Investigations of mechanism for transport of dietary polyphenols and their prevntive effects on in vivo oxidation at molecular levels

研究了以菜青素为酰化花青素，以花青素3-糖苷、花青素3-二葡萄糖苷和芦丁糖苷为低分子花青素的饮食多酚对大鼠胃肠吸收的影响，评价了它们对半乳糖胺所致大鼠肝损伤和链脲佐菌素所致糖尿病的预防作用。这些化合物对肝损伤和糖尿病进展的预防作用表明，这些化合物是从胃肠吸收的，并随后被转运到靶器官以显示其作用。通过测定花色苷的化学结构与其通过肠段的转运量的相关性，利用胃肠吸收模型、Ussing小室设备，研究了多酚，特别是花青素的吸收及其机制。所有由一个花青素分子和一个或几个糖基组成的花青素，以及…更多的花青素和额外的酚类化合物(酰化花色苷)从粘膜部位转运到浆膜部位，低分子花色苷的转运量比酰化花色苷高。花色苷在回肠的转运量明显高于空肠。转运蛋白抑制剂对花色苷的转运表明，花色苷主要通过回肠和空肠的紧密连接结合。然而，花色苷在空肠中的运输依赖于与花色苷结合的糖基的种类，这表明部分花色苷在空肠中是通过主动运输系统运输的。花青素的羟基数目及其甲基化程度不影响其对多酚类物质的吸收。通过测定被吸收的黄酮类化合物的荧光强度，比较了槲皮素与芦丁、槲皮素的糖苷对肝细胞的掺入，结果表明，槲皮素的吸光度远大于芦丁，且其吸光度与温度有关，且吸光度与MRP的存在无关。这些结果表明，Quecetin是被动结合的，部分也是通过其转运蛋白的主动转运系统结合的。较少

Dietary polyphenols such as nasunin as acylated anthocyanin, and cyanidin 3-glucoside, cyanidin 3-diglucoside and cyanidin 3-glucosylrutinoside as lower molecular anthocyanins, were investigated for their absorptivity from gastro intestine, by evaluating their preventive effects against galactsamine-induced liver injury and streptozotodn induced diabetes in rats. Preventive effects of all of these compounds on liver injury and on progression of diabetes suggested that these compounds were absorbed from gastro intestine and, and subsequently transported to target organs to show their effects.Absorption of polyphenols, especially of anthocynains, and its mechanism were also investigated by determining the correlation between chemical structures of anthocyanins and their amounts transported through intestine segment, using gastro intestinal absorption models, equipment of Ussing chamber. All of anthocyanins composed of a molecule of anthocyanidin and a or several sugar moieties, and antho … More cyanins witty further additional phenolic compounds (acylated anthocyanins) were transported from mucosal site to serosal site with high transported amounts in lower molecular anthocyanins than in acylated anthocyanins. The amounts of anthocyanins transported were much in ileum than in jejunum. Transport of anthocyanins in presence of transporter inhibitor suggested that anthocyanin mainly incorporated through tight junction in ileum and jejunum. However, transport of anthocyanins through jejunum depended the kinds of sugar moiety bound to anthocyanidin, suggesting that a part of anthocyanins are transported via active transport system in jejunum. The number of hydroxyl group of anthocynins and its methylation did not affect their absoptivity.Transporter of polyphenols was also investigated using primary culture hepatocytes prepared from rats. When incorporation of quercetin to hepatocytes was compared with that of rutin, glucoside of quecetin, by measuring the intensity of fluorescence due to the absorbed-flavonoids, it was demonstrated that the amount of quercetin absorbed was much than that of rutin, and that absorptivity depended to temparaure, and further that absorptivity was independent on the presence of MRP. These results suggested that quecetin was incorporated passively, and also partly by active transport system using its transporter. Less