Research Paper Volume 9, Issue 3 pp 955—963

Figure 1. Fisetin targets senescent cells. (a) Structure of fisetin. (b-d) Fisetin is more effective in reducing viability (ATPLite) of senescent HUVECs than IMR90 cells or primary human preadipocytes. Proliferating or senescent cells were exposed to different concentrations of fisetin for 3 days. The red lines denote ATPLite intensities on day 0 of senescent and non-senescent cells, both set to 100%. HUVEC and IMR90 data are means±SEM of 5 replicates at each drug concentration. Preadipocyte data are means±SEM of 5 replicates from each of 4 different subjects at each concentration. (e-g) Fisetin selectively reduces senescent but not proliferating HUVECs and IMR90 cell numbers (crystal violet). The red lines denote cell numbers at plating on day 0 of senescent and non-senescent cells, both set to 100%. HUVEC and IMR90 data are means±SEM of 5 replicates at each drug concentration. Preadipocyte data are means±SEM, 5 replicates from each of 4 different subjects at each concentration. (h) Fisetin induces apoptosis in senescent HUVECs. HUVECs were treated with fisetin for 12h and then caspases-3&7 were assayed using a luminescent substrate. Fisetin (500 nM) induced apoptosis in senescent cells by caspase 3/7 assay. For all figures: * = P<0.05; ** = P<0.01; *** = P<0.001 by one-way ANOVA (caspase activities by 2-way ANOVA). Bars with asterisks indicate differences between senescent cells following drug exposure compared to day 0.