Federal Institute for Risk Assessment, Department of Food Safety, Berlin, Germany.
Mol Nutr Food Res. 2011 Apr;55(4):644-53. doi: 10.1002/mnfr.201000394. Epub 2010 Dec 20.
Cassia cinnamon contains high levels (up to 1 %) of coumarin. Heavy consumption of this spice may result in a dose exceeding the tolerable daily intake (TDI). In this context, the question was raised whether coumarin in the plant matrix of cinnamon has the same bioavailability as isolated coumarin.
A four-way crossover study was performed, in which the same dose of 12 mg coumarin was administered in different formulations to 24 healthy volunteers. The relative extent of absorption measured as urinary excretion of the main metabolite 7-hydroxycoumarin (7OHC) was found to be 62.8% for isolated coumarin in a capsule (reference), 56.0% for cinnamon in capsules, 66.1% for cinnamon tea, and 54.7% for cinnamon in rice pudding (means, n=23, observation period 8 hours). Additionally, 7OHC plasma levels were measured for 105 minutes after administration and revealed a fast absorption of coumarin from cinnamon tea leading to the highest peak concentrations.
The relative extent of absorption of coumarin from powder of cassia cinnamon is only slightly lower than that of isolated coumarin. Therefore, the TDI of coumarin can be used for risk assessment of coumarin exposure from cinnamon-containing meals.
桂皮中含有高水平的香豆素（高达 1%）。大量食用这种香料可能会导致摄入剂量超过可耐受日摄入量（TDI）。在这种情况下，人们提出了一个问题，即肉桂植物基质中的香豆素是否与分离出的香豆素有相同的生物利用度。
进行了一项四向交叉研究，其中 24 名健康志愿者以不同的配方服用了相同剂量的 12 毫克香豆素。结果发现，以胶囊形式（参比）给予分离出的香豆素时，其主要代谢物 7-羟基香豆素（7OHC）的相对吸收程度为 62.8%，胶囊形式的肉桂为 56.0%，肉桂茶为 66.1%，肉桂米布丁为 54.7%（平均值，n=23，观察期 8 小时）。此外，给药后 105 分钟测量了 7OHC 血浆水平，结果表明肉桂茶中的香豆素吸收迅速，导致最高的峰值浓度。
从桂皮粉中香豆素的相对吸收程度仅略低于分离出的香豆素。因此，香豆素的 TDI 可用于评估含肉桂膳食中香豆素暴露的风险。
