Assistant Lecturer: AFRAH ISMAEL WAHEEB

University of Anbar _ College of basic education / Haditha

General sciences

Free radicals are defined as atoms or molecules that possess one of the unpaired electrons in their outer shell. They were discovered in 1785 by the scientist Lavoisier. These atoms or molecules are unstable, excitable, and have high energy due to the imbalance that occurs in the distribution and regularity of the electrons in their outer shell. Their orbits are therefore very effective in reaching a stable state by interacting with another free radical or any other molecule through various reactions, leading to the generation of sequential and successive free radicals. This process leads to the fission of neighboring molecules, causing major damage to cells and DNA, often they are produced by metabolic processes in the body and external factors such as pollution and ultraviolet radiation.

Among the important radicals that have shown a harmful effect on health and biological activities are single oxygen, the negative superoxide radical, the hydroxyl radical, and hydrogen peroxide (H2O2). The single oxygen molecule has a role in the oxidation of fats, proteins, and nucleic acids, which leads to a change in the genetic material. They cause genetic mutations and thus the appearance of cancerous tumors. Super oxide anion is also of great importance in biological systems, as it has the ability to interfere with DNA, leading to its disassembly. It also attacks polyunsaturated fatty acids and causes damage to membranes.

Oxygen free radicals are classified according to their interactions into reducing radicals and oxidizing radicals. These free radicals are very effective molecules and have the ability to oxidize vital molecules that include proteins, fats, nucleic acids, and carbohydrates, when oxygen free radicals combine with molecules of living matter in tissues and living cells. They are transformed into new free radicals. These reactions occur regularly in the body and increase in pathological cases, causing harm to living cells. The damage resulting from these reactions is imperceptible until an advanced stage of damage is reached, called oxidative damage or oxidative stress.

Oxidative stress occurs when there is an imbalance between the production of free radicals and the body's ability to counter their harmful effects. Oxidative stress is associated with many chronic diseases including cancer, cardiovascular disorders, and neurological conditions. Additionally, visible signs of aging, such as wrinkles and age spots, are often related to the cumulative damage caused by these free radicals over time. Its effect extends to complex mechanisms in the human body, weakening cellular communication and disrupting the delicate balance necessary for optimal health.

Understanding the effects and nature of free radicals is crucial in maintaining a delicate balance through the intervention of Antioxidant, as Antioxidant play a crucial role in neutralizing the harmful effects of free radicals. Found in abundance in fruits, vegetables, nuts, and grains, these compounds have the remarkable ability to donate electron without becoming unstable themselves. By doing so, they effectively end the harmful chain reaction started by free radicals, thus protecting the body's cells from potential damage.

   Vitamins C, E, beta-carotene, selenium, as well as a group of phytochemicals act as antioxidants against oxidative stress. Diets rich in antioxidants can reduce the risk of chronic diseases, strengthen the immune system, and even slow down the aging process, which confirms the crucial role they play in preserving the body’s cells.

A balanced lifestyle is also crucial in reducing the production of free radicals. Regular exercise, stress management, and avoiding environmental toxins play an essential role in achieving this balance. Combined with a diet rich in antioxidants, these lifestyle choices act as an integral shield, strengthening our bodies against the attack of these harmful entities.

Key words: Free Radicals, Oxidative Stress, Antioxidant