Nitric oxide and aging — does it determine how quickly we age?

Aim of the study: Aging is considered a state of low grade inflammation, occurring in the absence of any overt infection often referred to as 'inflammaging'. Maintaining intestinal homeostasis may be a target to extend a healthier status in older adults.

Results: In addition, employing multiple mouse models, we also show that while intestinal microbiota composition changes significantly during aging, fecal microbiota transplantation to old mice does not protect against aging-associated intestinal barrier dysfunction in small intestine. Rather, intestinal NO homeostasis and arginine metabolism mediated through arginase and NO synthesis is altered in small intestine of aging mice. Treatment with the arginase inhibitor norNOHA prevented aging-associated intestinal barrier dysfunction, low grade endotoxemia and delayed the onset of senescence in peripheral tissue e.g., liver. Intestinal arginine and NO metabolisms could be a target in the prevention of aging-associated intestinal barrier dysfunction and subsequently decline and 'inflammaging'.

Aim of the study: Nitric oxide (NO) is a ubiquitous signaling molecule that plays a crucial role in oocyte maturation and embryo development. However, its role in oocyte aging is unclear.

Results: Furthermore, NO exposure decreased the rate of spindle abnormalities in oocytes compared to unexposed controls. Interestingly, in old oocytes, the positive influence of NO was attenuated beyond 0.23 microM/min and disappeared at 0.46 microM/min NO. Overall, a significant dose-response relationship was noted between NO exposure and markers of aging with between 50 and 100 microM SNAP (0.11-0.23 microM/min NO, P < 0.0001). Collectively, our results demonstrate for the first time that exposure to NO delays oocyte aging and improves the integrity of the microtubular spindle apparatus in young and old oocytes.

Aim of the study: The global population aged ≥65 years is increasing, posing challenges for healthcare systems and aging strategies. Beetroot extract (BE), derived from Beta vulgaris, is rich in inorganic nitrate (NO3-), nitrite (NO2-), betalains, and polyphenols, and has been proposed as an intervention to mitigate age-related physiological decline.

Results: However, robust cardiovascular benefits, particularly regarding blood pressure, cannot be firmly established because of heterogeneity in study designs, intervention durations, dosing protocols, participant characteristics, and small sample sizes. Furthermore, most trials have been conducted in younger or mixed-age cohorts, with limited evidence in older adults. Therefore, randomized controlled trials in aging populations are required to establish the clinical relevance of BE supplementation. The available evidence is preliminary and hypothesis-generating rather than sufficient to support BE as a strategy for healthy ageing.

Aim of the study: Aging is associated with increased neuroinflammation and a decrease in neuroplasticity, contributing to cognitive decline and increased risk for neurodegenerative disease. Nutritional interventions, such as walnut supplementation, may counteract these effects due to walnuts' high content of polyunsaturated fatty acids, polyphenols, and other bioactive compounds.

Results: Our results demonstrated that walnut supplementation improved performance by decreasing the number of errors made in the RAWM. Serum from walnut-fed rats significantly reduced NO release and iNOS expression in LPS-stimulated microglia. Hippocampal BDNF mRNA expression also differed according to age and diet, with higher expression in aged than young rats receiving the 9% walnut diet. These findings suggest that dietary walnuts may support healthy brain aging through effects on cognitive performance and circulating factors that modulate inflammatory responses and BDNF expression.