ABSTRACT
OBJECTIVE: The purpose of this article is to estimate the anti-cancer effects of the major components of the green tea (polyphenols, catechin and EGCG) and the mechanism of EGCG on different cervical cancer cell lines. METHODS: Six cervical cancer cell lines (HeLa, HeLaS3, Caski, SiHa, HT3 and C33A) were treated with 20 microgram/ml green tea polyphenols (GTPs), 50 micrometer catechin and various concentrations of (-)-epigallo- catechin-3-gallate (EGCG). The viabilities were determined by trypan blue exclusion assay, neutral red assay and 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide assay. DNA fragmentation and nuclear condensation were used to see whether EGCG-induced anti-proliferation effect was due to apoptosis. RESULTS: Both GTPs, catechin and EGCG had growth inhibition effects on cervical cancer cell lines, but EGCG appeared to be the most effective. What's more, the sensitivity of each cell lines to EGCG was different. HT3 cells (HPV negative, mutant type p53) were most sensitive to EGCG (estimate IC50: 10 micrometer). Caski (HPV-16 positive, wild type p53) and HeLaS3 cells (HPV-18 positive, wild type p53) were less sensitive (estimate IC50: 35 and 70 micrometer respectively). EGCG-induced apoptosis can be seen in all the cell lines and it happened as early as 8 hours after EGCG treatment. CONCLUSION: Green tea or EGCG alone will be beneficial to the cervical cancer patients.