Lecture 9 Oxidative Stress and Antioxidants

Free Radicals

Molecules with unpaired electrons that are unstable and highly reactive, often leading to undesired reactions causing pathology

Reactive Oxygen Species (ROS)

Highly reactive, unstable oxygen-containing molecules causing oxidative damage to proteins, lipids, and DNA within cells. Examples include superoxide anion (O2-) and hydroxyl radical (OH·)

Oxidative Stress

Imbalance between the production of reactive oxygen species (ROS) and the body's ability to neutralize them, leading to cellular damage and dysfunction

Production of ROS

Generated during mitochondrial respiration for ATP production, in inflammation to combat infections, and due to exposure to environmental toxins and pollutants

Consequences of Oxidative Stress

Include cellular damage, disruption of normal cellular functions, inflammation, and contributing to neurodegenerative diseases, cardiovascular disease, cancer, and aging

Antioxidants

Molecules that neutralize ROS, protecting cells from oxidative damage by accepting and stabilizing free electrons and reactive molecules. Can be endogenous or exogenous, with several vitamins acting as antioxidants

Protective Strategies against Oxidative Stress

Include consuming an antioxidant-rich diet with fruits, vegetables, and whole grains to provide essential antioxidants

Antioxidant Defense

Mechanisms that protect against oxidative stress, involving enzymes and non-enzymatic antioxidants

Oxygen Toxicity

Harmful effects of excessive oxygen levels leading to ROS production and tissue damage

Vitamin C

Water-soluble antioxidant in fruits and vegetables, aids in regenerating other antioxidants

Vitamin E

Fat-soluble antioxidant found in nuts and seeds, protects cell membranes

Selenium

Trace element crucial for antioxidant enzyme synthesis, found in nuts and seafood

Glutathione

Tripeptide acting as a potent intracellular antioxidant, synthesized in the body

Carotenoids

Compounds in colorful fruits and vegetables with antioxidant properties, converted to vitamin A

Superoxide Dismutase (SOD)

Enzyme converting superoxide radicals to hydrogen peroxide

Catalase

Enzyme converting hydrogen peroxide to water and oxygen

Glutathione Peroxidase

Enzyme neutralizing hydrogen peroxide and lipid peroxides

Metal Binding Proteins

Proteins binding with metals to prevent free radical generation

Polyphenols

Chemical compounds in plants with antioxidant properties, e.g., flavonoids

Calcium

Mineral contributing to bone and teeth strength, blood clotting, and nerve function

Phosphorus

Mineral essential for bone structure, energy metabolism, and acid-base balance

Magnesium

Mineral crucial for nerve function, muscle contraction, and energy metabolism

Sodium

Mineral regulating fluid balance, nerve function, and blood pressure

Potassium

Mineral vital for fluid balance, nerve function, and cell growth

Chloride

Mineral important for electrolyte balance and nerve function

Iron

Mineral essential for oxygen transport in hemoglobin, preventing anemia

Zinc

Mineral supporting immune function, wound healing, and cell growth

Copper

Mineral involved in antioxidant defense, collagen synthesis, and immune support

Iodine

Mineral crucial for thyroid hormone synthesis and immune function

Fluoride

Mineral important for dental health and preventing tooth decay

Chromium

Mineral aiding in insulin function and macronutrient metabolism

Manganese

Mineral supporting enzyme function, bone health, and antioxidant defense

Molybdenum

Mineral essential for enzyme function and metabolism of certain compounds

What are the 9 water-soluble vitamins?

1) Vitamin C (ascorbic acid)
2) B1 (Thiamine)
3) B2 (Riboflavin)
4) B3 (Niacin)
5) B5 (Pantothenic Acid)
6) B6 (pyridoxine)
7) B7 (Biotin)
8) B9 ( Folate)
9) B12 (Cobalamin)

What are the 4 fat soluble vitamins?

A, D, E, K

What role(s) does Ca2+ play as a mineral?

1) strength and structure (bones)
2) Blood Clotting

What role(s) does K+ play as a mineral?

1) Electrolyte balance for nerve function
2) Blood pressure regulation
3) Blood Clotting
4) Fluid balance

What role(s) does Na+ play as a mineral?

1) Electrolyte balance for nerve function
2) Blood pressure regulation
3) Fluid balance

What role(s) does Zn play as a mineral?

1) Macronutrient Metabolism

2) Immune function

3) Critical co-factor in cell growth, division, repair and DNA synthesis

What role(s) does Fe play as a mineral?

1) Component of hemoglobin (transport of oxygen)
2) Prevention of anemia

What role(s) does Se play as a mineral?

1) assists in antioxidant defense mechanisms
2) essential for detoxification process

What role(s) does P play as a mineral?

1) Strength and Structure (bones)
2) Acid/Base balance through phosphate buffer system

What role(s) does Cu play as a mineral?

1) assists in antioxidant defense mechanisms
2) Immune functions
3)Collagen synthesis

What role(s) does Cl- play as a mineral?

1) Electrolyte balance for nerve function

What role(s) does Mg play as a mineral?

1) macronutrient metabolism
2) assists in glycolysis
3) essential for nerve transmission and muscle contractions
4) ATP activation

What role(s) does I play as a mineral?

1) Crucial for synthesis of thyroid hormone

What minerals are associated with structure and strength in bones

Ca2+ and P

which minerals assist with blood clotting?

Ca2+ and K+

Which minerals are assist in electrolyte balance for nerve function?

K+,Na+,Cl-, Ca2+*

Which mineral is critical for DNA synthesis?

Zinc

Which Mineral is crucial for thyroid hormone synthesis?

Iodine

What is Vitamin is essential for the synthesis of retinal?

Vitamin A

A deficiency in this vitamin can cause "night blindness"

Vitamin A

What are the main roles of Vitamin A?

1) retinal synthesis
2) Immune function
3) skin health

What are the main roles of Vitamin B1

1) metabolism
2) nerve function
3) heart function

What is another name for Vitamin B1

Thiamine

How does Vitamin B1 necessary for metabolism?

its a critical cofactor for the:
- pyruvate dehydrogenase reaction in glycolysis (pyruvate --> Acetyl-CoA)
- Alpha-ketoglutarate dehydrogenase reaction
- transketolase in the pentose phosphate pathway (for synthesis of nucleotides)

What is Vitamin B2 also known as?

Riboflavin

What is the role of Vitamin B2?

1) Form coenzymes
2) Corneal crosslinking
3) FAD creation

What two major coenzymes does Vitamin B2 help form?

1)FMN
2) FAD

What is Vitamin B3 also known as

Niacin

What is Vitamin B3 role?

1) Metabolism (by assisting in creation of NAD)
2) regulate Cholesterol

What are the 4 D's of Pellagra?

dermatitis, diarrhea, dementia, death

What is Vitamin B5 also called?

pantothenic acid

What is Vitamin B5 role?

Essential for synthesizing coenzyme A (CoA)

What is Vitamin B6 also called?

Pyridoxine

What is the role of Vitamin B6

cofactor in amino acid metabolism
neurotransmitter synthesis
hemoglobin synthesis
Gene expression
Glycogenolysis
Gluconeogenesis

A deficiency in vitamin B6 causes what?

Rash and inflammation around the eyes and mouth
Peripheral neuropathy

What is Vitamin B7 also called?

Biotin

What is the role of Vitamin B7 in the body?

1) metabolism
2) Healthy hair, skin, and nails
3) gene expression

Why is vitamin B7 useful in many research settings?

Binds crazy tight to streptavidin

What is Vitamin B9 also called?

folate

What is the role of Vitamin B9

Fetal development
Oocyte and sperm development
DNA and RNA synthesis
RBC formation

What is another name for Vitamin B12?

Cobalamin

What is the role of Vitamin B12?

1) nerve functions
2) DNA synthesis
3) RBC formation

What is Vitamin C also called?

ascorbic acid

What the role of Vitamin C?

Antioxidant
supports immune function
Collagen synthesis
Prevention of Scurvy

Does vitamin C prevent colds?

No

Does Vitamin C shorten colds?

Yes

What does vitamin D do?

Helps the body absorb calcium and phosphorus
Supports immune function
Mood regulation

What disease comes from a deficiency in Vitamin D?

Rickets (bowed bones)

What role does Vitamin E play?

1) antioxidant
2) Supports skin health
3) protects cell membranes from ROS
4) Helps regulate PKC (Protein Kinase C)

What role does Vitamin K play?

blood clotting
Bone health
Heart Health

What role does "Vitamin F" play?

Cell membrane structure
Supports brain function
Inflammation regulation

Which of the following is not a Vitamin?

Vitamin F

What are the real name of Vitamin F

Essential Fatty acids

What are the two Essential fatty acids

linoleic acid and alpha-linolenic acid

omega 3 vs omega-6 structure

oxygen

What is this ROS?

superoxide anion