Metabolism of Oak Leaf Ellagitannins and Urolithin Production in Beef Cattle
Metabolism of Oak Leaf Ellagitannins and Urolithin Production in Beef Cattle
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DOI：
10.1021/jf300718k
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发表时间：
2012-03-28
影响因子：
6.1
通讯作者：
Tomas-Barberan, Francisco A.
中科院分区：
文献类型：
--
作者：
Gonzalez-Barrio, Rocio;Truchado, Pilar;Tomas-Barberan, Francisco A.
橡树叶含有高浓度的鞣花单宁。这些植物化学物质对动物可能有益，也可能有毒。肉牛经常因食用橡树叶而中毒，特别是在受到饲料限制后。最近，中毒的严重程度与瘤胃微生物群有关，因为在耐受橡树叶的动物和表现出临床和病理毒性迹象的动物中发现了不同的细菌群。此前，中毒被认为与酚类代谢物的产生有关，特别是儿茶酚、间苯三酚和间苯二酚。这表明鞣花单宁的微生物代谢也可能与其在不同动物中的耐受性或中毒有关。因此，了解牛体内鞣花单宁的代谢非常重要。在这里，我们表明鞣花单宁在牛瘤胃中代谢为尿石素。在瘤胃液、粪便、尿液和血浆中检测到不同的尿石素。橡树叶鞣花单宁随着瘤胃和粪便微生物群转化为尿石素（主要是异尿石素 A 和尿石素 B）而下降。在瘤胃和粪便中观察到尿石素苷元，在血浆和尿液中检测到葡萄糖醛酸和硫酸盐衍生物。血浆中检测到的主要代谢物是硫酸衍生物，尿液中检测到的主要代谢物是葡萄糖醛酸衍生物。牛体内产生的主要尿石素是异尿石素 A 和尿石素 B。这与之前研究的单胃哺乳动物存在相关差异，其中尿石素 A 是产生的主要代谢物。还检测到苯甲酸、苯乙酸和苯丙酸基团的低分子量酚类以及儿茶酚、间苯二酚和相关化合物等代谢物。尽管在所有情况下它们都产生相似的代谢物，但个体动物中这些代谢物的产生动力学存在很大差异。这种巨大的变异性可能与之前观察到的瘤胃和肠道微生物群的巨大变异性有关。需要进一步的研究来证明微生物群代谢鞣花单宁的效率是否可以解释不同动物对中毒敏感性的差异。
Oak leaves have a high concentration of ellagitannins. These phytochemicals can be beneficial or poisonous to animals. Beef cattle are often intoxicated by oak leaf consumption, particularly after suffering feed restriction. The severity of the poisoning has recently been associated with the ruminal microbiota, as different bacterial populations were found in animals that tolerated oak leaves and in those that showed clinical and pathological signs of toxicity. Intoxication has previously been linked to the production of phenolic metabolites, particularly catechol, phloroglucinol, and resorcinol. This suggested that the microbial metabolism of ellagitannins could also be associated with its tolerance or intoxication in different animals. Therefore, it is essential to understand the metabolism of ellagitannins in cattle. Here we show that ellagitannins are metabolized in the cattle rumen to urolithins. Different urolithins were detected in ruminal fluid, feces, urine, and plasma. Oak leaf ellagitannins declined as they were converted to urolithins, mainly isourolithin A and urolithin B, by the ruminal and fecal microbiota. Urolithin aglycons were observed in rumen and feces, and glucuronide and sulfate derivatives were detected in plasma and urine. Sulfate derivatives were the main metabolites detected in plasma, while glucuronide derivatives were the main ones in urine. The main urolithins produced in cattle were isourolithin A and urolithin B. This is a relevant difference from the monogastric mammals studied previously in which urolithin A was the main metabolite produced. Low molecular weight phenolics of the benzoic, phenylacetic, and phenylpropionic groups and metabolites such as catechol, resorcinol, and related compounds were also detected. There was a large variability in the kinetics of production of these metabolites in individual animals, although they produced similar metabolites in all cases. This large variability could be associated with the large variability in the rumen and intestine microbiota that has previously been observed. Further studies are needed to demonstrate if the efficiency in the metabolism of ellagitannins by the microbiota could explain the differences observed in susceptibility to intoxication by the different animals.