Which Of The Following Has The Ability To Prevent Or Repair The Damage Caused By Oxidation?

Pharmacogn Rev. 2010 Jul-December; 4(eight): 118–126.

Free radicals, antioxidants and functional foods: Impact on man health

V. Lobo

Department of Phytology, Birla College, Kalyan – 421 304, Maharastra, India.

A. Patil

Department of Botany, Birla College, Kalyan – 421 304, Maharastra, Bharat.

A. Phatak

Department of Phytology, Birla Higher, Kalyan – 421 304, Maharastra, Bharat.

North. Chandra

Department of Botany, Birla College, Kalyan – 421 304, Maharastra, India.

Received 2010 Mar 4; Revised 2010 Mar viii

Abstract

In recent years, there has been a keen deal of attention toward the field of free radical chemical science. Complimentary radicals reactive oxygen species and reactive nitrogen species are generated by our trunk by diverse endogenous systems, exposure to different physiochemical conditions or pathological states. A balance betwixt free radicals and antioxidants is necessary for proper physiological function. If complimentary radicals overwhelm the torso's ability to regulate them, a condition known equally oxidative stress ensues. Free radicals thus adversely modify lipids, proteins, and DNA and trigger a number of human being diseases. Hence application of external source of antioxidants tin aid in coping this oxidative stress. Synthetic antioxidants such as butylated hydroxytoluene and butylated hydroxyanisole have recently been reported to be dangerous for homo health. Thus, the search for effective, nontoxic natural compounds with antioxidative activity has been intensified in recent years. The present review provides a brief overview on oxidative stress mediated cellular damages and role of dietary antioxidants as functional foods in the management of human diseases.

Keywords: Ageing, antioxidant, free radicals, oxidative stress

INTRODUCTION

The contempo growth in the knowledge of gratuitous radicals and reactive oxygen species (ROS) in biological science is producing a medical revolution that promises a new age of wellness and disease direction.[1] It is ironic that oxygen, an element indispensable for life,[2] under certain situations has deleterious effects on the human being body.[3] Most of the potentially harmful effects of oxygen are due to the formation and activeness of a number of chemical compounds, known every bit ROS, which have a tendency to donate oxygen to other substances. Gratis radicals and antioxidants have become commonly used terms in modern discussions of disease mechanisms.[4]

Complimentary RADICALS

A free radical can exist defined as any molecular species capable of independent beingness that contains an unpaired electron in an atomic orbital. The presence of an unpaired electron results in sure mutual properties that are shared by most radicals. Many radicals are unstable and highly reactive. They can either donate an electron to or take an electron from other molecules, therefore behaving as oxidants or reductants.[5] The about of import oxygen-containing free radicals in many illness states are hydroxyl radical, superoxide anion radical, hydrogen peroxide, oxygen singlet, hypochlorite, nitric oxide radical, and peroxynitrite radical. These are highly reactive species, capable in the nucleus, and in the membranes of cells of damaging biologically relevant molecules such equally DNA, proteins, carbohydrates, and lipids.[6] Free radicals attack important macromolecules leading to cell damage and homeostatic disruption. Targets of complimentary radicals include all kinds of molecules in the trunk. Among them, lipids, nucleic acids, and proteins are the major targets.

Product of free radicals in the human being trunk

Free radicals and other ROS are derived either from normal essential metabolic processes in the man torso or from external sources such as exposure to X-rays, ozone, cigarette smoking, air pollutants, and industrial chemicals.[3] Complimentary radical formation occurs continuously in the cells as a consequence of both enzymatic and nonenzymatic reactions. Enzymatic reactions, which serve as source of gratuitous radicals, include those involved in the respiratory concatenation, in phagocytosis, in prostaglandin synthesis, and in the cytochrome P-450 organisation.[7] Free radicals tin also be formed in nonenzymatic reactions of oxygen with organic compounds as well as those initiated by ionizing reactions.

Some internally generated sources of free radicals are[8]

Mitochondria
Xanthine oxidase
Peroxisomes
Inflammation
Phagocytosis
Arachidonate pathways
Practise
Ischemia/reperfusion injury
Some externally generated sources of free radicals are:
Cigarette smoke
Environmental pollutants
Radiations
Certain drugs, pesticides
Industrial solvents
Ozone

Free radicals in biological science

Costless radical reactions are expected to produce progressive agin changes that accumulate with age throughout the body [Tabular array i]. Such "normal" changes with age are relatively common to all. Notwithstanding, superimposed on this common pattern are patterns influenced by genetics and ecology differences that modulate gratuitous radical harm. These are manifested as diseases at certain ages determined by genetic and ecology factors. Cancer and atherosclerosis, ii major causes of death, are salient "free radical" diseases. Cancer initiation and promotion is associated with chromosomal defects and oncogene activation. It is possible that endogenous costless radical reactions, like those initiated by ionizing radiation, may result in tumor formation. The highly meaning correlation between consumption of fats and oils and expiry rates from leukemia and malignant neoplasia of the chest, ovaries, and rectum among persons over 55 years may be a reflection of greater lipid peroxidation.[9] Studies on atherosclerosis reveal the probability that the affliction may exist due to free radical reactions involving diet-derived lipids in the arterial wall and serum to yield peroxides and other substances. These compounds induce endothelial prison cell injury and produce changes in the arterial walls.[x]

Tabular array 1

Complimentary radicals[xi–13]

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CONCEPT OF OXIDATIVE STRESS

The term is used to describe the condition of oxidative harm resulting when the critical balance between free radical generation and antioxidant defenses is unfavorable.[14] Oxidative stress, arising as a result of an imbalance between free radical production and antioxidant defenses, is associated with impairment to a broad range of molecular species including lipids, proteins, and nucleic acids.[15] Curt-term oxidative stress may occur in tissues injured past trauma, infection, heat injury, hypertoxia, toxins, and excessive exercise. These injured tissues produce increased radical generating enzymes (e.g., xanthine oxidase, lipogenase, cyclooxygenase) activation of phagocytes, release of free iron, copper ions, or a disruption of the electron transport chains of oxidative phosphorylation, producing backlog ROS. The initiation, promotion, and progression of cancer, equally well as the side-furnishings of radiation and chemotherapy, have been linked to the imbalance between ROS and the antioxidant defence force system. ROS have been implicated in the consecration and complications of diabetes mellitus, age-related middle illness, and neurodegenerative diseases such as Parkinson'southward affliction.[16]

Oxidative stress and human diseases

A role of oxidative stress has been postulated in many weather, including anthersclerosis, inflammatory condition, certain cancers, and the process of crumbling. Oxidative stress is now thought to make a significant contribution to all inflammatory diseases (arthritis, vasculitis, glomerulonephritis, lupus erythematous, developed respiratory diseases syndrome), ischemic diseases (heart diseases, stroke, intestinal ischema), hemochromatosis, acquired immunodeficiency syndrome, emphysema, organ transplantation, gastric ulcers, hypertension and preeclampsia, neurological disorder (Alzheimer'due south illness, Parkinson'southward disease, muscular dystrophy), alcoholism, smoking-related diseases, and many others.[17] An excess of oxidative stress can lead to the oxidation of lipids and proteins, which is associated with changes in their structure and functions.

Cardiovascular diseases

Eye diseases continue to be the biggest killer, responsible for well-nigh half of all the deaths. The oxidative events may impact cardiovascular diseases therefore; it has potential to provide enormous benefits to the wellness and lifespan. Poly unsaturated fatty acids occur as a major function of the low density lipoproteins (LDL) in blood and oxidation of these lipid components in LDL play a vital role in atherosclerosis.[xviii] The three nearly of import cell types in the vessel wall are endothelial cells; smoothen muscle cell and macrophage tin can release complimentary radical, which affect lipid peroxidation.[19] With continued loftier level of oxidized lipids, blood vessel impairment to the reaction process continues and can lead to generation of foam cells and plaque the symptoms of atherosclerosis. Oxidized LDL is antherogenic and is thought to exist important in the germination of anthersclerosis plaques. Furthermore, oxidized LDL is cytotoxic and can direct damage endothelial cells. Antioxidants similar B-carotene or vitamin Due east play a vital role in the prevention of various cardiovascular diseases.

Carcinogenesis

Reactive oxygen and nitrogen species, such every bit super oxide anion, hydrogen peroxide, hydroxyl radical, and nitric oxide and their biological metabolites besides play an important role in carcinogenesis. ROS induce DNA damage, as the reaction of free radicals with DNA includes strand pause base of operations modification and Dna protein cross-links. Numerous investigators have proposed participation of gratis radicals in carcinogenesis, mutation, and transformation; it is clear that their presence in biosystem could lead to mutation, transformation, and ultimately cancer. Consecration of mutagenesis, the best known of the biological outcome of radiation, occurs mainly through damage of Deoxyribonucleic acid past the HO. Radical and other species are produced by the radiolysis, and also by directly radiations effect on Dna, the reaction furnishings on Deoxyribonucleic acid. The reaction of HO. Radicals is mainly addition to double bond of pyrimidine bases and abstraction of hydrogen from the saccharide moiety resulting in chain reaction of DNA. These furnishings cause cell mutagenesis and carcinogenesis lipid peroxides are also responsible for the activation of carcinogens.

Antioxidants can subtract oxidative stress induced carcinogenesis by a direct scavenging of ROS and/or by inhibiting cell proliferation secondary to the protein phosphorylation. B-carotene may exist protective against cancer through its antioxidant function, because oxidative products tin cause genetic harm. Thus, the photo protective properties of B-carotene may protect against ultraviolet calorie-free induced carcinogenesis. Immunoenhancement of B-carotene may contribute to cancer protection. B-carotene may also take anticarcinogenic effect past altering the liver metabolism effects of carcinogens.[20] Vitamin C may be helpful in preventing cancer.[21] The possible mechanisms past which vitamin C may affect carcinogenesis include antioxidant effects, blocking of germination of nitrosanimes, enhancement of the immune response, and dispatch of detoxification of liver enzymes. Vitamin E, an important antioxidant, plays a role in immunocompetence by increasing humoral antibiotic protection, resistance to bacterial infections, cell-mediated amnesty, the T-lymphocytes tumor necrosis cistron production, inhibition of mutagen formation, repair of membranes in DNA, and blocking micro jail cell line formation.[22] Hence vitamin Due east may be useful in cancer prevention and inhibit carcinogenesis by the stimulation of the immune system. The assistants of a mixture of the above three antioxidant reveled the highest reduction in risk of developing cardiac cancer.

Free radical and aging

The human body is in constant battle to keep from aging. Research suggests that free radical impairment to cells leads to the pathological changes associated with aging.[23] An increasing number of diseases or disorders, as well as crumbling procedure itself, demonstrate link either directly or indirectly to these reactive and potentially destructive molecules.[24] The major mechanism of aging attributes to DNA or the accumulation of cellular and functional impairment.[25] Reduction of free radicals or decreasing their charge per unit of product may delay aging. Some of the nutritional antioxidants will retard the aging procedure and prevent disease. Based on these studies, it appears that increased oxidative stress commonly occurs during the crumbling process, and antioxidant status may significantly influence the furnishings of oxidative damage associated with advancing age. Inquiry suggests that free radicals have a significant influence on aging, that free radical harm can be controlled with adequate antioxidant defence, and that optimal intake of antioxidant nutrient may contribute to enhanced quality of life. Recent inquiry indicates that antioxidant may even positively influence life bridge.

Oxidative damage to protein and DNA

Oxidative damage to protein

Proteins can be oxidatively modified in three means: oxidative modification of specific amino acid, free radical mediated peptide cleavage, and formation of protein cross-linkage due to reaction with lipid peroxidation products. Poly peptide containing amino acids such as methionine, cystein, arginine, and histidine seem to be the nearly vulnerable to oxidation.[26] Free radical mediated protein modification increases susceptibility to enzyme proteolysis. Oxidative damage to poly peptide products may touch on the activity of enzymes, receptors, and membrane transport. Oxidatively damaged poly peptide products may contain very reactive groups that may contribute to damage to membrane and many cellular functions. Peroxyl radical is usually considered to be free radical species for the oxidation of proteins. ROS can impairment proteins and produce carbonyls and other amino acids modification including formation of methionine sulfoxide and protein carbonyls and other amino acids modification including formation of methionine sulfoxide and poly peptide peroxide. Protein oxidation affects the alteration of betoken transduction mechanism, enzyme action, rut stability, and proteolysis susceptibility, which leads to aging.

Lipid peroxidation

Oxidative stress and oxidative modification of biomolecules are involved in a number of physiological and pathophysiological processes such as aging, artheroscleosis, inflammation and carcinogenesis, and drug toxicity. Lipid peroxidation is a free radical process involving a source of secondary gratis radical, which further can human activity every bit second messenger or can direct react with other biomolecule, enhancing biochemical lesions. Lipid peroxidation occurs on polysaturated fatty acrid located on the prison cell membranes and it further proceeds with radical chain reaction. Hydroxyl radical is idea to initiate ROS and remove hydrogen atom, thus producing lipid radical and further converted into diene conjugate. Further, by addition of oxygen it forms peroxyl radical; this highly reactive radical attacks another fatty acid forming lipid hydroperoxide (LOOH) and a new radical. Thus lipid peroxidation is propagated. Due to lipid peroxidation, a number of compounds are formed, for example, alkanes, malanoaldehyde, and isoprotanes. These compounds are used every bit markers in lipid peroxidation analysis and have been verified in many diseases such equally neurogenerative diseases, ischemic reperfusion injury, and diabetes.[27]

Oxidative harm to DNA

Many experiments clearly provide evidences that DNA and RNA are susceptible to oxidative impairment. It has been reported that particularly in aging and cancer, Deoxyribonucleic acid is considered as a major target.[28] Oxidative nucleotide as glycol, dTG, and 8-hydroxy-2-deoxyguanosine is found to be increased during oxidative damage to Deoxyribonucleic acid under UV radiation or free radical damage. Information technology has been reported that mitochondrial DNA are more susceptible to oxidative damage that have role in many diseases including cancer. It has been suggested that 8-hydroxy-two-deoxyguanosine tin can be used as biological marking for oxidative stress.[29]

ANTIOXIDANTS

An antioxidant is a molecule stable enough to donate an electron to a rampaging gratis radical and neutralize it, thus reducing its chapters to damage. These antioxidants filibuster or inhibit cellular damage mainly through their free radical scavenging property.[30] These low-molecular-weight antioxidants can safely interact with free radicals and end the chain reaction before vital molecules are damaged. Some of such antioxidants, including glutathione, ubiquinol, and uric acid, are produced during normal metabolism in the torso.[31] Other lighter antioxidants are found in the diet. Although there are several enzymes organization within the body that scavenge gratis radicals, the principle micronutrient (vitamins) antioxidants are vitamin Due east (α-tocopherol), vitamin C (ascorbic acid), and B-carotene.[32] The trunk cannot manufacture these micronutrients, so they must exist supplied in the diet.

History

The term antioxidant originally was used to refer specifically to a chemical that prevented the consumption of oxygen. In the tardily 19th and early 20th century, extensive written report was devoted to the uses of antioxidants in important industrial processes, such as the prevention of metal corrosion, the vulcanization of rubber, and the polymerization of fuels in the fouling of internal combustion engines.[33]

Early inquiry on the role of antioxidants in biological science focused on their utilise in preventing the oxidation of unsaturated fats, which is the cause of rancidity.[34] Antioxidant activity could be measured simply by placing the fatty in a closed container with oxygen and measuring the rate of oxygen consumption. However, information technology was the identification of vitamins A, C, and E as antioxidants that revolutionized the field and led to the realization of the importance of antioxidants in the biochemistry of living organisms.[35,36] The possible mechanisms of action of antioxidants were first explored when it was recognized that a substance with antioxidative action is probable to be one that is itself readily oxidized.[37] Research into how vitamin E prevents the process of lipid peroxidation led to the identification of antioxidants every bit reducing agents that prevent oxidative reactions, often past scavenging ROS before they can damage cells.[38]

Antioxidant defense system

Antioxidants act as radical scavenger, hydrogen donor, electron donor, peroxide decomposer, singlet oxygen quencher, enzyme inhibitor, synergist, and metal-chelating agents. Both enzymatic and nonenzymatic antioxidants be in the intracellular and extracellular environs to detoxify ROS.[39]

Machinery of action of antioxidants

Ii principle mechanisms of action have been proposed for antioxidants.[40] The first is a chain- breaking mechanism by which the chief antioxidant donates an electron to the free radical present in the systems. The second mechanism involves removal of ROS/reactive nitrogen species initiators (secondary antioxidants) by quenching concatenation-initiating catalyst. Antioxidants may exert their consequence on biological systems by different mechanisms including electron donation, metal ion chelation, co-antioxidants, or by gene expression regulation.[41]

Levels of antioxidant action

The antioxidants interim in the defense systems act at dissimilar levels such equally preventive, radical scavenging, repair and de novo, and the fourth line of defense, i.due east., the adaptation.

The first line of defense force is the preventive antioxidants, which suppress the formation of free radicals. Although the precise mechanism and site of radical formation in vivo are not well elucidated yet, the metal-induced decompositions of hydroperoxides and hydrogen peroxide must be ane of the important sources. To suppress such reactions, some antioxidants reduce hydroperoxides and hydrogen peroxide beforehand to alcohols and water, respectively, without generation of free radicals and some proteins sequester metal ions.

Glutathione peroxidase, glutathione-s-transferase, phospholipid hydroperoxide glutathione peroxidase (PHGPX), and peroxidase are known to decompose lipid hydroperoxides to corresponding alcohols. PHGPX is unique in that it tin reduce hydroperoxides of phospholipids integrated into biomembranes. Glutathione peroxidase and catalase reduce hydrogen peroxide to water.

The second line of defense is the antioxidants that scavenge the active radicals to suppress chain initiation and/or break the concatenation propagation reactions. Various endogenous radical-scavenging antioxidants are known: some are hydrophilic and others are lipophilic. Vitamin C, uric acid, bilirubin, albumin, and thiols are hydrophilic, radical-scavenging antioxidants, while vitamin E and ubiquinol are lipophilic radical-scavenging antioxidants. Vitamin E is accepted as the nigh potent radical-scavenging lipophilic antioxidant.

The 3rd line of defense is the repair and de novo antioxidants. The proteolytic enzymes, proteinases, proteases, and peptidases, present in the cytosol and in the mitochondria of mammalian cells, recognize, dethrone, and remove oxidatively modified proteins and prevent the accumulation of oxidized proteins.

The Deoxyribonucleic acid repair systems too play an of import role in the full defense system against oxidative impairment. Various kinds of enzymes such every bit glycosylases and nucleases, which repair the damaged DNA, are known.

At that place is some other of import function chosen adaptation where the signal for the production and reactions of free radicals induces germination and send of the appropriate antioxidant to the correct site.[42]

ENZYMATIC

Types of antioxidants

Cells are protected against oxidative stress by an interacting network of antioxidant enzymes.[43] Here, the superoxide released by processes such equally oxidative phosphorylation is offset converted to hydrogen peroxide and so further reduced to give water. This detoxification pathway is the result of multiple enzymes, with superoxide dismutases catalyzing the outset step then catalases and various peroxidases removing hydrogen peroxide.[44]

Superoxide dismutase

Superoxide dismutases (SODs) are a grade of closely related enzymes that catalyze the breakup of the superoxide anion into oxygen and hydrogen peroxide.[45,46] SOD enzymes are present in almost all aerobic cells and in extracellular fluids.[47] There are 3 major families of superoxide dismutase, depending on the metal cofactor: Cu/Zn (which binds both copper and zinc), Fe and Mn types (which bind either iron or manganese), and finally the Ni blazon which binds nickel.[48] In higher plants, SOD isozymes accept been localized in different prison cell compartments. Mn-SOD is present in mitochondria and peroxisomes. Fe-SOD has been found mainly in chloroplasts but has besides been detected in peroxisomes, and CuZn-SOD has been localized in cytosol, chloroplasts, peroxisomes, and apoplast.[48–50]

In humans (every bit in all other mammals and most chordates), three forms of superoxide dismutase are nowadays. SOD1 is located in the cytoplasm, SOD2 in the mitochondria, and SOD3 is extracellular. The offset is a dimer (consists of 2 units), while the others are tetramers (four subunits). SOD1 and SOD3 contain copper and zinc, while SOD2 has manganese in its reactive center.[51]

Catalase

Catalase is a common enzyme found in nearly all living organisms, which are exposed to oxygen, where it functions to catalyze the decomposition of hydrogen peroxide to water and oxygen.[52] Hydrogen peroxide is a harmful by-product of many normal metabolic processes: to foreclose damage, it must be quickly converted into other, less dangerous substances. To this end, catalase is frequently used past cells to apace catalyze the decomposition of hydrogen peroxide into less reactive gaseous oxygen and water molecules.[53] All known animals use catalase in every organ, with particularly high concentrations occurring in the liver.[54]

Glutathione systems

The glutathione arrangement includes glutathione, glutathione reductase, glutathione peroxidases, and glutathione S-transferases. This organization is establish in animals, plants, and microorganisms.[55] Glutathione peroxidase is an enzyme containing iv selenium-cofactors that catalyze the breakdown of hydrogen peroxide and organic hydroperoxides. There are at least four different glutathione peroxidase isozymes in animals.[56] Glutathione peroxidase i is the most abundant and is a very efficient scavenger of hydrogen peroxide, while glutathione peroxidase iv is most active with lipid hydroperoxides. The glutathione S-transferases testify high activity with lipid peroxides. These enzymes are at particularly high levels in the liver and likewise serve in detoxification metabolism.[57]

NONENZYMATIC

Ascorbic acid

Ascorbic acrid or "vitamin C" is a monosaccharide antioxidantfound in both animals and plants. As it cannot be synthesized in humans and must be obtained from the nutrition, it is a vitamin.[58] Most other animals are able to produce this chemical compound in their bodies and practise non require information technology in their diets. In cells, it is maintained in its reduced form by reaction with glutathione, which can be catalyzed past protein disulfide isomerase and glutaredoxins.[59] Ascorbic acid is a reducing agent and tin can reduce and thereby neutralize ROS such as hydrogen peroxide.[60] In improver to its directly antioxidant effects, ascorbic acid is likewise a substrate for the antioxidant enzyme ascorbate peroxidase, a function that is particularly important in stress resistance in plants.[61]

Glutathione

Glutathione is a cysteine-containing peptide found in mostforms of aerobic life.[62] It is not required in the nutrition and is instead synthesized in cells from its constituent amino acids. Glutathione has antioxidant backdrop since the thiol group in its cysteine moiety is a reducing agent and tin be reversibly oxidized and reduced. In cells, glutathione is maintained in the reduced form by the enzyme glutathione reductase and in turn reduces other metabolites and enzyme systems also equally reacting directly with oxidants.[63] Due to its loftier concentration and central role in maintaining the cell'due south redox country, glutathione is one of the most important cellular antioxidants.[33] In some organisms, glutathione is replaced past other thiols, such as by mycothiol in the actinomycetes, or by trypanothione in the kinetoplastids.[64]

Melatonin

Melatonin, besides known chemically as N-acetyl-5-methoxytryptamine,[65] is a naturally occurring hormone constitute in animals and in some other living organisms, including algae.[66] Melatonin is a powerful antioxidant that can easily cross prison cell membranes and the blood–brain barrier.[67] Unlike other antioxidants, melatonin does non undergo redox cycling, which is the ability of a molecule to undergo repeated reduction and oxidation. Melatonin, once oxidized, cannot be reduced to its one-time state because it forms several stable end-products upon reacting with free radicals. Therefore, it has been referred to as a terminal (or suicidal) antioxidant.[68]

Tocopherols and tocotrienols (Vitamin E)

Vitamin Eastward is the commonage name for a gear up of eight related tocopherols and tocotrienols, which are fat-soluble vitamins with antioxidant properties.[69] Of these, α-tocopherol has been most studied equally information technology has the highest bioavailability, with the trunk preferentially absorbing and metabolizing this form.[70] It has been claimed that the α-tocopherol course is the most important lipid-soluble antioxidant, and that it protects membranes from oxidation by reacting with lipid radicals produced in the lipid peroxidation concatenation reaction.[71] This removes the complimentary radical intermediates and prevents the propagation reaction from standing. This reaction produces oxidized α-tocopheroxyl radicals that can be recycled back to the active reduced form through reduction by other antioxidants, such as ascorbate, retinol, or ubiquinol.[72]

Uric acid

Uric acid accounts for roughly one-half the antioxidant power of plasma. In fact, uric acid may have substituted for ascorbate in man evolution.[73] However, like ascorbate, uric acrid tin likewise mediate the production of active oxygen species.

PLANTS AS SOURCE OF ANTIOXIDANTS

Synthetic and natural food antioxidants are used routinely in foods and medicine especially those containing oils and fats to protect the food against oxidation. At that place are a number of synthetic phenolic antioxidants, butylated hydroxytoluene (BHT) and butylated hydroxyanisole (BHA) being prominent examples. These compounds accept been widely uses every bit antioxidants in food industry, cosmetics, and therapeutic manufacture. However, some physical properties of BHT and BHA such as their high volatility and instability at elevated temperature, strict legislation on the apply of synthetic food additives, carcinogenic nature of some constructed antioxidants, and consumer preferences have shifted the attending of manufacturers from synthetic to natural antioxidants.[74] In view of increasing risk factors of man to diverse deadly diseases, in that location has been a global tendency toward the utilise of natural substance present in medicinal plants and dietary plats as therapeutic antioxidants. It has been reported that there is an inverse relationship between the dietary intake of antioxidant-rich food and medicinal plants and incidence of homo diseases. The use of natural antioxidants in food, cosmetic, and therapeutic industry would exist promising alternative for synthetic antioxidants in respect of low cost, highly compatible with dietary intake and no harmful effects inside the man body. Many antioxidant compounds, naturally occurring in institute sources accept been identified as gratuitous radical or active oxygen scavengers.[75] Attempts have been made to study the antioxidant potential of a wide variety of vegetables like potato, spinach, tomatoes, and legumes.[76] There are several reports showing antioxidant potential of fruits.[77] Strong antioxidants activities have been found in berries, cherries, citrus, prunes, and olives. Dark-green and black teas have been extensively studied in the recent by for antioxidant backdrop since they contain up to 30% of the dry weight as phenolic compounds.[78]

Apart from the dietary sources, Indian medicinal plants also provide antioxidants and these include (with common/ayurvedic names in brackets) Acacia catechu (kair), Aegle marmelos (Bengal quince, Bel), Allium cepa (Onion), A. sativum (Garlic, Lahasuna), Aleo vera (Indain aloe, Ghritkumari), Amomum subulatum (Greater cardamom, Bari elachi), Andrographis paniculata (Kiryat), Asparagus recemosus (Shatavari), Azadirachta indica (Neem, Nimba), Bacopa monniera (Brahmi), Butea monosperma (Palas, Dhak), Camellia sinensis (Green tea), Cinnamomum verum (Cinnamon), Cinnamomum tamala (Tejpat), Curcma longa (Turmeric, Haridra), Emblica officinalis (Inhian gooseberry, Amlaki), Glycyrrhiza glapra (Yashtimudhu), Hemidesmus indicus (Indian Sarasparilla, Anantamul), Indigofera tinctoria, Mangifera indica (Mango, Amra), Momordica charantia (Biting gourd), Murraya koenigii (Curry leafage), Nigella sativa (Black cumin), Ocimum sanctum (Holy basil, Tusil), Onosma echioides (Ratanjyot), Picrorrhiza kurroa (Katuka), Piper protrude, Plumbago zeylancia (Chitrak), Sesamum indicum, Sida cordifolia,Spirulina fusiformis (Alga), Swertia decursata, Syzigium cumini (Jamun), Terminalia ariuna (Arjun), Terminalia bellarica (Beheda), Tinospora cordifolia (Center leaved moonseed, Guduchi), Trigonella foenum-graecium (Fenugreek), Withania somifera (Winter cherry, Ashwangandha), and Zingiber officinalis (Ginger).[79]

ANTIOXIDANT POTENTIAL OF INDIAN FUNCTIONAL FOODS

Concepts of functional foods and nutraceuticals

In the last decade, preventive medicine has undergone a great advance, particularly in developed countries. Research has demonstrated that nutrition plays a crucial role in the prevention of chronic diseases, as nigh of them tin exist related to nutrition. Functional food enters the concept of considering food not only necessary for living merely also as a source of mental and physical well-being, contributing to the prevention and reduction of take chances factors for several diseases or enhancing sure physiological functions.[80] A nutrient can be regarded as functional if information technology is satisfactorily demonstrated to affect beneficially 1 or more target functions in the body, across adequate nutritional effects, in a fashion which is relevant to either the state of well being and health or reduction of the take chances of a disease. The benign effects could be either maintenance or promotion of a state of well being or health and/or a reduction of risk of a pathologic process or a disease.[81] Whole foods represent the simplest instance of functional food. Broccoli, carrots, and tomatoes are considered functional foods because of their high contents of physiologically active components (sulforaphen, B-carotene, and lycopene, respectively). Light-green vegetables and spices like mustard and turmeric, used extensively in Indian cuisine, also can autumn nether this category.[82] "Nutraceutical" is a term coined in 1979 by Stephen DeFelice.[83] It is defined "as a food or parts of food that provide medical or wellness benefits, including the prevention and treatment of disease." Nutraceuticals may range from isolated nutrients, dietary supplements, and diets to genetically engineered "designer" food, herbal products, and processed products such equally cereals, soups, and beverages. A nutraceutical is any nontoxic food excerpt supplement that has scientifically proven wellness benefits for both the treatment and prevention of affliction.[84] The increasing interest in nutraceuticals reflects the fact that consumers hear almost epidemiological studies indicating that a specific diet or component of the diet is associated with a lower risk for a certain disease. The major active nutraceutical ingredients in plants are flavonoids. As is typical for phenolic compounds, they can act every bit potent antioxidants and metal chelators. They as well take long been recognized to possess anti-inflammatory, antiallergic, hepatoprotective, antithrombotic, antiviral, and anticarcinogenic activities.[85]

Indian dietary and medicinal plants as functional foods

Ingredients that make food functional are dietary fibers, vitamins, minerals, antioxidants, oligosaccharides, essential fatty acids (omega-3), lactic acid bacteria cultures, and lignins. Many of these are present in medicinal plants. Indian systems of medicine believe that complex diseases can be treated with circuitous combination of botanicals different in west, with single drugs. Whole foods are hence used in Bharat as functional foods rather than supplements. Some medicinal plants and dietary constituents having functional attributes are spices such as onion, garlic, mustard, red chilies, turmeric, clove, cinnamon, saffron, curry leaf, fenugreek, and ginger. Some herbs as Bixa orellana and vegetables like amla, wheat grass, soyabean, and Gracinia cambogia accept antitumor furnishings. Other medicinal plants with functional properties include A.marmelos, A. cepa, Aloe vera, A. paniculata, Azadirachta india, and Brassica juncea.[86]

Determination

Gratis radicals damage contributes to the etiology of many chronic health problems such as cardiovascular and inflammatory affliction, cataract, and cancer. Antioxidants prevent gratuitous radical induced tissue harm by preventing the formation of radicals, scavenging them, or by promoting their decomposition. Synthetic antioxidants are recently reported to be unsafe to human health. Thus the search for constructive, nontoxic natural compounds with antioxidative activity has been intensified in recent years. In add-on to endogenous antioxidant defense systems, consumption of dietary and establish-derived antioxidants appears to exist a suitable culling. Dietary and other components of plants form a major source of antioxidants. The traditional Indian diet, spices, and medicinal plants are rich sources of natural antioxidants; higher intake of foods with functional attributes including high level of antioxidants in antioxidants in functional foods is one strategy that is gaining importance.

Newer approaches utilizing collaborative research and modernistic technology in combination with established traditional health principles volition yield dividends in near hereafter in improving health, especially amid people who do not have access to the utilise of costlier western systems of medicine.

Footnotes

Source of Support: Nada

Conflict of Involvement: None declared

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