Antioxidants: Free radical protection

Antioxidants: Free radical protection

1. Free radicals: nature, education and danger

Free radicals are unstable molecules characterized by the presence of one or more non -fed electrons in external orbit. This electronic “dissatisfaction” makes them extremely reactionary, striving to capture the electron from other molecules in order to stabilize. This process, known as oxidation, launches a chain reaction, damaging cell structures, such as DNA, proteins and lipids.

1.1. Mechanisms for the formation of free radicals:

• Normal metabolic processes: Energy production in mitochondria, detoxification in the liver, immune reactions of phagocytes – all these processes are inevitably accompanied by the formation of a small number of free radicals. This is a normal physiological process that supports cell alarm and an immune response.
• External factors: Environmental impact significantly increases the formation of free radicals. These include:
  • Ultraviolet radiation (UV): UV radiation of the Sun damages the skin, generating free radicals that contribute to photo glasses, pigmentation and increased risk of skin cancer.
  • Air pollution: Sow, exhaust gases of cars, industrial emissions contain various pollutants who launch the formation of free radicals in the lungs and other organs.
  • Smoking: Cigarette smoke contains thousands of chemicals, including powerful oxidants, which significantly increase the amount of free radicals in the body.
  • Radiation: Ionizing radiation, such as x -ray radiation and radioactive materials, damages DNA and other cellular structures, forming free radicals.
  • Pesticides and herbicides: Contact with pesticides and herbicides used in agriculture can lead to the formation of free radicals in the body.
  • Inal meals: A diet rich in processed food products, trans fats and sugar can contribute to the formation of free radicals.
  • Chronic stress: Long -term stress can disrupt the balance in the body and increase the production of free radicals.
  • Some drugs: Some drugs may have side effects associated with the formation of free radicals.

1.2. Types of free radicals:

• Superxy (O₂⁻): It is formed as a result of leakage of electrons from the electron-transport circuit of mitochondria. Is the predecessor of other free radicals.
• Hydroxide radical (OH •): One of the most reactive and dangerous free radicals. Can damage DNA, proteins and lipids. It is formed as a result of the panton reaction (Fe²⁺ + H₂o₂ → Fe³⁺ + OH • + OH⁻).
• Hydrogen peroxide (h₂o₂): Although it itself is not a free radical, it can be converted into a hydroxyl radical under the influence of certain metals.
• Single-Kislorod (¹o₂): An excited form of oxygen, which has a high reactionary ability and capable of damaging lipids and proteins. It is formed under the influence of light and certain chemicals.
• Alkil radicals (R •): Organic radicals formed as a result of the separation of the hydrogen atom from an organic molecule. They can participate in chain reactions, damaging lipids and proteins.
• Pensil-raids (ROO •): They are formed during the interaction of alkyl radicals with oxygen. Participate in the peroxidation of lipids.
• Nitrogen oxide (no •): He plays an important role in cell alarm, but in excess amounts can react with superoxide, forming peroxinitrite (ONOO⁻), highly toxic substance.
• Peroxinitrite (ONOO⁻): A powerful oxidizing agent damaging DNA, proteins and lipids. It is formed with the interaction of nitrogen oxide with superoxide.

1.3. The consequences of damage by free radicals (oxidative stress):

When the balance between the formation of free radicals and antioxidant protection is disrupted in favor of free radicals, a state occurs, called oxidative stress. Oxidative stress is associated with the development and progression of many chronic diseases, including:

• Cardiovascular diseases: Oxidation of low density lipoproteins (LDL) plays a key role in the development of atherosclerosis. Free radicals also damage the vascular endothelium, contributing to the development of hypertension and other cardiovascular diseases.
• Neurodegenerative diseases: Oxidative stress plays an important role in the pathogenesis of Alzheimer’s disease, Parkinson’s disease and lateral amyotrophic sclerosis (BAS). Damage to DNA and proteins in neurons with free radicals leads to their death and the progressive deterioration of cognitive functions and motor skills.
• Cancer: DNA damage to free radicals can lead to mutations that cause uncontrolled cell growth and cancer development. Oxidative stress can also contribute to the progression and metastasis of cancer.
• Diabetes: Oxidative stress damages pancreatic beta cells that produce insulin, which leads to the development of type 2 diabetes. It also contributes to the development of complications of diabetes, such as cardiovascular diseases, neuropathy and nephropathy.
• Inflammatory diseases: Oxidative stress activates the inflammatory pathways, which leads to the development of chronic inflammatory diseases, such as arthritis, inflammatory diseases of the intestine and asthma.
• Aging: Oxidative stress is considered one of the main causes of aging. Damage to DNA, proteins and lipids with free radicals leads to a deterioration in cellular functions and the development of age -related changes.
• Cataract and degeneration of the yellow spot: Oxidative stress damages the lens of the eye, leading to the development of cataracts. It also contributes to the degeneration of the yellow spot, the main reason for loss of vision in the elderly.
• Autoimmune diseases: Oxidative stress can contribute to the development of autoimmune diseases, such as rheumatoid arthritis and systemic lupus erythematosus, by damaging tissues and activating the immune system.

2. Antioxidants: action mechanism and classification

Antioxidants are substances that can neutralize free radicals, preventing or slowing down oxidative cell damage. They work, giving the electron to a free radical, stabilizing it and interrupting the chain oxidation reaction. The antioxidants do not become free radicals themselves after the removal of the electron, since they are quite stable in this state.

2.1. The mechanisms of the action of antioxidants:

• Electron returns: Most antioxidants act, giving the electron to a free radical, thereby neutralizing it. For example, vitamin C gives an electron to free radicals, turning into dehydro -core acid, which can then be restored by other antioxidants.
• The transformation of free radicals into less harmful substances: Some antioxidants, such as superoxidsmouth (SOD), catalase and glutathioneperoxidase, are enzymes that catalyze the transformation of free radicals into less harmful substances, such as water and oxygen.
• Helating of metals: Some antioxidants, such as EDTA (ethylendiamintetraxic acid) and phytic acid, are associated with metals, such as iron and copper, preventing their participation in the reactions of fenton and Khaber-Weiss, which form a hydroxyl radical.
• Restoration of other antioxidants: Some antioxidants, such as glutathione and lipoic acid, are able to restore other antioxidants, such as vitamin C and vitamin E, after they gave the electron to a free radical.
• Activation of endogenous antioxidant enzymes: Some substances, such as sulforafan (contained in broccoli), can activate genes encoding antioxidant enzymes, such as SOD, Catalase and Glutathioneperoxidase, increasing the antioxidant protection of the body.

2.2. Classification of antioxidants:

Antioxidants can be classified according to various criteria, including their origin (endogenous or exogenous), their chemical structure and their solubility (water -soluble or fat -soluble).

2.2.1. By origin:

• Endogenous antioxidants: It is produced by the body. These include enzymes, such as superoxidsmouth (SOD), catalase and glutathioneperoxidase, as well as non -enzymatic antioxidants, such as glutathione and uric acid.
• Exogenous antioxidants: It is obtained from food and additives. These include vitamins (vitamin C, vitamin E, beta-carotene), minerals (selenium, zinc, manganese), polyphenols (flavonoids, anthocyanins, resveratrol) and other substances.

2.2.2. In chemical structure:

• Vitamins:
  • Vitamin C (ascorbic acid): A water -soluble antioxidant that protects against free radicals in the water phase of the body. It is important for the synthesis of collagen, strengthening immunity and assimilation of iron.
  • Vitamin E (tocopherol): A fat -soluble antioxidant that protects cell membranes from lipid oxidation. It is important for the health of the skin, hair and eyes.
  • Beta-carotene: Fatable provitamin A, which also has antioxidant properties. Protects cells from damage to UV radiation and improves vision.
• Minerals:
  • Selenium: Component of glutathioneperoxidase, an important antioxidant enzyme.
  • Zinc: It is necessary for the activity of superoxidsmouth (SOD) and other enzymes.
  • Manganese: It is also necessary for the activity of SOD.
• Polyphenols: A large group of plant compounds with powerful antioxidant properties.
  • Flavonoids: Widely distributed in fruits, vegetables, tea and wine. They have anti -inflammatory, anti -cancer and cardi -protective properties. Examples: quercetin, routine, catechins.
  • Anthocials: Contained in berries, red wine and other products with dark red, purple or blue. Have powerful antioxidant and anti -inflammatory properties.
  • Resveratrol: Contained in red wine, grapes and peanuts. It has antioxidant, anti -inflammatory and anti -cancer properties.
  • Phenolic acids: Contained in fruits, vegetables and grain. Have antioxidant and anti -inflammatory properties. Examples: chlorogenic acid, coffee acid.
• Carotinoids (except beta-carotene):
  • Liquopin: Contained in tomatoes and other red fruits and vegetables. It has antioxidant and anti -cancer properties, especially in relation to the prostate cancer.
  • Lutein and Zeaxanthin: Contained in dark green leafy vegetables and egg yolk. Important to the health of the eyes and protection against degeneration of the yellow spot.
• Other:
  • Glutathione: Tripeptide, which is an important antioxidant in cells. Participates in detoxification and protection against oxidative stress.
  • Lipoic acid: A powerful antioxidant, which is soluble in both water and in fats. Participates in energy metabolism and restores other antioxidants.
  • Coenzim Q10 (Uthihinone): It is important for energy production in mitochondria and also has antioxidant properties.
  • Melatonin: The hormone produced by the pineal gland that regulates sleep and also has powerful antioxidant properties.

2.2.3. In solubility:

• Water -soluble antioxidants: Soluble in water and act in the water phase of cells and extracellular fluid. Examples: vitamin C, glutathione, polyphenols.
• Fat -soluble antioxidants: Soluble in fats and act in cell membranes and other fat structures. Examples: vitamin E, beta-carotene, lycopine, coenzyme Q10.

3. Sources of antioxidants in food:

Proper nutrition, rich in fruits, vegetables, whole grains and legumes, is the best way to provide sufficient consumption of antioxidants. A variety of products guarantees the production of a wide range of antioxidants acting synergically.

3.1. Fruits:

• Berries: Blueberries, raspberries, strawberries, blackberries, cranberries are rich in anthocyans, vitamin C and other antioxidants.
• Citrus: Orange, grapefruits, lemons, limes are excellent sources of vitamin C and flavonoids.
• Pomegranate: Contains punikalagins and anthocyans, powerful antioxidants.
• Grape: Contains resveratrol, especially in red grapes.
• Apples: Contain quercetin and other flavonoids.
• Kiwi: Rich in vitamin C and other antioxidants.
• Avocado: Contains vitamin E and other antioxidants.

3.2. Vegetables:

• Dark green leafy vegetables: Spinach, cabbage, broccoli, leaf mustard are rich in lutein, zeaxantin, vitamin C and other antioxidants.
• Cross -stained vegetables: Broccoli, cauliflower, Brussels cabbage, white cabbage – contain sulforafan and other antioxidants.
• Carrot: Rich beta-carotine.
• Tomatoes: Contain lycopines.
• Sweet pepper: Rich in vitamin C and carotenoids.
• Onions and garlic: Contain allicin and other sulfur -containing compounds with antioxidant and anti -inflammatory properties.
• Beet: Contains betalains, powerful antioxidants.
• Eggplant: Contain anthocyans.

3.3. Other sources:

• Nuts and seeds: Almonds, walnuts, flax seeds, chia seeds – contain vitamin E, selenium and other antioxidants.
• Legumes: Beans, lentils, peas – contain flavonoids and other antioxidants.
• Whole grains: Brown rice, oats, cinema – contain vitamin E, selenium and other antioxidants.
• Tea: Green tea, black tea, white tea are rich in catechins and other flavonoids.
• Coffee: Contains chlorogenic acid and other antioxidants.
• Dark chocolate: Contains flavonoids.
• Herbs and spices: Turmeric, ginger, rosemary, oregano, basil – contain various antioxidants.

4. Antioxidant additives: benefits and risks

Antioxidant additives can be useful in certain situations, for example, with a deficiency of certain nutrients or with an increased risk of oxidative stress. However, it is important to remember that the additives do not replace a balanced nutrition, and they should be taken with caution and under the supervision of a doctor.

4.1. The benefits of antioxidant additives:

• Filling a deficiency of nutrients: Additions can be useful for people who experience a deficiency of certain vitamins and minerals such as vitamin C, vitamin E or selenium.
• Oxidative stress protection: Additives can help protect the cells from damage to free radicals in situations where oxidative stress is increased, for example, with intense physical exertion, the effects of air pollution or smoking.
• Improving the health of the eyes: Addresses containing lutein and zeaxantin can help protect the yellow spot from degeneration.
• Support for the immune system: Vitamin C and other antioxidants can help strengthen the immune system.
• Slow down aging: Some studies show that antioxidant supplements can help slow down the aging process.

4.2. Risks of antioxidant additives:

• High doses can be harmful: Taking high doses of antioxidant additives can be harmful and even paradoxically increased oxidative stress. For example, high doses of vitamin E can increase the risk of cardiovascular diseases, and high doses of beta-carotene can increase the risk of lung cancer in smokers.
• Interaction with drugs: Antioxidant additives can interact with some drugs, changing their effectiveness or increasing the risk of side effects.
• Disadvantage of research: The effectiveness of many antioxidant additives is not well studied, and research results are often contradictory.
• Poor products: There are many poor antioxidant additives on the market that may contain impurities or not correspond to the declared composition.

4.3. Recommendations for taking antioxidant additives:

• Consult a doctor: Before taking any antioxidant additives, you need to consult a doctor, especially if you have any diseases or you take medications.
• Choose quality products: Choose additives from well -known manufacturers that guarantee the quality and cleanliness of the product.
• Follow the recommended dosage: Do not exceed the recommended dosage indicated on the packaging.
• Take additives with food: Some antioxidant additives are better absorbed if you take them with food.
• Do not rely only on additives: Antioxidant additives do not replace a balanced nutrition. Try to receive food antioxidants.

5. Antioxidants in cosmetics:

Antioxidants are widely used in cosmetics to protect the skin from damage to free radicals caused by UV radiation, air pollution and other environmental factors. They help slow down the aging of the skin, reduce wrinkles, improve complexion and protect from skin cancer.

5.1. Popular antioxidants in cosmetics:

• Vitamin C: A powerful antioxidant, which stimulates collagen synthesis, brightens the skin, reduces pigmentation and protects from UV radiation.
• Vitamin E: Protects cell membranes from lipid oxidation, moisturizes the skin and reduces inflammation.
• Retinol (Vitamin A): It stimulates the renewal of skin cells, reduces wrinkles and improves the complexion.
• Coenzim q10: Protects cells from damage by free radicals and improves energy metabolism in skin cells.
• Green tea: Contains catechins that have antioxidant and anti -inflammatory properties.
• Resveratrol: It has antioxidant, anti -inflammatory and anti -cancer properties.
• Ferulic acid: Enhances the action of vitamins C and E and protects against UV radiation.
• Niacinamide (vitamin B3): Improves the barrier function of the skin, reduces inflammation and improves complexion.
• Plant extracts: Many plant extracts, such as grenade extract, grape seed extract and green tea extract, contain antioxidants.

5.2. Forms of antioxidants in cosmetics:

Antioxidants in cosmetics can be represented in various forms, such as:

• Serum: They contain a high concentration of antioxidants and are quickly absorbed into the skin.
• Creams: Moisturize and nourish the skin, and also contain antioxidants.
• Lotions: Light moisturizers, which can also contain antioxidants.
• Masks: Intensively nourish and moisturize the skin, and also contain antioxidants.
• Sunscreen: Contain antioxidants to protect the skin from damage to UV radiation.

5.3. How to choose cosmetics with antioxidants:

• Pay attention to the composition: Check what antioxidants are contained in a cosmetic product.
• Choose products with a high concentration of antioxidants: Usually, antioxidants are indicated at the beginning of the list of ingredients.
• Choose products in opaque packaging: Antioxidants can collapse under the influence of light and air.
• Consider your skin type: Choose products that are suitable for your skin type.
• Consult a dermatologist: If you have any skin problems, consult with a dermatologist before using antioxidants cosmetics.

6. Antioxidants in medicine: promising areas of research

Antioxidants are actively examined in medicine as potential means for the prevention and treatment of various diseases associated with oxidative stress.

6.1. Cardiovascular diseases:

Studies show that antioxidants, such as vitamin C, vitamin E, resveratrol and Q10 coenzyme, can help reduce the risk of cardiovascular diseases by preventing LDL oxidation, improving the function of endothelium and reducing inflammation. However, the results of clinical trials are often contradictory, and additional studies are necessary to confirm the effectiveness of antioxidants in the prevention and treatment of cardiovascular diseases.

6.2. Neurodegenerative diseases:

Oxidative stress plays an important role in the pathogenesis of Alzheimer’s disease, Parkinson’s disease and other neurodegenerative diseases. Studies show that antioxidants, such as vitamin E, vitamin C, coenzyme Q10, glutathione and polyphenols, can help protect neurons from damage to free radicals and slow down the progression of these diseases. However, the results of clinical trials are also contradictory, and additional studies are necessary to determine the optimal doses and combinations of antioxidants for the treatment of neurodegenerative diseases.

6.3. Cancer:

Antioxidants can help prevent cancer by protecting DNA from damage by free radicals. Some studies show that a diet rich in antioxidants can reduce the risk of developing some types of cancer, such as prostate cancer, lung cancer and colon cancer. However, some clinical trials have shown that high doses of antioxidant additives can even increase the risk of cancer. It is necessary to conduct additional studies to determine the role of antioxidants in the prevention and treatment of cancer.

6.4. Diabetes:

Oxidative stress plays an important role in the development of complications of diabetes, such as cardiovascular diseases, neuropathy and nephropathy. Studies show that antioxidants, such as vitamin C, vitamin E, lipoic acid and Q10 coenzyme, can help reduce oxidative stress and improve blood sugar in people with diabetes. However, the results of clinical trials are also contradictory, and additional studies are necessary to determine the optimal doses and combinations of antioxidants for the treatment of diabetes and its complications.

6.5. Inflammatory diseases:

Oxidative stress activates the inflammatory pathways, which leads to the development of chronic inflammatory diseases, such as arthritis, inflammatory diseases of the intestine and asthma. Studies show that antioxidants, such as vitamin C, vitamin E, selenium and polyphenols, can help reduce inflammation and alleviate the symptoms of these diseases. However, the results of clinical trials are also contradictory, and additional studies are necessary to determine the role of antioxidants in the treatment of inflammatory diseases.

6.6. Other areas of research:

Antioxidants are also investigated as potential means for the treatment of other diseases associated with oxidative stress, such as:

• Cataract and degeneration of the yellow spot: Luthein and Zeaksantin can help protect the yellow spot from degeneration.
• Autoimmune diseases: Antioxidants can help reduce inflammation and alleviate the symptoms of autoimmune diseases.
• Aging: Antioxidants can help slow down the aging process.
• Infertility: Antioxidants can help improve the quality of sperm and eggs.

7. Conclusion (lowered in accordance with the task)