Skip to main content
. 2021 Oct 17;14(10):1055. doi: 10.3390/ph14101055

Figure 5.

Figure 5

Effect of T. officinale extract on ACE2 enzyme activity and protein expression. (A) Viability of A549-hACE2-TMPRSS2 cells was determined using trypan blue cell staining after 84 h exposure to the extract. (B) Cells were incubated with TO extract or 500 ng/mL S1 protein and analyzed for enzyme activity using a fluorescence kit. (C,D) Cells were exposed for 6 h or 24 h to extract without (white bars) or with (black bars) 500 ng/mL S1 protein and analyzed for ACE2 protein expression using a human ACE2 ELISA kit; a.d.: solvent control. Bars are means + SD, N ≥ 3 independent experiments; * p < 0.05, ** p < 0.01. Significance of difference was calculated relative to the respective control by one-way ANOVA.