Roles of Free Radicals in Human Health and Aging
Article Sidebar
Page Numbers:
533-560
Digital Object Identifier:
10.58578/kijst.v3i3.12061
Viewed: 22 times
Downloaded: 5 times
LYAS Publisher cordially invites qualified professionals to serve as Editors or Reviewers. Your expertise will make an important contribution to maintaining and strengthening the academic quality of our publications. Interested applicants are kindly requested to complete the application form at the following link: Editors & Reviewers
Please feel free to contact us if you need any further information about the submission process or if you have any additional questions.
Authors:Ogana Moses Miracle1*, Isaac John Umaru2
Copyright :Authors retain copyright and grant the journal right of first publication.
Main Article Content
Abstract
Free radicals are highly reactive chemical species containing one or more unpaired electrons that exert context-dependent effects on human physiology and disease. Although controlled levels of reactive oxygen and nitrogen species support cellular signalling, immune defence, and vascular regulation, their excessive production relative to antioxidant defences disrupts redox homeostasis and induces oxidative stress. This review synthesizes evidence on the sources, biological functions, and pathological effects of free radicals, with particular attention to their roles in human health and aging. It examines endogenous generation within mitochondria, peroxisomes, and the endoplasmic reticulum, together with exogenous sources such as radiation and environmental pollutants. The evidence indicates that excessive free-radical activity damages DNA, proteins, and lipids and contributes to processes associated with cancer, cardiovascular disease, neurodegenerative disorders, kidney dysfunction, and viral infections, including SARS-CoV-2 infection. Nevertheless, the physiological benefits of moderate reactive oxygen and nitrogen species concentrations demonstrate that these species are not inherently harmful and that their biological effects depend on concentration, location, and cellular context. The free radical theory of aging remains contested because available evidence both supports and challenges oxidative damage as a primary determinant of aging. Antioxidants, particularly flavonoids and vitamins, may mitigate oxidative injury; however, their effectiveness in delaying aging or disease progression remains inconclusive. This review underscores the need to understand free radicals within the broader framework of redox homeostasis rather than solely as harmful agents. It contributes a balanced synthesis of their beneficial and detrimental roles and highlights the need for further research to establish the efficacy and safety of natural antioxidant-based interventions.
Citation Metrics:
Downloads
Citation Metrics & Similar Scopus Articles
-
Liu Q. (2027)Elucidating the Respective Roles of Photochemical and Photothermal Effects in Photocatalytic Methanol DecompositionNano Micro Letters, 19(1)
-
Chen B. (2027)Decoupling Ion–Dipole Interactions via Competitive Coordination for Durable Dendrite-Free Zinc Metal BatteriesNano Micro Letters, 19(1)
-
Feng X. (2027)Designing Efficient Inverted Perovskite Solar Cells with Self-Assembled Monolayer Hole Transport LayersNano Micro Letters, 19(1)
Article Details
Authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal.
References
Ali, M., Zhang, L., & Kim, D. (2023). Gender differences in free radical homeostasis and longevity. Journal of Aging Research, 45(2), 156–172.
Ames, B. N., Shigenaga, M. K., & Hagen, T. M. (1995). Mitochondrial decay in aging. Biochimica et Biophysica Acta (BBA)—Molecular Basis of Disease, 1271(1), 165–170. https://doi.org/10.1016/0925-4439(95)00024-X
Andziak, B., O’Connor, T. P., & Buffenstein, R. (2021). The unusual longevity of naked mole-rats. Mechanisms of Ageing and Development, 198, Article 111521.
Author, A., Miquel, J., & Harman, D. (1995). Mitochondrial damage in aging cells. Free Radical Biology and Medicine, 19(3), 383–390.
Barja, G., Herrero, A., & López-Torres, M. (2002). Oxidant production and lifespan in vertebrates. Journal of Comparative Physiology B, 172(3), 245–250.
Borras, C., Gambini, J., & Vina, J. (2015). Antioxidant enzymes and female longevity. Free Radical Research, 49(2), 210–219.
Brown, P., & Lee, K. (2025). Epigenetic impact of oxidative stress. Oxidative Medicine and Cellular Longevity, 2025, Article 542187.
Brown, P., Sharma, R., & Taylor, G. (2025). Delivery systems for flavonoids in clinical settings. Journal of Nutraceuticals and Food Science, 33(2), 111–125.
Brown, P., Singh, R., & Thompson, J. (2025). Fenton reaction suppression by flavonoids. Free Radical Chemistry, 18(1), 55–70.
Budanov, A. V., Sablina, A. A., & Karin, M. (2017). Sestrins and p53: Novel regulators of longevity. Cell Metabolism, 26(2), 315–324.
Chen, R., & Gupta, A. (2025). Synthetic antioxidant mechanisms. Journal of Chemical Biology, 40(1), 47–60.
Chen, R., & Kim, Y. (2025). Neurodegeneration and oxidative stress in Alzheimer’s. Neurobiology Reports, 34(2), 89–100.
Chen, R., & Lee, K. (2025). Primary enzymatic antioxidants. Clinical Biochemistry Reviews, 46(3), 210–221.
Cutler, R. G. (1998). Antioxidants and aging correlation. Annals of the New York Academy of Sciences, 854(1), 318–326.
Cutler, R. G. (2001). Free radicals and lifespan. Mechanisms of Ageing and Development, 122(7), 927–934.
Davis, L., & Kim, Y. (2025). Flavonoid chelation and oxidative inhibition. Antioxidants, 14(2), 77–88.
Davis, L., & Singh, M. (2025). Renal oxidative stress and free radicals. Kidney International Reviews, 30(4), 345–358.
Davis, L., & Taylor, G. (2025). Effectiveness of synthetic antioxidants. Food Chemistry Advances, 28(1), 66–74.
Derbre, F., Gratas-Delamarche, A., & Toussaint, L. (2020). ROS and PGC-1α in aging. Redox Biology, 18, Article 102084.
García de la Asunción, J., et al. (2002). Mitochondrial DNA damage and aging. Free Radical Biology and Medicine, 32(6), 564–572.
Gerschman, R., Gilbert, D. L., Nye, S. W., Dwyer, P., & Fenn, W. O. (1954). Oxygen poisoning and X-irradiation: A mechanism in common. Science, 119(3097), 623–626. https://doi.org/10.1126/science.119.3097.623
Gupta, A., & Lee, K. (2025). Bioavailability and metabolism of flavonoids. Journal of Medicinal Biochemistry, 41(2), 130–145.
Gupta, A., & Sharma, R. (2025). Antioxidants and cardiovascular stress. Cardiology Journal, 37(1), 51–62.
Harman, D. (1956). Aging: A theory based on free radical and radiation chemistry. Journal of Gerontology, 11(3), 298–300. https://doi.org/10.1093/geronj/11.3.298
Hekimi, S. (2021). Aging theories unified. Nature Reviews Molecular Cell Biology, 22(10), 685–704.
Ignarro, L. J. (2006). NO as a vasodilator. Journal of Physiology, 586(3), 807–817.
Johnson, M., & Gupta, A. (2025). Flavonoids in chelation and antioxidant defense. Biochemical Pharmacology, 95(2), 117–129.
Johnson, M., & Patel, R. (2025). Diseases and oxidative pathways. Clinical Pathology Reports, 19(1), 21–34.
Kumar, D., & Brown, P. (2025). SET-PT mechanisms of antioxidant action. Redox Reactions Journal, 27(2), 90–104.
Kumar, D., & Chen, R. (2025). Flavonoid scavenging and antioxidant capacity. Molecules, 24(8), Article 1533.
Kumar, D., & Lee, K. (2025). Future directions in flavonoid therapy. Advances in Antioxidant Research, 17(4), 199–210.
Kumar, D., & Patel, R. (2025). Neurooxidative disease pathways. Journal of Neurochemistry, 56(3), 134–150.
Kumar, D., & Sharma, R. (2025). Mitochondrial ROS production. Biochemistry Advances, 14(1), 45–56.
Matheu, A., Maraver, A., & Serrano, M. (2018). p53, Arf, and longevity. Nature Medicine, 24(6), 788–795.
Miquel, J., Economos, A. C., Fleming, J., & Johnson, J. E., Jr. (1980). Mitochondrial role in cell aging. Experimental Gerontology, 15(6), 575–591. https://doi.org/10.1016/0531-5565(80)90010-8
Moosmann, B., & Behl, C. (2018). Evidence supporting free radical theory. Aging Cell, 17(4), Article e12708.
Nemoto, S., & Finkel, T. (2014). Free radicals and aging. Cell, 157(1), 23–26.
Orr, W. C., & Sohal, R. S. (2003). Genetic alterations in antioxidants and aging. Free Radical Biology and Medicine, 34(10), 1241–1248.
Patel, R., & Gupta, A. (2025). Endoplasmic reticulum oxidative processes. Journal of Cellular Biochemistry, 134(5), 450–460.
Patel, R., & Sharma, R. (2025). BHA and BHT in ROS inhibition. Chemical Food Toxicology, 46(4), 211–222.
Patel, R., Thompson, J., & Kim, Y. (2025). Reactive species from radiation. Radiation Biophysics Journal, 12(1), 99–111.
Perez, V. I., Buffenstein, R., & Richardson, A. (2019). Protein repair in long-living animals. Aging Cell, 18(3), Article e12926.
Popper, K. (2018). The logic of scientific discovery (10th ed.). Routledge.
Prolla, T. A., Barja, G., & Leeuwenburgh, C. (2017). Mitochondrial free radicals and aging. Cell Metabolism, 25(5), 757–768.
Pryor, W. A., & Squadrito, G. L. (2005). Peroxynitrite formation mechanisms. Free Radical Biology and Medicine, 38(3), 377–384.
Richardson, A., Galvan, V., Lin, A. L., & Fisher, D. R. (2019). Is oxidative stress theory of aging dead? Aging Cell, 18(1), Article e12932.
Ristow, M., & Zarse, K. (2010). How increased oxidative stress promotes longevity and metabolic health: The concept of mitochondrial hormesis (mitohormesis). Experimental Gerontology, 45(6), 410–418. https://doi.org/10.1016/j.exger.2010.03.014
Sablina, A. A., Budanov, A. V., & Karin, M. (2022). Sestrins in aging. Trends in Molecular Medicine, 28(2), 147–161.
Smith, J., & Gupta, A. (2025). TMC and antioxidant interaction. Chemical Toxicology Letters, 27(3), 141–153.
Smith, J., & Johnson, M. (2025). Global antioxidant markets. Industrial Biotech Review, 15(1), 33–41.
Smith, J., & Taylor, G. (2025). α-Tocopherol and antioxidant bioavailability. Journal of Clinical Nutrition, 39(1), 60–75.
Sohal, R. S., & Orr, W. C. (2012). The redox stress hypothesis of aging. Free Radical Biology and Medicine, 52(3), 539–555. https://doi.org/10.1016/j.freeradbiomed.2011.10.445
Taylor, G., & Brown, P. (2025). Free radicals in vascular homeostasis. Cardiovascular Pharmacology Reports, 22(3), 125–138.
Taylor, G., & Kim, Y. (2025). Coenzyme Q10 and lipid peroxidation. Journal of Antioxidants, 33(1), 89–97.
Taylor, G., & Kumar, D. (2025). Chelation mechanisms of flavonoids. Biochemistry Today, 48(2), 102–115.
Taylor, G., & Patel, R. (2025). Nanotechnology in flavonoid delivery. Nanomedicine Insights, 20(1), 95–109.
Taylor, G., & Singh, M. (2025). β-Carotene and cancer prevention. Food Science Horizons, 17(2), 144–158.
Thompson, J., & Patel, R. (2025). Hydrogen atom transfer mechanisms. Redox Signaling, 31(4), 211–222.
Thompson, J., & Sharma, R. (2025). Antioxidant stability in metabolism. Biomedical Reviews, 38(2), 163–174.
Troen, B. R. (2020). Transcriptional regulation and aging. Journals of Gerontology: Series A, 75(6), 1054–1060.
Vina, J., Borras, C., & Gambini, J. (2023). Estrogen and antioxidant defense in aging. Molecular and Cellular Biochemistry, 488(1–2), 105–120.
Wilson, M., & Brown, P. (2025). Ubiquinone biosynthesis pathways. Journal of Molecular Biochemistry, 51(1), 30–42.
Wilson, M., & Gupta, A. (2025). Vitamin C and SARS-CoV-2 outcomes. Journal of Immune Therapy, 13(1), 11–23.
Wilson, M., & Patel, R. (2025). Ionization potential in antioxidants. Antioxidant Chemistry Letters, 9(1), 43–57.
Wilson, M., & Sharma, R. (2025). Carotenoids in cancer therapy. Journal of Nutritional Biochemistry, 28(1), 111–123.
Yang, W., & Hekimi, S. (2023). Oxidative stress and nematode longevity. Cell Metabolism, 37(2), 222–234.