ABSTRACT
O6-Alkylguanine-DNA alkyltransferase (AGT) is an important DNA repair enzyme that protects cells from being killed and mutagenesis by alkylating agents. This protein can correct DNA damage in the O-6 position of guanine DNA. The purpose of this study was to determine the effects of (–)–Epigallocatechin Gallate (EGCG) from green tea on increasing the AGT level in the liver cell culture of Wistar rats. AGT activity was measured by determining the transfer of [3H]methyl groups from [3H] methylated calf thymus DNA to AGT in the cell culture. The radioactivity of AGT after the transfer of [3H]methyl groups was measured by a liquid scintillation counter. The results indicate that 48 h after EGCG exposure at 8.3–66.7 ppm, AGT activity was found to be 16.1–41.2 fmol/μg DNA. This means that the AGT level increases from 1.4- to 3.7-fold (p < 0.01). These findings suggest that EGCG plays an important role as a chemopreventive agent and a possible regulator for cancer incidence.
