Antioxidants and Radical Scavengers Flashcards
What 3 things does urate scavenge and what does it bind to for chelation from the body?
It scavenges singlet oxygen, hydroxyl radicals, and peroxyl radicals in addition to binding transition metals that may initiate LDL oxidation.
What is the MOST important free radical scavenger endogenously and where does it come from?
Uric acid; product of purine metabolism
Urate can be ________ by Vit C.
reduced
True/False: Urate can reduce a-tocopherol?
FALSE! Unlike Vit C, urate cannot reduce a-tocopherol
Coenzyme Q (ubiquinone) is found in which cells of the body?
ALL cells! They are present in the membrane. It is the most important membrane antioxidant.
Where does CoQ come from and what is its half-life?
Dietary uptake is limited and its half-life is 49-125 hours.
What are 4 functions of CoQ?
- It is an electron carrier in the respiratory chain,
- It is an effective lipid-soluable antioxidant (incorporated into micelles)
- Protects LDL from oxidation
- Can regenerate Vit C
What does CoQ prevent?
Oxidation of lipids, proteins, and DNA
How does CoQ exert anti-inflammatory effects?
It influences gene expression and stimulates the release of nitric oxide.
Bioactive compounds derived from plants are…
phytochemicals
Plant-derived phenolic compounds serve what three potential purposes?
antioxidant, anti-inflammatory, and anti-cancer
More of what chemical group gives a compound greater antioxidant capacity?
Hydroxyl groups
Where does the yellow color of turmeric come from?
It comes from the fat-soluble phenolics known as curcuminoids.
Bioavailablity of curcumin is _____.
Low
What are the inhibitory actions of curcumin?
- oxidative DNA damage in GI tract
- phospholipase A2, COX2, and 5-LOX
- expression of COX2 and inducible NO synthase genes
