DEFENCE MECHANISM OF ANTIOXIDANT IN HUMAN BODY

presented By Aamir Majeed 15-arid-356

Contents IntroductionWhat is free radicalMain source of antioxidantAntioxidant defence systemLevel of antioxidant actionClassification of Antioxidant Antioxidant and their intake levelFactor potentially effecting the bioavailability of antioxidant.Importance of antioxidant in human body.

Introduction

Introduction

An antioxidant is a molecule that inhibits the oxidation of other molecules in human body. Antioxidants protect the body from damage caused by harmful molecules called free radicals.This damage is a factor in the development of  blood vessel disease atherosclerosis, cancer and other conditions.

What is a free radical ?

Free radical is an atom that has at list one unpaired electron.Free radical are released are during normal metabolism, as well as by pollution, smoking, radiation & stress ,air pollution, Alcohol intake , Toxins, High blood sugar levels etc.Free radicals are also a by product of converting food into energy.Under normal circumstance the body keep them in check.

Main sources of Antioxidant

Rank food Serving size

Total antioxidant capacity per serving size

1 Small red beans ½- cup 137272 Wild blueberry 1-cup 134273 Red kidney bean ½ -cup 132594 Blueberry 1-cup 90195 cranberry 1-cup 89836 blackberry 1-cup 77017 strawberry 1-cup 59388 Red delicious apple 1-cup 59009 Sweet cherry 1-cup 487310 Black plum 1-cup 484411 Black bean ½ cup 418112 plum 1-cup 411813 Gala apple 1-cup 3903

Antioxidant defense system(ADS).

A biological antioxidant may be defined as a substance(present in low concentrations compared to an oxidizable substrate) that significantly delays or inhibits oxidation of a substrate. Substance that neutralize potential ill effect of free radicals are generally grouped in so called a Antioxidant defense system(ADS).

Mode of Antioxidant defense system (ADS)

Antioxidant defense system (ADS) traditionally have been termed .

primary defense systemsecondary defense systemPrimary defense systemIncludes antioxidant compounds like a Vitamin A,E,C and Glutathione and uric acid.b) AO scavenging enzymes such as peroxidasesSecondary defense systemIncludes Lipo lytic enzymes, Phospholipases, pro teo lytic enzymes and DNA repair enzymes

Some Antioxidant & their mode of action.

Example of antioxidant action

Levels of Antioxidant ActionAntioxidants, capable of neutralizing free radicals or their actions at the following level1-Prevention2-Interception 3-Repair.Preventive antioxidants Attempt to stop the formation of ROS. These include superoxide dismutase (SOD) that catalyses the dismutation of superoxide to H2O2 and catalase that breaks it down to water.Interception of free radicalsIs mainly by radical scavenging, while at the secondary level scavenging of peroxyl radicals are effected. The effectors include various antioxidants like vitamins C and E, glutathione, other thiol compounds, carotenoids, flavonoids, etc.At the repair and reconstitution level, mainly repair enzymes are involved e.g ligase enzyme

About 90% of the oxygen in the body is utilized in small compartments in living cell called mitochondria.It produce ATP most of the generation of oxygen free radicals that occur with in the human body take place with in mitochondria .

Classification of antioxidant.Antioxidants are classified into two broad divisions, depending on whether

they are soluble in water (hydrophilic) in lipids (lipophilic)In general, water-soluble antioxidants react with oxidants in the cell cytosol and the blood plasma .while lipid-soluble antioxidants protect cell membranes from lipid peroxidation.. The different antioxidants are present at a wide range of concentrations in body fluids and tissues, with some such as glutathione or ubiquinone mostly present within cells, while others such as uric acid are more evenly distributed.

Mechanism of antioxidant working.

Some Antioxidant and their intake level

antioxidant Per daily dose (1 capsule)

RDA %age

Vitamin A 1333 IU 50

Biotin 80 micro gram 200

Vitamin C 80 micro gram 100

Vitamin E 50 micro grm 125

selenium 25 micro gram 46

Molybdenum 50 micro gram 100

Conti……

"More than 70% of Americans will die prematurely from diseases caused by or compounded by deficiencies of the antioxidant network… these conditions can be prevented, controlled, and in some cases even cured."

Dr. Lester Packer, PhD.

Factors potentially affecting antioxidant bioavailability.

 

Importance of Antioxidant in human body

Negative impact of antioxidants in human body

Once in the body, free radicals are destructive. They alter cellular structure and function. They initiate disease processes and damage the DNA, or genetic material of the cells, thus disrupting normal, healthy cellular function. Antioxidants are substances, ingested from foods that prevent free radical damage in the body, according to the Harvard School of Public Health.

Summary of antioxidant defense mechanism