Bioactive Dietary Polyphenols Decrease Heme Iron Absorption by Decreasing Basolateral Iron Release in Human Intestinal Caco-2 Cells
Bioactive Dietary Polyphenols Decrease Heme Iron Absorption by Decreasing Basolateral Iron Release in Human Intestinal Caco-2 Cells
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DOI：
10.3945/jn.109.117499
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发表时间：
2010-06-01
影响因子：
4.2
通讯作者：
Han, Okhee
中科院分区：
文献类型：
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作者：
Ma, Qianyi;Kim, Eun-Young;Han, Okhee
由于膳食多酚化合物在体内和体外具有广泛的作用，包括螯合金属，如铁，它是谨慎的测试是否经常食用的膳食生物活性多酚损害膳食铁的利用。因为我们以前的研究表明，（-）-表没食子儿茶素-3-没食子酸酯（EGCG）和葡萄籽提取物（GSE）对非血红素铁吸收的抑制作用，我们研究了EGCG和GSE是否也影响铁从血红素的吸收。将在微孔膜插入物上生长的完全分化的肠Caco-2细胞与血红素Fe-55在含有EGCG或GSE的摄取缓冲液中在顶室中孵育7小时。EGCG和GSE均降低血红素铁的跨上皮转运（P < 0.05）。但GSE可增加根尖血红素铁摄取（P < 0.05）。尽管血红素Fe-55的细胞水平增加，铁跨肠基底外侧膜的转移是非常低的，表明基底外侧出口受损GSE。与此相反，EGCG适度降低血红素Fe-55的细胞同化，但基底外侧铁转移是非常低的，这表明血红素铁的基底外侧流出也被EGCG抑制。血红素加氧酶、膜铁转运蛋白和肝素蛋白的表达不受EGCG和GSE的影响。在完全分化的Caco-2细胞中，血红素铁的顶端摄取具有温度依赖性和饱和性。我们的数据表明，生物活性膳食多酚抑制血红素铁吸收主要是通过减少基底外侧铁出口，而不是减少顶端血红素铁吸收肠细胞。J.营养140：1117-1121，2010.
Because dietary polyphenolic compounds have a wide range of effects in vivo and vitro, including chelation of metals such as iron, it is prudent to test whether the regular consumption of dietary bioactive polyphenols impair the utilization of dietary iron. Because our previous study showed the inhibitory effect of (-) -epigallocatechin-3-gallate (EGCG) and grape seed extract (GSE) on nonheme iron absorption, we investigated whether EGCG and GSE also affect iron absorption from heme. The fully differentiated intestinal Caco-2 cells grown on microporous membrane inserts were incubated with heme Fe-55 in Uptake buffer containing EGCG or GSE in the apical compartment for 7 h. Both EGCG and GSE decreased (P < 0.05) transepithelial transport of heme-derived iron. However, apical heme iron uptake was increased (P < 0.05) by GSE. Despite the increased cellular levels of heme Fe-55, the transfer of iron across the intestinal basolateral membrane was extremely low, indicating that basolateral export was impaired by GSE. In contrast, EGCG moderately decreased the cellular assimilation of heme Fe-55, but the basolateral iron transfer was extremely low, suggesting that the basolateral efflux of heme iron was also inhibited by EGCG. Expression of hems oxygenase, ferroportin, and hephaestin protein was not changed by EGCG and GSE. The apical uptake of heme iron was temperature dependent and saturable in fully differentiated Caco-2 cells. Our data show that bioactive dietary polyphenols inhibit heme iron absorption mainly by reducing basolateral iron exit rather than decreasing apical heme iron uptake in intestinal cells. J. Nutr. 140: 1117-1121, 2010.