Nguyen T D, Canada A T
Department of Medicine, Duke University, Medical Center, Durham, NC.
J Nutr. 1993 Feb;123(2):259-68. doi: 10.1093/jn/123.2.259.
Flavonoids, compounds containing a 2-phenylbenzo(gamma)pyrane nucleus, are universally distributed among vascular plants. Even though flavonoids are ingested in a normal diet in average quantities of 1 g daily, their effects on the digestive system have only been recently investigated. This study used an in vitro model of colonic secretion, monolayers of T84 colonic adenocarcinoma cells mounted in Ussing chambers, to demonstrate that 100 mumol/L of either tangeritin or nobiletin, polymethoxylated flavonoids contained in citrus fruits, stimulated sustained electrogenic chloride secretion with a maximal short-circuit current of 3.3 microA/cm2. In contrast, naringin and hesperidin, glycosylated citrus flavonoids, stimulated minimal secretion, suggesting that carbohydrate substitutions inhibited their secretory potential. The secretion stimulated by tangeritin and nobiletin was synergistic with carbachol but not with vasoactive intestinal peptide and was inhibited by barium chloride, bumetanide, H-89, and Cl- depletion. These properties suggest that tangeritin and nobiletin stimulated Cl- secretion via the cAMP pathway; however, these flavonoids did not stimulate cAMP production to the extent seen with vasoactive intestinal peptide. These flavonoids did not autooxidize, suggesting that reactive oxygen species did not mediate this secretion. These observations suggest that dietary citrus flavonoids may modulate colonic secretion, possibly through direct interaction with intracellular secretory pathways.
黄酮类化合物是一类含有2-苯基苯并（γ）吡喃核的化合物，广泛分布于维管植物中。尽管人们在正常饮食中每天平均摄入1克黄酮类化合物，但它们对消化系统的影响直到最近才得到研究。本研究使用结肠分泌的体外模型，即安装在尤斯灌流小室中的T84结肠腺癌细胞单层，来证明柑橘类水果中含有的100微摩尔/升的橘红素或川陈皮素（多甲氧基黄酮）能刺激持续性的氯分泌，最大短路电流为3.3微安/平方厘米。相比之下，柚皮苷和橙皮苷（糖基化的柑橘类黄酮）刺激的分泌极少，这表明碳水化合物取代抑制了它们的分泌潜能。橘红素和川陈皮素刺激的分泌与卡巴胆碱具有协同作用，但与血管活性肠肽没有协同作用，并且受到氯化钡、布美他尼、H-89和氯缺失的抑制。这些特性表明，橘红素和川陈皮素通过环磷酸腺苷（cAMP）途径刺激氯分泌；然而，这些黄酮类化合物并没有像血管活性肠肽那样刺激cAMP的产生。这些黄酮类化合物不会自动氧化，这表明活性氧物种并没有介导这种分泌。这些观察结果表明，膳食中的柑橘类黄酮可能通过与细胞内分泌途径的直接相互作用来调节结肠分泌。
