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)生會隨著衰老而減少,。作為非處方藥,，男性服用DHEA是因為它有抗衰老作用，或者說它在體內(nèi)代謝后會生成雄性激素,。飲食中異黃酮攝入量的增加會降低前列腺癌發(fā)病危險。
紅三葉草是異黃酮的來源之一,。DHEA和異黃酮這兩種補充劑對前列腺都能發(fā)揮激素作用,，但對它們的安全性還缺乏了解,。美國癌癥研究會雜志《癌癥預(yù)防研究》最近發(fā)表的一項研究報告說，可以在實驗室對細胞的DHEA水平進行調(diào)解,，以了解它的作用,。
美國國家衛(wèi)生研究院全國補充與替代醫(yī)學(xué)中心的科學(xué)家朱莉婭﹒阿諾德博士說，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藥,，面對這種情況,，我們還需做更多研究來評估這些補充劑的安全性。
為此,，中心實驗室對培養(yǎng)的前列腺癌細胞和它的基質(zhì)細胞之間所發(fā)信號作了研究,。“DHEA對前列腺組織的作用依賴于這兩種細胞之間‘交談’，進一步說,，對含有炎癥或早期癌癥損傷的組織是有害的,，因為這些細胞可誘導(dǎo)DHEA形成更多的雄性激素。” 阿諾德說,。
DHEA與轉(zhuǎn)化生長因子β-1結(jié)合后,，基質(zhì)細胞產(chǎn)生的睪丸素和前列腺特異性抗原蛋白的分泌會增加2-4倍，癌細胞的基因表達增加50倍,。當在這些培養(yǎng)細胞中加入三葉草異黃酮后,，DHEA產(chǎn)生雄性激素作用會受到抑制。
“在前列腺微環(huán)境中所發(fā)生這些變化說明,，三葉草異黃酮有潛在的癌癥預(yù)防作用,。” 阿諾德說。
紅三葉草異黃酮可以改變前列腺中雄激素的作用,，但還需要更多的實驗室和臨床研究來證實這些作用,。
這項實驗室研究讓科學(xué)家進一步了解了前列腺的生物學(xué)基礎(chǔ)，也認識了DHEA和紅三葉植物的細胞和分子機制,。阿諾德說,，中心將進一步對DHEA和其他補充劑進行研究，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.
