Basic Facts about Antioxidants Flashcards
Oxidative stress is caused by
an overproduction of free radicals in the body without enough antioxidants to quench them
Free radicals are unstable molecules that have unpaired______
electrons
Free radicals seek to become stable by
attacking cells in the body, destroying cell membranes and structures inside the cell especially DNA.
Free radicals damage:
DNA RNA PROTEINS FATS CARBOHYDRATES MEMBRANES
OXIDATIVE STRESS IS LINKED TO MOST CHRONIC DISEASES SUCH AS:
CANCER HEART DISEASE ALZHEIMERS DISEASE DIABETES ARTHRITIS
Free radicals can be endogenous MEANING-
made by the body.
Endogenous free radicals are derived from
oxygen or nitrogen
Free radicals formed from oxygen are called
Reactive Oxygen Species (ROS)
the most damaging free radical
The hydroxyl radical
The hydroxyl radical reacts with DNA and causes
lesions in DNA strands – the start of chronic diseases such as cancer.
Nitric oxide made from
L-arginine
Peroxynitrite
formed from reaction of nitric oxide and the superoxide radical.
Hydrogen peroxide
Peroxynitrite
Lipid peroxide
Other radical species formed by biological reactions.
OTHER OXIDIZING AGENTS FORMED IN THE BODY
Free radicals are produced by the body during energy production in the___.
mitochondria
Free radicals are produced by the body during energy production in the mitochondria.
This process uses
oxygen and glucose.
The by products of free radical production are:
- Hydroxyl radical
- Superoxide
- Hydrogen peroxide
Free radicals are also produced from exposure to:
Ionizing radiation
Smoking
Free iron in the body –usually from destruction of red blood cells
Free copper
Free radicals perform critical functions in the body.
They control blood flow through arteries and veins
Used by the immune system to fight infection. The superoxide radical and nitric oxide is used to kill viruses and bacteria.
Free radicals kill cancer cells. Cancer drugs increase the production of free radicals.
Free radicals (ROS) are used as signaling molecules that
regulate growth, differentiation and apotosis.
Oxidation occurs when an atom or molecule
Gains oxygen
Loses hydrogen
Loses electrons
Increased oxidation in the body leads to chronic diseases.
Reduction occurs when an atom or molecule
Loses oxygen Gains hydrogen Gains electrons Antioxidants are reducing agents There must be a balance between oxidation and reduction for a healthy state
Inflammation is the process by which
the body removes bacteria, viruses and damaged cells caused by injury.
Usually the injures site becomes red, swollen, warm and painful.
ACUTE INFLAMMATION
Plasma and leucocytes leave blood vessels due to increased permeability of the membranes
engulf viruses and bacteria by phagocytosis and kill the by generating ROS. can also degrade dead cell debris by using enzymes.
Leucocytes
If injury is extensive the acute response is not turned off and damage to tissues can lead to
organ failure or death.
Causes the production of endogenous antigens resulting in autoimmune diseases such as:
Alzheimer’s disease
Arthritis
Diabetes heart disease
CHRONIC INFLAMMATION
Increases the expression of the gene that codes proteins that holds normal cells together
Carotenoids
Retinyl palmitate, retinyl acetate; converted to retinol in body.
Vit A
improves lutein and lycopene bioavailability.
Beta Carotene
Lutein:
eyes
Lycopene:
prostate
Beta Carotene:
eyes and fatty tissues
recycles oxidized vitamin E
Vitamin c
reduces inflammation
Vit E, glutathione
Most effective form is alpha-tocopheryl succinate (alpha-TS) which can enter cells more easily; alpha-TS form only acts as AO when converted to AT
Vitamin E
most important AO in cells.
Glutathione
synthesized in the body from three AA’s: L-cysteine, L-glutamic acid, and glycine
Glutathione
cofactor = selenium
Glutathione
n-acetylcysteine and lipoic acid can be taken, instead, to increase cellular levels.
Glutathione
Increases glutathione levels in cells
NAC
More commonly known as amucolytic (“mucus-dissolving”) agent
NAC
recycles vit C & E
ALA
increases glutathione levels in cells
ALA
mitochondria use______ in energy production
CoQ10
weaker of the AOs but recycles vitamin E
CoQ10
in all cells- in cell organelles esp. in heart and liver as they require more.
CoQ10
can recycle oxidized vitamin E
NADH
essential for mitochondria to generate ATP
NADH
Nicotinamide adenine dinucleotide
Nicotinamide adenine dinucleotide
Polyphenols
Flavonoids
Polyphenols
chemical substances found in plants:
Examples: quercetin, epicatechin, and oligomericproanthocyaninids).
Flavonoids
citrus fruits, berries, ginkgo biloba, onions, parsley, tea, red wine, dark chocolate
Flavonoids
Poorly absorbed in intestinal tract
Flavonoids
Reduces inflammation
Melatonin
hormone produced by pineal gland in brain & retina, lens and GI tract. Synthesized from AA, tryptophan. also produced by plants, IE rice.
Melatonin
can’t be regenerated by other AOs
Melatonin
readily absorbed from intestinal tract
Melatonin
From diet (red meat) & body synthesized from AAs: lysine and methionine; vitamin C- dependent.
L-Carnitine
Crosses blood-brain barrier
L-Carnitine
Kidneys conserve this AO well; not usually needed as a supplement unless one has kidney problems or deficiency.
L-Carnitine
destroy FRs and hydrogen peroxide
AO enzymes: superoxide dismutase (SOD)- requires manganese or copper-zinc
catalase-requires iron
glutathione peroxidase.
Precurser to AO-Glutathione
NAC
Increases glutathione levels in cells
NAC
More commonly known as amucolytic (“mucus-dissolving”) agent
NAC
