Green tea extract inhibits proliferation of uterine leiomyoma cells in vitro and in nude mice.

OBJECTIVE: The purpose of this study was to investigate the effect of epigallocatechin gallate (EGCG) on rat leiomyoma (ELT3) cells in vitro and in a nude mice model. STUDY DESIGN: ELT3 cells were treated with various concentrations of EGCG. Cell proliferation, proliferation cell nuclear antigen (PCNA), and cyclin-dependent kinase 4 (Cdk4) protein levels were evaluated. ELT3 cells were inoculated subcutaneously in female athymic nude mice. Animals were fed 1.25 mg EGCG (in drinking water)/mouse/day. Tumors were collected and evaluated at 4 and 8 weeks after the treatment. RESULTS: Inhibitory effect of EGCG (200 mu mol/L) on ELT3 cells was observed after 24 hours of treatment (P<.05). At >= 50 mu mol/L, EGCG significantly decreased PCNA and Cdk4 protein levels (P<.05). In vivo, EGCG treatment dramatically reduced the volume and weight of tumors at 4 and 8 weeks after the treatment (P<.05). The PCNA and Cdk4 protein levels were significantly reduced in the EGCG-treated group (P<.05). CONCLUSION: EGCG effectively inhibits proliferation and induces apoptosis in rat ELT3 uterine leiomyoma cells in vitro and in vivo.