Antioxidants

WEL COME1

AntioxidantsPresented byG. Anvesh Kumar(M Pharm Pharmacology)10T21S0103.Under the guidance ofMrs. Geeta Reddy(Dept of Biotechnology)Anantioxidantis amolecule capable of inhibiting theoxidationof other molecules. Oxidation is achemical reactionthat transferselectronsor hydrogen from a substance to anoxidizing agent.

Oxidation reactions can producefree radicals. In turn, these radicals can startchain reactions.

Types of FreeRadicals

1. Hydroxyl radical (OH)2. Superoxide anion radical (O2)3.Singletoxygen4. Hydrogen peroxide5. Lipid peroxyl free radical6. Nitric oxide7. Alkoxyl radical8. Peroxynitrite

ROS GenerationROS Generation in the Mitochondria:

Hydroxyl radical (OH) Superoxide anion radical (O2)

Non mitochondrial Generation of ROS:

Hydrogen peroxide ROS are also introduced through external sources such as exposure to the sun orpollution. Other mediums include stress, as well as things that people put into their bodies, such as alcoholic beverages, unhealthy foods, and cigarette smoke5Types of antioxidants: Mainly Hydrophilic and HydrophobicAntioxidant enzymes:1. Catalase2. Glutathione peroxidase3. Glutathione reductase4. Super oxide dismutase (both Cu-Zn and Mn)Metals binding proteins:1. Ceruloplasmin2. Ferritin3. Lactoferrin4. Metallotheinein5. Transferrin6. Hemoglobin7.MyoglobinCommonantioxidants(scavengers)1. Bilirubin2. Carotenoidsa. Beta-carotene b. Alpha-carotenec. Beta-cryptoxanthin d. Luteine. Zeaxanthin f. Lycopene3. Flavonoidsa. Quercetinb. Rutinc. Catechin4. Uric acids5. Thiols (R-SH)6. Coenzyme Q107. Vitamin A, C, E, D.Others antioxidants1. Copper2.glutathione(GSH)3. Alpha lipoic acid 4.Manganise5. Selenium6. Zinc

Mechanism of action of antioxidantsAlpha tocopherol (vitamin E):

Prevent the peroxidation of membrane phospholipids, and avoids cell membrane damage through its antioxidant action Ascorbic acid (vitamin C)

Scavenges free radicals and reactive oxygen molecules, which are produced during metabolic pathways of detoxificationAbility to quench singlet oxygen, scavenge free radicals and protect the cell membrane lipids from the harmful effects of oxidative degradation .Beta Carotene

Superoxide dismutase (SOD) Eliminating ROI byreducing(adding an electron to) superoxide to form H2O2. Catalase and the selenium-dependent glutathione peroxidase are responsible for reducing H2O2to H2O.Catalase and glutathione peroxidase seek out hydrogen peroxide and convert it to water and diatomicoxygen. The catalase enzyme Glutathione peroxidase enzymeGlutathione peroxidase reduces H2O2 to H2O by oxidizing glutathione (GSH)Antioxidant System in our bodySuperoxide dismutase (SOD)CatalaseGlutathione peroxidaseThe enzymatic antioxidants The nonenzymatic antioxidants Vitamins E, C, A or Provitamin A(beta-carotene), GSHPro-oxidant activitiesAntioxidants that are reducing agents can also act as pro-oxidants. For example, vitamin C has antioxidant activity when it reduces oxidizing substances such as hydrogen peroxide, however, it will also reduce metal ions that generate free radicals through theFenton reaction.

2 Fe3++ Ascorbate 2 Fe2++ Dehydroascorbate2 Fe2++ 2 H2O2 2 Fe3++ 2 OH+ 2 OHDetermining Antioxidant Activity ORAC, Oxygen Radical Absorbance Capacity method TRAP, Total Radical-Trapping Antioxidant Parameter method. TEAC, Trolox Equivalent Antioxidant Capacity method DPPH TOSC, Total Oxyradical Scavenging Capacity method PSC, Peroxyl Radical Scavenging Capacity method FRAP, Ferric Reducing/Antioxidant Power method.Oxidative stress in disease:Oxidative stress is thought to contribute to the development of a wide range of diseases includingAlzheimer's disease,Parkinson's disease,the pathologies caused by diabetes,rheumatoid arthritis,andneurodegenerationinmotor neuron diseasesHow to measure the oxidative stressd-ROMs TThis test is used to determine the antioxidant capacity of plasma, mainly due to the level of hydroperoxides - a subclass of reactive oxygen metabolites (ROM) - amplifiers and considered markers of cell damage by free radicals.

BAP Test This test is used to determine the efficiency of the plasma barrier opposes the attack of free radicals in terms of iron-reducing activityAn increase in the values of d-ROMs Test (> 300 U CARR) and / or a reduction of the values of the BAP Test (