Figure 4.

Glycyrrhizin can reduce the expression of ACE2 in cells. (A) Heat map of differentially expressed genes in groups control and glycyrrhizin, which are part of the genes required for SARS-CoV-2 entry (n = 3 biologically independent cell samples; FDR < 0.001). Statistical tests were embedded in Cuffdiff. (B) When the Vero E6 cells grow to 80–90% confluence in the well plate, the supernatant was discarded and cells were treated with the addition of fresh medium containing various concentrations or without glycyrrhizin for 48 h. After that, the total protein of the cells was extracted for Western blot analysis of the expression of ACE2 in the cells. (C) After treatment of Vero E6 cells with various concentrations of glycyrrhizin for 48 h, the cells were harvested and total RNA was extracted. After measuring the concentration of total RNA, reverse transcription and quantitative PCR were performed to measure mRNA expression levels of ACE2. Each independent experiment was repeated at least three times and presented as mean ± SD, n = 3. The results were analyzed through one-way ANOVA test (* indicates p < 0.05).