This document discusses antioxidants and provides information on their types, mechanisms of action, origins, and functions. It summarizes that antioxidants delay or prevent oxidation reactions by reacting with free radicals and reactive oxygen species. Antioxidants can be categorized by their mode of action, location, solubility, and whether they are enzymatic or non-enzymatic nutrients and non-nutrients. The document outlines several major groups of antioxidants found in plants and discusses some important individual antioxidant compounds like vitamins C and E, carotenoids, polyphenols, and melatonin. It concludes by describing the biological roles of antioxidants in boosting immunity, preventing diseases, and promoting cardiovascular and eye health.

1. Advance Pharmacology - II
Topic:- Protective Activity
Of Certain Important
Antioxidant
Name :- Chetana Pandurang Dakhare
Roll No. :- 01 ( 2nd Semester )
First year M.Pharm (Pharmacology)

2. Antioxidant
• An antioxidant is a substances that when present in low
concentrations relative to the oxidizable substrate
significantly delays or reduces oxidation of the substrate
(Halliwell,1995).
• Antioxidants get their name because they combat
oxidation.
• They are substance that protect other chemicals of the
body from damaging oxidation reactions by reacting with
free radicals and other reactive oxygen species.

3. Antioxidant
• Antioxidant is a molecule capable of inhibiting the
oxidation of other molecules.
• Oxidation is a chemical reaction that transfer electrons or
hydrogen from a substance to an oxidizing agent.
• Eg: Hydroxyl radical, Superoxide anion radical, Singlet
oxygen, Hydrogen peroxide, Nitric oxide.

4. Antioxidants can be categorized by several
methods:
1) Types
a) Mode of action
b) Location
c) Solubility
2) Structural dependents
3) Origin

5. 1) According to types
Antioxidants
Non-
enzymatic
Nutrient: alpha
tocopherol, beta
carotene, ascorbate,
selenium
Non-nutrient
ceruloplasmin,
transferrin, uric acid.
Enzymatic
Superoxide dismutase,
glutathione peroxidase,
reductase, transferase,
catalase

6. • Mechanism of action:
• PREVENTIVE
• Enzymes: Superoxide dismutase, Catalase,
Glutathione.
• Metal ion sequestrators: Carotenoids,
Superoxide dismutase, Catalase, Glutathione,
Uric acid, Flavonoids.
• SCAVENGING
• Ascorbate, Carotenoids, Uric acid, a-tocopherol,
Flavonoids.

7. • Location:
• Intracellular :- SOD 1 and 2, Catalase,
Glutathione peroxidase, DNA repair enzymes.
• Extracellular :- SOD 3, reduced glutathione,
Ascorbate, Carotenoids, Uric acid.
• Membrane associated :- a-Tocopherol.

8. • 4) solubility
• Water soluble: Ascorbate, Uric acid, Thiols,
Flavonoids, Cysteine, Transferrin
• Lipid soluble: Alpha tocopherols, Carotenoids,
bilirubin.
• 5) structures they protect:
• DNA: SOD1&2, Glutathione peroxidase, DNA
repair enzymes, reduced glutathione,cysteine.
• Protein: Sequestration of transition metals by
preventive antioxidants.
• Lipid: Alpha tocopherols, Ascorbate, carotenoids,
glutathione

9. • 6) Origin:
• Exogenous: Carotenoids, Ascorbic acid,
Tocopherols, Polyphenols
• Endogenous: Catalase, Superoxide
dismutase, Glutathione

10. • Functions of Antioxidant:
• Antioxidant such as Vitamin-C and E boost our immune
system.
• Certain phytochemicals have beneficial effect on heart
disease.
• Antioxidant lowers the level of LDL-Cholesterol, thus
preventing plaque deposition in the blood vessel.
• Its beneficial in cancer prevention.
• Antioxidant neutralize substances that can damage the
genetic material by oxidation.

11. Major Group of Antioxidant" Metabolite
 Important group of antioxidant activity are
• Phenol
• Phenolic acid
• Anthocyanin
• Flavones
• Flavonoids
• Flavonols
• Tannins
• Isoflavanoids
• These group of compound shows antioxidant activity and
plant defence mechanism against microorganism

12. Major Antioxidant Compounds in Plants
• 1. Enzymes
1.1 Superoxide dismutase (SODs):
• SOD isoenzyme are present in chloroplasts, cytosol and
in mitochondria It catalyses the decomposition of
hydrogen peroxide into water and oxygen.
• 1.2 Glutathione: Participating directly in the
neutralisation of free radicals and reactive oxygen
compounds Maintaining of exogenous antioxidant such
as vitamin C & E in their reduced forms.
• 1.3 Glutathione Peroxide: Glutathione peroxide uses
glutathione as substrate and catalyses the reduction
ofhydrogen peroxide and lipid hydro peroxide

13. 2. Mineral:
• Minerals are elements that originate in the soil and can't
be created by living things.
• Selenium in the only mineral produced by plants. The
richest plants sources of selenium is Brazil nut.
3. Low Molecular Weight & High Molecular Weight
Compounds:
• HMW compounds includes albumin, cariplasmin and
transferrin.
• LMW antioxidant are divided into
• Lipid soluble:- Polyphenols, Tocopherols & ascorbic acid.
• Water soluble:- Same Polyphenols.
• Both types of these compounds act as reducing agents,
free radical scavengers quenchers of singlet
oxygen formation.

14. 4. Vitamins:
Carotenes:
• A carotene is one of four antioxidant that are
vital our general health and wellbeing.
• a-carotene,y-carotenes,6-carotenes and B-
carotenes types of carotenes
• a&B carotenes are the powerful antioxidant.
• B-carotene is an anti aging micronutrient and
play a significant role in reducing the effects of
certain illness such as heart disease, decreased
immune function, cataracts, cancer.

15. • Ascorbic acid (Vit-C):
• Its an hydrophilic antioxidant
• Neutralisation of H2O2
• Maintain healthy collagen in skin.
• Repair damaged tissue, healthy teeth and bones,
immune system.
• As a free radical fights against cataracts, arthritis, heart
disease, cancer & Oxidation.
• Vitamin C functions us anti-inflammatory and helps the
body fight against inflammatory diseases including
fibromyalgia, chronic fatigue, angina, bronchitis,
constipation and diabetes.
• Its also helpful in treating iron deficiency and anaemia.

16. Tocopherols (Vit-E)
• Vitamin E is primary fat-soluble antioxidant nutrient.
• Vitamin E resides in fatty tissues, especially cell walls and
membranes.
• It helps to protect the stability and integrity of cellular
tissues membranes throughout the body bypreventing
free radical (lipid peroxidation) damage.
It helps in
• Improving skin conditions
• Improving appearance of scars.
• Protecting the body's membrane.
• Maintaining healthy blood vessels.
• thinning blood in body

17. 5.Hormone as antioxidant:
• Melatonin:
• Its powerful antioxidant that can easily cross cell
membrane and the blood brain barrier.
• It doesn't undergo redox cycling.
• Melatonin cant be reduced its former state as it forms
stable compounds after reacting with free radical.
• It has been referred as a terminal or
suicidal antioxidant

18. 6. Essential Oils as Antioxidant:
• These are the class of volatile oils obtained by steam
distillation and these may be extracted from plants,
flowers, barks and seeds.
Advantages:
• Due to their small molecular size, they can easily
penetrate the skin tissue.
• As essential oils are lipid soluble they are capable of
penetrating the membrane easily even inn conditions
when oxygen deficiency present.
• They serve as powerful antioxidant & they prevent
mutants and oxidants in cells.

19. Biological role of Antioxidant:
• To counter the harmful effects of free radicals,
antioxidants defence mechanism operates to detoxify or
scavenge theses free radicals.
• Boost up immune system.
• Prevent the neurodegenerative disorder.
• Prevent DNA damage and there for have anticarcinogenic
effects.
• Promotes the cardiovascular health.
• Antioxidants can decrease LDL and cholesterol, Increases
HDL and blood pressure.
• Promotes the eye health and prevent macular
degeneration, cataract and other degenerative disorder.

20. Therapeutic uses of antioxidants:
• Alzheimer's disorder
• Cataract
• Diabetes
• Thrombosis
• Asthma
• Prevent the skin aging
• Parkinson's disease

21. THANK YOU