Antioksidan & Radikal Bebas

Presentasi berjudul: "Antioksidan & Radikal Bebas"— Transcript presentasi:

1 Antioksidan & Radikal Bebas

2 Antioksidan Antioksidan adalah substansi yang diperlukan tubuh menetralisir radikal bebas dan mencegah kerusakan yang ditimbulkan o/ radikal bebas dengan melengkapi kekurangan elektrolit yg dimiliki radikal bebas dan menghambat terjadinya reaksi berantai dari pembentukan radikal bebas yg dpt menimbulkan stres oksidatif

3 RADIKAL BEBAS Radikal bebas merupakan jenis oksigen yg memiliki tingkat reaktif yg tinggi dan scr alami ada didlm tubuh sebagai hasil dari reaksi biokimia tubuh Radikal bebas juga terdapat di lingkungan sekitar kita yg berasal dari polusi udara, asap tembakau, penguapan alkohol yg berlebihan, bahan pengawet dan pupuk, sinar ultr violet, x-rays dan ozon

4 Antioxidants Oxidant : RO•, •O2- HO•, HOO•, H2O2 ROO• , 1O2 RO•, ·O2-

5 Effect of Reactive Oxygen Species on Degenerative Diseases
Dermatitis Age pigment Heart attack Joints Arthritis Reactive Oxygen Species Multiorgan failure Lung Asthma Hyperoxia

6 RADIKAL BEBAS Radikal bebas dpt merusak sel tubuh apabila tubuh kekurangan zat anti oksidan atau saat tubuh kelebihan radikal bebas. Hal ini menyebabkan berkembangnya sel kanker,penyakit hati, arthritis, katarak, dan penyakit degeneratif lainnya, bahkan mempercepat proses penuaan. Radikal bebas dpt merusak membran sel serta merusak dan merubah DNA . Merubah zat kimia dlm tubuh dpt meningkatkan resiko terkena kanker serta merusak dan menonaktifkan protein

7 Antioksidan Vit A Vit C Vit E Karotenoid selenium

8 Vitamins Alpha tocopherol Breaks lipid peroxidation Lipid peroxide and O2·⁻ and ·OH scavenger Fat soluble vitamin Beta carotene Scavenges ·OH, O2·⁻ and peroxy radicals Prevents oxidation of vitamin A Binds to transition metals Ascorbic acid Directly scavenges O2·⁻, ·OH, and H2O2 Neutralizes oxidants from stimulated neutrophils Contributes to regeneration of vitamin E Water soluble vitamin

9 Vitamin E Family of related compounds tocopherols & tocotrienols
tocotrienols less widely distributed than tocopherols - considered of less nutritional importance 4 major forms based on # & position of methyl groups on ring - , , ,  all-rac -tocopherol

10 Activity roughly corresponds to number of methyl groups
3 H O H C C H H C H 3 H 3 3  2 -Tocopherol Activity roughly corresponds to number of methyl groups H C O 4' 8' C H 3 3 C H C H 3 3

11 Carotenoids About 600 identified so far
Most familiar is yellow-orange pigments of carrots, -carotene Two major groups: carotenes and xanthophylls

12 Carotene Groups Caroteniods carotenes xanthophylls ά-carotene
crypto-xanthin lutein zeaxanthin

13 Ascorbic acid (vitamin C)
Biochemical function: cofactor for at least eight enzymes At the tissue level, a major function  collagen synthesis ( vit C deficiency can lead scurvy) The antioxidant properties protect NO, protect against age-related cataract

14 Fruits Grapes Berry fruits Prunes Citrus fruits Apples

15 Vegetables Tomato Beans Broccoli Beet Mushroom Corn White cabbage Kale
Cauliflower Spinach Garlic Onion

16 Soybean Isoflavone R1 R2 Genistein OH OH Genistin OH O-glucose
Daidzein H OH Daidzin H O-glucose Isoflavone R1 R2

17 Herb and Spice Carnosoic Acid Carnosol Rosemarinic Acid C H O O H C H
3 O O H C H 3 H O O C H 3 C O H C C H 3 3 Carnosoic Acid Carnosol O H H O O C O O H O H O Rosemarinic Acid O H

18 Tea Epigallocatechin Epicatechin O H O H O H O H O H O O O H O H O H O

19 Wine Red wine decreases coronary heart disease mortality in some part of France. Please drink up to two glasses !!! The coumaric, cinnamic, caffeic, and ferulic acids catechin, epicatechin and quercetin in are good antioxidants.

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22 Biological Activities of Phytochemicals
Antioxidants Anticancer Agent s Isoflavones lignans DNA repair Agents Vanillin cinnamaldehyde coumarin anisaldehyde Carotenoids tocopherol catechins quercetin kaempferol genistein daidzein

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