Fecalase: a model for activation of dietary glycosides to mutagens by intestinal flora.
Fecalase: a model for activation of dietary glycosides to mutagens by intestinal flora.
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粪便酶：肠道菌群将膳食糖苷激活为诱变剂的模型。
DOI：
10.1073/pnas.77.8.4961
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发表时间：
1980
影响因子：
11.1
通讯作者：
Ames,BN
中科院分区：
文献类型：
--
作者：
Tamura,G;Gold,C;Ferro-Luzzi,A;Ames,BN
植物界和人类饮食中的许多物质都以糖苷的形式存在。最近的研究表明，许多糖苷在沙门氏菌试验等试验中不具有诱变性，但在糖苷键水解后却具有诱变性。沙门氏菌测试利用肝脏匀浆来近似哺乳动物的代谢，但不提供肠道菌群中存在的酶的来源，这些酶可以水解自然界中存在的各种糖苷。我们描述了一种稳定的人类粪便无细胞提取物，粪化酶，它被证明含有多种糖苷酶，可以在沙门氏菌/肝脏匀浆试验中体外激活许多天然糖苷来对抗诱变剂。许多饮料，如红葡萄酒（但显然不是白葡萄酒）和茶，含有诱变槲皮素的糖苷。在试验中，添加粪酶时，红酒、红葡萄汁和茶具有诱变作用，而在不添加粪酶时，红酒具有相当大的直接诱变作用。讨论了槲皮素的致突变性和致癌性。
Many substances in the plant kingdom and in man's diet occur as glycosides. Recent studies have indicated that many glycosides that are not mutagenic in tests such as the Salmonella test become mutagenic upon hydrolysis of the glycosidic linkages. The Salmonella test utilizes a liver homogenate to approximate mammalian metabolism but does not provide a source of the enzymes present in intestinal bacterial flora that hydrolyze the wide variety of glycosides present in nature. We describe a stable cell-free extract of human feces, fecalase, which is shown to contain various glycosidases that allow the in vitro activation of many natural glycosides to mutagens in the Salmonella/liver homogenate test. Many beverages, such as red wine (but apparently not white wine) and tea, contain glycosides of the mutagne quercetin. Red wine, red grape juice, and tea were mutagenic in the test when fecalase was added, and red wine contained considerable direct mutagenic activity in the absence of fecalase. The implications of quercetin mutagenicity and carcinogenicity are discussed.