Research Center for Food Safety, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan.
J Pharm Pharmacol. 2012 Jan;64(1):52-60. doi: 10.1111/j.2042-7158.2011.01374.x. Epub 2011 Nov 10.
We recently reported that flavanone aglycones (hesperetin, naringenin and eriodictyol) are efficiently absorbed via proton-coupled active transport, in addition to transcellular passive diffusion, in Caco-2 cells. Here, we aimed to evaluate in detail the absorption mechanisms of these flavanones, as well as homoeriodictyol and sakuranetin.
We evaluated the absorption mechanisms of the above compounds by means of in vitro studies in Caco-2 cells in parallel with an artificial membrane permeation assay (PAMPA) under pH-gradient and iso-pH conditions.
Comparison of the permeability characteristics of flavanones in Caco-2 cells and in PAMPA under these conditions, as well as a consideration of the physicochemical properties, indicated that hesperetin, naringenin, eriodictyol and homoeriodictyol were efficiently transported by passive diffusion according to the pH-partition hypothesis, except in the case of sakuranetin. However, transport of all flavanones were remarkably temperature-dependent, and was significantly reduced when Caco-2 cells were treated with amino acid-modifying reagents.
Our data confirm that both passive diffusion and an active transport mechanism contribute to flavanone absorption through human intestinal epithelium.
我们最近报道，黄烷酮苷元（柚皮素、柚皮苷和圣草酚）除了通过细胞旁被动扩散外，还可以通过质子偶联主动转运有效地被吸收。在此，我们旨在详细评估这些黄烷酮以及同型圣草酚和樱花素的吸收机制。
我们通过 Caco-2 细胞的体外研究以及在 pH 梯度和等 pH 条件下的人工膜渗透测定（PAMPA）平行评估了上述化合物的吸收机制。
在这些条件下比较黄烷酮在 Caco-2 细胞和 PAMPA 中的渗透性特征，以及考虑其物理化学性质，表明除了樱花素外，柚皮素、柚皮苷、圣草酚和同型圣草酚均通过 pH 分配假说以被动扩散的方式高效转运。然而，所有黄烷酮的转运都显著依赖于温度，并且当 Caco-2 细胞用氨基酸修饰试剂处理时，转运显著减少。
我们的数据证实，被动扩散和主动转运机制均有助于黄烷酮通过人肠道上皮细胞的吸收。
