The purpose of this study was to determine the effects of short-term supplementation with the active compounds in
green tea on serum
biomarkers in patients with
prostate cancer. Twenty-six men with positive prostate biopsies and scheduled for radical
prostatectomy were given daily doses of
Polyphenon E, which contained 800 mg of (-)-epigallocatechin-3-gallate (EGCG) and lesser amounts of (-)-
epicatechin, (-)-
epigallocatechin, and (-)-epicatechin-3-gallate (a total of 1.3 g of
tea polyphenols), until time of radical
prostatectomy. Serum was collected before initiation of the
drug study and on the day of
prostatectomy. Serum
biomarkers hepatocyte growth factor (HGF),
vascular endothelial growth factor (
VEGF),
insulin-like growth factor (
IGF)-I, IGF binding protein-3 (IGFBP-3), and
prostate-specific antigen (PSA) were analyzed by ELISA. Toxicity was monitored primarily through liver function
enzymes. Changes in serum components were analyzed statistically using the Wilcoxon signed rank test. Cancer-associated fibroblasts were treated with EGCG, and HGF and
VEGF protein and
mRNA levels were measured. HGF,
VEGF, PSA,
IGF-I,
IGFBP-3, and the
IGF-I/
IGFBP-3 ratio decreased significantly during the study. All of the liver function tests also decreased, five of them significantly: total
protein,
albumin,
aspartate aminotransferase,
alkaline phosphatase, and
amylase. The decrease in HGF and
VEGF was confirmed in
prostate cancer-associated fibroblasts in vitro. Our results show a significant reduction in serum levels of PSA, HGF, and
VEGF in men with
prostate cancer after brief treatment with EGCG (
Polyphenon E), with no elevation of liver
enzymes. These findings support a potential role for
Polyphenon E in the treatment or prevention of
prostate cancer.