花椰菜是時下流行的蔬菜,，多吃有益?？墒悄阒绬?，花椰菜其實還有更重要的作用。美國科學(xué)家近日研究發(fā)現(xiàn),，花椰菜的一種提取物能夠幫助人體預(yù)防太陽紫外線傷害,，從而降低患皮膚癌的風(fēng)險。相關(guān)論文10月23日在線發(fā)表于美國《國家科學(xué)院院刊》（PNAS）上,。
紫外線照射和許多化學(xué)物質(zhì)會對人體DNA造成氧化傷害,，并可能導(dǎo)致癌癥。研究人員一直在尋找多種方法來激活人體內(nèi)的天然抗氧化劑,，以分解這些會對人體造成傷害的氧化因子,。
之前在小鼠身上進(jìn)行的研究發(fā)現(xiàn)，花椰菜中含有的異硫氰酸鹽（sulforaphane）能幫助減少紫外線照射造成的炎癥,。在最新的研究中,，美國約翰·霍普金斯大學(xué)的藥理學(xué)家Paul Talalay和同事讓六個志愿者背部接受不同量的紫外線照射，其中有些志愿者使用了花椰菜提取物作為防護，另一些則沒有,。研究人員在不同的照射間隔測量了志愿者產(chǎn)生的皮膚紅塊,，以確定細(xì)胞損傷的程度。結(jié)果發(fā)現(xiàn),，如果在紫外線照射前三日每天都使用花椰菜提取物,，在照射后，細(xì)胞損傷平均會下降37%,。
Talalay說,，這表明異硫氰酸鹽能夠幫助細(xì)胞抵御傷害，所以含有異硫氰酸鹽成分的藥膏能夠降低因紫外線照射而患皮膚癌的風(fēng)險,。
美國羅切斯特大學(xué)的皮膚病專家Francisco Tausk表示,，世界上患皮膚癌的人數(shù)正在不斷增加，此次研究將可能對改善這一狀況發(fā)揮重要作用,。
美國達(dá)特默斯醫(yī)學(xué)院的藥理學(xué)家Michael Sporn認(rèn)為,，這一研究對于進(jìn)行器官移植的患者也將發(fā)揮作用，這些患者往往因服用免疫抑制藥物而增加患皮膚癌的風(fēng)險,。同時,，此次研究還清楚地說明，化學(xué)預(yù)防（chemoprevention）能對人體發(fā)揮作用,，值得繼續(xù)研究,。（科學(xué)網(wǎng) 梅進(jìn)/編譯）
（《國家科學(xué)院院刊》（Proceedings of the National Academy of Sciences），10.1073/pnas.0708710104,，Paul Talalay,，Albena T. Dinkova-Kostova）
原始出處:
Published online before print October 23, 2007
Proc. Natl. Acad. Sci. USA, 10.1073/pnas.0708710104
Sulforaphane mobilizes cellular defenses that protect skin against damage by UV radiation
Paul Talalay,, Jed W. Fahey,, Zachary R. Healy, Scott L. Wehage, Andrea L. Benedict, Christine Min, and Albena T. Dinkova-Kostova,¶
Lewis B. and Dorothy Cullman Cancer Chemoprotection Center, Department of Pharmacology and Molecular Sciences, ¶Division of Clinical Pharmacology, Department of Medicine, School of Medicine, and Department of International Health, Bloomberg School of Public Health, The Johns Hopkins University, Baltimore, MD 21205
Contributed by Paul Talalay, September 13, 2007 (sent for review September 10, 2007)
Abstract
UV radiation (UVR) is a complete carcinogen that elicits a constellation of pathological events, including direct DNA damage, generation of reactive oxidants that peroxidize lipids and damage other cellular components, initiation of inflammation, and suppression of the immune response. Recent dramatic increases in the incidence of nonmelanoma skin cancers are largely attributable to higher exposure of an aging population to UVR. Therefore, the development of cellular strategies for intrinsic protection of the skin against the deleterious effects of UVR is imperative. Here we show that erythema resulting from UVR is a comprehensive and noninvasive biomarker for assessing UVR damage and can be precisely and easily quantified in human skin. Topical application of sulforaphane-rich extracts of 3-day-old broccoli sprouts up-regulated phase 2 enzymes in the mouse and human skin, protected against UVR-induced inflammation and edema in mice, and reduced susceptibility to erythema arising from narrow-band 311-nm UVR in humans. In six human subjects (three males and three females, 28–53 years of age), the mean reduction in erythema across six doses of UVR (300–800 mJ/cm2 in 100 mJ/cm2 increments) was 37.7% (range 8.37–78.1%; P = 0.025). This protection against a carcinogen in humans is catalytic and long lasting.
erythema | nicotinamide:quinone oxidoreductase 1 | skin tumor | chemoprotection
