The Flavonol Quercetin-3-Glucoside Inhibits Cyanidin-3-Glucoside Absorption in Vitro
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- 作者：Michaela C. Walton ; Tony K. McGhie ; Gordon W. Reynolds ; and Wouter H. Hendriks
- 刊名：Journal of Agricultural and Food Chemistry
- 出版年：2006
- 出版时间：June 28, 2006
- 年：2006
- 卷：54
- 期：13
- 页码：4913 - 4920
- 全文大小：196K
- 年卷期：v.54,no.13(June 28, 2006)
- ISSN：1520-5118
文摘
At present, little is known about the mechanisms responsible for intestinal absorption of anthocyanins(ACNs). For example, it has not yet been established if ACNs are absorbed through an active transportmechanism, such as the sodium-dependent glucose transporter (SGLT1), or by passive diffusion.Previously, we found that the absorption of ACNs differs between regions of the digestive tract andis maximal in the jejunum, suggesting that an active transport mechanism is involved. In the presentstudy, we examined the effect of D-glucose (main substrate of SGLT1), phloridzin (inhibitor of SGLT1),and quercetin-3-glucose (Q3G, a flavonol) on the absorption of cyanidin-3-glucoside (C3G; ~5 
mol/L) by mouse jejunum mounted in Ussing chambers. We found that the presence of either D-glucose(10, 20, and 40 mmol/L) or phloridzin (50, 100, and 200 mol/L) resulted in a small but insignificantinhibition of C3G disappearance from the mucosal solution (decrease of disappearance with glucose,33%; with phloridzin, 18%; NS). However, when the flavonol Q3G (50 mol/L) was added to themucosal solution together with the C3G, the disappearance of C3G was significantly decreased (74%;p < 0.001), and Q3G disappeared instead. In addition, we found phloretin and quercetin, the aglyconesof phloridzin and Q3G, respectively, present in the mucosal solution and tissue extracts, indicatinghydrolysis of these compounds by the enterocytes of the jejunum. In contrast, the aglycone cyanidinwas not detected at all. Our results show that in the mouse small intestine, ACN absorption is notsolely dependent on the activity of the SGLT1 transporter, as D-glucose and phloridzin had only aslight effect on uptake. Q3G, however, clearly inhibited C3G disappearance. These results suggestthat there might be a competitive inhibition between C3G and Q3G absorption. It is possible that anabsorption mechanism other than the SGLT1 is involved, which has a structural preference towardflavonols.Keywords: Anthocyanins; cyanidin-3-glucoside; quercetin-3-glucoside; phloridzin; D-glucose; Ussingchamber; SGLT1; absorption; jejunum
mol/L) by mouse jejunum mounted in Ussing chambers. We found that the presence of either D-glucose(10, 20, and 40 mmol/L) or phloridzin (50, 100, and 200 mol/L) resulted in a small but insignificantinhibition of C3G disappearance from the mucosal solution (decrease of disappearance with glucose,33%; with phloridzin, 18%; NS). However, when the flavonol Q3G (50 mol/L) was added to themucosal solution together with the C3G, the disappearance of C3G was significantly decreased (74%;p < 0.001), and Q3G disappeared instead. In addition, we found phloretin and quercetin, the aglyconesof phloridzin and Q3G, respectively, present in the mucosal solution and tissue extracts, indicatinghydrolysis of these compounds by the enterocytes of the jejunum. In contrast, the aglycone cyanidinwas not detected at all. Our results show that in the mouse small intestine, ACN absorption is notsolely dependent on the activity of the SGLT1 transporter, as D-glucose and phloridzin had only aslight effect on uptake. Q3G, however, clearly inhibited C3G disappearance. These results suggestthat there might be a competitive inhibition between C3G and Q3G absorption. It is possible that anabsorption mechanism other than the SGLT1 is involved, which has a structural preference towardflavonols.Keywords: Anthocyanins; cyanidin-3-glucoside; quercetin-3-glucoside; phloridzin; D-glucose; Ussingchamber; SGLT1; absorption; jejunum