Broccoli sprouts: An exceptionally rich source of inducers of enzymes that protect against chemical carcinogens
Broccoli sprouts: An exceptionally rich source of inducers of enzymes that protect against chemical carcinogens
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DOI：
10.1073/pnas.94.19.10367
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发表时间：
1997-09-16
影响因子：
11.1
通讯作者：
Talalay, P
中科院分区：
文献类型：
--
作者：
Fahey, JW;Zhang, YS;Talalay, P
诱导2期解毒酶[例如，谷胱甘肽转移酶，环氧化物水解酶，NAD（P）H：醌还原酶和葡萄糖醛酸基转移酶]是一种有效的策略，用于实现对致癌作用、诱变和亲电体和活性形式的氧的其它形式的毒性的保护。由于大量食用水果和蔬菜与发生多种恶性肿瘤的风险的显著降低有关，令人感兴趣的是，许多可食用植物含有大量调节哺乳动物异生物质代谢酶的化合物。因此，属于十字花科和芸苔属的可食用植物（例如，花椰菜和花椰菜）含有大量的异硫氰酸酯（主要是以它们的芥子油苷前体的形式），萝卜硫素或4-甲基亚磺酰基丁基异硫氰酸酯）是非常有效的2相酶诱导剂。出乎意料的是，某些十字花科植物（包括花椰菜和花椰菜）的栽培品种的3天大的芽含有比相应成熟植物高10-100倍的萝卜硫苷（萝卜硫素的硫代葡萄糖苷）水平。芥子油苷和异硫氰酸酯可以有效地从植物中提取，而不水解芥子油苷的黑芥子酶，通过均质化在等体积的二甲基亚砜，二甲基甲酰胺，和乙腈的混合物在-50摄氏度，3天大的西兰花芽提取物（含有萝卜硫苷或萝卜硫素作为主要的酶诱导剂）在降低发病率，多样性，和二甲基苯蒽处理的大鼠中乳腺肿瘤的发展速度。值得注意的是，许多西兰花品种的芽含有可忽略不计量的吲哚芥子油苷，其在成熟蔬菜中占主导地位，并可能产生降解产物（例如，因此，少量的十字花科蔬菜芽可以有效地防止癌症的风险，因为大量的成熟蔬菜的同一品种。
Induction of phase 2 detoxication enzymes [e.g., glutathione transferases, epoxide hydrolase, NAD(P)H: quinone reductase, and glucuronosyltransferases] is a powerful strategy for achieving protection against carcinogenesis, mutagenesis, and other forms of toxicity of electrophiles and reactive forms of oxygen, Since consumption of large quantities of fruit and vegetables is associated with a striking reduction in the risk of developing a variety of malignancies, it is of interest that a number of edible plants contain substantial quantities of compounds that regulate mammalian enzymes of xenobiotic metabolism. Thus, edible plants belonging to the family Cruciferae and genus Brassica (e.g., broccoli and cauliflower) contain substantial quantities of isothiocyanates (mostly in the form of their glucosinolate precursors) some of which (e.g., sulforaphane or 4-methylsulfinylbutyl isothiocyanate) are very potent inducers of phase 2 enzymes, Unexpectedly, 3-day-old sprouts of cultivars of certain crucifers including broccoli and cauliflower contain 10-100 times higher levels of glucoraphanin (the glucosinolate of sulforaphane) than do the corresponding mature plants. Glucosinolates and isothiocyanates can be efficiently extracted from plants, without hydrolysis of glucosinolates by myrosinase, by homogenization in a mixture of equal volumes of dimethyl sulfoxide, dimethylformamide, and acetonitrile at -50 degrees C, Extracts of 3-day-old broccoli sprouts (containing either glucoraphanin or sulforaphane as the principal enzyme inducer) were highly effective in reducing the incidence, multiplicity, and rate of development of mammary tumors in dimethylbenz(a)anthracene-treated rats. Notably, sprouts of many broccoli cultivars contain negligible quantities of indole glucosinolates, which predominate in the mature vegetable and may give rise to degradation products (e.g., indole-3-carbinol) that can enhance tumorigenesis, Hence, small quantities of crucifer sprouts may protect against the risk of cancer as effectively as much larger quantities of mature vegetables of the same variety.