RSVT is a potent stimulator of Notch signaling.

(A) RSVT does not induce HMEC apoptosis at 1–10 μM. HMEC cells were treated with increasing concentrations of RSVT +/- DAPT. Cellular apoptosis was indirectly examined by monitoring cleavage of cleaved caspase 3 from pro-caspase 3 by western blot. HMEC cells were treated with UV light as a positive apoptosis control and protein loading was monitored by western blotting for α-actin. Data shows that RSVT induces apoptosis at 100 μM. (B) Notch activation measured by three luciferase reporter constructs in HAVSMC cells. Student’s t-test was performed to determine statistical significance compared to 0 μM RSVT control. P-values are reported as * < .05, ** < .01, *** < .001. Data represents n≥5. Data shows that RSVT induces Notch target gene transcription in HAVSMC cells. (C) Notch activation measured by three luciferase reporter constructs in HMEC-1 cells. Student’s t-test was performed to determine statistical significance compared to 0 μM RSVT control. P-values are reported as * < .05, ** < .01, *** < .001. Data represents n≥5. Data shows that RSVT induces Notch target gene transcription in HMEC-1 cells. (D) Cell viability of HMEC-1 cells measured using WST-1 cell viability assay. Cell viability was quantified 24 hours after treatment with nine different polyphenolic compounds. Cell viability as a percentage of DMSO control (0 μM) is graphed. Data represents the average of three replicate experiments. Structures of each polyphenol are shown above respective graph. Bolded line depicts cell viability measured for each polyphenol. Student’s t-test was performed to determine statistical significance compared to DMSO control. P-values are reported as * < .05, ** < .01, *** < .001. Data demonstrates that most polyphenols did not drastically compromise cell viability when used at 1 μM and 10 μM concentrations. However, 100 μM polyphenol concentrations significantly reduced cell viability for all nine polyphenols tested.