Mechanisms by which plant extracts delay aging in yeast by targeting certain signaling pathways and modulating lipid metabolism

The yeast Saccharomyces cerevisiae is a unicellular eukaryote that has been successfully used as a model organism for discovering signaling pathways and chemical compounds that modulate cellular aging, define organismal lifespan, and influence organismal fitness not only in yeast but also in various multicellular eukaryotes. Using a robust quantitative assay for measuring yeast chronological lifespan, we discovered six plant extracts (PE; i.e. PE4, PE5, PE6, PE8, PE12 and PE21) whose longevity-extending efficiencies greatly exceed those of currently known natural anti-aging compounds, such as resveratrol, rapamycin, spermidine, caffeine, and lithocholic acid. Our genetic, biochemical, and mass spectrometry-based lipidomic analyses uncovered the following mechanisms by which these PE delay yeast chronological aging by targeting certain signaling pathways and modulating lipid metabolism: (1) PE4 attenuates the inhibiting effect of the pro-aging TOR (target of rapamycin) signaling pathway on the anti-aging A...