Tea polyphenols and theaflavins are present in prostate tissue of humans and mice after green and black tea consumption

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Цель
Дизайн
DESIGN
CONCLUSIONS

Tea polyphenols and theaflavins are present in prostate tissue of humans and mice after green and black tea consumption.

Henning SM¹, Aronson W, Niu Y, Conde F, Lee NH, Seeram NP, Lee RP, Lu J, Harris DM, Moro A, Hong J, Pak-Shan L, Barnard RJ, Ziaee HG, Csathy G, Go VL, Wang H, Heber D.

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¹Department of Pathology, VA West Los Angeles, CA 90073, USA. shenning@mednet.ucla.net

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.

Биодоступность и антиоксидантная активность чая флаванолов после употребления зеленого чая, черный чай, или зеленый чай, экстракт добавки.

Зеленый и черный чай полифенолы были самым тщательным образом изучены, как рак химические агенты. Многие в экспериментах in vitro поддержали их сильную антиоксидантную активность. Дополнительные исследования in vivo необходимы для изучения фармакокинетики отношении поглощения и антиоксидантной активности полифенолов чая приеме внутрь в виде зеленого или черного чая или чая, экстракт добавки.

Цель:

Целью данного исследования было сравнение фармакокинетических распоряжения полифенолы чая и их влияние на антиоксидантную емкость плазмы 8 ч после болюса потребления либо зеленый чай, черный чай, или зеленый чай, экстракт добавки.

Дизайн:

Тридцать здоровых субъектов были рандомизированы в 3 различных последовательностей зеленый чай, черный чай, или зеленый чай, экстракт приложение в 3 x 3 дизайн кроссовера с 1-wk размыва в период между процедурами.

Flavanol поглощения была усилена, когда чай полифенолы, которые вводили в виде зеленого чая, добавки в форме капсул и привело к небольшому, но значительному увеличению антиоксидантной активности плазмы по сравнению с тем, когда полифенолы чая было выпито, как черный чай или зеленый чай. Все 3 мероприятия при аналогичной суммы (-)-эпигаллокатехин-3-галлат.

Наши наблюдения показывают, что экстракт зеленого чая дополняет сохранить благотворное воздействие зеленого и черного чая, и может быть использовано в будущем проведение химиопрофилактики исследований с целью получения большой дозы полифенолов чая без побочных эффектов кофеина, связанные с зеленого и черного чая, напитков.

Am J Clin Nutr. 2004 Dec;80(6):1558-64.

Bioavailability and antioxidant activity of tea flavanols after consumption of green tea, black tea, or a green tea extract supplement.

Henning SM¹, Niu Y, Lee NH, Thames GD, Minutti RR, Wang H, Go VL, Heber D.

¹Center for Human Nutrition, David Geffen School of Medicine and the Department of Biostatistics, School of Public Health, University of California, Los Angeles, 90095, USA. shenning@mednet.ucla.edu

Green and black tea polyphenols have been extensively studied as cancer chemopreventive agents. Many in vitro experiments have supported their strong antioxidant activity. Additional in vivo studies are needed to examine the pharmacokinetic relation of absorption and antioxidant activity of tea polyphenols administered in the form of green or black tea or tea extract supplements.

The purpose of this study was to compare the pharmacokinetic disposition of tea polyphenols and their effect on the antioxidant capacity in plasma 8 h after a bolus consumption of either green tea, black tea, or a green tea extract supplement.

DESIGN:

Thirty healthy subjects were randomly assigned to 3 different sequences of green tea, black tea, or a green tea extract supplement in a 3 x 3 crossover design with a 1-wk washout period in between treatments.

RESULTS:

Flavanol absorption was enhanced when tea polyphenols were administered as a green tea supplement in capsule form and led to a small but significant increase in plasma antioxidant activity compared with when tea polyphenols were consumed as black tea or green tea. All 3 interventions provided similar amounts of (-)-epigallocatechin-3-gallate.

CONCLUSIONS:

Our observations suggest that green tea extract supplements retain the beneficial effects of green and black tea and may be used in future chemoprevention studies to provide a large dose of tea polyphenols without the side effects of caffeine associated with green and black tea beverages.