Figure 4. Quercetin causes glycogen depletion and increases trehalose levels.

(A) Schematic representation of genes up regulated in cells treated with quercetin related with glycogen and trehalose metabolism. (B, C) S. cerevisiae BY4741 cells were grown to exponential phase and treated with 300 µM of quercetin or equal volume of DMSO (vehicle) for 15 min. (B) Glycogen and (C) trehalose levels were measured as described in Materials and Methods. Values are mean ± SD of three independent assays. *p<0.05; **p<0.01 (paired t-test). D) Hydrogen peroxide resistance. S. cerevisiae BY4741 (WT) and tps1Δ cells were treated with 300 µM of quercetin or equal volume of DMSO (control cells) for 15 min and subsequently exposed to 1.5 mM H₂O₂ for 1 h. Cell viability was determined by standard dilution plate counts and expressed as the percentage of the colony-forming units of non-stressed cells. Values are mean ± SD of at least three independent assays. **p<0.01; *p<0.05 (two-way ANOVA).