Oxidative stress and disease

1. Oxidative stress and
disease

2. What is oxidative stress?
disturbance in the balance between the production
of reactive oxygen species (free radicals) and
antioxidant defenses
Has been implicated in the ageing process & many
diseases e.g. atherosclerosis

5. Leads to
Oxidative damage to :-
-DNA
-Proteins
-Lipids (unsaturated fatty acids)
Diseases
-rheumatoid arthritis
-atherosclerosis and coronary heart disease
-cancers
-G6PD deficiency hemolytic anemia

6. antioxidants
Trace
elements
vitaminsenzymes
SeleniumVitamin A
Vitamin C
Vitamin E
-superoxide dismutase
-catalase
-glutathione system

8. Glutathione system
Consists of :-
Glutathione , NADPH ,reductase , peroxidase
and selenium .
N.B.
G6PD (Glucose 6-Phosphate Dehydrogenase)
Is essential for formation of NADPH which is
essential for proper function of glutathione
system.

9. Reactive oxygen species (ROS)
Types
Free radicals
-superoxide O2
-
-hydroxyl radical OH-
-peroxyl radical ROO-
Non free radicals
-hydrogen peroxide H2O2

11. Sources of ROS
During course of metabolism
E.G. O2
- auto-oxidation of hemoglobin and
xanthine oxidase
OH- by fenton reaction
Ingestion of toxins,chemicals and drugs

13. Nitric oxide NO-

16. Oxidative stress diseases

17. G6PD (hemolytic anemia)

18. Molecular effects of oxidative stress
-lipid peroxidation
-protein denaturation
-DNA damage
-inactivation of enzymes
-release of ca ions from intracellular stores
-cytoskeletal damage
-chemotaxis

19. Vascular effects
-- altered vascular tone
--increased endothelial permeability

20. atherosclerosis

23. Thank you