Tea Polyphenols and Theaflavins Are Present in Prostate Tissue of Humans and Mice after Green and Black Tea Consumption

Abstract

Green and black tea have shown promise in the chemoprevention of prostate cancer. The objective of this study was to determine the bioavailability and bioactivity of tea polyphenols (PP) and theaflavins in human serum and human and mouse tissues. A decaffeinated black tea diet was administered to C57BL/6 mice. PPs and theaflavins were found in the small and large intestine, liver, and prostate in conjugated and free forms. The relative prostate bioavailability of theaflavin was 70% higher than that of epigallocatechin gallate (EGCG). In the second mouse study, a green tea (GT) diet was administered followed by the control diet for 1-5 d. Epicatechin (EC), EGCG, and epicatechin gallate (ECG) concentrations in prostate tissue were significantly decreased after 1 d of consuming the control diet. Epigallocatechin gallate (EGC), however, did not decrease significantly. For the human study, 20 men scheduled for surgical prostatectomy were randomly assigned to consume 1.42 L daily of GT, BT, or a caffeine-matched soda control (SC) for 5 d before radical prostatectomy. Tea PPs were greater in prostate samples from men consuming BT and GT than in men consuming SC (P = 0.0025). Although tea PP were not detectable in serum, ex vivo LNCaP prostate cancer cell proliferation was less when cells were grown in media containing patient serum collected after BT (P < 0.001) and GT (P = 0.025) consumption relative to baseline serum This is the first human study to show that tea polyphenols and theaflavins are bioavailable in the prostate where they may be active in the prevention of prostate cancer.

Black Tea Polyphenols Promotes GLUT4 Translocation through Both PI3K-and AMPK-dependent Pathways in Skeletal Muscle Cells

“…BTP contained theaflavin, theaflavin-3-gallate, theaflavin-3'-gallate and theaflavin-3,3'-digallate. As to the bioavailability of theaflavins, theaflavin and theaflavin-3-gallate were detected in the liver as free form at 0.5 and 0.05 nmol/g tissue and were also detected in the prostate as both free and conjugated forms, though these compounds were not detected in the plasma of mice (Henning et al, 2006). In a human study, the maximum theaflavin plasma concentrations of females and males were 1.8 and 0.9 nM, respectively, and the maximum concentrations in urine were 1.1 and 7.4 nM, respectively, 2 h after intake of 700 mg (approximately 1 mmol) mixed theaflavins (Mulder et al, 2001).…”

Tea Polyphenols Inhibit Rat Osteoclast Formation and Differentiation

“…Therefore, the current results regarding EGCG are consistent (10 -100 μmol) with the earlier findings. In contrast, fewer published reports pertaining to plasma concentrations of TFDG appear in the literature; to be sure, Henning et al noted that theaflavins were absorbed more readily by the mouse prostate than was EGCG (47). MMPs, matrix metalloproteinases, are enzymes responsible for the degradation of collagen fibrils.…”

Green Tea Catechins for Prostate Cancer Prevention: Present Achievements and Future Challenges

“…The Authors instead found a very low to undetectable level of catechins in the prostate surgical samples collected from the same patients, possible due to a combination of rapid systemic clearance (less than 24 h) and low bioaccumulation of polyphenols in the tissue [146]. Different GTCs concentrations ranging from 21 to 107 pmol/g tissue were found in the prostate of men who consumed 1.42 L of green tea for 5 days before prostatectomy [153]. In human prostate glands of PCa patients who consumed 6 cups of green tea daily for up to six weeks before prostatectomy, EGCG is detectable mainly in the free form (nonglucuronidated/sulfated) [154].…”