A review of biochemical mechanisms underlying the known approaches to extension of lifespan and/or slowing down of ageing suggests that they all modify balances between generation of active oxygen and carbonyl species and the mechanisms that protect from their damaging effects or repair their consequences. A likely common target of the geroprotector effects of antioxidants, melatonin, and antidiabetic biguanides is the mitochondrial respiratory chain.
Nihon Rinsho. Japanese Journal of Clinical Medicine
Exciting recent findings are remarkable extension of lifespan of model animals in which single genes are mutated. Studies on model animals have provided valuable as well as limited and often misleading information in understanding human aging and anti-aging practice. It is important to realize that extension of lifespan and retardation of aging processes are two different things in principle, the latter being apparently more important for improving QOL in human. Discussed here are selected topics on the limitation of model animal studies and potential problems of popular anti-oxidants.
The Korean Journal of Gastroenterology = Taehan Sohwagi Hakhoe Chi
BACKGROUND/AIMS: The prevalence of colonic diverticulosis in Korea is increasing in conjunction with the adoption of western dietary pattern, extension of lifespan, and advances in diagnostic modalities. The clinical characteristics of colonic diverticulosis seem to be gradually becoming similar to those of Western societies. Therefore, factors associated with the clinical characteristics of colonic diverticulosis in Korea were investigated.
BACKGROUND: Physical activity is associated with reduced risks of chronic diseases and premature death. Whether physical activity is also associated with improved overall health among those who survive to older ages is unclear. METHODS: A total of 13,535 Nurses' Health Study participants who were free of major chronic diseases at baseline in 1986 and had survived to age 70 years or older as of the 1995-2001 period made up the study population.
The consequence of decreased nicotinamide adenine dinucleotide (NAD(+)) levels as a result of oxidative challenge is altered activity of sirtuins, which, in turn, brings about a wide range of modifications in mammalian cellular metabolism. Sirtuins, especially SIRT1, deacetylate important transcription factors such as p53, forkhead homeobox type O proteins, nuclear factor ?B, or peroxisome proliferator-activated receptor ? coactivator 1? (which controls the transcription of pro- and antioxidant enzymes, by which the cellular redox state is affected).
Oxidative stress results from damage to tissues caused by free radicals and is increased by exercise. Peroxiredoxins (PRXs) maintain the cellular reducing environment by scavenging intracellular hydrogen peroxide. It has been recently noted that physical exercise has a positive effect on the PRX system, exerting a protective effect against oxidative stress-induced damage. However, other compounds, such as sestrins (SESNs), a stress-inducible protein family with antioxidant properties, should also be considered in the function of PRXs.
The research of the last decade highlighted the existence of a family of genes activated by cellular stresses that allow the cells to reactivate defense and repair activities regardless of age. The prolonged activation of these genes enhances the organism health and lifespan. Members of this gene family are called sirtuins (SIRT). The founding member of the SIRT protein family, Sir2 is a limiting component of yeast longevity. Many members of this family have been also identified as key longevity regulators in species ranging from yeast to fly.
Climacteric: The Journal of the International Menopause Society
Interactions between genetic (genome) and environmental factors (epigenome) operate during a person's entire lifespan. The aging process is associated with several cellular and organic functional alterations that, at the end, cause multi-organic cell failure. Epigenetic mechanisms of aging are modifiable by appropriate preventive actions mediated by sirtuins, caloric input, diet components, adipose tissue-related inflammatory reactions, and physical activity.
Oxidative stress is both the cause and consequence of impaired functional homeostasis characterizing human aging. The worsening efficiency of stress response with age represents a health risk and leads to the onset and accrual of major age-related diseases.