Role of Free Radicals in the Pathogenesis of Some Common Diseases

Dr. Chithra V.

Abstract: Free radicals and other oxidants have gained importance in the field of biology due to their central role in various physiological conditions as well as their implication in a diverse range of diseases. Biological free radicals, notably reactive oxygen species (ROS) and reactive nitrogen species (RNS) are derived from both endogenous sources (mitochondria, peroxisomes, endoplasmic reticulum, phagocytic cells etc.) and exogenous sources (pollution, alcohol, tobacco smoke, heavy metals, transition metals, industrial solvents, pesticides, certain drugs like halothane, paracetamol, and radiation). However, when their production overwhelms the body?s antioxidant defences, a state of oxidative stress develops. Antioxidants- both enzymatic (e.g., superoxide dismutase, catalase, glutathione peroxidase) and non-enzymatic (e.g., vitamins C and E, glutathione, polyphenols)- serve as critical protective systems that neutralize free radicals and prevent biomolecular damage. Effective antioxidant defences are crucial in mitigating free radical-induced cellular damage and maintaining biological homeostasis. The free radicals induced oxidative stress can damage critical biomolecules including DNA, lipids, and proteins, has been reported to be involved in several diseased conditions such as diabetes mellitus, neurodegenerative disorders (Parkinson?s disease-PD, Alzheimer?s disease-AD and Multiple sclerosis-MS), cardiovascular diseases (atherosclerosis and hypertension), respiratory diseases (asthma), cataract development, rheumatoid arthritis and in various cancers (colorectal, prostate, breast, lung, bladder cancers). This review deals with the general aspects of free radicals and antioxidant defence mechanism and the role of free radicals in the development of pathogenesis of some common diseases.

Keywords: Free radicals, Reactive oxygen species (ROS), Reactive nitrogen species (RNS), Oxidative stress, antioxidants, pathogenesis

How to Cite?: Dr. Chithra V., "Role of Free Radicals in the Pathogenesis of Some Common Diseases", Volume 14 Issue 12, December 2025, International Journal of Science and Research (IJSR), Pages: 2217-2228, https://www.ijsr.net/getabstract.php?paperid=SR251226212630, DOI: https://dx.doi.org/10.21275/SR251226212630