Your cart is currently empty
Antioxidants are natural compounds which help protect the body from harmful free radicals. These are atoms or groups of atoms which can cause cell damage, impairing the immune system and leading to infections and various degenerative diseases such as heart disease and cancer. Antioxidants therefore play a beneficial role in prevention of disease. Scientists think free radical damage to be the basis for the aging process as well.
There are several known free radicals that occur in the body, the most common of which are oxygen derived free radicals, such as superoxide radicals and hydroxyl radicals, hypochlorite radicals, hydrogen peroxide, various lipid peroxides, and nitric oxide. They may be formed by exposure to radiation, including exposure to the sun’s rays; exposure to toxic chemicals such as those found in cigarette smoke, polluted air, and industrial and household chemicals; and various metabolic processes, such as the process of breaking down stored fat molecules for use as an energy source. Free radicals are normally kept in check by the action of free radical scavengers that occur naturally in the body.
These scavengers neutralize the free radicals. Certain enzymes serve this vital function. Four important enzymes that neutralize free radicals are superoxide dismutase (SOD), methionine reductase, catalase, and glutathione peroxidase. The body makes these as a matter of course. There are also several phytochemicals and nutrients that act as antioxidants, including vitamin A, beta-carotene and other carotenoids, flavonoids, vitamins C and E, and the mineral selenium. Researchers have recently found that eggplant contains high levels of chlorogenic acid, which has proven to be a highly effective antioxidant. Another antioxidant is the hormone melatonin, which is a powerful free radical neutralizer. Certain herbs have antioxidant properties as well.
Although many antioxidants can be obtained from food sources such as sprouted grains and fresh fruits and vegetables, it is difficult to get enough of them from these sources to hold back the free radicals constantly being generated in our polluted environment. We can minimize free radical damage by taking supplements of key nutrients. A high intake of antioxidant nutrients appears to be especially protective against cancer.
Antioxidants work synergistically in giving protection against free radical damage, so it is better to take smaller doses of several different antioxidants than a large amount of only one. For example, while beta-carotene by itself is an excellent antioxidant, a mix of natural carotenoids provides more health benefits than beta-carotene alone. There are many good combination formulas available that make it easy to take multiple antioxidants every day. Similarly, taking vitamin E and vitamin C, appears more effective than taking either one alone.
Free Radicals
A free radical is an atom or group of atoms that contains at least one unpaired electron. Electrons are negatively charged particles that usually occur in pairs, forming a chemically stable arrangement. If an electron is unpaired, another atom or molecule can easily bond with it, causing chemical reaction. Because they join so readily with other compounds, free radicals can effect dramatic changes in the body, and they can case a lot of oxidative damage . Each free radical may exist for only a second, but the damage it leaves behind can be irreversible, particularly damage to heart muscle cells, nerve cells, and certain immune system sensor cells.
Free radicals are normally present in the body in small numbers. Oxygen-charged particles are created in the body as we breathe. Diets rich in antioxidants can more than neutralize these particles. Dietary supplements rich in antioxidants act in the same way. Biochemical processes naturally lead to the formation of free radicals, and under normal circumstances the body can keep them in check. Indeed, not all free radicals are bad. Free radicals produced by the immune system destroy viruses and bacteria. Other free radicals are involved hormones activating enzymes that are needed for life. We need free radical to produce energy and various substances that the body requires. If there is excessive free radical formation, however, damage to cells and tissues can occur. The formation of a large number of free radicals stimulates the formation of more free radicals, leading to even more damage.
Many different factors can lead to an excess of free radicals. Exposure to radiation, whether from the sun or small amounts from medical x-rays, activates the formation of free radicals, as does exposure to environmental pollutants such as tobacco smoke and automobile exhaust.
Diet also can contribute to the formation of free radicals. When the body obtains nutrients through the diet, it utilizes oxygen and these nutrients to create energy. In the oxidation process, oxygen molecules containing unpaired electrons are released. These oxygen free radicals can cause damage if produced in extremely large amounts. Being overweight or consuming a diet that is high in fat can increase free radical activity because oxidation occurs more readily in fat molecules than it does in carbohydrate or protein molecules. Cooking fats at high temperatures, particularly frying foods in oil, can produce large numbers of free radicals.
The presence of a dangerous number of free radicals can alter the way in which the cells code genetic material. Changes in protein structures can occur as a result of errors in protein synthesis. The body’s immune system may then see this altered protein as a foreign substance and try to destroy it. The formation of mutated proteins can eventually damage the immune system and lead to leukemia and other types of cancer, as well as to many other diseases.
In addition to damaging genetic material, free radicals can destroy the protective cell membranes. Calcium levels in the body may upset as well. Over time, the body produces more free radicals than it does scavengers. The resulting imbalance contributes to the aging process.
Substances known as antioxidants neutralize free radicals by binding to their free electrons. Antioxidants available in supplement form include the enzymes superoxide dismutase and glutathione peroxidase; vitamin A, beta-carotene, and vitamins C and E; the minerals selenium and zinc; and the hormone melatonin. By destroying free radicals, antioxidants help to detoxify and protect the body.
THE ANTIOXIDANTS
Alpha-Lipoic Acid
Alpha-lipoic acid (ALA) is a powerful antioxidant – both on its own and as a “recycler” of vitamin E and vitamin C. It can restore the antioxidant properties of these vitamins after they have neutralized free radicals. ALA also stimulated the body’s production of glutathione and aids in the absorption of coenzyme Q10, both important antioxidants. Because ALA is soluble in both water and fat, it can move into all parts of the cells to deactivate free radicals. Supplemental ALA has been used for almost three decades in Europe to treat peripheral nerve degeneration and to help control blood sugar levels in people with diabetes. It also helps detoxify the liver of metal pollutants, block stress, and reduce blood cholesterol levels. It can be used with carnitine to provide an antiaging effect. ALA is also known as a metabolic antioxidant, because without it, cells cannot use sugar to produce energy. The body does not produce large amounts of ALA, but because it is found naturally in only a few foods, including spinach, broccoli, potatoes, brewer’s yeast, and organ meats, supplementation may be necessary.
Bilberry
The herb bilberry (Vaccinium myrtillus), a European relative of the American blueberry, contains naturalantioxidants that keep capillary walls strong and flexible. They also help maintain the flexibility of the walls of red blood cells and allow them to pass through the capillaries more freely. Everyone knows that vitamins C and E are good sources of antioxidants, but bilberry, which contains anthocyanidins phytochemicals, also act as an antioxidant. It also helps lower blood pressure, inhibit clot formation, and enhance blood supply to the nervous system. Studies indicate that anthocyanidins can provide up to fifty times the antioxidant protection of vitamin E and ten times the protection of vitamin C. In addition, this herb protects the eyes and may enhance vision; supports and strengthens collagen structures; inhibits the growth of bacteria; acts as an anti-inflammatory; and has antiaging and anticarcinogenic effects. One study that looked at the effects of bilberry on night vision found that vision was not improved with the amounts that are typically sold. Tests have shown that bilberry extract helps to lower blood sugar levels.
Burdock
The herb burdock (Arctium lappa) was tested by researchers at the Chia Nan College of Pharmacy and Science in Taiwan for its antioxidant properties. They found that burdock is a powerful antioxidant, capable of scavenging hydrogen peroxide and superoxide radicals. It also showed a marked scavenging effect against hydroxyl radicals. The study showed also that burdock and vitamin E quench more free radicals when used in combination. Burdock also might protect against cancer by helping to control cell mutation.
Coenzyme Q10
Coenzyme Q10 is an antioxidant that is structurally similar to vitamin E. It plays a crucial role in generation of cellular energy, is a significant immunologic stimulant, increases circulation, has antiaging effects, and is beneficial for the cardiovascular system. Also known as ubiquinone (from quinone, a type of coenzyme, and ubiquitous, because it exists everywhere in the body), coenzyme Q10 is found in highest concentrations in the heart, followed by the liver, kidney, spleen, and pancreas. Within the mitochondria, the cells’ energy production centers, coenzyme Q10 helps metabolize fats and carbohydrates. It also helps maintain the flexibility of cell membranes.
Various research reports suggest that coenzyme Q10 also may be beneficial in treating cancer, AIDS, muscular dystrophy, allergies, gastric ulcers, myopathy, Parkinson’s disease, and deafness. Natural sources of coenzyme Q10 include meats, peanuts, sardines, and spinach.
Curcumin (Turmeric)
Found in the spice turmeric, the phytochemical curcumin has antioxidant properties that prevent the formation of and neutralize existing free radicals. It stops precancerous changes within DNA and interferes with enzymes necessary for cancer progression. Curcumin stops the oxidation of cholesterol, thus protecting against the formation of plaque in the arteries. In a study of chronic smokers, those who took curcumin excreted a substantially lower level of mutagens (substances that induce cells to mutate) in the urine, a reflection of how the body is dealing these cancer-causing substances. Curcumin
has been shown to be of benefit to some patients with advanced pancreatic cancer. It may also calm an overactive immune system in patients with ulcerative colitis, reducing inflammation, redness, and soreness. In one study curcumin helped keep patients with ulcerative colitis from experiencing intestinal flare ups. But it does not seem to be effective for inflammatory conditions such as psoriasis. Curcumin also blocks toxic compounds from reaching or reacting with body tissues and may prevent cataracts.
Curcumin should not be taken by anyone who has biliary tract obstruction or is taking anticoagulants, as curcumin stimulates bile secretion and acts as a blood thinner.
Flavonoids
Flavonoids are especially potent antioxidants and metal chelators. They are the largest category of plant compounds called polyphenols. They are chemical compounds that plants produce to protect themselves from parasites, bacteria, and cell injury. More than 4,000 chemically unique flavonoids are known; they occur in fruits, vegetables, spices, seeds, nuts, flowers, and bark. Wine (particularly red wine), apples, blueberries, bilberries, onions, soy products, and tea are some of the best food sources of flavonoids. Certain flavonoids in fruits and vegetables have much greater antioxidant activity than vitamin C and E or beta-carotene. In fact, flavonoids protect the antioxidant vitamins from oxidative damage.
Numerous medicinal herbs contain therapeutic amounts of flavonoids; they often are a major component of an herb’s medicinal activity, which include helping prevent heart disease and cancer, and reducing incidence of neurodegenerative diseases.
Natural sources of flavonoids include almonds, apples, broccoli, citrus fruits, tea, tomatoes, onions, soybeans, and red wine. In the United States, the greatest intake of flavonoids comes from citrus fruits, tea, and wine.
Garlic
The versatile healing herb also has antioxidant properties. The sulfhydryl (sulfur and hydrogen) compounds in garlic are potent chelators of toxic heavy metals, binding with them so that they can be excreted. These same compounds are effective protectants against oxidation and free radicals.
Garlic aids in the detoxification of peroxides such as hydrogen peroxide and helps to prevent fats from being oxidized and deposited in tissues and arteries. Garlic also contains antioxidant nutrients such as vitamins A and C and selenium.
Studies on aged garlic extract (AGE) have shown that the aging process substantially boosts garlic’s antioxidant potential. AGE protects against DNA damage, keeps blood vessels healthy, and guards against radiation and sunlight damage. According to researcher and nutritionist Robert I-Sin Lin, Ph.D., aged garlic extract can prevent liver damage caused by carbon tetrachloride, a common indoor pollutant and free radical generator. Overall, aged garlic supplements provide a greater concentration of garlic’s beneficial compounds. It is particularly helpful to reduce oxidation associated with aging. If you’re worried about “garlic breath’ putting a strain on your social life, chose odorless and tasteless form such as Kyolic aged garlic extract. Aged garlic extract reduces blood cholesterol levels, thus lowering the risk of heart attack; provides protection from heart disease by preventing clots that can lead to heart attacks and strokes; and helps lower high blood pressure. Time-released garlic has been shown to reduce blood cholesterol levels, and to lower fasting blood sugar levels in patients with type 2 diabetes.
Ginkgo Biloba
Ginkgo Biloba is an herb with powerful antioxidant effects in the brain, retina, and cardiovascular system. It is well known for its ability to enhance circulation, and a study reported in the Journal of American Medical Association showed that it has a measurable effect on dementia in people recovering from strokes. Other studies indicate that it can improve both long and short-term memory and enhance concentration.
Ginkgo biloba has also been used to treat hearing problems, impotence, and macular degeneration.
Anyone who takes prescription anticoagulant (blood thinning) medication or who uses over-the-counter pain killers regularly should consult a health care provider before using ginkgo biloba, as the combination may result in internal bleeding.
Glutathione
Glutathione is a protein that is produced in the liver from the amino acid cysteine, glutamic acid, and glycine. It is a powerful antioxidant that inhibits the formation of, and protects against cellular damage from, free radicals. It helps to defend the body against damage from cigarette smoking, exposure to radiation, cancer chemotherapy, and toxins such as alcohol. As a detoxifier of heavy metals and drugs, it aids in the treatment of blood and liver disorders.
Glutathione protects cells in several ways. It neutralizes oxygen molecules before they can harm cells. Together with selenium, it forms the enzyme glutathione peroxidase, which neutralizes hydrogen peroxidase. It is also a component of another antioxidant enzyme, glutathione-S-transferase, which is a broad-spectrum liver-detoxifying enzyme.
Glutathione can be taken in supplement form. The production of glutathione by the body can be boosted by taking the supplement dehydroepiandrosterone (DHEA), a hormone, N-acetylcysteine or L-cysteine; and L-methionine. Studies suggest that this may be a better way of raising glutathione levels than taking glutathione itself but check with your health care professional if you have any hormonal problems.
Green Tea
Green Tea contains compounds known as polyphenols, including phytochemicals that have antioxidant, antibacterial, antiviral, and health-enhancing properties. Tests on epigallocatechin gallate (EGCG), a particular type of polyphenol in green tea, have shown that it is able to penetrate the body’s cells and shield DNA from hydrogen peroxide, a potent free radical. Epidemiological studies have shown that green tea protects against cancer, lowers cholesterol levels, and reduces clotting tendency of the blood. Because green tea boosts immune function and acts as an antiviral and anti-inflammatory agent, it may help prevent cancer. In one study, it was shown to prevent symptoms associated with colds and flu, and even reduced the number of illnesses. It also shows promise as a weight-loss aid that can promote the burning of fat and help to regulate blood sugar and insulin levels. Instead of drinking green tea, a supplement containing known quantities of it can produce weight loss, especially as fat-and lower blood pressure and “bad” (LDL) cholesterol.
Green tea is simply dried leaves of the tea plant. All green teas are from the species Camellia sinensis but depending on the locale where they are grown and, on the processing, they can be quite different. Chinese teas are pre-dominant and comprise about 90 percent of what is sold. There are numerous regional Chinese teas, the best-known being lung ching (dragon well).
Japanese green teas are two basic types, sencha or gyokuro. Sencha is grown in full sun, while gyokuro is shaded a few weeks before it is harvested.
While there are many brands the basic difference is that gyokuro makes a sweeter, darker green tea than sencha, which is somewhat grassy in flavor. It also costs over twice as much. Gyokuro is the source of the special hand-made powdered tea used in the traditional tea ceremony.
Green tea is not fermented and has more polyphenol than black tea. Black tea undergoes natural fermentation which converts tannins, astringent phytochemicals, into more complex compounds. This fermentation process destroys some of black tea’s polyphenols, and it was once thought that it was thus rendered less effective as an antioxidant. Tests have shown, however, that both green and black teas contain about the same amount of antioxidant polyphenols, but that the combinations of antioxidants between black and green teas depending on the method of processing. Black tea lowers blood sugar and raises insulin levels after a meal. The polyphenolic content of black tea is thought to stimulate the pancreas to release insulin.
Green tea does contain caffeine (15 to 25 milligrams per ¾ cup), but it is less than in similar amounts of coffee (80 to 115 milligrams per ¾ cup) or caffeinated carbonated beverages (38 to 46 milligrams per can). Those who have heart problems or sensitivity to caffeine or are pregnant may want to limit their intake of caffeine. Green tea contains vitamin K, which can make anticoagulant medication less effective. Consult your health care provider if you are using them.
Methionine
A unique amino acid, methionine neutralizes hydroxyl radicals, one of the most dangerous types of free radicals. Most often a by-product of reactions between heavy metals and less toxic free radicals, hydroxyl radicals can be formed also during strenuous exercise or exposure to high levels of radiation and can damage any type of body tissue.
N-Acetylcysteine (NAC)
The sulfur-containing amino acid cysteine is needed to produce the free radical fighter glutathione and to help maintain it at adequate levels in the cells. NAC is a more stable form of cysteine that can be taken in supplement form.
NAC is used by the liver and the lymphocytes to detoxify chemicals and other poisons. It is a powerful detoxifier of alcohol, tobacco smoke, and environmental pollutants, all of which are immune suppressors. Taking supplemental NAC can boost the levels of protective enzymes in the body, thus slowing some of the cellular damage that is characteristic of aging. NAC supplementation may also decrease both the frequency and duration of infectious diseases. It has been used in the management of AIDS and chronic bronchitis. People with diabetes should not take supplemental NAC without first consulting a health care provider, as it can interfere with the effectiveness of insulin.
Nicotinamide Adenine Dinucleotide (NADH)
Also known as coenzyme 1, nicotinamide adenine dinucleotide with high-energy hydrogen, or NADH, is the “spark” that ignites energy production in the body’s cells.
NADH’s high antioxidant capacity derives from its ability to reduce levels of substances. NADH plays a central role in DNA repair and maintenance, and in the cellular immune defense system. Studies report that NADH also can inhibit the auto-oxidation of the neurotransmitter dopamine, which causes the release of toxic chemicals that may damage sensitive parts of the brain.
Oligomeric Proanthocyanins (OPCs)
OPCs are naturally occurring substances present in a variety of food and botanical sources. They are unique phytochemicals known as flavonoids that have powerful antioxidant capabilities. OPCs are highly water soluble, so the body can absorb them rapidly. Clinical tests suggest that OPCs are fifty times more potent than vitamin E and twenty times more potent than vitamin C in terms of bioavailable antioxidant activity. What’s more, OPCs work with the antioxidant glutathione to recycle and restore oxidized vitamin C, thus increasing the vitamin’s effectiveness. Because they can cross the blood brain barrier, OPCs can protect the brain and spinal nerves against free radical damage. In addition to their antioxidant activity, OPCs protect the liver from damage caused by toxic doses of acetaminophen, a non-prescription pain reliever, they strengthen and repair connective tissue, including that of the cardiovascular system; and they support the immune system and slow aging. They also moderate allergic and inflammatory responses by reducing histamine production. OPC’s are found throughout plant life; however, the two main sources are pine bark extract (Pycnogenol), produced from a French coastal pine tree, and grape seed extract, made from the seeds of the wine grape (Vitis vinifera). Pycnogenol was the first source of OPCs discovered, and the process for extracting it was patented in the 1950’s. Pycnogenol is a trademarked name for pine bark extract, not a generic term for OPCs from other sources.
Selenium
Selenium is an essential trace mineral that functions as an antioxidant in partnership with vitamin E to protect tissues and cell membranes. Among other things, it increases antioxidant enzyme levels in cells. Selenium is also an integral component of the antioxidant enzyme glutathione peroxidase (each molecule of this enzyme contains four atoms of selenium). Glutathione peroxidase targets harmful hydrogen peroxide in the body and converts it to water. It is a particularly important guardian of blood cells and of the heart, liver, and lungs.
Numerous plants contain selenium, including garlic, asparagus, and grains, but the levels depend on soil content, which varies from one geographic region to another.
Use caution when taking supplemental selenium. A maximum safe dosage in 400 micrograms (mcg) daily. Amounts higher than 1000 micrograms (1 milligram) daily may be toxic.
Silymarin (Milk Thistle)
Extracted from the seeds of the herb milk thistle, silymarin has been used for centuries to treat liver disease. The active ingredients in milk thistle are several types of flavonoids (powerful antioxidants), known collectively as silymarin.
Silymarin guards the liver from oxidative damage. It also protects the liver from toxins, drugs, and the effects of alcohol, and promotes the growth of new liver cells. In addition, silymarin increases levels of glutathione, superoxide dismutase, and catalase, potent antioxidant enzymes that protect the liver. It also has shown to reduce insulin resistance, which may help patients with diabetes. In one study, patients with diabetes who received silymarin experienced blood glucose control and better blood test related to liver function.
Superoxide Dismutase
Superoxide Dismutase (SOD) is an enzyme. SOD revitalizes cells and reduces the rate of cell destruction. It neutralizes the most common, and possibly the most dangerous, free radicals—superoxide radicals. Superoxide radicals instigate the breakdown of synovial fluid, the lubricant for the body’s joints. This leads to friction and, ultimately inflammation.
SOD works synergistically with the enzyme catalase, which is abundant throughout the body. Catalase removes hydrogen peroxide by-products created by SOD reactions. SOD also aids in the body’s utilization of zinc, copper, and manganese. Its levels tend to decline with age, while free radical production increases. Its potential as an antiaging treatment is currently being explored.
Chemically, there are two forms of this enzyme. The copper/zinc form (known as Cu/Zn SOD) exerts its antioxidant properties in the cytoplasm of cells. This is the watery fluid that surrounds all the other cellular components. Metabolic activity that takes place in the cytoplasm results in the production of free radicals, and Cu/Zn neutralizes them. The manganese form (Mn SOD) is active in mitochondria, structures within cells where energy is produced. The production of cellular energy also leads to the creation of free radicals.
SOD occurs naturally in barley grass, broccoli, Brussels sprouts, cabbage, wheatgrass, and most green plants. It is also available in supplement form.
Vitamin A and the Carotenoids
A class of phytochemicals, carotenoids are fat soluble pigments found in yellow, red, green, and orange vegetables and fruits. They are a potent family of antioxidants that include alpha-carotene, beta-carotene, lycopene, lutein, and zeaxanthin. Of the more than five hundred carotenoids found in nature, about fifty can be converted into vitamin A in the body.
Carotenoids quench singlet oxygen, which is not, chemically speaking, a free radical, but is nevertheless highly reactive and can damage body molecules. Carotenoids also act as anticancer agents, decrease the risk of cataracts and age-related macular degeneration, and inhibit heart disease.
Studies have shown that carotenoids found in tomato juice (lycopene), carrots (alpha- and beta-carotene), and spinach (lutein) may help to protect against cancer by reducing oxidative and other damage to DNA. Together the antioxidants alpha-lipoic acid, coenzyme Q10, vitamin C, and vitamin E help conserve carotenoids in tissues. Another carotenoid, astaxanthin, when taken as a supplement, was shown to be well-absorbed and tended to reduce damage to fat particles floating in the blood. That means that astaxanthin may be a beneficial supplement to reduce the risk of heart disease.
The body converts beta-carotene into vitamin A as needed. Any leftover beta-carotene then acts as an antioxidant, breaking free radical chain reactions and preventing the oxidation of cholesterol. It reduces the oxidation of DNA and disables reactive oxygen species molecules generated by exposure to sunlight and air pollution, preventing damage to eyes, lungs and skin.
A recent laboratory study found that taking very high doses of supplemental beta-carotene alone (50,000 IUs or more daily) may interfere with the normal cell control of cell division. It is best to take a carotenoid complex containing a variety of carotenoids.
Vitamin C
Vitamin C is a very powerful antioxidant that also recharges other antioxidants, such as vitamin E, to keep them potent. Its water solubility makes it an efficient free radical scavenger in body fluids. Some studies have shown that vitamin C is the first line of antioxidant defense in plasma against many different kinds of free radicals. The cells of the brain and spinal cord, which frequently incur free radical damage, can be protected by significant amounts of vitamin C. This vitamin also guards against atherosclerosis by preventing damage to the artery walls. Vitamin C acts as a more potent free radical scavenger in the presence of the phytochemical hesperidin.
Vitamin E
Vitamin E is a powerful antioxidant that prevents the oxidation of lipids (fats). Fat oxidation has been implicated in the process that leads to atherosclerosis. Vitamin E is fat soluble and, since cell membranes are composed of lipids, it effectively prevents the cells’ protective coatings from becoming rancid as a result of the assault of free radicals.
Vitamin E also improves oxygen utilization, enhances immune response, plays a role in the prevention of cataracts caused by free radical damage, and may reduce risk of coronary artery disease. The natural form of Vitamin E (d-alpha-tocopherol) is superior to the synthetic version (dl-alpha-tocopherol). New evidence suggests that zinc is needed to maintain normal blood concentration of vitamin E. Selenium enhances vitamin E uptake.
Zinc
Zinc’s main antioxidant function is in the prevention of fat oxidation. It also plays a role in the correct functioning of lipid and glucose metabolism, regulating and forming the expression of insulin. In numerous studies, zinc supplementation has been found to improve blood pressure, glucose, and LDL cholesterol serum level.
Zinc is an inhibitor of NADPH oxidase, which results in decreased generation of free radicals or reactive oxygen species (ROS). Zinc is also a co-factor of super oxide dismutase (SOD) an enzyme that catalyzes the dismutation of O2- to H2O2. It also induces the generation of metallothionein, which is very rich in cysteine and is an excellent scavenger of ⋅OH.
______________________________________________________________________________________________________________