Glucoraphanin hydrolysis by microbiota in the rat cecum results in sulforaphane absorption
Glucoraphanin hydrolysis by microbiota in the rat cecum results in sulforaphane absorption
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DOI：
10.1039/c0fo00110d
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发表时间：
2010-11-01
期刊：
影响因子：
6.1
通讯作者：
Jeffery, Elizabeth
中科院分区：
文献类型：
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作者：
Lai, Ren-Hau;Miller, Michael J.;Jeffery, Elizabeth
在没有植物酶黑芥子酶的情况下，例如在煮熟的西兰花中，萝卜硫苷被认为是由下肠道中的细菌水解，以产生生物活性的异硫氰酸酯萝卜硫素。使用美国药典方法进行的模拟消化未导致萝卜硫苷损失，证实萝卜硫苷在通过消化道期间不被消化酶破坏，并且能够完整地到达大鼠盲肠。将萝卜硫素（150 μ mol/kg BW）直接引入盲肠导致肠系膜血浆中异硫氰酸酯的出现时间为120 min。相反，将萝卜硫素（150 μ mol/kg BW）直接引入盲肠导致肠系膜血浆中异硫氰酸酯的出现时间为15 min。血浆水平保持恒定超过1小时。来自雄性F344大鼠的盲肠微生物群与硫代葡萄糖苷的离体厌氧孵育导致非常低水平的水解代谢物芥酸腈，表明芥子油苷的水解是由盲肠微生物群进行的，但微生物群的离体代谢并不反映原位代谢。这些数据首次报告了萝卜硫苷在大鼠盲肠中水解为萝卜硫素的直接证据，并表明萝卜硫素能够穿过盲肠肠上皮细胞进行全身吸收。
In the absence of the plant enzyme myrosinase, such as in cooked broccoli, glucoraphanin is considered to be hydrolyzed by bacteria in the lower gut to produce the bioactive isothiocyanate sulforaphane. Simulated digestion using US Pharmacopeia methods caused no loss of glucoraphanin, confirming that glucoraphanin is not destroyed by digestive enzymes during passage through the digestive tract and is able to reach the rat cecum intact. Introduction of glucoraphanin (150 mu mol/kg BW) directly into the cecum resulted in appearance of isothiocyanates in the mesenteric plasma by 120 min. In contrast, introduction of sulforaphane (150 mu mol/kg BW) directly into the cecum resulted in the appearance of isothiocyanates in the mesenteric plasma within 15 min. Plasma levels remained constant for over an hour. Anaerobic incubation ex vivo of cecal microbiota from male F344 rats with glucoraphanin resulted in very low levels of the hydrolytic metabolite erucin nitrile, showing that hydrolysis of glucosinolates is carried out by cecal microbiota, but metabolism ex vivo by microbiota did not reflect not reflect metabolism in situ. These data are the first to report direct evidence of hydrolysis of glucoraphanin to sulforaphane in the cecum of rats and to show that sulforaphane is able to cross the cecal enterocyte for systemic absorption.