Category: Moms

Oxidative stress and free radicals

Oxidative stress and free radicals

The electrons want to exist with Energy-boosting foods partner, to Oxisative a pair. Cells contain small structures called mitochondria, Rest and recovery meals work gree generate energy in Oxivative form of adenosine triphosphate ATP. Oxidative stress Oxidative stress and free radicals sttess to Oxidatige important Body recomposition diet neurodegenerative diseases including Lou Oxidative stress and free radicals fgee aka MND ardicals ALSParkinson's diseaseAlzheimer's diseaseHuntington's diseasedepressionand multiple sclerosis. For example, oxidative stress that results from physical activity may have beneficial, regulatory effects on the body. Two main principal mechanisms of action of that described for antioxidants are: The first mechanism is chain breaking in which primary antioxidants donated an electron to the free radicals whereas the second mechanism directs the removal of reactive species initiators secondary antioxidants by quenching the catalyst that initiate the chain of reaction. Wang H, H. Scientific evidence supporting the beneficial effects of isoflavones on human health.

Oxidative stress and free radicals -

In general, the body is able to maintain a balance between antioxidants and free radicals. Several factors contribute to oxidative stress and excess free radical production. These factors can include:. This type of oxidative stress causes mild inflammation that goes away after the immune system fights off an infection or repairs an injury.

Uncontrolled oxidative stress can accelerate the aging process and may contribute to the development of a number of conditions. To discover more evidence-based information and resources for healthy aging, visit our dedicated hub.

Free radicals, including reactive oxygen species, are molecules with one or more unpaired electron. Examples of free radicals include:. Cells contain small structures called mitochondria, which work to generate energy in the form of adenosine triphosphate ATP.

Mitochondria combine oxygen and glucose to produce carbon dioxide, water, and ATP. Free radicals arise as byproducts of this metabolic process. External substances, such as cigarette smoke, pesticides, and ozone, can also cause the formation of free radicals in the body. Antioxidants are substances that neutralize or remove free radicals by donating an electron.

The neutralizing effect of antioxidants helps protect the body from oxidative stress. Examples of antioxidants include vitamins A, C, and E. Like free radicals, antioxidants come from several different sources.

Cells naturally produce antioxidants such as glutathione. Foods such as fruits and vegetables provide many essential antioxidants in the form of vitamins and minerals that the body cannot create on its own. The effects of oxidative stress vary and are not always harmful.

For example, oxidative stress that results from physical activity may have beneficial, regulatory effects on the body. Exercise increases free radical formation, which can cause temporary oxidative stress in the muscles. However, the free radicals formed during physical activity regulate tissue growth and stimulate the production of antioxidants.

Mild oxidative stress may also protect the body from infection and diseases. In a study , scientists found that oxidative stress limited the spread of melanoma cancer cells in mice. This can contribute to aging and may play an important role in the development of a range of conditions. Immune cells called macrophages produce free radicals while fighting off invading germs.

These free radicals can damage healthy cells, leading to inflammation. Under normal circumstances, inflammation goes away after the immune system eliminates the infection or repairs the damaged tissue. However, oxidative stress can also trigger the inflammatory response, which, in turn, produces more free radicals that can lead to further oxidative stress, creating a cycle.

Chronic inflammation due to oxidative stress may lead to several conditions, including diabetes, cardiovascular disease, and arthritis.

The brain is particularly vulnerable to oxidative stress because brain cells require a substantial amount of oxygen. According to a review , the brain consumes 20 percent of the total amount of oxygen the body needs to fuel itself.

Brain cells use oxygen to perform intense metabolic activities that generate free radicals. The body naturally makes some free radicals as a byproduct of the processes it normally does, but you can also get more free radicals by exposure to certain toxic substances.

Antioxidants, like those found naturally in fruits and vegetables, are a key way to "fight" free radicals and the oxidative stress they cause in your body.

However, antioxidant supplements are less likely to help and may even do more harm than good. Phaniendra A, Jestadi DB, Periyasamy L. Free radicals: properties, sources, targets, and their implication in various diseases. Indian J Clin Biochem. Michigan State University.

What you need to know about antioxidants. Lobo V, Patil A, Phatak A, Chandra N. Free radicals, antioxidants and functional foods: Impact on human health. Pharmacogn Rev. Jiang D, Rusling JF. Oxidation Chemistry of DNA and p53 Tumor Suppressor Gene. Published Feb Neha K, Haider MR, Pathak A, Yar MS.

Medicinal prospects of antioxidants: A review. European Journal of Medicinal Chemistry. Choi Y, Larson N, Steffen LM, et al. Journal of the American Heart Association. Alsharairi N. The Effects of Dietary Supplements on Asthma and Lung Cancer Risk in Smokers and Non-Smokers: A Review of the Literature.

Jung A, Cai X, Thoene K, et al. Antioxidant Supplementation and Breast Cancer Prognosis in Postmenopausal Women Undergoing Chemotherapy and Radiation Therapy. The American Journal of Clinical Nutrition.

Lignitto L, LeBoeuf SE, Hamer H, et al. Nrf2 Activation Promotes Lung Cancer Metastasis by Inhibiting the Degradation of Bach1. doi: By Lynne Eldridge, MD Lynne Eldrige, MD, is a lung cancer physician, patient advocate, and award-winning author of "Avoiding Cancer One Day at a Time.

Use limited data to select advertising. Create profiles for personalised advertising. Use profiles to select personalised advertising. Create profiles to personalise content. Use profiles to select personalised content. Measure advertising performance.

Measure content performance. Understand audiences through statistics or combinations of data from different sources.

Develop and improve services. Use limited data to select content. List of Partners vendors. By Lynne Eldridge, MD. Medically reviewed by Doru Paul, MD. Table of Contents View All. Table of Contents.

TABLE 1. Classification of major antioxidants and their roles. Vitamin E alpha-tocopherol is considered to be an important antioxidant that involves in the chain-breaking process in the case of humans. Vitamin E is present within the cell membrane to interrupt the peroxidation of lipid and also play a major role in the modulation of cell signaling pathways that are dependent on reactive oxygen intermediates ROI.

Vitamin E also plays a potent role in decreasing the cases of cancer. It functions by donating the hydrogen atom to fatty peroxyl radicals and disrupting the lipid peroxidation process. It also has the potential to make a reaction with two peroxyl radicals as shown below:.

The vitamin E synthesized in Equation assumes to have a resonance-stabilized conformation which allows this vitamin to react with other peroxyl radicals to form a stable adduct, LOO-α-tocopherol. Alpha-tocopherol restricts the generation of new free radical whereas gamma-tocopherol neutralizes or trap the existing reactive species.

OS has been associated with various possible diseases but rather vitamin E helps to delay or prevent the chronic ailments associated with free reactive molecules Traber and Stevens, Uric acid, cysteine, glutathione, and vitamin C ascorbic acid work as a hydrophilic scavenger of oxygen radicals Lobo et al.

Natural ascorbate restricts the carcinogenic process of various nitroso compounds, fed to animals by converting them to an inactive form. This vitamin C can be utilized to detoxify the different organic compounds in vivo by a simple reduction process Combet et al.

Ascorbic acid is a potent scavenger and reducing agent of reactive species in the biological system. It is included in the first line of ddefenceof antioxidants, protecting the proteins and lipid membrane from damage Pehlivan, Due to its water-soluble nature, vitamin C can work both outside and inside the cells and can neutralize the free reactive species to avoid any damage.

This vitamin works as an excellent source of electrons for the reactive species that are finding out an electron to acquire their stability. They can donate electrons to those free radicals and scavenge their reactivity Padayatty and Levine, Cysteine is the physiological precursor of glutathione GSH and has been known widely for its protective function against mutagenesis and radiation.

ß -Carotene is also found to be useful in decreasing the incidence of cancer. Two major functions of ß -carotene are the ability to neutralize and trap certain organic free radicals and to deactivate the oxygen radicals present in exciting form, produced as a byproduct of metabolic reactions Fiedor and Burda, The consistent and strongest conformation regarding the protective effect of large consumption of carotene-rich food comes from studies of the esophagus and lung cancer Patel et al.

ß -Carotene act as an antioxidant under low oxygen tension and can also act as a prooxidant under more oxidizing and high concentration level in the case of smokers Tapiero et al. A sole molecule of ß -carotene is determined to eliminate around 1, of singlet oxygen with the help of a physical mechanism which involves the transfer of energy before it gets oxidized and loses its antioxidant activity Tan et al.

The rate of ß -carotene oxidation is dependent upon the partial pressure of oxygen. The carbon-centred radicals get resonance stabilized when the oxygen pressure is lowered. The ß -carotene activity towards peroxyl radicals and the stability of other carbon-centred radicals are the two main features that provide the carotene molecule with its antioxidant properties Fiedor and Burda, Selenium is a natural element which has gained focus due to its potential to decrease the process of carcinogenesis.

The antioxidant activity of selenium concerning vitamin C was studied broadly Tan et al. Deficiency of selenium results in the consequent cellular and tissue damage raised peroxidation of lipids and leads to the formation of free radicals.

Damage caused to unsaturated fatty acids in the subcellular membrane by peroxidation reaction can be reduced by Se and vitamin E Mourente et al. The metabolisms of Se and vitamin E are interrelated and Se plays a major role in vitamin E storage. Phenolic compounds are a heterogenous group of phytocompounds that are broadly spread in the plant kingdom Chaudhary et al.

Flavonoid belongs to a class of naturally occurring polyphenolic compounds and they provide different colors to leaves, fruit, and flower Chaudhary et al.

Flavonoids are further divided into the following classes: anthocyanidins, flavones, flavonols, flavanones, and flavonols. Among the classes, variations are based on the arrangement and number of hydroxyl groups, and glycosylation or alkylation of these groups.

The broad varieties of flavonoids and the greatest difference in their content make it difficult to determine the daily intake estimate of flavonoids Panche et al.

Phenolics and flavonoids act as an antioxidant through several pathways The most potent one is likely to be by scavenging the free radicals in which polyphenols carried out the breakdown of several free radical chain reactions Kaurinovic and Vastag, For a molecule to act as an antioxidant, it must fulfil the two criteria.

i at low concentrations, it can prevent the oxidation of the substrate. ii the radical generated on the polyphenols must be stable enough so that it can prevent itself from acting as a chain-propagating radical Dangles, This stabilization is usually through intramolecular hydrogen bonding and delocalization or by reaction with other lipid radicals and further oxidation.

A large number of investigations have been done on the structure-antioxidant activity relationship of flavonoids Table 2. Some of the common ones are flavanol, flavonoid, and quercetin which are abundant in onion, broccoli, and apple; catechin, another flavanol present in different tea and fruits; naringenin, the major flavanone in grapefruit; glycitein, genistein, and daidzein are the major isoflavanones in soybean; and cyanogen glycosides are abundant in blackberry, raspberry, and black currant.

Curcumins target free radicals through various mechanisms. Additionally, curcumin is a lipophilic molecule, which makes it useful in the scavenging of peroxyl radicals. Therefore, like vitamin E, curcumin is also utilized as a chain-breaking natural agent. Tannin is the common name for phenolic molecules that are used for tanning leather and the precipitation of gelatin from solution.

They are further categorized into the condensed form of proanthocyanidins, in which the main structural unit is the phenolic flavanol nucleus and hexahydroxydiphenoyl and galloyl ester and their derivatives, ellagitannins and gallotannins Clifford and Scalbert, The two main groups of phenolic acids are hydroxycinnamic acid and hydroxybenzoic acid, both of which are obtained from cinnamic acid and benzoid molecule, respectively Kumar and Goel, These phenolic acids contain benzoic acid derivatives such as cinnamic acid derivatives ferulic, caffeic and coumaric acid and gallic acid.

Caffeic acid is majorly found in vegetables and fruits, most commonly esterified with quinic acid as in chlorogenic acid, the main phenolic in coffee. Another common phenolic acid is ferulic acid which is esterified with hemicellulose and present in cereals Dai and Mumper, Caffeic acid is produced by different plant species and is found to be available in various food products such as tea, wine, and coffee and other medicines such as propolis.

Phenolic acid and its derivatives have anticarcinogenic, anti-inflammatory, and antioxidant activities. In vivo and in vitro investigations have determined the anticarcinogenic property of this agent in the case of hepatocarcinoma, which is considered to be a highly aggressive form of cancer, responsible for the large rate of mortality across the globe.

The anticancer activity of this compound is related to its pro-oxidant and antioxidant capacity due to its complex structure including double bond in the carbonic chain, the position and number of OH group and free phenolic hydroxyl in the catechol group, respectively Kiokias et al.

The pharmacokinetic investigation determined that this compound is being hydrolyzed by the microbial colonies and metabolized in the mucosa of the intestine through phase II enzymes, submitted to methylation and conjugation process, forming methylated, glucuronic, and sulphated conjugates by the action of o-methyltransferase, UDP-glucosyltransferases, and sulfotransferases, respectively Monteiro Espindola et al.

The transmembrane flux of this compound in intestinal cells occurs via the active transport carried out by the carriers of monocarboxylic acid. It can act by suppressing the expression of MMP-9 and MMP-2, blocking STATs, reducing the angiogenesis of tumor cells, inducing the oxidation of DNA of tumor cells, and preventing the generation of ROS Monteiro Espindola et al.

It can induce apoptosis, autophagy, and cell cycle arrest via activating the ROS generation and caspase pathway. Additionally, they can restrict metastasis and invasion by reducing the activity and expression of matrix metalloproteinase Kahkeshani et al.

The antioxidant activity of ferulic acid is very complex. It is majorly based on the restriction of RNS and ROS formation and neutralization of free radicals. This compound also acts as a hydrogen donor; donating atoms directly to free radicals. This acid is found to be important for the protection of lipidic acids in the cell membrane from the unwanted autoxidation process.

As a secondary compound, ferulic acid and its derivatives can bind with copper and iron and avoid the generation of toxic hydroxyl radicals, which direct cellular damage Zduńska et al. This acid is extracted from Rosmarinus and Salvia species and reported with various antioxidant and functional properties.

It is most commonly used in the pharmaceuticals and cosmetic sector. This acid is most commonly found in cereals, vegetables and fruits. It acts as a potent antioxidant and scavenges free radicals and reactive species.

p-coumaric acid is a phenolic acid and is a hydroxyl derivative of cinnamic acid. It reduces the prefigure oxidation of low-density lipoprotein and decreases the risk of stomach cancer Kiliç and Yeşiloğlu, Stilbenes comprise two phenyl moieties which are connected by the methylene bridge of two carbon atoms.

Majorly these compounds act as an antifungal phytoalexin, the compound which is synthesized in response to injury. One of the widely known stilbenes is resveratrol, found majorly in grapes. Products of red wine and grapes contain a significant amount of resveratrol, respectively Rocha-González et al.

Lignans are the phenolic compounds and have 2,3-dibenzylbutane structures that is resulted from the dimerization of two cinnamic acid residues; lignans such as secoisolariciresinol are considered phytoestrogen. The increasing interest in the beneficial effect of phenolic compounds has resulted in the development of such diets that are rich in vegetables and fruits and provide protection against cancer and cardiovascular diseases.

The linseed act as a source which provides secoisolariciresinol up to 3. Erythroxylum cuneatum , a tropical flowering plant of the Erythroxylaceae family utilized in Thailand and Malaysia as traditional medicine. The alkaloid extract of E. cuneatum leaf possesses both anti-inflammatory and antioxidative activity suggesting its role in the development of anti-inflammatory and antioxidant drugs Li S et al.

Two isoquinoline alkaloids kareemine 2 and iraqiine 1 , along with N-methylouregidione 7 , atherospermidine 6 , O-methylmoschatoline 5 , kinabaline 4 , and muniranine 3 were isolated from the dichloromethane extract of Alphonsea cylindrica bark.

Compounds 4, 3, and 1 possess higher DPPH scavenging activity Obaid Aldulaimi et al. The antioxidant activity of alkaloid boldine and Peumus boldus extract was reported against Fe II -citrate-induced damage in rat liver mitochondria in vitro Klimaczewski et al. Stephania rotunda Lour.

The antioxidant activity of fangchinoline and cepharanthine was reported from Stephania rotunda by in vitro assays Gülçin et al. The results determined an effective radical scavenging and antioxidant activity of fangchinoline and cepharanthine.

Five new alkaloids 1—5 along with two new phenanthrene and three aporphine alkaloids, in total 10 6—15 compounds were isolated from the roots of Stephania tetandra. Based on electronic circular dichroism, single crystal X-ray, and spectroscopic analysis, compound 13, and 7—10 exhibited great antioxidant activities Wang R et al.

Terpenes play an important role in the metabolic processes of a broad range of microorganisms, plants, and animals in which they are formed Naturally, terpenoids can be utilized for different purposes including as key agents in metabolic processes, signaling, and defense Baccouri and Rajhi, These terpenes have had applications in medicine, cosmetics, and perfumery for thousands of years and are still procured from different plants for the above-mentioned uses.

The antioxidant activities of terpenes may explain their capacity to adjust the neural signal transmission, immunological effects, and inflammation. They protect against oxidative stress situations including ageing, diabetes, neurodegenerative, cardiovascular disease, cancer, liver, and renal mechanisms Baccouri and Rajhi, Bourgou et al.

essential oils and also their ability in restricting the production of nitric oxides. The chemical characterization and antioxidant activity of essential oils isolated from Euphorbia heterophylla L.

Elshamy et al. Sesquiterpenes-rich essential oil isolated from the above parts of Pulicaria somalensis showed great antioxidant activity and allelopathic effect against weeds Assaeed et al. In a study to determine the antitumor effects of terpenoids, it was found that paclitaxel, geraniol, and perillyl alcohol are the terpenoids with better anticancer activities Yang et al.

The anti-inflammatory activity of paeoniflorin and its derivatives, 4-O-methylbenzoyl paeoniflorin, 4-O-methyl paeoniflorin, and other monoterpenes was reported Bi et al. The results reported that most of these monoterpenes can inhibit the production of tumor necrosis factor-alpha TNF-α , interleukins-6 IL-6 , and inflammatory factor nitric oxide NO induced by lipopolysaccharides LPs.

Other free radicals such as ROOH, and organic hydroperoxide are generated by the reaction of radicals with the cellular components such as nucleobases and lipids.

The RO, ROO. peroxyl, and alkoxy radicals are oxygen centered organic types of radicals. Lipids form take part in the peroxidation reaction of lipids. They are generated in the presence of oxygen by abstraction of hydrogen and addition of radicals to double bonds.

Hypochlorous acid or HOCl are generated from hydrogen peroxide in the presence of myeloperoxidase. They are highly reactive and readily oxidized protein constituents such as methionine, amino groups, and thiol groups.

Peroxynitrite radical is generated in a reaction of superoxide with nitric oxide. The protonation reaction results in the formation of peroxynitrous acid which undergo hemolytic cleavage to form nitrogen dioxide and hydroxyl radicals Lobo et al. Therefore, various methods have been applied to decrease the damage caused by oxidative stress.

Endogenous antioxidant enzymes which are generated inside the cells work as a protective mechanism against reactive free species. Heme oxygenase, reductase, thioredoxin, GST, GR, GPx, CAT and SOD are the most vital antioxidant enzymes. Thus, there is a conversion of toxic species to the harmless product.

Peroxides generated during the process of metabolism, get eliminated by GPx and GST. So, GRd functions by raising the concentration of GSH, which is required for the maintenance of oxide-redox conditions in a living organism.

The GPx is available throughout the cells whereas CAT is restricted to the peroxisome. The brain is very sensitive towards the damage caused by free radicals so; it contains 7 times more concentration of GPx than the CAT. The greatest level of CAT is found in erythrocytes, kidneys, and the liver, where it decomposes most of the hydrogen peroxide Aziz et al.

The utilization and consumption of oxygen in physiological processes result in the production of ROS. The production of energy in mitochondria is dependent upon the metabolism of oxygen since oxygen gets reduced to water. Other antioxidant agents such as green tea extract are also capable of reducing the damage resulting from superoxide radicals.

These radicals are found to be toxic to macromolecules such as proteins, lipids, and DNA. The application of various polyphenol and polyene from different vegetables and fruits protect against the damaging effect of hydroxyl radicals Lipinski, Large numbers of metals are responsible for inducing carcinogenicity and toxicity in the animal body.

An excessive amount of iron in the body leads to cancer, vascular diseases and other neurological complications. Copper at higher concentrations is known to result in metastasis. The complexes of cobalt ion led to the production of ROS which cause heart complications. Research showed that Se can chelate copper ions efficiently and prevent the damage caused to DNA by hydroxyl radicals.

The component of red wine binds to high-density lipoprotein HDL and low-density lipoprotein LDL and protect lipoproteins from metal-independent and meta-dependent lipid and protein oxidation Ivanov et al. According to some studies, melanoidin possessed better scavenging and metal-ion chelating activity which were due to its molecular weight Wu et al.

It has been determined that the major source of free radicals in diverse pathological and physiological circumstances is related to the enzyme number. The enzymes that lead the generation of superoxide include NADPH-dependent oxidase, cyclooxygenase, lipoxygenase, and xanthine oxidase.

The production of hydrogen peroxide is catalyzed by the superoxide dismutase enzyme. Various enzymes of peroxisomes such as D-aspartate oxidase, xanthine oxidase, urate oxidase, D-amino acid oxidase and acyl CoA oxidase direct the production of different ROS.

Many natural agents have revealed their potential to restrict the enzymes that direct the generation of free radicals as well as in the development of novel therapeutics agents against oxidative stress-induced diseases Phaniendra et al.

Plant alkaloids such as berberine carried out the inhibition of NADPH oxidase activity via reducing the mRNA expression of gp91phox in macrophages. Lipid peroxidation is damaging due to the production of products which leads to the spread of free radical reactions. The potent function of lipids in the cellular system emphasizes the need to understand the consequences and mechanism of lipid peroxidation in the human body.

Polyunsaturated fatty acids PUFAs are utilized as the substrate for the peroxidation of lipids due to the presence of active bis-allylic methylene groups.

The hydrogen-carbon bonds on these methylene units have very low bond-dissociation energy, making the hydrogen atom to be abstracted easily in the radical reactions Davies and Guo, It has been determined that the a -tocopherol is the most suitable antioxidant and protect the membrane from oxidation by reacting with the various lipid radicals generated in the peroxidation chain reaction of lipid.

It carried out the removal of free radical intermediates and prevents the continuation of the propagation reaction Mostafa Abd El-Aal, The natural agent, rosmarinic acid spontaneously penetrates the cell membrane to inhibit the peroxidation of lipids in situ as reported by Fadel et al.

Oxidative stress is the major reason behind the majority of DNA damage in the case of human beings. Various factors are responsible for the production of free radicals and ROS. Antioxidant agents include external antioxidants and internal antioxidants that can be consumed through a diet to fulfil the natural need of the human body.

These agents can scavenge free radicals and prevent further damage Jamshidi et al. The fraction obtained from normal and transformed roots of Rhaponticum carthamoides provides DNA repair and antioxidant effect against oxidative stress-induced DNA damage in Chinese hamster ovary CHO cells ; Skala et al.

The methanolic fraction of Tamarind indica, Adhatoda vasica, Centella asiatica, Pseudomugii furcatus, and Kocuria indica protect against DNA damage. Trans-resveratrol and p-coumaric acid extracted from the ethanolic fraction of germinated peanut also protect against DNA damage Limmongkon et al.

The reactive species oxidize the different types of amino acids present in the protein and result in the generation of the protein-protein cross linkage which further results in the denaturation, loss of protein functioning, loss of transport protein and receptor functioning, and loss of enzymatic activity.

Hydroxyl radicals are reactive, they can further react with both inorganic and organic molecules like carbohydrates, lipids, proteins, and DNA and results in severe damage to cells Phaniendra et al. Both biliverdin and bilirubin exhibited greater antioxidant activity than alpha-tocopherol against peroxynitrite and peroxyl-radical-induced protein oxidation in the brain microsome of rats in vitro Mancuso et al.

Chemoprevention of cancer is defined as the reverse process or inhibition of carcinogenesis by the administration of synthetic and natural agents as shown in Table 3.

These agents have helped to understand the molecular and cellular levels of carcinogenesis. The chemopreventive agents can be divided into three wide categories.

i Those which prevent the generation of procarcinogens from the precursor components e. C, which avoids nitroso compounds formation Landis-Piwowar and Iyer, ii Blocking agents: These prevent the cancer casing compounds from interacting with the cellular target e.

Further, blocking agents are sub-categorized into three major categories: those which restrict the activation of carcinogen to its carcinogenic form; those which induce the enzyme system capable of carcinogen detoxification, and those which can react with cancer-causing species and prevent their reaction with the cellular targets Steward and Brown, ; Landis-Piwowar and Iyer, iii Suppressing agents: These restrict carcinogenesis by suppressing their activity e.

Antioxidant defence such as the enzymes involved in the DNA damage repair cannot counteract all the oxidants and this results in damage which may lead to mutation and further contribute to carcinogenesis. Dietary antioxidants are ubiquitous and protect plants against oxidative assault and this property of them may be found to be useful in humans in terms of decreasing the risk of cancer.

ROS are involved at all stages of tumor development, consequently, dietary agents are found to be protected throughout the stages of carcinogenesis.

The tumour-inhibitory effects imparted by these plant foods are due to the presence of various antioxidants such as carotenoids, polyphenolics, selenium, vitamin C, vitamin E, and provitamin A, respectively. It is determined that various constituents contribute to the overall protective effect Bouayed and Bohn, Lung tumor risk has been reported to be decreased by the consumption of high vegetables and fruits in both retrospective epidemiological and prospective studies Dela Cruz et al.

Efficient inactivation of both endogenous and xenobiotics toxins results in the restriction of several cytotoxic events, and in the prevention of cellular integrity, which may lead to various diseases. The contribution of various families of enzymes such as conjugation catalyzing transferase, hydrolases, peroxidases, reductases, dehydrogenases, and monooxygenases results in protection against different hazardous components like N-nitroso compounds, which are very different in their cellular defense mechanism.

Some carcinogens act directly while others need activation Rendic and Guengerich, The metabolism of the xenobiotic component is carried by many enzymes that are included in Phase II and I reactions Jančová and Šiller, Phase I reactions include hydrolysis, reduction, hydroxylation, and oxidation, which results in water-soluble metabolites and further facilitate their excretion and conjugation.

Cytochrome Pdependent monooxygenase is the broadly studied phase I enzyme that is responsible for xenobiotic metabolism.

These enzymes are encoded by the superfamily of CYP genes. In the NADPH monooxygenase system: P oxidoreductase transfer the electrons from NADPH to P and results in the formation of ferrocytochrome P which carried out molecular oxygen activation and one of the atoms of oxygen is added to the substrate molecule Riddick et al.

Other enzymes of phase I include: reductase, aromatase, dehydrogenase, monoamine oxidase, hydrolase, lipoxygenase, cyclooxygenase, and monooxygenase. The products of phase I reactions act as a substrate for the phase II enzymes but some of the xenobiotics are conjugated directly bypassing the metabolism of phase I.

Cytochrome b5 is one of the competitive inhibitors of CytP phosphorylation by protein kinase. Thus, b5 has a key role in the activity of cytP Mixed function oxidase is the flavin comprising monooxygenase present in the ER and contains one FAD molecule.

The endogenous substrate for this is cysteamine and it can oxidize the nucleophilic sulphur and nitrogen atom Porter, Detoxification enzymes of phase II compete with the activating enzymes of phase I to restrict the generation of electrophiles and catalyze the conversion of these electrophilic molecules to inactivate conjugates, making them more soluble in water and more easily get excreted from the body.

Some of the conjugating reactions are glutathione conjugation, sulfation, and glucuronidation, respectively Hodges and Minich, The consumption of antioxidants through vegetables and fruits that are determined to be the better source of antioxidants helping in the treatment of cardiovascular diseases.

Excessive production of reactive species leads to various pathological diseases such as ulcerogenic, depression, cardiovascular disorders, and rheumatoid arthritis. Antioxidants have been considered to play an important role in the prevention of these diseases.

It has been found that antioxidants have a better potential for the treatment of problems related to sexual maturity, male infertility, and nephrolithiasis Sindhi et al. Despite of various outcomes reported in vitro and in animal models, some studies are concentrated to humans and the results obtained are represented below in Table.

Natural antioxidant agents have many modes of action and can be useful in preventing diseases without side effects Chaudhary and Janmeda, b. The availability of antioxidants should be regulated by a prescription from a healthcare professional.

Consumers should be advised about the health benefits of antioxidants and be encouraged to eat foods rich in vegetable oils, nuts, seeds, leafy vegetables and fresh fruits, which are the main sources of antioxidants. The main therapeutic limitation is the excessive consumption of antioxidant supplements that can cause side effects because in high concentrations antioxidants can act as pro-oxidants.

There is also a significant difference between taking antioxidants from food and administering an isolated substance as a supplement. Many substances that show beneficial effects in the laboratory do not work when they are introduced into the human body.

Many antioxidants do not have good bioavailability. The concentration of antioxidants such as polyphenols is sometimes so low in the blood that no significant effect is observed Del Rio et al.

Free radicals-directed oxidative stress is known to be harmful to the health of a human being. Various experimental studies determine that free radicals contribute towards the progression and inhibition of various pathologies, ranging from cardiovascular disease to cancer.

Antioxidants can counteract oxidative stress and mitigate all the effects on human health. These compounds gained a lot of attention from the field of biomedical research as they showed a better degree of efficacy in terms of the cure and prevention of various diseases.

Synthetic antioxidants are found to be detrimental to the health of an organism. Therefore, the search for a non-toxic and natural compound with greater antioxidant activity has increased in the last few years. Through the literature survey, we can conclude that oxidative stress should be exploited as a tool for the treatment when and if we would be able to understand the fine-tuning of this phenomenon inside a living body.

Newer approaches that utilise modern technology and collaborative research in combination with established conventional health practices can be used in near future for the improvement of health status, especially among individuals who do not have access to costlier therapeutic drugs.

Conceptualization and design were performed by PC, PJ, and JS-R; investigation, data curation, and writing were performed by PC, AD, and BM; validation, review and editing were performed by PJ, BY, AA, DC, and JS-R; supervision PJ, DC, and JS-R; All the authors contributed equally, read and approved the final manuscript.

All authors have read and agreed to the published version of the manuscript. We acknowledge the Bioinformatics Centre, Banasthali Vidyapith, supported by DBT and DST for providing computation and networking support through the FIST and CURIE programs at the Department of Bioscience and Biotechnology, Banasthali Vidyapith, Rajasthan.

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.

Adewoyin, M. Male infertility: The effect of natural antioxidants and phytocompounds on seminal oxidative stress. CrossRef Full Text Google Scholar. Akazawa, N. Effects of curcumin intake and aerobic exercise training on arterial compliance in postmenopausal women. Artery Res.

Al-Waili, N. Natural antioxidants in the treatment and prevention of diabetic nephropathy; a potential approach that warrants clinical trials. Redox Rep. PubMed Abstract CrossRef Full Text Google Scholar.

Ander, B. Polyunsaturated fatty acids and their effects on cardiovascular disease. PMID: , PMCID: PMC PubMed Abstract Google Scholar. Ansar, S. Protective effect of butylated hydroxytoluene on ferric nitrilotriacetate induced hepatotoxicity and oxidative stress in mice.

Asbaghi, O. The effect of vitamin E supplementation on selected inflammatory biomarkers in adults: A systematic review and meta-analysis of randomized clinical trials.

Assaeed, A. Sesquiterpenes-rich essential oil from above ground parts of Pulicaria somalensis exhibited antioxidant activity and allelopathic effect on weeds. Agronomy 10 3 , Aziz, M. Baccouri, B. Bahonar, A. Carotenoids as potential antioxidant agents in stroke prevention: A systematic review.

Bhatia, M. Understanding toxicology: Mechanisms and applications. Bi, X. Anti-inflammatory effects, SAR, and action mechanism of monoterpenoids from Radix paeoniae alba on LPS-stimulated RAW Molecules 22 5 , Bouayed, J. Exogenous antioxidants-double edged swords in cellular redox state: Health beneficial effects at physiologic doses versus deleterious effects at high doses.

Bourgou, S. Terpenoids isolated from Tunisian Nigella sativa L. essential oil with antioxidant activity and the ability to inhibit nitric oxide production. Flavour Frag. Buettner, G. Superoxide dismutase in redox biology: The roles of superoxide and hydrogen peroxide.

Anticancer Agents Med. Ceni, E. Pathogenesis of alcoholic liver disease: Role of oxidative metabolism. World J. Chang, X. Natural Drugs as a treatment strategy for cardiovascular disease through the regulation of oxidative stress.

Chaudhary, P. Quantification of phytochemicals and in vitro antioxidant activities from various parts of Euphorbia neriifolia Linn. Comparative pharmacognostical standardization of different parts of Euphorbia neriifolia Linn. Plant Res. Euphorbia neriifolia Indian spurge tree : A plant of multiple biological and pharmacological activities.

Sustainability 15 2 , Chen, H. Allicin inhibits proliferation and invasion in vitro and in vivo via SHPmediated STAT3 signaling in cholangiocarcinoma.

Cheng, J. Cicero, A. Metabolic and cardiovascular effects of berberine: From preclinical evidences to clinical trial results. Clifford, M. Ellagitannins-Nature, Occurrence and dietary burden. Food Agric. Combet, E. Fat transforms ascorbic acid from inhibiting to promoting acid-catalysed N-nitrosation.

Gut 56 12 , — Conti, V. Antioxidant supplementation in the treatment of aging-associated diseases. Coughlin, S. Oxidative stress, antioxidants, physical activity, and the prevention of breast cancer initiation and progression.

Health Sci. Crisafulli, D. Effects of the phytoestrogen genistein on cardiovascular risk factors in postmenopausal women. Menopause 12 2 , — The role of oxidative stress in cardiac disease: From physiological response to injury factor.

Dai, J. Plant phenolics: Extraction analysis and their antioxidant and anticancer properties. Molecules 15 10 , — Dangles, O.

Oxidative stress vree an imbalance of Rest and recovery meals Pomegranate Sauce and antioxidants in the body, which can lead to Oxudative and Rest and recovery meals damage. Oxidative stress occurs Health benefits flavonoids and plays a role in the streas process. A strexs body of scientific evidence suggests that long-term oxidative stress contributes to the development in a range of chronic conditions. Such conditions include cancerdiabetesand heart disease. In this article, we explore what oxidative stress is, how it affects the body, and how to reduce it. Oxidative stress can occur when there is an imbalance of free radicals and antioxidants in the body. However, cells also produce antioxidants that neutralize these free radicals. Free radicals Radiczls other reactive oxygen species ROS are streas formed in the human Heart-healthy cholesterol management techniques. Free-radical mechanisms steess been implicated in the pathology of several human diseases, including cancer, atherosclerosis, Oxidative stress and free radicals, and rheumatoid arthritis and neurodegenerative diseases. Catalases in peroxisomes convert H 2 O 2 into water and O 2 and help to dispose of H 2 O 2 generated by the action of the oxidase enzymes that are located in these organelles. Other important H 2 O 2 -removing enzymes in human cells are the glutathione peroxidases. When produced in excess, ROS can cause tissue injury. Oxidative stress and free radicals

Author: Malajind

2 thoughts on “Oxidative stress and free radicals

Leave a comment

Yours email will be published. Important fields a marked *

Design by ThemesDNA.com