脫氫表雄酮（青春素,，DHEA）是一種天然激素,，它在人體內(nèi)的產(chǎn)生會(huì)隨著衰老而減少。作為非處方藥,，男性服用DHEA是因?yàn)樗锌顾ダ献饔?，或者說(shuō)它在體內(nèi)代謝后會(huì)生成雄性激素,。飲食中異黃酮攝入量的增加會(huì)降低前列腺癌發(fā)病危險(xiǎn)。
紅三葉草是異黃酮的來(lái)源之一,。DHEA和異黃酮這兩種補(bǔ)充劑對(duì)前列腺都能發(fā)揮激素作用,，但對(duì)它們的安全性還缺乏了解。美國(guó)癌癥研究會(huì)雜志《癌癥預(yù)防研究》最近發(fā)表的一項(xiàng)研究報(bào)告說(shuō),，可以在實(shí)驗(yàn)室對(duì)細(xì)胞的DHEA水平進(jìn)行調(diào)解,，以了解它的作用。
美國(guó)國(guó)家衛(wèi)生研究院全國(guó)補(bǔ)充與替代醫(yī)學(xué)中心的科學(xué)家朱莉婭﹒阿諾德博士說(shuō),，許多男性和女性從健康出發(fā)根據(jù)網(wǎng)上找到的信息為自己開(kāi)藥,，面對(duì)這種情況，我們還需做更多研究來(lái)評(píng)估這些補(bǔ)充劑的安全性,。
為此,，中心實(shí)驗(yàn)室對(duì)培養(yǎng)的前列腺癌細(xì)胞和它的基質(zhì)細(xì)胞之間所發(fā)信號(hào)作了研究。“DHEA對(duì)前列腺組織的作用依賴于這兩種細(xì)胞之間‘交談’,，進(jìn)一步說(shuō)，對(duì)含有炎癥或早期癌癥損傷的組織是有害的,，因?yàn)檫@些細(xì)胞可誘導(dǎo)DHEA形成更多的雄性激素,。” 阿諾德說(shuō)。
DHEA與轉(zhuǎn)化生長(zhǎng)因子β-1結(jié)合后,，基質(zhì)細(xì)胞產(chǎn)生的睪丸素和前列腺特異性抗原蛋白的分泌會(huì)增加2-4倍,，癌細(xì)胞的基因表達(dá)增加50倍。當(dāng)在這些培養(yǎng)細(xì)胞中加入三葉草異黃酮后,，DHEA產(chǎn)生雄性激素作用會(huì)受到抑制,。
“在前列腺微環(huán)境中所發(fā)生這些變化說(shuō)明，三葉草異黃酮有潛在的癌癥預(yù)防作用,。” 阿諾德說(shuō),。
紅三葉草異黃酮可以改變前列腺中雄激素的作用，但還需要更多的實(shí)驗(yàn)室和臨床研究來(lái)證實(shí)這些作用,。
這項(xiàng)實(shí)驗(yàn)室研究讓科學(xué)家進(jìn)一步了解了前列腺的生物學(xué)基礎(chǔ),，也認(rèn)識(shí)了DHEA和紅三葉植物的細(xì)胞和分子機(jī)制。阿諾德說(shuō),，中心將進(jìn)一步對(duì)DHEA和其他補(bǔ)充劑進(jìn)行研究,，以找到一些癌癥預(yù)防辦法。（生物谷Bioon.com）
生物谷推薦原始出處：
Cancer Prevention Research, February 1, 2009.doi: 10.1158/1940-6207.CAPR-08-0062
Endocrine-Immune-Paracrine Interactions in Prostate Cells as Targeted by Phytomedicines
Nora E. Gray, Xunxian Liu, Renee Choi, Marc R. Blackman and Julia T. Arnold
Authors' Affiliation: Endocrine Section, Laboratory of Clinical Investigation, Division of Intramural Research, National Center for Complementary and Alternative Medicine, NIH, Bethesda, Maryland
Requests for reprints: Julia T. Arnold, Endocrine Section, Laboratory of Clinical Investigation, National Center for Complementary and Alternative Medicine, Building 10, Room 2B47, 9000 Rockville Pike, Bethesda, MD 20892-1547.
Dehydroepiandrosterone (DHEA) is used as a dietary supplement and can be metabolized to androgens and/or estrogens in the prostate. We investigated the hypothesis that DHEA metabolism may be increased in a reactive prostate stroma environment in the presence of proinflammatory cytokines such as transforming growth factor β1 (TGFβ1), and further, whether red clover extract, which contains a variety of compounds including isoflavones, can reverse this effect. LAPC-4 prostate cancer cells were grown in coculture with prostate stromal cells (6S) and treated with DHEA +/– TGFβ1 or interleukin-6. Prostate-specific antigen (PSA) expression and testosterone secretion in LAPC-4/6S cocultures were compared with those in monocultured epithelial and stromal cells by real-time PCR and/or ELISA. Combined administration of TGFβ1 + DHEA to cocultures increased PSA protein secretion two to four times, and PSA gene expression up to 50-fold. DHEA + TGFβ1 also increased coculture production of testosterone over DHEA treatment alone. Red clover isoflavone treatment led to a dose-dependent decrease in PSA protein and gene expression and testosterone metabolism induced by TGFβ1 + DHEA in prostate LAPC-4/6S cocultures. In this coculture model of endocrine-immune-paracrine interactions in the prostate, TGFβ1 greatly increased stromal-mediated DHEA effects on testosterone production and epithelial cell PSA production, whereas red clover isoflavones reversed these effects.
