Antioxidants General Dentistry / orthodontic courses by Indian dental academy

Leader in continuing dental educationwww.indiandentalacademy.com

INDIAN DENTAL ACADEMY

www.indiandntalacademy.comwww.indiandntalacademy.com

ANTI OXIDENTS

OBJECTIVE : TO DISCUSS THE PROTECTIVE EFFECT OF ANTIOXIDANTS IN PLANTS ( PHYTO CHEMICALS ) & ALSO ABOUT FLAVONOIDS ( BLACK TEA ) & THEOFLAVINS AS A CHEMO PREVENTORS TO ORAL CANCER .

CONCLUSION: CANCER IS A CRAB LIKE DISEASE WHERE 17.9 MILLION PERSONS OF THE WORLD ARE SUFFERING FROM DISEASE

THE MOST IMPORTANT PREDISPOSING FACTORS FOR DEVELOPING CANCER ARE BIDI,CHUTTA,SMOKING KHAINI CHEWING

USE OF ANTIOXIDANTS IS VERY HELPFUL IN PREVENTING MANY DISEASES LIKE CANCER CARDIAC DISEASE & STROKE & ALSO TO MAINTAIN GOOD HEALTH IN LEADING DAILY LIFE


oral cavity is exposed to a lot of carcinogen & is more prone to develop precancerous lesions & condition & also prone to develop oral cancer & malignancy

Proper supplement of vit-A,E,C retinoic acid selenium lipoic acid spirulina & all plant antioxidants has tremendous chemopreventive properties to protect the population from oral cancer

Dietary substitutes can prevent oral cancer at an very early stage These are beta carotene, pro vit- A lipoic acid ,zinc selenium & spirulina


DEFINITION :

ANTIOXIDANTS ARE SUBSTANCES THAT INTERACT WITH FREE RADICALS & WILLINGLY OFFERS ELECTRONS TO THE FREE RADICALS TO PREVENT CELLULAR DAMAGE

ANTIOXIDANTS ARE PRODUCTS WHICH ARE DERIEVED FROM GREEN / COLOURED VEGETABLES / FOOD GRAINS & ALSO FROM ANIMAL FATS / VITAMINS & SPICES LIKE CUCUMARIN OR GARLIC

IT IS A SUBSTANCE ADDED TO A PRODUCT TO PREVENT OR DELAY ITS DETERIORATION BY THE OXYGEN IN AIR


FUNCTION OF ANTI OXIDANTS

It is to remove free oxygen radicals from the body & as a result prevent the cell from cell damage or undergoing any carcinomatous change

Hydroperoxide may undergo hemolytic fission of covelent bonds to form more free radicals . Upon hemolytic fission of the hydroperoxide a free radical chain reaction may again be initiated

Responses & signals during severe oxidative stress cause negetive effect

This negetive effect cause excess reactive oxygen speecies (ros) & low antioxidant defence leads to damage to biomolecules like lipids, DNA,& protiens


Lipid peroxidation cause damage to membrane ion channel ,ion transporters with raised intracellular calcium DNA damage cause strand breakage ,base modification Protien damage cause damage to receptor enzyme

All the above reactions leads to cellular damage with release of more radicals ,cell death & tissue damage carcinogenesis ,atherosclerosis & aging

Superoxide anion generated by xanthene oxidase gives rise to singlet oxygen which subsequently cause lipid peroxidation

Superoxide anion directly effects the activity of catalase&peroxidase results in a chromosome breakage , rearrangement& with increased risk of carcinogenesis


Reactive oxygen speecies (ROS) are superoxide anions hydrogen peroxide Hydroxyl radical Nitric oxide

Production of ROS from various sources Tumour cells Platelets, endothelial cells , fibroblast cells PMNS, monocytes ,B-lymphocytes , eosinophils Glucose oxidase, uric acid oxidase

Hydoxyl anion cause DNA strand breakage,base modification, damage to tumour suppressor gene& enhance expression of proto oncogenes www.indiandntalacademy.comwww.indiandntalacademy.com

FREE RADICAL MEDIATED DISEASES ARE :

Aging , arthritis , asthma, bronchopulmonary dysplasia,pulmonary fibrosis ,autoimmune diseases & cancer .

ANTIOXDANT DEFENCE SYSTEM IS CLASSIFIED AS 1) Enzymatic 2) Non enzymatic i) Nutrient superoxide dysmutase Alpha tocoferol glutathione peroxidase beta carotene catalase ascorbate glutathione reductase ii) Non nutrient glutathione transferase ceruloplasmin transferrin uric acid


ENZYMATIC ANTIOXIDANTS : spontaneous dismutation of superoxide ion into hydrogen peroxide by dismutase

Superoxide dismutase is high in tissues where oxygen utilisation is high Eg : liver selenium dependant glutathione peroxidase is abundant in heart brain & lung

NUTRIENT ANTIOXIDANTS :

Act as scavenging agents – vit- E,flavanoids

Act as suppressing agents – decrease tumour progression & promotion which decrease metabolic processes Eg : flavones , phytoestrogens


NON NUTRIENT ANTIOXIDANTS :

They act as inhibitors of carcinogen – inhibit nitosamine formation & prevents progression of malignancy Eg: Ascorbic acid , caffeic acid , ferulic acid

They act as blocking agents : blocks the activities of enzymes which biotransform a procarcinogen to carcinogen Eg : iso thiocyanates


MECANISM OF ACTION OF ANTIOXIDANTS :

1)VIT-A acts by making WBC ,causing destruction of harmful bacteria & virus . It regulates the immune system & helps to fight against infection

2)VIT-A helps to maintain the integrety of skin & mucous membrane which functions as a barrier to bacteria & virus

3)Antioxidant scavenge peroxyl radical

4) Antioxidants manufactures & had defence to connective tissue & eloberate matrix that hold the body together


ACTIONS OF ANTIOXIDANTS

1) VEGETABLES & FRUITS : VIT –C,E,betacarotene selenium & flavanoids provide defense mechanism for removing or scavenging free radicals

Eg : cabbage, turnip

2)SPICES : Turmeric were found to reduce urinary mutagens in smokers & to promote mechanisms that enhance detoxification

Garlic powder has been shown to inhibit cancer development in different species & at different sites / organs

3) VITAMIN –A : retinol is most active & is called preformed vit-A . It can be converted to retinol & retinoic acid


Darkly coloured pigments called provitamin A & carotenoids that can be converted to vit –A

First sign of vit – A deficiency is night blindness .this cause dry ness of cornea & promotes damage to retina & cornea

4) VITAMIN – C : It combats the effect of toxins including ozone,carbon monoxide & heavy metals Inhibits development of cataract ,sickle cell anemia bone disorders & treatment of oral cancer

VITAMIN-C prevents cancer by a) combats peroxidation of lipids –linked with aging & degeneration


b)Work inside the cell to protect DNA from the damage caused by free radicals

c) Vit- c blocks the formation of fatal mutagens

5) LIPOIC ACID : Protect liver & detoxify the body from heavy metal pollutants

lipoic acid reduces the progression of HIV infection to clinical AIDS

LIPOIC ACID HAS BEEN CALLED THE UNIVERSAL ANTIOXIDANT( OR) IDEAL ANTIOXIDANT ( WILD CARD ANTIOXIDANT )

This substitute for other antioxidants such as vit- C,E plays an important role in controlling blood glucose level


6)SPIRULINA : ALSO CALLED GREEN BLOOD Spirulina enhances natural cleansing & detoxification

Spirulina contains components like 9 cis isomer had increased power of antioxidant activity & anticarcinogenesis .

REFERENCES :

1) Antioxidants– Health encyclopedia& reference 2) Antioxidant – wikipedia 3) Antioxidant – benefits & food high in antioxidant 4) Antioxidant– functional food facts 5) The real health risk is not taking antioxidant by –

David Ash & Dr lisbeth Ash www.indiandntalacademy.comwww.indiandntalacademy.com

ACCORDING TO ANTIOXIDANT WIKIPEDIA :

Antioxidants are a group of vitamins ( vit- c,e,carotinoids)that slow or prevent the oxidation of other molecules

Antioxidants are a diverse group of chemicals that can be naturally found in vegetables,fruits & plants

Antioxidants are essential for proper function of immune system . This is because immune cells prevents free radicals & produce normal defense mechanism

Oxidation reactions can produce free radicals which start chain reactions and will damage cells

Too low levels of antioxidants or inhibition of the antioxidant enzymes causes oxidative stress & may damage or kill cells


oxidative stress has been implicated in the pathogenesis of many human diseases Eg: oral cancer, coronary heart disease, neurodegenerative disease

Antioxidants that occur naturally in the body & certain foods may block the damage by donating electrons to stabilize & neutralize the harmful effects of the free radicals

If the level of the free radical in the immune cells surpasses beyond the normal level it negetavely effect the immune system

Imbalance between free radicals & antioxidants in cells due to deficiency in single or multiple number , antioxidants has been reported to result in weakness of immune function .


OXIDATIVE CHALLENGE IN BIOLOGY :

Life requires oxygen for its existence . Oxygen is a highly reactive molecule that damages living organisms by producing reactive oxygen species (ROS )

Organisms contain a complex network of antioxidant metabolites & enzymes that work together to prevent oxidative damage to cellular components such as DNA, protiens & lipids

Antioxidant system either prevent these reactive species from being formed or remove them before they can damage vital components of the cell .

ROS produced in the cells include hydrogen peroxide , hypochlorous acid & free radicals such as hydroxyl ion & the superoxide ion


Hydroxyl radical is particularly unstable & will react rapidly & non specifically with most biological molecules

This species is produced from hydrogen peroxide in metal catalyzed redox reactions such as FENTON reactions

These oxidants can damage cells by starting chemical chain reactions such as lipid peroxidation or by oxidising DNA/ protiens

Damage to DNA can cause mutations & possibly cancer. If not reversed by DNA mechanisms damage to protiens cause enzyme inhibition , denaturation & protien degradation .

The action of one antioxidant may depend on proper function of other members of antioxdant system


The amount of protection provided by any one antioxidant there fore depends on its concentration ,its reactivity towards the particular ROS species

Synergy & balance is vital in antioxidant activity

Vitamin E prevents lipid peroxidation .but in this processes it becomes oxidised into a damaging tocoperoxyl radical

This process can be reversed by vitamin- c . Vitamin c regenerates vitamin E & glutathione

Glutathione & vitamin E both requires selenium for this action

Avoid taking single vitamins . Choose a properly formulated balance of essential antioxidants .www.indiandntalacademy.comwww.indiandntalacademy.com

CLASSIFICATION :Antioxidants are classified into 2 broad divisions

1) soluble in water ( hydrophlic) : they react with oxidants in cell cytoplasm & blood plasma

2) soluble in lipids ( hydrophobic ) : they protect cell membrane from lipid peroxidation

Antioxidants are synthesised in the body Dietary antioxidants are vit- A,C,E , phenolic acid

chlorophil,carotinoids ,glutathione ,co-enzyme Q,& lycopeneSynthetic diet antioxidants are 1)Butylated hydroxy anisole ( BHA ) 2)Butyl hydroxy tolune ( BHT )

Chemicals with antioxidant activity produced in human body include uric acid , HDL & aminoacids such as arginine


EXAMPLES OF FUNCTIONAL COMPONENTS OF ANTIOXIDANTS :

1)CAROTINOIDS : a) Beta carotene – carrots , fruits b) Leutin – spinach , eggs, citrus c) Lycopene – tomato , chillies

2) Isothiocynates : a) sulforaphane – cauliflower , cabbage

3) Sulfides / Thiols : Garlic, onions


4) FLAVANOIDS :

a) Anthocyanidins – Berries , cherries b) Flavanols ( cathechins, epicathecins ) – Tea, coca c) Flavanones – citrus foods

5) PHENOLS:

a) Caffeic acid , Ferulic acid – Apples , citrus fruits

6) WHOLE GRAINS : Cereal grains


ACTIONS OF ANTIOXIDANTS :

1) By suppressing free radical formation

2)Acts as a scavenger – promote immunity

3) Act as a substrate

ANTIOXIDANT BOOST IMMUNE SYSTEM & PLAYS ROLE IN :

1) Cellular metabolism 2) Signal transduction 3) Gene activation 4 ) Transcription


High density lipo protien (HDL) has inhibitory effect against oxidation of LDL which is implicated with development of atherosclerosis & cardiac diseases

HDL prevents endothelial dysfunction & activation .it maintain the integrity of endothelial cell lining & reduce the deleterious effect of oxidised LDL & levels of thrombogenic factors

Consumption of antioxidants is thought to provide protection against oxidative damage & contribute possitive health benefits

ANTIOXIDANTS PREVENTS 3 MAJOR CAUSES OF DEATH 1) Cancer 2) Cardiac disease 3) Stroke


USES OF ANTIOXIDANTS :

1) Antioxidants have many industrial uses such as preservatives in foods & cosmetics

2) Vitamin E prevents the processes of lip[id peroxidation often by scavenging ROS before they can damage cells

3) Ascorbic acid is a reducing agent & there by neutralize reactive oxygen species

A NEW ERA OF RESEARCH LEAD BY THE STUDY OF HUMAN GENOME SUGGESTS THAT THE INTERPLAY OF HUMAN GENETICS & DIET MAY PLAY A ROLE IN THE DEVELOPMENT OF CHRONIC DISEASES


In the words of Dr. Watter Willet of Harward university ‘’Until quite recently it was taught that every one in the country gets enough vitamins through their diet and that taking vitamin supplements just creates EXPENSIVE URINE .

CONCLUSION : Antioxidants obtained from food sources including fruits , vegetables& whole grains are potentially active in disease risk reduction and can be beneficial to human health


www.indiandentalacademy.comLeader in continuing dental education


Antioxidants General Dentistry / orthodontic courses by Indian dental academy

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