation is used on 20 per cent of the world’s cropland but helps to produce 40 per cent of the world’s food. Irrigated agriculture is likely to play an even larger role in global food security, as about half to two-thirds of future gains in crop production are expected to come from irrigated land.
With the growing use of irrigation as a method to achieve global food security, the risk of salinisation increases. Salt contamination, which leads to stunted and uneven plant growth, is already estimated to affect 20 per cent of cultivated land worldwide. Soil salinisation has long been a looming issue for global agriculture with about one billion hectares of agricultural land being affected globally; 60 million hectares damaged by salinisation and a staggering 76 million hectares of arable land permanently lost. While salt-affected land can still produce crops, albeit at a lower yield, cultivated land that is damaged will not be able to produce any agricultural product because it is affected to such an extent that nothing will grow. If rising global salinity is not addressed, it poses a real threat to the world achieving a 70 per cent increase in food production that the United Nations has projected will be needed by 2050.
Tuning of Redox Regulatory Mechanisms, Reactive Oxygen Species & Redox Homeostasis Under Salinity Stress - 2016
Soil salinity is a crucial environmental constraint that limits biomass production at many sites on a global scale. Saline growth conditions cause osmotic and ionic imbalances, oxidative stress and perturb metabolism, for example the photosynthetic electron flow. A plants ability to tolerate salinity is determined by multiple biochemical and physiological mechanisms protecting cell functions, in particular by regulating proper water relations and maintaining ion homeostasis.
Redox homeostasis is a fundamental cell property. Its regulation includes control of reactive oxygen species (ROS) generation, sensing deviation from and readjustment of the cellular redox state. All these redox related functions have been recognized as decisive factors in salinity acclimation and adaptation. This review focuses on the core response of plants to overcome the challenges of salinity stress through regulation of ROS generation and detoxification systems and to maintain redox homeostasis. Emphasis is given to the role of NADH oxidase (RBOH), alternative oxidase (AOX), the plastid terminal oxidase (PTOX) and the malate valve with the malate dehydrogenase isoforms under salt stress. Overwhelming evidence assigns an essential auxiliary function of ROS and redox homeostasis to salinity acclimation of plants.
Fish Health: An Oxidative Stress Perspective
An emerging concept to define and monitor the metabolic status of animals and to determine to what extent their phenotype, as well as their environment, is providing conditions sufficient to fulfil their metabolic requirements is oxidative stress. Oxidative stress results from the imbalance between the production of Reactive Oxygen Species (ROS) principally from mitochondria and the ROS buffering activity of some enzymes or other antioxidant molecules. Especially, mitochondria seem to be good sensors of the general stress status of the cell or the animal, and transduce this status in terms of ROS production level. The impairment of the balance, and therefore the occurrence of oxidative stress, has been related to an increased susceptibility to different environmental or biotic stress and to the development of different types of pathology in different animal species.
We therefore suggest that the monitoring of oxidative stress or of the different markers of oxidative stress could be powerful tools to evaluate the metabolic and general health status of fish. This new approach could grant development of healthier strains or populations that could better resist stress, pathogens and disease and therefore limit chemical and biochemical intervention for curing fish. We could for example include in the selection programs metabolic criteria that guarantee the development of strains with good oxidative stress management ability and higher resistance to biotic and abiotic stress. Monitoring these oxidative stress markers could also be of major interest for the management and conservation of wild populations.
Effects of Oxidative Stress During Exercise in the Horse - 2016
Oxidative stress is an imbalance of the oxidant-to-antioxidant ratio in the body. Increases in oxidative stress and changes in antioxidant status have been shown during endurance, intense exercise and eventing competition in horses. Antioxidants include vitamins, minerals, enzymes and proteins that must be synthesized in the body or obtained from the diet. Therefore, exercise level and diet are both factors that play a role in influencing the oxidative stress and antioxidant status of the equine athlete.
Along with exercise intensity and duration, the diet, age and training program can also affect oxidative stress in the horse. The “free radical theory of aging” states that long-term effects of the degenerative changes associated with aging may induce oxidative stress. Exercise training reduced oxidative stress markers and improved antioxidant status in mares, whereas few effects were seen in yearlings. This indicates that youth provided more defence against oxidative stress due to exercise than the exercise training program itself.
Due to the laws we are regulated by, we can only show a snapshot of the already
science available, however there is much more to learn and share and we will
continue to expand further on all information as the research unfolds.