A Yeast Chronological Lifespan Assay to Assess Activity of Proteasome Stimulators

AbstractAmino acid deprivation or supplementation can affect cellular and organismal lifespan, but we know little about the role of concentration changes in free, intracellular amino acids during aging. Here, we determine free amino-acid levels during chronological aging of non-dividing fission yeast cells. We compare wild-type with long-lived mutant cells that lack the Pka1 protein of the protein kinase A signalling pathway. In wild-type cells, total amino-acid levels decrease during aging, but much less so in pka1 mutants. Two amino acids strongly change as a function of age: glutamine decreases, especially in wild-type cells, while aspartate increases, especially in pka1 mutants. Supplementation of glutamine is sufficient to extend the chronological lifespan of wild-type but not of pka1Δ cells. Supplementation of aspartate, on the other hand, shortens the lifespan of pka1Δ but not of wild-type cells. Our results raise the possibility that certain amino acids are biomarkers of aging, and their concentrations during aging can promote or limit cellular lifespan.

Download Full-text

COCOA (Theobroma cacao) POLYPHENOL-RICH EXTRACT INCREASES THE CHRONOLOGICAL LIFESPAN OF Saccharomyces cerevisiae

Journal of Frailty & Aging ◽

10.14283/jfa.2016.100 ◽

2016 ◽

pp. 1-5

Author(s):

I. BAIGES ◽

L. AROLA

Keyword(s):

Stationary Phase ◽

Caloric Restriction ◽

High Throughput ◽

Animal Studies ◽

Model Organism ◽

Dependent Manner ◽

Aging Effects ◽

Screening Assay ◽

Chronological Lifespan ◽

Synthetic Complete

Background:Saccharomyces cerevisiae is a model organism with conserved aging pathways. Yeast chronological lifespan experiments mimic the processes involved in human non-dividing tissues, such as the nervous system or skeletal muscle, and can speed up the search for biomolecules with potential anti-aging effects before proceeding to animal studies. Objective: To test the effectiveness of a cocoa polyphenol-rich extract (CPE) in expanding the S. cerevisiae chronological lifespan in two conditions: in the stationary phase reached after glucose depletion and under severe caloric restriction. Measurements: Using a high-throughput method, wild-type S. cerevisiae and its mitochondrial manganese-dependent superoxide dismutase null mutant (sod2Δ) were cultured in synthetic complete dextrose medium. After 2 days, 0, 5 and 20 mg/ml of CPE were added, and viability was measured throughout the stationary phase. The effects of the major components of CPE were also evaluated. To determine yeast lifespan under severe caloric restriction conditions, cultures were washed with water 24 h after the addition of 0 and 20 mg/ml of CPE, and viability was followed over time. Results: CPE increased the chronological lifespan of S. cerevisiae during the stationary phase in a dose-dependent manner. A similar increase was also observed in (sod2Δ). None of the major CPE components (theobromine, caffeine, maltodextrin, (-)-epicatechin, (+)-catechin and procyanidin B2) was able to increase the yeast lifespan. CPE further increased the yeast lifespan under severe caloric restriction. Conclusion: CPE increases the chronological lifespan of S. cerevisiae through a SOD2-independent mechanism. The extract also extends yeast lifespan under severe caloric restriction conditions. The high-throughput assay used makes it possible to simply and rapidly test the efficacy of a large number of compounds on yeast aging, requiring only small amounts, and is thus a convenient screening assay to accelerate the search for biomolecules with potential anti-aging effects.

Download Full-text

The Anti-Aging Potential of Neohesperidin and Its Synergistic Effects with Other Citrus Flavonoids in Extending Chronological Lifespan of Saccharomyces Cerevisiae BY4742

Molecules ◽

10.3390/molecules24224093 ◽

2019 ◽

Vol 24 (22) ◽

pp. 4093 ◽

Cited By ~ 4

Author(s):

Chunxia Guo ◽

Hua Zhang ◽

Xin Guan ◽

Zhiqin Zhou

Keyword(s):

Synergistic Effects ◽

Future Research ◽

Dependent Manner ◽

Ros Scavenging ◽

Concentration Dependent Manner ◽

Chronological Lifespan ◽

Flavonoid Compounds ◽

Citrus Flavonoids ◽

High Throughput Assay

The anti-aging activity of many plant flavonoids, as well as their mechanisms of action, have been explored in the current literature. However, the studies on the synergistic effects between the different flavonoid compounds were quite limited in previous reports. In this study, by using a high throughput assay, we tested the synergistic effects between different citrus flavonoids throughout the yeast’s chronological lifespan (CLS). We studied the effect of four flavonoid compounds including naringin, hesperedin, hesperitin, neohesperidin, as well as their different combinations on the CLS of the yeast strain BY4742. Their ROS scavenging ability, in vitro antioxidant activity and the influence on the extracellular pH were also tested. The results showed that neohesperidin extended the yeast’s CLS in a concentration-dependent manner. Especially, we found that neohesperidin showed great potential in extending CLS of budding yeast individually or synergistically with hesperetin. The neohesperidin exhibited the strongest function in decreasing the reactive oxygen species (ROS) accumulation in yeast. These findings clearly indicated that neohesperidin is potentially an anti-aging citrus flavonoid, and its synergistic effect with other flavonoids on yeast’s CLS will be an interesting subject for future research of the anti-aging function of citrus fruits.

Download Full-text