Molecular Mechanisms of Physiological Aging: Hallmarks, Environmental Impacts, and Pathways to Healthy Longevity

Document Type : Original Article

Authors

1 Department of Forensic Medicine and Toxicology, Faculty of Veterinary Medicine, Benha University, Toukh 13736, Egypt

2 1- Department of Forensic Medicine and Toxicology, Faculty of Veterinary Medicine, Benha University, Toukh 13736, Egypt 2- Menoufia University Hospital, Faculty of Medicine, Menoufia University, Shibeen Elkom, Egypt

3 Department of Chemistry, Faculty of Science, Suez Canal University, Ismailia, Egypt

4 Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, USA

5 Center for Health Research, Northern Border University, Arar 91431, Saudi Arabia

6 Department of Physiology, Bangladesh Agricultural University, Mymensingh 2202, Bangladesh

7 Department of Pharmacology, College of Pharmacy, Al-Ayen Iraqi University, AUIQ, An Nasiriyah, Iraq

8 Department of Basic and Clinical Medical Sciences, Faculty of Dentistry, Zarqa University, Zarqa 13110, Jordan

9 Department of Biomedical Sciences, Dubai Medical College for Girls, Dubai Medical University, Dubai 19099, United Arab Emirates

10 Department of Stem Cell and Regenerative Biotechnology, School of Advanced Biotechnology, Molecular & Cellular Reprogramming Center, Institute of Advanced Regenerative Science, and Institute of Health, Aging & Society, Konkuk

11 Translational Medical Sciences, School of Medicine, Royal Derby Hospital Centre, University of Nottingham, Derby DE22 3DT, UK

12 forensic medicine and toxicology,faculty of veterinary medicine, benha university

Abstract

Aging is a multifaceted biological process shaped by intrinsic molecular mechanisms and extrinsic environmental factors, culminating in systemic functional decline and heightened vulnerability to age-related diseases. This review explores the hallmarks of physiological aging, including genomic instability, telomere attrition, epigenetic alterations, loss of proteostasis, cellular senescence, chronic inflammation, and gut dysbiosis. These interconnected pathways drive the gradual deterioration of cellular and tissue function, underpinning both natural aging and the onset of pathologies such as neurodegeneration, cardiovascular disease, and cancer. Environmental toxins including mycotoxins, heavy metals, chemical clastogens, and pollutants exacerbate aging by inducing oxidative stress, disrupting DNA repair, and altering epigenetic regulation, thereby accelerating cellular damage and systemic dysfunction. We highlight the role of mitochondrial dysfunction in senescence, the dual nature of autophagy in proteostasis, and the inflammatory cascade triggered by senescent cells, which perpetuates tissue degeneration. Furthermore, dysbiosis of the gut microbiota emerges as a critical modulator of aging, linking microbial imbalance to metabolic and immune dysregulation. By synthesizing current insights into these mechanisms, this review underscores the importance of targeting aging hallmarks to develop interventions that promote healthy longevity. Strategies such as dietary modulation, proteasome activation, and probiotic therapies demonstrate potential in mitigating age-related decline. Understanding the interplay between molecular pathways and environmental stressors offers a roadmap for innovative therapies aimed at decelerating aging processes, enhancing healthspan, and reducing the burden of age-associated diseases. This holistic perspective bridges fundamental aging biology with translational applications, emphasizing the urgency of interdisciplinary approaches to address the challenges of global population aging.

Keywords

Main Subjects