[
FASEB J,
1994]
The postponement of human aging is a long-standing aspiration in many cultures, particularly non-Western ones. Renewed interest in this goal is now being shown within the biomedical research context. This interest has probably arisen because several different approaches have yielded dramatic increases in mean and maximum life span in laboratory organisms. Among the cases where aging has been postponed in animal models are the nematode, Caenorhabditis elegans, the common lab fruit fly, Drosophila melanogaster, and the dietarily restricted rodent, both Mus and Rattus. These successes raise the question of whether similar postponement of aging might be achieved in humans. Among the broad research strategies available, five can be delineated: 1) random testing of favorite interventions; 2) searching for genes that can postpone aging among all or most species; 3) study of in vitro mammalian cell cultures; 4) study of dietarily restricted mammals; and 5) selecting mammals for postponed aging. Although all these methods could conceivably lead to the postponement of human aging, they are very different from each other with respect to their degree of uncertainty, cost, and delay.
[
Exp Gerontol,
2017]
Methionine restriction (MR) extends lifespan across different species. The main responses of rodent models to MR are well-documented in adipose tissue (AT) and liver, which have reduced mass and improved insulin sensitivity, respectively. Recently, molecular mechanisms that improve healthspan have been identified in both organs during MR. In fat, MR induced a futile lipid cycle concomitant with beige AT accumulation, producing elevated energy expenditure. In liver, MR upregulated fibroblast growth factor 21 and improved glucose metabolism in aged mice and in response to a high-fat diet. Furthermore, MR also reduces mitochondrial oxidative stress in various organs such as liver, heart, kidneys, and brain. Other effects of MR have also been reported in such areas as cardiac function in response to hyperhomocysteinemia (HHcy), identification of molecular mechanisms in bone development, and enhanced epithelial tight junction. In addition, rodent models of cancer responded positively to MR, as has been reported in colon, prostate, and breast cancer studies. The beneficial effects of MR have also been documented in a number of invertebrate model organisms, including yeast, nematodes, and fruit flies. MR not only promotes extended longevity in these organisms, but in the case of yeast has also been shown to improve stress tolerance. In addition, expression analyses of yeast and Drosophila undergoing MR have identified multiple candidate mediators of the beneficial effects of MR in these models. In this review, we emphasize other in vivo effects of MR such as in cardiovascular function, bone development, epithelial tight junction, and cancer. We also discuss the effects of MR in invertebrates.
[
Mech Ageing Dev,
2018]
Past investigations have shown that various plant extracts are capable of promoting longevity in lower model organisms like Caenorhabditis elegans, Drosophila melanogaster, Saccharomyces cerevisiae, Bombyx mori etc. Longevity studies on such organisms provide a foundation to explore anti-aging efficacies of such plant extracts in higher organisms. Plant extracts of acai palm, apple, asparagus, blueberry, cinnamon, cocoa, Damnacanthus, maize, mistletoe, peach, pomegranate, Rhodiola, rose, Sasa, turmeric, and Withania have extended lifespan in lower model organisms via diverse mechanisms like insulin like growth factor (IGF) signaling pathway, and antioxidant defense mechanisms. Knowledge of pathways altered by the extracts can be investigated as potential drug-targets for natural anti-aging interventions. Thus, the aim of the review is to scrutinize longevity promoting efficacies of various plant extracts in lower model organisms.