What is the function of superoxide dismutase?
It converts superoxide to hydrogen peroxide
What substances are involved in physiological defense against oxidants?
*Enzymes
*Vitamins
*Primary metabolites
*Secondary metabolites
What is the role of resveratrol in health?
It activates sirtuin proteins for health benefits
What is the clinical evidence regarding green tea and cancer risk?
Evidence remains inconclusive for cancer risk reduction
What is the antioxidative activity of carnosic acid?
It has high antioxidative activity
What are the antioxidative activities of plant metabolites?
*Vitamins (ascorbic acid, tocopherols)
*Carotenoids (active against singlet oxygen)
*Polyphenols (radical scavengers, metal chelators)
*Sulfides (radical scavengers)
What are the sources of oxidants and free radicals?
Endogenous sources:
Mitochondrial respiratory chain
Microsomal electron transport chain
Oxidative enzymes
Phagocytic cells
Exogenous sources:
UV radiation
Ionizing radiation
Drugs
Tobacco smoke
Air pollution
Food
Metal ions
What role do free radicals play in certain pathologies?
They contribute to diseases like cancer and diabetes
What is the role of catalase?
It decomposes hydrogen peroxide into water and oxygen
How do free radicals affect biological systems?
They cause damage through oxidation
What is the significance of the French Paradox?
It links red wine consumption to lower heart disease: contains polyphenols and proanthrocyadins which are antioxidants
How do polyphenols function as antioxidants?
They act as radical scavengers and chelators
What are procyanidins?
Polyphenols found in red wine
What is the conclusion regarding antioxidants from food?
*They help prevent diseases like cancer.
*Secondary metabolites like carotenoids and polyphenols are important.
*The bioavailability of polyphenols needs further study.
*Supplements may not have the same effect as food.
