The decline in physical performance with increasing age is a crucial problem in our aging society. We examined the effects of resveratrol, a natural polyphenolic compound present in grapes, in combination with habitual exercise on the agingassociated decline in physical performance in senescence-accelerated prone mice (SAMP1). The endurance capacity of SAMP1 mice undergoing an exercise regimen (SAMP1-Ex) decreased over 12 weeks whereas that of SAMP1 mice fed 0.2% (w/w) resveratrol along with exercise (SAMP1-Ex- Res) remained significantly higher. In the SAMP1-ExRes group, there was a significant increase in oxygen consumption and skeletal muscle mRNA levels of mitochondrial function-related enzymes. These results suggest that the intake of resveratrol, together with habitual exercise, is beneficial for suppressing the aging-related decline in physical performance and that these effects are attributable, at least in part, to improved mitochondrial function in skeletal muscle.
In the aging process, mitochondrial function gradually declines with an increase of mutations in mitochondrial DNA (mtDNA) in tissue cells. Some of the aging-associated mtDNA mutations have been shown to result in not only inefficient generation of ATP but also increased production of reactive oxygen species (ROS) such as superoxide anions (O2 U−) and hydrogen peroxide (H2O2) in the mitochondria of aging tissues. Extensive studies have revealed that such an increase of oxidative stress is a contributory factor for alterations in the expression and activities of antioxidant enzymes and increased oxidative damage to DNA, RNA, proteins, and lipids in tissues and cultured cells from elderly subjects. Recently, we observed that gene expression of several proteins and enzymes related to iron metabolism is altered and that aconitase is extremely susceptible to oxidative damage in senescent skin ibroblasts and in cybrids harboring agingassociated A8344G mutation of mtDNA. Of great importance is the perturbation at the protein and activity levels of several enzymes containing iron–sulfur clusters in skin fibroblasts of elderly subjects. Taken together, these findings suggest that cellular response to oxidative stress and oxidative damage elicited by mitochondrial dysfunction and/or mtDNA mutations plays an important role in human aging.
Objective: Age-related changes in multiple components of the musculoskeletal system may contribute to the well established link between aging and osteoarthritis (OA). This review focused on potential mechanisms by which age-related changes in the articular cartilage could contribute to the development of OA.
Methods: The peer-reviewed literature published prior to February 2009 in the PubMed database was searched using pre-defined search criteria.Articles, selected for their relevance to aging and articular chondrocytes or cartilage, were summarized.
Results: Articular chondrocytes exhibit an age-related decline in proliferative and synthetic capacity while aintaining the ability to produce pro-inflammatory mediators and matrix degrading enzymes. These findings are characteristic of the senescent secretory phenotype and are most likely a consequence of extrinsic stress-induced senescence driven by oxidative stress rather than intrinsic replicative senescence. Extracellular matrix changes with aging also contribute to the propensity to develop OA and include the accumulation of proteins modified by non-enzymatic glycation.
Conclusion: The effects of aging on chondrocytes and their matrix result in a tissue that is less able to maintain homeostasis when stressed, resulting in breakdown and loss of the articular cartilage, a hallmark of OA. A better understanding of the basic mechanisms underlying senescence and how the process may be modified could provide novel ways to slow the development of OA.
The significance of herbals and herbal products is gaining worldwide recognition. The concept of complementary or alternative medicine is becoming much more widely accepted, and there is an increasing belief in the efficacy of herbal remedies. Recently, the role of herbal drugs, herbal products and certain phytochemicals in the control of ageing has been documented using modern scientific approaches. This review pulls together such studies and critiques the efficacy and value of herbal medicines in the control of the ageing process.