FIG. 2.

Activity of HeLa 229 cells incubated with (−)-epicatechin (EC), (−)-epicatechin gallate (ECg), and (−)-epigallocatechin gallate (EGCg) evaluated by a CK01 cell counting kit, a colorimetric assay for cell proliferation. Serial dilutions of tea polyphenols in SPG buffer were incubated with HeLa 229 cells for 60 min, and the cell activity was determined. Cell activity was assessed by the optical density. The activity of the HeLa 229 cells did not decrease after 60 min of incubation with 0.4 mg/ml EC but did decrease after 60 min of incubation with ECg and EGCg at the concentrations used.