Posts tagged Impact

1. Introduction to the aerobic environment are the most dangerous products of reactive oxygen species. The role of antioxidants is reactive oxygen intermediates (ROI) in the body to detoxify. In recent years antioxidants have great interest in the popular press as potential treatment for a variety of pathological conditions including cancer and other diseases such as cancer, chronic inflammatory diseases attracted and aging (Delany L. 1993).

natural inhibitors of oxidation in food generally originate from plant materials. The active components, namely, phenols and polyphenols, including tocopherols, are secondary metabolites of plants and are the first derivatives of phenylalanine and in some cases and in some plant tyrosine. The resultant phenylpropanoids may then be further processed to produce derivatives of benzoic acid and flavonoids, isoflavones and other polyphenols complex. Thus, natural food phenolics present as a complex mixture of compounds present a cocktail of many active components in the free form, provide esterified, glycosylated and bound (and Naczk Shahidi, 1995). The effectiveness of the preparations is therefore dictated by their chemical structure and dominated by the hydrophilic-lipophilic balance (HLB) of the molecules in a concentration-dependent manner, and into the system. Yet include the action of natural antioxidants may be several mechanisms, depending on the source and the possible presence of synergists and antagonists.

* Correspondence to: wasim04101981@yahoo.co.in

To use an antioxidant in food preparation, it must be safe, easy to integrated, effective at low concentrations, odor, taste or color reaction, heat-stable, not volatile and do with decency properties and economy. In addition, the possible effects of the present and antagonists are carefully examined as an antioxidant may be pro-oxidant in the presence of certain other molecules. For example, chlorophylls overwhelm the antioxidant activity of phenols by photosensitized oxidation and ions of transition metals such as iron and copper, the conditions for this oxidation to make. The synergy between the various phenolic antioxidants and between phenolics and non-phenolic should be considered in all applications.

Definition Free radicals are atoms or groups of atoms formed with an odd (unpaired) number of electrons and can, when oxygen interacts with certain molecules. Once formed these highly reactive radicals can start a chain reaction. Their main threat comes from the damage they do when they react with important cellular components such as DNA or the cell membrane. Cells may function poorly or die if this is the case. To prevent free radicals from the body with a defense of antioxidants.

An antioxidant is a substance that at low concentrations compared to the oxidizable substrate significantly delays or reduces oxidation of the substrate (Halliwell, 1995).

Antioxidants get their name because they combat oxidation. These are substances that protect other chemicals of the body from harmful oxidation by free radical and other reactive oxygen species in the body and thus prevents the oxidation process. During this reaction the antioxidant sacrifices itself by oxidized. However, the supply is not unlimited antioxidant as an antioxidant molecule can only react with a single free radicals. Therefore, there is a constant need to replenish antioxidant, either endogenously or through supplementation.

2 Literature Review

Qin Yan and Zhu. al. (2001) studied the antioxidant properties of oolong tea tree. inhibitory effect on FeCl2 / H2O2 – induced damage and the inhibitory effect on the hemolysis of red blood cells of oolong tea extract (OTE) were evaluated. The OTE was found a high antioxidant activity in all model system. When OTE was separated into fractions of molecular weight, it was found that part greatest amount of phenolic compound (low molecular weight) have high antioxidant activity.

Yi Fang Chu and Wu Xianzona (2002) reported that increased consumption of fruits and vegetables containing high levels have been recommended in secondary plant compounds to chronic diseases, to prevent oxidative stress in the human body. 10 common vegetables were selected. The study showed that red peeper highest antioxidant activity of broccoli, carrots, spinach, cabbage, onions, potatoes, etc., was followed

Sun Jie and Yi Fang (2002) reported that consumption of fruit and vegetables with a reduced risk of chronic diseases linked because of the antioxidants. They believe vitamin C is the most important antioxidant in fruits.

Lee Jeong-Chae (2002) evaluated a mixture of ethanol extract from the root Opuntia determine the mechanism of anti-oxidant. The ethanol extract showed a concentration-dependent inhibition of linoleic acid oxidation.

Keni Chi Ya na Gimoto and. al. (2002) studied the antioxidant activity of column chromatographic fractions obtained from ground coffee to find antioxidant and assess the benefits of drinking coffee. can coffee contains many antioxidants and consumption of antioxidant-rich brewed coffee, the disease to prevent oxidative damage.

Anaberta Cardadose et.al. (2003) showed that the fraction extracted with ethyl acetate have antioxidant activity with potent free radical scavengers.

Joon Hee Lee et al. al. (2003) reported that the Muscat grape and its product range bi winary have antioxidant capacity.

Kizhiyedathu and. al. (2003) reported that the recovered oil from sesame cake extract and a free radical scavenger antioxidant properties and the property.

KS and Seiichiro Isobe Shivashankara (2004) reported that if greenhouse tree ripe (TR) and mature green (MG) mangoes (cv. Irwin) were added to a strong electric field treatment exposed before 20 and 30 days of storage fruit 5O C. MG were allowed to ripen at room temperature after storage at low temperatures and antioxidant capacity were estimated before and after the storage period. Antioxidant capacity of fruits remained unchanged up to 20 days shelf life and decrease thereafter. Antioxidant capacity of fruits was significantly correlated only ascorbic acid.

Joseph O. Kuti et al (2004) reported that total phenolics and antioxidant capacity were higher than raw, cooked leaf extracts. Cooking reduced antioxidant activity. The results of their study indicate that tree spinach leaves are a rich source of natural antioxidants.

Mahinda Wella Singh and Kirk Parkin (2004) has studied a wide range of antioxidant activity in the crude extract of beetroot tissue. Betalaines pigment has been shown to possess different antioxidant function.

3 Table 1 Classification of antioxidants. Classification of antioxidants based on their roles

Antioxidant

Role

comments

superoxide dismutase (SOD)

mitochondrial

cytoplasmic

extracellular

dismutates O2 · of H2O2

/ p>

contains copper and zinc (CuZnSOD)

contains copper (CuSOD)

Catalase

dismutates

H2O2

tetrameric hemoprotein in peroxisomes

/ p> glutathione peroxidase (GSH. Px)

selenoproteins (contains Se2 +)

main ‘in the cytosol and mitochondria

Uses GSH

/ p> vitamins

Alpha tocopherol

Breaks lipid peroxidation

lipid peroxides and * and * OH scavenger O2

fat-soluble vitamin

Beta-carotene

scans · OH, · O2 peroxy

prevents the oxidation of vitamin A

Linked

Transition Metals

/ p> fat-soluble vitamin

ascorbic acid

scans directly O2 · OH, and H2O2

p Neutralizes <> oxidants from stimulated Contributes to the regeneration of Vitamin E

Table 2 summarizes. Classification of antioxidants on their sources

Source Material

Basic example

antioxidant /

p> Oils

tocopherols

Tropical oils

/ p>

vegetable oil

herbs and spices

rosemary and sage

cereal

wheat and flavenoids

Pulses

<

soy / p>

seed

rapeseed and mustard

The phenolic acids and phenylpropanoids

tea

Green tea

catechins and polyphenols

Fruit of the skin and grapeseed oil and skin / p> The tannins and polyphenols

4 . Chemical antioxidant vitamins about 4.1 Alpha Tocopherol (Vitamin E) Vitamin E-2D structure – C26H44O2 4.1.1 Nomenclature It is the most important fat-soluble antioxidant in cells is present. The name comes from the early 1920s, was found to be vegetable oil to restore fertility in rats. This unknown substance was used as vitamin E Sure 1924.The term tocopherol was from Evans. Since this compound has an animal to have offspring, he named it tocopherol from the Greek word Tokoš, meaning birth and PHERO, the verb, meaning to make. To indicate the type of the alcohol molecule, the OL has been added to the end.

Vitamin E is a collective term that all the facilities, the biological activity of natural vitamin E, d-alpha-tocopherol have included. In nature, eight substances have been found to have vitamin E activity: d-alpha-beta-D-, D-gamma-and delta-tocopherol are different (the methylation site and the saturation of the chain Side (Kellof et al 1996th ), and d-alpha-D-beta-, gamma-d-and d-delta-tocotrienol acetate and succinate also derivatives of natural tocopherols have vitamin E activity, and synthetic tocopherols and their acetate and succinate. derivatives.

Among all d-alpha-tocopherol is the biopotency, and its activity is the standard by which all others must be compared. It is the predominant isomer in plasma.

4.1.2 source and nature

Vitamin E is an essential nutrient that functions as an antioxidant in the human body. It is important, by definition, because the body does not manufacture its own vitamin E and have to be supplied through diet and supplements.

tocopherols in oils nuts, seeds, wheat germ and cereal. recording seems to be associated with the absorption of intestinal fat. About 40% of the ingested tocopherol is absorbed. Most of the tocopherols in the blood entering through the lymphatic system where they are associated with chylomicrons. Vitamin E been shown to be stored in fatty tissue. phospholipids of mitochondria and endoplasmic reticulum endoplasmic and plasma membranes possess affinities for alpha-tocopherol and vitamin tends to concentrate in these pages.

is 4.1.3

mechanisms of action of vitamin E more accurately described as an antioxidant vitamin. Unlike most vitamins, it does not act as a cofactor of enzymatic reactions.

In addition, do not develop, produce vitamin E deficiency disease with symptoms such as scurvy or beriberi quickly manifest symptoms. by vitamin E deficiency connect only develop in cases with fat malabsorption syndromes, premature infants and patients with total parenteral nutrition. effects of inadequate intake of vitamin E is usually over a long period, typically decades, and bringing them to chronic diseases such as cancer and atherosclerosis related.

Therefore, his main function to prevent peroxidation of membrane phospholipids, and avoids damage to the cell membrane through its antioxidant effect of tocopherol, the lipophilicity makes it possible to search within the cell membrane bilayers (Halliway and Getteridge 1992; Borg, 1993). transferred Tocopherol-OH can a hydrogen atom with a single. electron to a free radical, so the rest before it can interact with cell membrane proteins or generate lipid peroxidation. When tocopherol-OH combines with free radicals, it · is O-tocopherol, a radical himself. If ascorbic acid is · tocopherol plus ascorbate-O this (with its available hydrogen) semidehydroascorbate income (low radical) plus tocopherol-OH (Halliway and Guttmann, 1992). For a dynamic ROI (Reactive Oxygen Intermediate) is eliminated and a low ROI (dehydroascorbate) formed, and tocopherol-OH is regenerated. Despite this complex defense system, there are no known endogenous enzymatic antioxidant systems hydroxyl radical.

Vitamin E also promotes immune response. Some studies have reduced incidence of infections in vitamin E levels are high, and vitamin E can inhibit at the initiation of cancer through improved immune competence.

Vitamin E also has a direct chemical function. It inhibits the conversion of nitrites in smoked, pickled and cured to foods nitrosamines in the stomach. Nitrosamines are promoters of solid tumors.

Alpha-tocopherol has been shown to be able to reduce trivalent iron to iron (ie, as pro-oxidant). In addition, the ability of alpha-tocopherol to act like a pro oxidant (reducing agent) or antioxidant depends on whether all alpha-tocopherol in the conversion of ferrous iron are used to iron or whether, as a result of this interaction is remaining alpha-tocopherol available to make up for the catch resulting ROI (Yamamoto and Nike, 1988).

4.1.4 Therapeutic effects

Ø Vitamin E, the incidence of ischemic heart disease (Gey et al reduced. 1991).

Ø the incidence of cataract (Packer, 1991 decreased, 1992)

reduced the incidence of osteoarthritis (Blankenhorn, 1986)

Ø the incidence of rheumatoid arthritis (Kheir El-Al drops .. and yours. 1992).

4, 2 ascorbic acid (vitamin C) Vitamin C-2D structure C6H8O6 4.2.1 source and nature

ascorbic acid (vitamin C) is a soluble water, antioxidants found in citrus fruits, potatoes, tomatoes and leafy green vegetables.

People inability to L-ascorbic acid from D-glucose, synthesize because the lack of the enzyme L-oxidase gulacolactone (Ensimnger and al.1995). Man must therefore obtain ascorbic acid from food.

4.2.2 The mechanism of action Chemoprevention is of vitamin C attributed to two of his properties. It is a water-soluble antioxidant chain breaking (Ishwarial and 1991). As an antioxidant, free radicals and reactive molecules of oxygen produced during the detoxification pathways. It also prevents the formation of carcinogens reminiscent of precursor compounds (Block and Menkes, 1988). The structure of ascorbic acid on glucose, where it originated in most mammals.

A key feature is its ability to act as a reducing agent (electron donor). ascorbic acid is a reducing agent with a potential hydrogen + O.08V, making it capable of reducing compounds such as oxygen, nitrate and molecular Cytochrome c and a donation of one electron by ascorbate gives the semi-dehydroascorbate radical (DHA). Ascorbate reacts rapidly with O2 · ⁻ and faster with OH • Enter DHA. DHA, may itself be a source of vitamin C.

ascorbic acid + 2O2 · + 2H + DHA ® H2O2 act

<> It was also shown that vitamin C is stronger than a-tocopherol in inhibiting the oxidation of LDL (low density lipoprotein) in a cell-free system (Jialal and 1990). coincubation with LDL-ascorbate in similar oxidative condition inhibited LDL oxidation and resulted in the conservation of endogenous antioxidant in LDL particles (Ishwarial et al, 1991). The concentration used to inhibit the oxidation of LDL ascorbate (40-60 mm) is well within the normal plasma (23 to 85 h).

Vitamin C also contributes to the regeneration of vitamin E. It is related oxidized membrane to react with a radical tocopheroxyl, which is oxidized to the generation of tocopherol in this process itself to dehydroascorbic acid (Ward &;. Peters 1995) Vitamin C supplementation in animals leads to increased plasma and tissue levels of vitamin E.

4.3 Beta-carotene

Me

2-D Structure of beta-carotene 4.3.1 source and nature Carotenoids are pigmented micronutrients in fruits and vegetables found

.

carotenoids are precursors of vitamin A and have an antioxidant effect. While over 600 carotenoids in the food, the most common forms are alpha-carotene, beta-carotene, lycopene found, crocetin, canthaxanthin, and fucoxanthin. Beta-carotene is studied the most. It consists of two molecules of vitamin A, retinol () combined. dietary beta-carotene Retinol is converted in the intestinal mucosa together.

4.3. two mechanisms of action

The antioxidant function of beta-carotene is due to its ability to remove singlet oxygen to scavenge free radicals and cell membrane lipids to protect against the harmful effects of oxidative degradation (Krinsky and Deneke, 1982, Santa Maria et al, 1991). The quenching involves a physical reaction in which the energy of the excited oxygen is transferred to the carotenoid. form an excited state molecule (Krinsky, 1993). cooling the singlet oxygen is the basis of beta-carotene is known to remove therapeutic efficacy in erythropoietic protoporphyria (light sensitivity of the skin) (Matthews-Roth, 1993). The ability of beta-carotene and other carotenoids to excited oxygen is limited because the carotenoid itself can be oxidized during the process (autoxidation). Burton and Ingold (Burton and Ingold, 1984) and others have shown that even the oxidation of beta-carotene in vitro dose-dependent and dependent on the oxygen concentration. At higher concentrations, It can be used as a pro-oxidative function and activate proteases.

In addition to singlet oxygen, carotenoids are also thought to clear free radicals for others. It is also suggested that beta-carotene may react directly with the peroxyl radical at low oxygen tension, some synergy with vitamin E can react with peroxyl radicals at higher oxygen tensions

carotenoids also (Cotgreave et al 1988) .. It was reported a number of biological activities including immune enhancement, inhibition of have mutagenesis and transformation;.. and regression of precancerous lesions

5

chemistry of some antioxidant enzymes including superoxide dismutase, catalase and peroxidases

5.1 superoxide dismutase (SOD) 5.1.1 source and nature

SOD is an enzyme found endogenously produced intracellular in almost every cell in the body.Cellular SOD is actually represented by a group of metalloenzymes with various prosthetic groups.The prevalence of the enzyme copper-zinc (CuZn) SOD, which is a stable dimeric protein (32,000 D) SOD appears in three forms: (1) Cu-Zn-SOD in the cytoplasm with two subunits, and (2) Mn-SOD in the mitochondria (Mayes, 1993; Warner, 1994) A third extracellular SOD was.. recently described contains Copper (CuSOD)

2O2 · + 2H + SOD ®. H2O2 + O2

5.1.2 Mechanism of action SOD is

as fundamental in the process of eliminating ROI by reduction (adding an electron) superoxide form H2O2. catalase and glutathione peroxidase, selenium-dependent responsible for the reduction of H2O2 to H2O.

interaction with the respective enzymes superoxide and H2O2 closely with a feedback-regulated system. Excessive superoxide inhibits glutathione peroxidase and catalase modulate the equation from H2O2 to H2O (see Figure 5) The increase of H2O2 slowly inactivates CuZn-SOD, catalase and glutathione peroxidase Meanwhile, by H2O2, conserve SOD;.. and SOD, superoxide reduction, catalase and glutathione reserves This feedback system, stable low SOD, glutathione. peroxidase and catalase and superoxide and H2O2 are required to keep the entire system into a fully functioning state (Fridovich, 1993).

SOD also has an antioxidant effect by O2 ⁻ · else in the reduction of Fe3 + to Fe2 lead + and promote this · OH formation. When the catalase activity is insufficient to the metabolism of H2O2 SOD activity produces increased oxidative tissue. Therefore, it was found, antioxidant enzymes, the balance as a system function, disorders of this system would result in the promotion of oxidation.

5.2, the enzyme catalase

This enzyme is an enzyme in most cell proteins Aerobics in animal tissues. catalase is present in all organs of the body are , concentrated especially in the liver and red blood cells. The brain, heart, skeletal muscle contains only small amounts.

catalase and glutathione peroxidase search hydrogen peroxide and convert it to water and diatomic oxygen. An increased production of SOD without a subsequent increase in catalase and glutathione peroxidase leads to the accumulation of hydrogen peroxide, which is converted to the hydroxyl radical. In fact, research in the pathogenesis of Down syndrome, the existence of trisomy 21 leads to an overproduction of SOD, the gene is for the also on chromosome 21 revealed. This interesting finding is that it reveals a possible genetic link to the increased activity of free radicals. (Kriner, 1992)

5.3 is enzyme glutathione peroxidase

glutathione redox cycle a central mechanism for the reduction of intracellular hydroperoxides.

5.3.1 source and nature

It is a tetrameric protein 85 000 D. It has 4 atoms of selenium (Se) fractions as seleno-cysteine, that the catalytic activity confers. One of the key requirements is bound reduced glutathione as cosubstrate.

H2O2 by glutathione oxidation of glutathione (GSH) (Equation A) H2O. Rereduction of oxidized glutathione (GSSG) is then by glutathione reductase (Equation B) These enzymes also require trace metal cofactors for maximum effectiveness, including glutathione peroxidase selenium catalyzed. copper, zinc, manganese, or SOD, and iron for catalase (Halliwell, 1995).

H2O2 + 2 GSH GSSG ® + 2 H2O (equation A) <

GSSG + NADPH + H + ® 2 GSH + NADP + (equation B <. />) p> / p /

6 mode of action of antioxidants / p> There are four ways:>

Pause 1.Chain as alpha-tocopherol, to catch the acts in lipid phase “Rod” group

2.Reducing concentration of reactive oxygen species such as glutathione 3.Scavenging introduction of such radicals superoxide dismutase, which acts in the aqueous phase to trap superoxide free radicals

4.Chelating catalysts of transition metals. A group of compounds has an antioxidant function by sequestration of transition metals, which are well-established pro-oxidants. In this way, transferrin, lactoferrin, ferritin and function to keep iron-oxidative stress in check and ceruloplasmin and 7 induced albumin as a copper complexing agent.

antioxidant system in our body

The body has several endogenous antioxidant systems, . designed to cope with the production of ROI, these systems can be divided into groups by enzymatic and nonenzymatic

The enzymatic antioxidants include superoxide dismutase (SOD), which is the reaction of H2O2 and O2 ⁻ · H2O catalyzed;. catalase, which then converts H2O2 to H2O and O2, and glutathione peroxidase, which non-enzymatic antioxidants are fat-soluble vitamins, vitamin E and vitamin A or provitamin. A (beta carotene), vitamin C and soluble in water and GSH. Vitamin E as antioxidant, the most important has been described chain terminators play found in humans (Packer, 1992). Because of its lipid solubility, vitamin E is in the cell membranes, where it interrupts lipid peroxidation and may play a role in modulating signaling pathways of intracellular signaling pathways that rely on ROI (Kagan et al 1990; .. Azzi et al 1993) Vitamin E can also directly delete ROI, including: • O2 · OH, and (Algayer et al 1992) O2

8-commercial sources of natural antioxidants …

Preparations most common natural antioxidant on the market are mixed tocopherols, the by-products of refining of vegetable oils. In addition, spices oleoresins and extracts such as rosemary and sage, green tea extract and other herbal mixtures, such as mustard and certain unsaponifiables Oils and of course, carotenoids are also important (Table 2) (Ho et al, 1994;. Shahidi, 1997)

9 effectiveness of antioxidants in different systems ..

The chemical composition and structure of the active components extracted important factors for the effectiveness of natural antioxidants in different foods. This phenolic compounds with ortho-and para-dihydroxylation or hydroxy and methoxy are more effective than simple phenolics. In addition, phenylpropanoids with extended conjugation effective than benzoic acid derivatives . Also, the hydrophilic and lipophilic substances is determined by the ability of antioxidants in the systems. In general, more hydrophilic antioxidants to stabilize better engine oil temperature and oil in water, while the lipophilic antioxidant activity follows the opposite trend. There are also many taking into account other factors will be considered in the review and selection of antioxidants and extracts for food applications. More precisely, attention should be paid in part to the effects of chlorophyll photosensitizing course. Moreover, the speed optimized the intake of antioxidants in food and considers the use of chelating agents, if appropriate. Many antioxidants behave prooxidatively at high concentrations or when present with