Aging Hallmarks and the Role of Oxidative Stress

Abstract

Aging is a complex biological process accompanied by a progressive decline in the physical function of the organism and an increased risk of age-related chronic diseases such as cardiovascular diseases, cancer, and neurodegenerative diseases. Studies have established that there exist nine hallmarks of the aging process, including (i) telomere shortening, (ii) genomic instability, (iii) epigenetic modifications, (iv) mitochondrial dysfunction, (v) loss of proteostasis, (vi) dysregulated nutrient sensing, (vii) stem cell exhaustion, (viii) cellular senescence, and (ix) altered cellular communication. All these alterations have been linked to sustained systemic inflammation, and these mechanisms contribute to the aging process in timing not clearly determined yet. Nevertheless, mitochondrial dysfunction is one of the most important mechanisms contributing to the aging process. Mitochondria is the primary endogenous source of reactive oxygen species (ROS). During the aging process, there is a decline in ATP production and elevated ROS production together with a decline in the antioxidant defense. Elevated ROS levels can cause oxidative stress and severe damage to the cell, organelle membranes, DNA, lipids, and proteins. This damage contributes to the aging phenotype. In this review, we summarize recent advances in the mechanisms of aging with an emphasis on mitochondrial dysfunction and ROS production.

Human diet‐derived polyphenolic compounds and hepatic diseases: From therapeutic mechanisms to clinical utilization

“…Upon exposure to external or internal stimuli, cellular oxidative stress triggers the generation of reactive oxygen species (ROS) and reactive nitrogen species (RNS), which include OH, O2‐, NO, and H2O2. These compounds play a pivotal role in the progression of hepatocyte damage (Maldonado et al, 2023). Furthermore, cellular inflammation prompts the release of various pro‐inflammatory factors into the extracellular environment, including interleukin (IL)‐1β, IL‐6, interferon (IFN)‐γ, and tumor necrosis factor‐α (TNF‐α).…”

Composition of healthy diets for older persons

“…Natural compounds (such as fibers, omega-3, vitamins A and E, selenium, and polyphenols) found in the core elements of healthy diets have antiinflammatory properties, antioxidant properties, or favor microbial diversity in the gut [51][52][53][54][55]. In this context, a healthy diet may slow down the aging process, which is contributed by elevated production of oxygen-free radicals, declined antioxidant defense, sustained systemic inflammation, and/or gut microbiota dysbiosis [56,57].…”

Construction of Magnolol Nanoparticles for Alleviation of Ethanol-Induced Acute Gastric Injury

“…Oxidative stress, exacerbated by EtOH through excessive ROS production, is a key factor in gastric ulcer development. − The metabolism of EtOH leading to overproduction of ROS stimulates macrophages, promoting the release of inflammatory factors and activating inflammatory pathways, resulting in tissue inflammation and damage. − Moreover, ROS are known to be key initiators of apoptosis and can cause extensive damage to cellular components such as proteins, lipids, and DNA. The body’s defense mechanisms against these harmful effects involve a complex oxidative stress response system, which includes the activation of transcription factors like nuclear factor erythroid 2-related factor 2 (Nrf2) and enzymes such as NADPH oxidase 4 (NOX4), a key producer of hydrogen peroxide. − Activation of the Nrf2 signaling pathway has been shown to effectively reduce oxidative stress by restoring mitochondrial homeostasis and decreasing NOX4 expression both in vitro and in vivo …”