Abstract

The yeast Saccharomyces cerevisiae has been successfully used to identify genes, signaling pathways and chemical compounds that delay cellular and organismal aging in evolutionarily distant eukaryotes. These findings provided evidence that the mechanisms of biological aging on a cellular level have been conserved in the course of evolution. Recent studies revealed 6 plant extracts that delay chronological aging in S. cerevisiae. All these plant extracts are more efficient aging-delaying interventions than any of the currently known longevity-extending chemicals. As a first step towards uncovering molecular mechanisms through which the 6 plant extracts delay yeast chronological aging, I used quantitative mass spectrometry to compare the concentrations of different classes of lipids in cells and cellular organelles of chronologically aging yeast exposed to each of these extracts or remained untreated. I demonstrate that each of the 6 aging-delaying plant extracts causes age-related changes in cellular and organellar lipidomes of chronologically aging yeast. My findings suggest that each of these extracts differently alters the relative rates of phosphatidic acid flow into the biosynthetic pathways for triacylglycerols in the endoplasmic reticulum, glycerol phospholipids in the endoplasmic reticulum and mitochondria, and cardiolipin in mitochondria. Such re-wiring of phosphatidic acid conversion into triacylglycerols, glycerol phospholipids and cardiolipin delays aging by mechanisms that remain to be established. My study provides important knowledge on which aspects of lipid metabolism are essential for the ability of the 6 plant extracts to delay aging.