Epigallocatechin-3-gallate inhibits cell growth, induces apoptosis and causes S phase arrest in hepatocellular carcinoma by suppressing the AKT pathway.

Epigallocatechin-3-gallate (EGCG) has been shown to inhibit the growth and induce apoptosis of certain cancer cells. The aim of this study was to determine the role of EGCG in hepatocellular carcinoma (HCC) and the underlying mechanism(s) thereof. MTT assay was used to determine the cell growth inhibition by EGCG. Apoptosis induced by EGCG was investigated by both AO/EB staining and flow cytometry. The cell cycle distribution was analyzed by flow cytometry. The mRNA levels of the AKT pathway were analyzed by quantitative PCR. The expression of AKT and its phosphorylation at Ser473 were detected by western blotting. The IC50 of EGCG at 48 h for HepG2, SMMC7721 and SK-hep1 cells were 74.7, 59.6 and 61.3 µg/ml, respectively. Significantly higher proportion of SMMC7721 cells entered the S phase upon treatment with EGCG for 48 h compared with control cells. EGCG decreased the mRNA levels of PI3K, AKT and NF-κB. The protein levels of AKT decreased and its phosphorylation at Ser473 was downregulated with EGCG treatment. EGCG inhibited growth by affecting the cell cycle and induced apoptosis in different HCC cells by downregulating PI3K/AKT activity. The results suggest the potential of EGCG as an anticancer agent in the prevention or treatment of HCC.