Lecture 6 Essay

Submitted By sgore1995
Words: 637
Pages: 3

Lecture 6: Antioxidants and chemoprevention

Antioxidants
Are they Nutraceutical or NHP?
There was confusion, first it was NHPD because faster and allowed medical claims
Health Canada says if it is sold in capsule or tablet it is NHP but sold as drink or additive in food it is food
Many natural products can be formulated as either NHP or Nutraceutical
Ex. Cranberry extract in capsules is NHP but cranberry juice is Nutraceutical.
ROS
ROS- reactive oxygen species, generated many processes including in oxidation of food in mictochondria.
ROS like superoxide, hydroxyl radical and singlet oxygen have been degenerative in ageing, cancer cardiovascular disease and diabetes.
Antioxidant hypothesis
Theory of ageing: vit c and e not effective in clnical trials but work shows dietary fruits and veggies are high in +ve long term effects.
Cardiovascular disease, cancer, stroke
Dietary antioxidants include vit c and e, carotenoids, but recent studies show still beans flavonoids and anthocyanin’s highly significant
Flavonoid intake from fruits and vegs is 50-800 mg per day, red wine and tea contain 200 mg/serving
Antioxidant redox assay
Hydrogen atom transfer assay (HA): ORAC radical scavenging
Single electron transfer: FRAP
Combined methods : DPPH and total phenolics

ORAC
Oxygen radical absorbance capacity: flurosence destroys by ROO.
Antioxidant removes ROO
Uses fluorescent probe, green dye and destroy peroxide with peroxide dye.
FRAP
Ferric reduction antioxidant power assay- single electron by ant oxidant, take radical give up h from oh and convert to RH radical stabalized.
Antioxidant bioassays
1. COX (cyclooxygynase) enzyme inhibitor
2. MDA (TBARS) – lipid peroxidation
Measure of lipid peroxides
3. 8OHdG DNA damage
Mesure nucleic acid oxidation (damage)
4. Savaenging of superoxide radicals

-green tea catechins are potent antioxidant but lose some of their activity when fermented to black tea
-ability scavenge super oxide radicals. Need certain amount of epicatechin to get rid of 50% superoxide radicals. Need least amount of substrance!!
Anti oxidants and French paradox
Red wine cause lower in cardiovascular and cancers
Red wines contain potent antioxidant-stillbean called RESVERETROL, also found in blueberries.
ROS suspected roles in CVD, cancer diabetes and many other degenerative disease.
Resveratrol from red wine inhibits inflammatory enzyme COX(cyclooxygenase), hydroperoxidase activity and formation of cancer lesions in mouse model
Mouse Study
Resveratrol added mouse diet, mice has reduced # of tumors
Resveratrol inhibits tumorigenesis
Can reduce high glucose levels and insulin, improving insulin sensitivity.
Anti-diabetic pharmaceuticals.
Gains
Corn has highest antioxidant potential any grain due to higher phenolic content.
Purple corn
Purple corn ceremonial variety used indigenous