Research Paper Volume 10, Issue 11 pp 3294—3307

Azithromycin and Roxithromycin define a new family of “senolytic” drugs that target senescent human fibroblasts

Figure 11. Assessing the efficacy of Azithromycin in the selective targeting of senescent MRC-5 cells, using the xCELLigence system. The xCELLigence system allows for the real-time, label-free, monitoring of cell health and behavior, via high frequency measurement of cell-induced electrical impedance. Panel (A) A representative cell tracing is shown. Note that senescent cells (BrdU-treated/MRC-5 fibroblasts) were effectively killed; directly compare the red curve (BrdU only) versus the green curve (BrdU plus Azithromycin). For normal MRC-5 fibroblasts, compare the black curve (Control) with the browncurve (Azithromycin). Panel (B) Bar graphs highlighting the final cell index, are shown as the average + the SEM. Approximately 97% of the senescent MRC-5 cells are targeted by Azithromycin treatment. In contrast, normal control MRC-5 cells are only transiently affected by Azithromycin, and they rapidly recover via cell proliferation, exceeding vehicle-alone control cell levels by greater than 30%. **** p < 0.001.