Fig 4. Effects of epigallocatechin gallate (EGCG) treatment for 2 h on the growth of angiotensin-converting enzyme 2 (ACE2)-receptor expressing Caco-2 cells.

(A) Images of 293FT and Caco-2 cells grown on 100-mm plates taken under a phase-contrast microscope. Scale bar: 100 μm. (B) Cropped image of western blot performed with ACE2 and Glyceraldehyde 3-phosphate dehydrogenase antibodies. (C) Outline of the experimental procedure. Caco-2 cells were treated with or without EGCG for 2 h. After treatment, the cells were washed with PBS thrice, and fresh medium was added. After 22 h of incubation, cell growth was determined. (D) Effects of EGCG on Caco-2 cell growth. Cell growth was assessed by the cell proliferation assay and expressed as a percentage of dimethyl sulfoxide (DMSO)-treated control cells. Asterisks indicate the significant difference compared with the DMSO-treated control (**p < 0.01).