Antioxidant Supplementation Flashcards
What are the 4 classes of reactive species
- Reactive Oxygen Species: Radicals
- Reactive Oxygen Species: Non-Radicals
- Reactive Nitrogen Species: Radicals
- Reactive Nitrogen Species: Non-Radicals
Give an example of Reactive Oxygen Species: Radicals
a. Superoxide
b. Hydroxyl Groups
Give an example of Reactive Oxygen Species: Non-Radicals
a. Hydrogen Peroxide
b. Singlet oxygen
Give an example of Reactive Nitrogen Species: Radicals
a. Nitric oxide
Give an example of Reactive Nitrogen Species: Non-Radicals
a. Peroxynitrite
What do reactive species do to other compounds
Steal electrons
What are the opposites of ROS/RNS in the body
Anti-oxidants
Define peroxidation
a chain oxidative reaction causing the dysfunction of the phospholipid bilayer
What happens when LDL are oxidised
more atherogenic, and increasing likelihood of atherosclerosis, as they deposit cholesterol in the blood vessels more readily
What happens when ROS/RNS reduce bioavaliability
impairs blood vessel function, as NO binds to singlet oxygen forming Peroxynitrite (very damaging, causing peroxidation)
How do ROS/RNS damage proteins
carbonylation or nitrosylation
How does carbonylation or nitrosylation effect the body
impairs enzymatic function,
and altered function causes symptoms of ageing.
What response do ROS/RNS trigger that can lead to CVD, obesity and diabetes
Inflammatory response
Give 2 ways ROS/RNS can negatively impact sports performance
- Cell membranes become leaky- and enzymes etc can leave the cell e.g. creatine kinase
- Altered function of transporters, enzymes, and contractile proteins
- Reduced NO bioavailability, which decreases perfusion
- Inflammation leads to soreness, and pain as well as increased RPE
True or False: exercise produces greater levels of ROS/RNS
True
Why does exercise produce greater levels of ROS
NADPH Oxidase produces superoxide. Its activity is increased during exercise
Give 2 beneficial uses of ROS/RNS
- Vasodilation (alter blood pressure)
- Immune function- damage to pathogens e.g. the oxidative burst
- Cell communication
What are the two classes of endogenous antioxidants
- enzymatic
- non-enzymatic
Give 2 examples of enzymatic antioxidants
Superoxide Dismutase (SOD) Glutathione Peroxidase (GPX) Catalase (CAT) Peroxiredoxin
Give 2 examples of non-enzymatic antioxidants
Uric Acid Glutathione Bilirubin Thiols Albumin
What are the 3 classes of nutritional antioxidants
Vitamins
Minerals
Phytochemicals
Give 2 examples of antioxidant vitamins
C
E
Carotene
Give 2 examples of antioxidant minerals
Copper
Zinc
Manganese
Selenium
Give 2 examples of antioxidant phytochemicals
Phenolic acids
Stilbenes
Flavonoids
True or false: Training results in increases in enzymatic antioxidants
True
Where specifically are enzymatic antioxidants found
cell mitochondria
Where specifically are non-enzymatic antioxidants found
Blood vessels
Catalase is the detoxifying enzyme for H202 resulting in what
H20 + 02
Iron is the detoxifying element for H202 resulting in what
OH
Give 2 indirect methods of measuring ROS/RNS
- Protein carbonyls and nitrotyrosine
- F2 isoprostanes- liver
- TBARS- lipids
- MDA- lipids
Give a direct method of measuring ROS/RNS
• Spin traps for specific radicals
ROS can be useful for adaptation. Give 2 processes they signal for
mitochondriongenesis, hypertrophy, angiogenesis and an increase in antioxidant enzymes.
ROS lead to the transcription of —– dependent genes
NF-KB
State 2 negative effects of exercise generated ROS
- reduced ca sensitivity
- muscle damage (activated neutrophils)
- ischaemic reperfusion
- decreased perfusion
Why is decreased Ca sensitivity a bad thing
impairs muscle force production
Give 3 effects Antioxidant supplementation may have
• Increased E-C Coupling (Ca release) • Central drive (Decreased with ROS) • Substrate depletion (Decreased glucose with ROS) • Muscle perfusion o Increased NO bioavailability • Inhibition of ROS production
What is N-acetylcysteine
A direct oxidant scavenger, which provides the cysteine for glutathione
How did N-acetylcysteine effect performance
improved sprint power output, and decreased levels of ROS biomarkers. IL-6 was decreased, and glutathione was increasing
What is glutathione
an antioxidant
What is quercetin
A polyphenol (flavonol) which has a widespread presence in fruits and vegetables. It has antioxidant, anticarcinogenic, cardioprotective and ergogenic properties.
What is a beneficial dose of acute polyphenol
300mg.d-1
When should acute polyphenols be taken in to be beneficial
~2 hours prior to exercise
What are polyphenols made up of (structurally)
6-C phenolic rings, and 2 hydroxyl groups
State 2 classes of polyphenols
- Flavonoids
- Lignans
- Phenolic Acids
- Stilbenes
- Other e.g. curcumin
Give 2 classes of flavonoids
- Anthocyanidins e.g. delphinidin and malvidin (dictate the colour of the fruit)
- Flavonols
- Flavones
- Flavonones
- Isoflavones
- Flavanols
Which fruit has the greatest polyphenol levels
Blackcurrants
Why do we use freeze-dried powders not fresh fruit
extremely large amount of fruit is needed to be consumed for performance benefits. This is expensive and has GI issues
What are the direct antioxidant effects polyphenols possess called
radical scavengers
What are the direct antioxidant effects of polyphenols limited by
Bioavaliability
True or false: 5-10% of dietary polyphenols are absorbed by the colon; 90-95% are absorbed in the small intestine.
False- other way around 5-10% of dietary polyphenols are absorbed by the colon; 90-95% are absorbed in the small intestine.
How does ROS/RNS effect NR-f2
cause the dissociation of the NR-F2 transcription factor, which moves to the nucleus, and upregulates antioxidant response elements
True or false: An increase in antioxidants has been shown to reduce the initial injury from ROS and lessen this positive feedback cycle.
True
What is the optimal dose for Montmorency cherry?
~1000mg.d-1 for 3 days prior to exercise.
How does montmorency cherry improve recovery
by attenuating a loss of muscle force, soreness and inflammation
How do cherries impact sleep
Cherries contain melatonin, which has been linked to improved sleep quality and duration
