Protein, Lipid and DNA Repair Systems in Oxidative Stress: The Free-Radical Theory of Aging Revisited

Gerontology ◽  
1991 ◽  
Vol 37 (1-3) ◽  
pp. 166-180 ◽  
Author(s):  
Robert E. Pacifici ◽  
Kelvin J.A. Davies
Keyword(s):  
Oxidative Stress ◽  
Dna Repair ◽  
Free Radical ◽  
Free Radical Theory ◽  
Radical Theory ◽  
Theory Of Aging ◽  
Repair Systems

scholarly journals Oxidative Stress and Longevity in Okinawa: An Investigation of Blood Lipid Peroxidation and Tocopherol in Okinawan Centenarians

2010 ◽  
Vol 2010 ◽  
pp. 1-10 ◽  
Author(s):  
Makoto Suzuki ◽  
D. Craig Willcox ◽  
Matthew W. Rosenbaum ◽  
Bradley J. Willcox
Keyword(s):  
Oxidative Stress ◽  
Free Radical ◽  
Vitamin E ◽  
Age Groups ◽  
Plasma Lipid ◽  
Lipid Peroxide ◽  
Human Longevity ◽  
Free Radical Theory ◽  
Radical Theory ◽  
Theory Of Aging

Background. The Free Radical Theory of Aging mechanistically links oxidative stress to aging. Okinawa has among the world's longest-lived populations but oxidative stress in this population has not been well characterized.Methods. We compared plasma lipid peroxide (LPO) and vitamin E—plasma and intracellular tocopherol levels (total α, β, and γ), in centenarians with younger controls.Results. Both LPO and vitamin E tocopherols were lower in centenarians, with the exception of intracellular β-tocopherol, which was significantly higher in centenarians versus younger controls. There were no significant differences between age groups for tocopherol: cholesterol and tocopherol: LPO ratios. Correlations were found between α-Tocopherol and LPO in septuagenarians but not in centenarians.Conclusions. The low plasma level of LPO in Okinawan centenarians, compared to younger controls, argues for protection against oxidative stress in the centenarian population and is consistent with the predictions of the Free Radical Theory of Aging. However, the present work does not strongly support a role for vitamin E in this phenomenon. The role of intracellular β-tocopherol deserves additional study. More research is needed on the contribution of oxidative stress and antioxidants to human longevity.

scholarly journals GLUTATHIONE DEFICIENCY AND OXIDATIVE STRESS IN AGING: METABOLIC MECHANISM AND TARGETED INTERVENTION

2019 ◽  
Vol 3 (Supplement_1) ◽  
pp. S416-S416
Author(s):  
Farook Jahoor ◽  
George E Taffet ◽  
Rajagopal V Sekhar
Keyword(s):  
Oxidative Stress ◽  
Free Radical ◽  
Functional Decline ◽  
Free Radical Theory ◽  
Radical Theory ◽  
Isotope Tracer ◽  
Age Related ◽  
Theory Of Aging ◽  
Metabolic Mechanism ◽  
Glutathione Deficiency

Abstract The free-radical theory of aging suggests that age-related functional decline is mediated by increases in free-radical induced oxidative-stress. Cells normally depend on antioxidants for protection against oxidative-stress. Glutathione is the most abundant endogenous intracellular antioxidant protein composed of 3 amino-acids, cysteine, glycine and glutamic-acid, and is known to be deficient in older-humans. We investigated Glutathione kinetics in older humans using a stable-isotope tracer-based approach, and found that compared to younger humans, older-humans had severe Glutathione deficiency as a result of decreased synthesis caused by limited availability of glycine and cysteine, and associated with elevated oxidative-stress. Orally supplementing glycine and cysteine (provided as N-acetylcysteine) at doses of 1.33mmol/kg/d and 0.81mmol/kg/d respectively for 2-weeks corrected their intracellular deficiency, normalized Glutathione synthesis rates and lowered oxidative-stress to levels in younger controls. These results suggest that short-term supplementation of GlyNAC at these doses can successfully correct intracellular Glutathione deficiency in older-humans.

scholarly journals Effects of Caloric Restriction on Cardiac Oxidative Stress and Mitochondrial Bioenergetics: Potential Role of Cardiac Sirtuins

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Ken Shinmura
Keyword(s):  
Oxidative Stress ◽  
Free Radical ◽  
Oxidative Damage ◽  
Caloric Restriction ◽  
Functional Decline ◽  
Cellular Damage ◽  
Free Radical Theory ◽  
Radical Theory ◽  
Stress Theory

The biology of aging has not been fully clarified, but the free radical theory of aging is one of the strongest aging theories proposed to date. The free radical theory has been expanded to the oxidative stress theory, in which mitochondria play a central role in the development of the aging process because of their critical roles in bioenergetics, oxidant production, and regulation of cell death. A decline in cardiac mitochondrial function associated with the accumulation of oxidative damage might be responsible, at least in part, for the decline in cardiac performance with age. In contrast, lifelong caloric restriction can attenuate functional decline with age, delay the onset of morbidity, and extend lifespan in various species. The effect of caloric restriction appears to be related to a reduction in cellular damage induced by reactive oxygen species. There is increasing evidence that sirtuins play an essential role in the reduction of mitochondrial oxidative stress during caloric restriction. We speculate that cardiac sirtuins attenuate the accumulation of oxidative damage associated with age by modifying specific mitochondrial proteins posttranscriptionally. Therefore, the distinct role of each sirtuin in the heart subjected to caloric restriction should be clarified to translate sirtuin biology into clinical practice.

scholarly journals Oxidative stress in ageing

2017 ◽  
Vol 5 (11) ◽  
pp. 4826 ◽  
Author(s):  
Fasna K. A. ◽  
Geetha N. ◽  
Jean Maliekkal
Keyword(s):  
Oxidative Stress ◽  
Lipid Peroxidation ◽  
Free Radicals ◽  
Free Radical ◽  
Age Groups ◽  
The Body ◽  
Antioxidant Systems ◽  
Lipid Peroxidation Product ◽  
Free Radical Theory ◽  
Radical Theory

Background: Ageing is characterized by a gradual decline in body functions and decreased ability to maintain homeostasis. The free radical theory of ageing proposed by Harman D states that ageing is a result of cumulative damage incurred by free radical reactions. Free radicals are highly reactive molecular species with unpaired electrons; generated in the body by several physiological processes. Prime target to free radical attack are the polyunsaturated fatty acids of cell membranes causing lipid peroxidation. The free radicals are neutralized by the exogenous and endogenous antioxidant systems. Oxidative stress occurs when large number of free radicals are produced or the antioxidant activity is impaired. The present study is focused to find out the role of oxidative stress in ageing.Methods: A cross sectional observational study was undertaken to assess the oxidative stress in ageing; by determining the levels of lipid peroxidation product- malondialdehyde (MDA), the antioxidants- superoxide dismutase (SOD) and ceruloplasmin in various age groups. 150 healthy subjects were selected randomly and categorised into three different age groups of 20-30 years, 40-59 years and 60-90 years; with 50 subjects in each group. Results were expressed as mean ± standard deviation.Results: a significant elevation in serum MDA level and a decline in SOD were observed in 40-59 years and 60-90 years age groups. However, an elevated ceruloplasmin level was found in the above age groups.Conclusions: Aforementioned observations are suggestive of an association between oxidative stress and the progression of ageing process.

scholarly journals A midlife crisis for the mitochondrial free radical theory of aging

2014 ◽  
Vol 3 (1) ◽  
Author(s):  
Jeffrey A Stuart ◽  
Lucas A Maddalena ◽  
Max Merilovich ◽  
Ellen L Robb
Keyword(s):  
Free Radical ◽  
Free Radical Theory ◽  
Radical Theory ◽  
Midlife Crisis ◽  
Theory Of Aging
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